Collect | Home Page 
   
Office Online  
Journal Online
· Forthcoming Articles
· Current Issue
· Archive
· Advanced Search
· View by Fields
· Archive By Subject
· Special Issues
· Download Articles
· Read Articles
· Email Alert
· Recommended
Links
·
·
·
·
·
·
·
·
·
·
·
   Science & Technology Review
2010, Vol.28, No. 08
28 April 2010

Exclusive
Articles
Reviews
Focus
Select | Export to EndNote
卷首语

Carrying Out the Strategy of Invigorating the Country through Science, Technology and Education Establishing the Advanced System of Scientific Research and Higher Education

Science & Technology Review. 2010, 28 (08): 2-2. ;  doi:
Full text: HTML (1 KB)  PDF  (287 KB)  ( 246 )
Abstract ( 445 )
特别栏目

Science & Technology Review. 2010, 28 (08): 8-8. ;  doi:
Full text: HTML (1 KB)  PDF  (446 KB)  ( 200 )
Abstract ( 360 )

Science & Technology Review. 2010, 28 (08): 8-8. ;  doi:
Full text: HTML (1 KB)  PDF  (446 KB)  ( 255 )
Abstract ( 414 )

Science & Technology Review. 2010, 28 (08): 10-10. ;  doi:
Full text: HTML (1 KB)  PDF  (461 KB)  ( 209 )
Abstract ( 483 )

Science & Technology Review. 2010, 28 (08): 12-13. ;  doi:
Full text: HTML (1 KB)  PDF  (422 KB)  ( 190 )
Abstract ( 379 )

Science & Technology Review. 2010, 28 (08): 14-15. ;  doi:
Full text: HTML (1 KB)  PDF  (911 KB)  ( 231 )
Abstract ( 430 )

Science & Technology Review. 2010, 28 (08): 16-17. ;  doi:
Full text: HTML (1 KB)  PDF  (431 KB)  ( 225 )
Abstract ( 397 )

Science & Technology Review. 2010, 28 (08): 125-125. ;  doi:
Full text: HTML (1 KB)  PDF  (916 KB)  ( 220 )
Abstract ( 417 )

Science & Technology Review. 2010, 28 (08): 138-138. ;  doi:
Full text: HTML (1 KB)  PDF  (1884 KB)  ( 233 )
Abstract ( 403 )

Science & Technology Review. 2010, 28 (08): 139-139. ;  doi:
Full text: HTML (1 KB)  PDF  (448 KB)  ( 235 )
Abstract ( 429 )
半月科技风云

Science & Technology Review. 2010, 28 (08): 9-9. ;  doi:
Full text: HTML (1 KB)  PDF  (82 KB)  ( 272 )
Abstract ( 454 )
科技事件

Science & Technology Review. 2010, 28 (08): 11-11. ;  doi:
Full text: HTML (1 KB)  PDF  (362 KB)  ( 211 )
Abstract ( 425 )
科技工作者建议

Science & Technology Review. 2010, 28 (08): 18-18. ;  doi:
Full text: HTML (1 KB)  PDF  (87 KB)  ( 256 )
Abstract ( 457 )
Exclusive

To Enhance the Academic Level of National Societies Based on Studies of History and Development of Respective Sciences

Science & Technology Review. 2010, 28 (08): 19-22. ;  doi:
Full text: HTML (1 KB)  PDF  (554 KB)  ( 277 )
Abstract ( 537 )
27 national societies held meetings on the development of respective sciences, sponsored by China Association for Science and Technology, which are reviewed in this paper, focusing on main achievements, development trends and special features. It is pointed out that the studies of history and development of sciences will help public in general and people in charge of various decision making departments in particular to grasp the laws governing the development of respective sciences, which may promote the interactions of different branches of sciences. For societies of sciences and technologies, it is the best way to enhance their academic level.

The Current State of Scientific and Technological Journals Sponsored by CAST in 2009

Science & Technology Review. 2010, 28 (08): 23-25. ;  doi:
Full text: HTML (1 KB)  PDF  (216 KB)  ( 322 )
Abstract ( 712 )
According to the report on the current state of scientific and technological journals sponsored by China Association for Science and Technology(CAST), this paper analyzes some important issues, such as, how to keep a high quality standard of academic journals, the digitization, the network construction, and the training of personnel related with editing and publishing. Some development strategies in these respects are proposed.
Articles

Weather Conditions and Spatio-Temporal Spreading Risk of the Beijing 2009 Influenza A(H1N1) Epidemic

Science & Technology Review. 2010, 28 (08): 26-32. ;  doi:
Full text: HTML (1 KB)  PDF  (579 KB)  ( 295 )
Abstract ( 1300 )
In early August 2009, influenza A(H1N1) started to spread widely among the local residents in Beijing. H1N1 test results
indicate that the percentage of H1N1 infections among all out-patient influenza-like illnesses rose steadily from 0.0086 to 0.7035. Using statistical correlation analysis, we have studied the relationship between H1N1 cases and four weather conditions including temperature, relative humidity, precipitation, and wind speed. The correlation between H1N1 positive rate and temperature is significant, with a Pearson correlation coefficient of -0.9458(P<0.05). At the significant level of 0.1, the correlation between H1N1 positive rate and relative humidity is significant as well, with a Pearson correlation coefficient of -0.4581. H1N1 positive rate in dry and cold environment is significantly higher. Furthermore, we have constructed a logistic regression model to predict H1N1 positive rate from temperature and relative humidity and identified the spatio-temporal spreading risk of the Beijing 2009 influenza A(H1N1) Epidemic.

Schistosoma Japonium Immunosensor Based on Silver Enhancement and Colloidal Gold Label

Science & Technology Review. 2010, 28 (08): 33-36. ;  doi:
Full text: HTML (1 KB)  PDF  (579 KB)  ( 389 )
Abstract ( 1376 )
A high-sensitivity piezoelectric quartz crystal immunosensor based on silver enhancement and immuno-colloidal gold technique was developed. Using the sandwich method, the Schistosoma japonicum antigen was fixed in the electrode surface for capturing the Schistosoma japonicum antibody, which then was conjugated with the secondary antibody of goat anti-rabbit IgG labeled marked colloidal gold. Through the reaction catalyzed by colloidal gold upper silver ions reduction, a large number of silver deposited on the nano-around gold to enhance the sensitivity of piezoelectric quartz crystal immunosensor. The results show that the piezoelectric quartz crystal immunosensor based on colloidal gold labeling and silver enhancement is simple to operate, with high sensitivity, wide linear range, and low detection limit. The method has been applied to the rabbit serum antibodies in the determination of Schistosoma japonicum, and satisfactory results have been achieved.

Peak Oxygen Uptake and Ventilatory Efficiency of Patients with Ischemic Heart Disease and Dilated Cardiomyopathy by Cardiopulmonary Exercise Testing

Science & Technology Review. 2010, 28 (08): 37-41. ;  doi:
Full text: HTML (1 KB)  PDF  (875 KB)  ( 331 )
Abstract ( 1552 )
Studies in patients with heart failure have consistently shown a reduction in cardiac output and stroke volume at a given work rate and a lower peak heart rate when compared to normal subjects. Previous studies suggest that an attenuated exercise heart rate response and ventilation efficiency may be associated with chronic heart failure and with mortality. Heart rate response to exercise and ventilation function in patients with chronic heart failure due to ischemic heart disease or dilated cardiomyopathy remains a research issue. This paper studies the sinoatrial rate response and peak VO2 and ventilatory efficiency in heart failure patients with ischemic heart disease and dilated cardiomyopathy. 170 patients with chronic heart failure were selected, with 100 patients with ischemic heart disease, and 70 patients with dilated cardiomyopathy. All patients underwent modified Bruce treadmill exercise protocol. Exercise electrocardiogram and gas metabolic analysis were recorded. 75 normal subjects were taken as the control group. Heart rate on ECG response to treadmill exercise was determined as the percentage of target predicted Heart rate and the percentage of peak VO2 to predicted VO2. VE/VCO2 slop, anaerobic threshold AT were derived from cardiopulmonary exercise test. The patients with ischemic heart disease are older than those with dilated cardiomyopathy(P<0.001). Rest heart rate was found similar in both patients with ischemic or nonischemic heart disease. Peak heart rate response to peak exercise was reduced in patients with ischemic heart disease as compared with those with dilated cardiomyopathy(P=0.002). 45 patients have chronotropic imcompetence(CI), with less than 80% of predicted target heart rate, among which 28 patients are with ischemic heart disease and 17 patients with dilated cardiomyopathy(P>0.05). Age is correlated with peak VO2 in both patients with ischemic heart disease or dilated cardiomyopathy. But age is not correlated with percentage predicted VO2 in patients of both groups. Peak VO2 were reduced in patients with ischemic heart disease as compared with those with dilated cardiomyopathy(P=0.02), predicted VO2 was similar for patients of both groups, ratio of peak VO2 to predicted MVO2 was also similar (P=0.38). VE/VCO2 slop was increased (P=0.0001). AT was reduced in patients with ischemic heart disease (P=0.016). RQ ratio was not significant different between patients of two groups(P=1.0). In patients with heart failure, coronary artery disease has a more significant influence on sino-atrial node function than in those without. Gas metabolism and exercise tolerance were significant limited as is similar to dilated cardiomyopathy. Respiratory Q ratio was similar between two groups. Peak VO2 was reduced in both ischemic heart disease and nonischmeic dilated cardiomyopathy. But there was no significant difference in MVO2/predicted VO2 between two groups. Ratio of MVO2 to predicted VO2 was similar. Heart rate response to exercise in patients with ischemic heart disease was more severely impaired than those with dilated cardiomyopathy. Ventilatory efficiency(VE/VCO2 slop) was significantly reduced in ischemic heart disease as compared with those with dilated cardiomyopathy. Chronotropic imcopletence was found in patients with ischemic heart disease and dilated cardiomyopathy. Appropriate medical and revascularization management or electrophysiology approach may modulate these disturbances in such patients.

Measuring Instantaneous Temperature Rise in Tissue Phantom to Describe Sound Field Characteristics of High Intensity Focused Ultrasound

Science & Technology Review. 2010, 28 (08): 42-45. ;  doi:
Full text: HTML (1 KB)  PDF  (822 KB)  ( 370 )
Abstract ( 530 )
In view of the difficulty in the measurement of High Intensity Focused Ultrsound(HIFU) at high pressure, this paper presents a method of characterization of the sound field of HIFU by measuring the instantaneous temperature in a tissue phantom. The HIFU field in water is measured by using hydrophone when the power is 5W. The temperature distribution of the focal region in tissue phantom with the HIFU exposure time of 1 second, is measured by using thermocouple, with expected US power of 40,70,100,150 and 200W, respectively. The instantaneous temperature rise and the acoustic pressure are positively correlated through the sound absorption coefficient and the HIFU field nonlinear characterization is obtained through the variations of the sound absorption coefficient. The results show that the -6dB width of the radial focal region and the axial focal region measured by Hydrophone is much smaller than the radial and axial size focal region obtained by thermocouple under different high-power HIFU; under high power,as the power increase,the -6 dB width of the radial focal region and the axial focal region gradually changes, and the peak of the temperature field distribution is more pointed, reflecting the fact that the energy is more concentrated.

Disorder of Neuro-Endocrine-Immune Network in Patients with Type-2 Diabetes Milletus and Its Clinical Significance

Science & Technology Review. 2010, 28 (08): 46-50. ;  doi:
Full text: HTML (1 KB)  PDF  (423 KB)  ( 223 )
Abstract ( 503 )
To investigate the disorder of neuro-endocrine-immune network in patients with type-2 diabetes milletus and its clinical significance, 174 patients with clinical proven type-2 diabetes mellitus were enrolled in the study. Radio-immune technology and flow cytometer technology were used to detect the blood levels of CD4+, CD8+, NK and CD4+/CD8+, and cytokines including IL-1β, IL-6, TNF-α, ACTH, CORT and DA as well as NE. Analyses were performed on the basis of gender with 33 normal people served as the control group. A significant decrease of CD4+, CD8+, NK lymphocytes count, and a significant increase of CD4+/CD8+ were found in type-2 diabetes milletus patients compared with the control group(P<0.01). Low IL-1β, IL-6 and TNF-α levels were found in type-2 diabetes milletus groups (P<0.01). The serum ACTH, CORT levels were decreased in type-2 diabetes milletus patients (P<0.01); both serum DA and NE levels were increased in type-2 diabetes milletus groups compared with the normal group(P<0.01). The disturbance of neuro-endocrine-immune network in patients with type-2 diabetes milletus is characterized by the humoral immunity activated and cellular immunity depressed; symphathetic nerve activated;the stress related endocrine depressed. It is important to strengthen and recover the balance of neuro-endocrine-immune network, for the treatment of type-2 diabetes mellitus, which is an important issue for the future research on diabetes.

An Algorithm of Window Choice in Depth by Statistics Feature in GPR Target Detection and Location

Science & Technology Review. 2010, 28 (08): 51-54. ;  doi:
Full text: HTML (1 KB)  PDF  (569 KB)  ( 325 )
Abstract ( 559 )
Target detection and location is important in the application of the ground penetrating radar. Target location is based on the result of the detection, which in turn depends on the hyperbolas of the ground penetration radar. Many algorithms for this purpose involve a large amout of computational effort, such as SAR and overlay amplitude-velocity algorithm. They include an algorithm on window-statistics to consider noises and non-targets data. At the same time, Hough transform algorithm has also to be used. Based on the similarity of time samples of ground penetrating radar and the fact that the possible target lies in some area, an algorithm is proposed in this paper for ground penetrating radar target detection and location. First, the algorithm considers energy and variance as statistics features of one-dimensional data in depth, to determine the probable depth of target signals by the right threshold. Then the energy variant is used as the statistics feature of an A-scan in the above special depth window by the threshold. Finally, the target location is determined. Because it only uses a part of A-scan data without considering the non-targets data, the location is more accurately determined than the algorithm that uses the whole A-scan data. Moreover, the algorithm is more effective than above mentioned other algorithms. The result of the test shows that the algorithm is very effective in the fast target detection and location.

Application of Genetic Neural Network in GMI Sensor Design

Science & Technology Review. 2010, 28 (08): 55-59. ;  doi:
Full text: HTML (1 KB)  PDF  (1668 KB)  ( 366 )
Abstract ( 530 )
The GMI sensor enjoys many advantages, such as high sensitivity, fast response, but its response characteristics are highly nonlinear. Although by introducing ac bias, with the AGMI effect, the degree of sensor's linearity can be improved to some extent, the linear range and error are still not satisfactory. The BP neural network has the abilities of self-learning, self-adaptation and non-linear mapping, but its convergence is slow and it is easy to fall into a local minimum. Genetic algorithm has a high global optimization ability, but its local search ability is weak. To give full play to the advantages of the two methods, a genetic neural network is proposed to solve the problem of non-linear correction in sensor systems, and according to the designed GMI sensor, using the software of Matlab, we have implemented the designed genetic neural network. Test result shows that the trained network has an ordered data structure and good nonlinear mapping properties, which can accurately reflect the function relation of the sensor system. The proposed method has the advantages of fast calculation and high precision, which may find important applications in designing smart GMI sensors.

Discovery of Bioclastic Dolostone in the Second Member of Shahejie Formation in Bozhong Depression and Its Significance in Oil Exploration

Science & Technology Review. 2010, 28 (08): 60-64. ;  doi:
Full text: HTML (1 KB)  PDF  (2142 KB)  ( 356 )
Abstract ( 1415 )
Due to the characteristics in deep buried depth, poor physical properties of reservoir and difficulty in the effective reservoir prediction, the exploration of mid-deep oil and gas in mid-deep reservoirs is constrained mainly by reservoir quality. In QHD36-3 oil field, the storage properties are significantly superior to those of clastic reservoir at the same depth, including bioclastic dolostone and terrigenous clastic dolostone discovered in the second member of Shahejie Formation, and it will be one of the new fields in the mid-deep oil and gas exploration. This study suggests that the formation of dolomite reservoir is mainly affected by paleogeomorphology, paleao-water depth, and development degree, which is affected by the distance from the source area. The bioclastic dolostone formed by chemical and biochemical depositions is distributed in shallow to deep lake areas, and the reserving spaces include interlayer fractures and solution channels. Under the guidance of the sedimentary principle, the paper proposes a mixed sedimentation model of bioclastic dolostone in the second member of Shahejie Formation in Bozhong depression and further discusses the controlling factors of the mixed sedimentation. The establishment of the corresponding deposition pattern is essential for the oil and gas exploration related with bioclastic dolostone and terrigenous clastic dolostone.

Determination of Safety Factor of Rock Slope with Weak Interlayer Using Strength Reduction Technique

Science & Technology Review. 2010, 28 (08): 65-68. ;  doi:
Full text: HTML (1 KB)  PDF  (723 KB)  ( 261 )
Abstract ( 551 )
FLAC3D numerical simulation software and strength reduction technique were applied to determine the safety factor of rock slope with soft interlayer in a section of Changde-Zhangjiajie highway. Solution efficiency, stability criterion and other problems are discussed, related with the simulation course. The case study indicates that the convergence criterion combined with the interpenetration of the plastic zone criteria can well simulate the practical project. And the convergence criterion takes the slope failure as the indicator to achieve the automation of loop computation. At the same time, the plastic zone criterion can be used to decide the number of steps in the calculation. The calculated error of the strength reduction method can be made much smaller while combining with dichotomy, and the result tends to be more conservative and more accurate as compared to the limit equilibrium. In addition, the strength reduction method can accelerate the speed of calculation to a great degree, the calculated time for safety factor of 1 and 2 weak interlayers is 2046s and 5929s, respectively. Compared to the calculated time of the strength reduction method inside FLAC3D, the speed of calculation is six times faster, and the safety factor is also more reliable.

Synthesis of Coke Inhibitor Intermediate Phosphate

Science & Technology Review. 2010, 28 (08): 69-71. ;  doi:
Full text: HTML (1 KB)  PDF   (0 KB)  ( 163 )
Abstract ( 539 )
Coke formation is a serious problem in the ethylene production process. Adding inhibitors into raw materials is an important method of inhibiting coke formation. Phosphorus ester-drewamine salt is an important coke inhibitor. In this study, phosphate was synthesized with phosphoric acid and iso-octanol, catalyzed by activated aluminum oxide, activated sodium sulfate and tungsten phosphoric acid. It is shown that tungsten phosphoric acid as catalyst gives the best results because of its high catalytic performance. The reaction conditions were shown to have a great effect on the yield of target product. The experiment results indicate that the optimum conditions are as follows: tungsten phosphate content of 5.0%, tungsten phosphoric acid as the catalyst, catalyst dosage of 2.0%, iso-octanol and acid molar ratio of 2.3, and the reaction time of 4 hours. The yield of phosphate was found to be 72.8% under the above conditions. IR spectra analysis shows that the product is indeed the target product phosphate.

Effects of Playgoskite on Growth Development and Yield of Heysarum polybotrys Hand-Mazz

Science & Technology Review. 2010, 28 (08): 72-76. ;  doi:
Full text: HTML (1 KB)  PDF  (397 KB)  ( 431 )
Abstract ( 664 )
This paper discusses growth rules of Hedysarum polybotrys Hand-Mazz. With playgoskite being added, a set of production technologies is established for Hedysarun polybotrys Hand-Mazz. The single factor randomized block is designed in the experiment to study the growth development and yield of Hedysarum polybotrys Hand-Mazz, under 5 types of treatments with playgoskite of 0, 750, 1500, 2250 and 3000kg/hm2. The results show that playgoskite can enhance the stilbazolium height, main root length, root diameter, dry material accumulation quantity in ground and root and the yield of Hedysarum polybotrys Hand-Mazz, when it is used in the range of 750~3000kg/hm2. And the yield is the highest, when it is used in 1500kg/hm2, with an increase of 23.44%(P<0.01) compared to the control group, and with optimum overall characteristics. The next comes with 1500kg/hm2. This study provides an important scientific basis for reasonably using N, P and K fertilizers and playgoskite in the cultivation of Hedysarum polybotrys Hand-Mazz.

The Fault Diagnosis for Diesel Engine Inlet and Exhaust System Basedon Adaptive LS-SVM

Science & Technology Review. 2010, 28 (08): 77-80. ;  doi:
Full text: HTML (1 KB)  PDF  (1116 KB)  ( 307 )
Abstract ( 536 )
A novel fault diagnosis method is proposed for diesel engine inlet and exhaust system based on least squares support vector machine (LS-SVM). Normal running and several common faults (gas leak and abnormal valve lash) are decomposed into wavelet packets, the energies of different frequency bands after wavelet packet decomposition serve as the input vectors of LS-SVM, the feature vectors. An adaptive optimizing algorithm is used to optimize LS-SVM. The engine fault is identified using LS-SVM based on optimized parameters by the adaptive optimizing algorithm and the minimum output coding. A comparative experiment shows that the proposed approach can overcome the shortcomings of the slow convergence and of falling easily into a local minimum in the BP algorithm and the long training time in the traditional LS-SVM algorithm by cross-validation, and the method enjoys advantages such as fast training speed and high identification accuracy percentage as compared with the BP neural network and the traditional LS-SVM. It also performs well with small number of samples. The simulation verifies its validity in identifying diesel engine inlet and exhaust system faults.

Representations of Pointwise Convex Modulus in Euclidean Spaces

Science & Technology Review. 2010, 28 (08): 81-83. ;  doi:
Full text: HTML (1 KB)  PDF  (251 KB)  ( 320 )
Abstract ( 587 )
With a support function as a tool, the estimations and representations of pointwise convex modulus in two-dimensional and three-dimensional Euclidean spaces are discussed, and the calculations of the pointwise convex modulus in the surface of ellipse and ellipsoid surface are carried out. It is shown that the smaller this spot, the stronger its convexity degree. The convex modulus describes an overall degree of convexity of the unit sphere in the space, which is very different from the degree of convexity at each point and which may have very great influence on the whole feature of the space. Therefore, the study of pointwise properties is very important. The pointwise constant geometry of the space can enhance the understanding of the nature of the space.

A Geospatial Index Architecture Based on Geological Information Metadata Standard

Science & Technology Review. 2010, 28 (08): 84-88. ;  doi:
Full text: HTML (1 KB)  PDF  (876 KB)  ( 269 )
Abstract ( 497 )
According to the deployment of the spatial database in a distributed network environment, based on current geological information metadata standards, a specific geological survey information platform is established for metadata structures, including both the spatial database level and the layer of spatial index. So the spatial data are integrated, a unified spatial index database is built in the space within the framework of the index generating Hilbert space-filling curve scan matrix, to get one-dimensional mapping between Hilbert space arrangement of coding and spatial index information. A reasonable and efficient spatial index algorithm is designed for the overall planning and design. Unified operating methods are proposed for data integration, with a system architecture to improve the level of work for Geological Survey of information technology and complete data sharing and information service system. Experiments show that the system can directly access a relational database table for operation and maintenance, to avoid as much as possible the calls of the ArcGIS platform package ArcObjects correlation functions. In the realization of spatial indexing at the same time, the efficiency of spatial index is greatly enhanced. It provides a key spatial index system and a good support for data sharing for the geological survey information platform.

A Control Strategy for Braking Energy Distribution and Regenerative Braking in an SP-HEV

Science & Technology Review. 2010, 28 (08): 89-93. ;  doi:
Full text: HTML (1 KB)  PDF  (1185 KB)  ( 324 )
Abstract ( 498 )
The regenerative braking system is a unique system in electric vehicles and hybrid electric vehicles. The system can restore the kinetic energy and potential energy, during start and accelerating, into battery through electrical machines. The focus of this paper is on Changfeng CFA6470E HEV. Based on the braking theory of conventional vehicles and security braking and high efficient energy recovery, a control strategy for braking energy distribution and regenerative braking of an SP-HEV is proposed. The ideal braking force distribution is used in the front axle and real axle braking force distributions. After the front axle and real axle's braking force is distributed, regenerative braking and friction braking are assigned. The characteristics of motor and battery's life have been taken into account in the quadratic distribution method, The motor's speed and SOC are taken as the braking power's influencing factors. ADVISOR2002 is re-developed for the simulation model. The simulation result shows that the control strategy for braking energy distribution and regenerative braking can satisfy demand for vehicle braking and extend the life of battery. The strategy proves to be practical.
Reviews

Modal Analysis Based on Distributed Strain Measurements: Theory and Application

Science & Technology Review. 2010, 28 (08): 94-103. ;  doi:
Full text: HTML (1 KB)  PDF  (2242 KB)  ( 720 )
Abstract ( 571 )
With the past five years' study by the authors, an advanced distributed strain sensing technique has been developed for the health monitoring of infrastructures. A series of research work including theoretical and experimental modal analyses were conducted based on the dynamic measurements of strain distribution. This paper systematically reviews the work. With a brief introduction of the basic features of the developed dynamic distributed strain sensing techniques in the first place, the strain-response-based modal analysis theory is further presented. Modal testing techniques are then discussed to obtain the macro-strain Frequency Response Function (FRF) and identify the modal parameters, including resonant frequencies, damping ratio, and Modal Macro-Strain Vector (MMSV). In time and frequency domains, the macro-strain FRF is close to a displacement FRF rather than a velocity or acceleration one, so the relation between macro-strain FRF and frequency can provide a more sensitive indicator at low modes, especially, when the resonant frequencies are small. The identified resonant frequency and damping ratio from dynamic strain measurements have the same precision as those from the conventional transducers such as accelerometers and strain gauges. The curves of MMSV versus mode shape share the same mapping relation with the time-series and frequency responses of the measured macro-strain versus displacement responses, which means that MMSV essentially is a direct modal strain measurement. Based on the above findings, the advantages of modal strain over modal displacement in the engineering applications of low-frequency measurements, dynamic model reconstruction and structural damage identification are discussed as well.

Well Logging Residual Oil Saturation Evaluation

Science & Technology Review. 2010, 28 (08): 104-109. ;  doi:
Full text: HTML (1 KB)  PDF  (4372 KB)  ( 637 )
Abstract ( 674 )
The major logging methods employed to investigate the residual oil saturation in the cased hole include through-casing resistivity logging, carbon-oxygen ratio logging, neutral lifetime logging, neutral GR logging by injecting gadolinium into the reservoir and pulsed neutral-neutral logging (PNN). These residual oil saturation logging methods are reviewed in this paper, with the focus on their interpretation of field data, covering the working principle, geological applications and the technical capability of these methods. The latest developed through-casing resistivity logging tool by Russia, named as ECOS, enjoys many technical advantages in residual oil saturation calculation, hydrocarbon leakage zone evaluation, and reservoir management determination. As a relative mature technique, the carbon-oxygen ratio logging could be employed to calculate the oil saturation and the water salinity and to investigate the water flooded zones, as is more suitable for studies in the formation with low salinity and large saturation. The neutral lifetime logging is one of the most important methods to determine the residual oil saturation, but it is valuable just for perforated zones with medium or low salinity. Comparatively, the method of the neutral GR logging by injecting gadolinium into the reservoir is more useful for studies in the formation with low salinity.

Development of Space Environmental Monitors on Chinese Manned Spacecraft

Science & Technology Review. 2010, 28 (08): 110-115. ;  doi:
Full text: HTML (1 KB)  PDF  (1839 KB)  ( 405 )
Abstract ( 574 )
Around the manned spacecraft's orbits in 300 to 500km altitude, there are all kinds of charged particles, neutral atmosphere, the electromagnetic fields, space debris etc. The space environment fluctuations in a manned spacecraft's orbit can significantly affect the safety of astronauts and spacecraft. The charged particles can cause SEU, SEL and the discharge of spacecraft's surface, even threaten the astronauts' safety. The retarded effects of neutral atmosphere make the spacecraft's orbit to descend. Oxygen denudation and oxygen contaminations of atmosphere also affect the solar cell's efficiency and the normal work of thermoregulation materials. To ensure astronauts' safety and normal operations of manned spacecraft, Space Environmental Monitors (SEMs) have been or will be mounted on Chinese manned spacecraft. Detection of SEMs enables us to understand better the space environment in the manned spacecraft's orbit, and to provide a good space environment service for astronauts and spacecraft. In addition, from the data of SEMs, we will conduct various scientific researches. The development of Chinese manned spacecraft is divided into 3 steps, and SEMs are used in each step. Space environmental detection in the first step is to have a preliminary understanding of space environment of manned spacecraft's orbits, and to provide the ensuring service for the formal manned flight. The second step considers Chinese feature. The two instruments installed can realize an integrated detection of charged particles and atmospheric environment. The first detector can detect multi-direction particles, multi-energy spectrum, radiation dose and LET spectrum. The second detector can monitor atmospheric density, composition and contamination. The following step of space environmental detection pays attention to the safety of astronauts and spacecraft, as well as the new areas of detecting plasma, neutrals, cosmic rays and debris.

Science & Technology Review. 2010, 28 (08): 116-116. ;  doi:
Full text: HTML (1 KB)  PDF  (59 KB)  ( 298 )
Abstract ( 399 )
科技评论

Science & Technology Review. 2010, 28 (08): 117-117. ;  doi:
Full text: HTML (1 KB)  PDF  (220 KB)  ( 209 )
Abstract ( 413 )

Science & Technology Review. 2010, 28 (08): 120-120. ;  doi:
Full text: HTML (1 KB)  PDF  (222 KB)  ( 244 )
Abstract ( 443 )

Science & Technology Review. 2010, 28 (08): 121-121. ;  doi:
Full text: HTML (1 KB)  PDF  (200 KB)  ( 240 )
Abstract ( 421 )

Science & Technology Review. 2010, 28 (08): 122-122. ;  doi:
Full text: HTML (1 KB)  PDF  (113 KB)  ( 251 )
Abstract ( 418 )

Science & Technology Review. 2010, 28 (08): 123-123. ;  doi:
Full text: HTML (1 KB)  PDF  (322 KB)  ( 230 )
Abstract ( 383 )

Science & Technology Review. 2010, 28 (08): 124-124. ;  doi:
Full text: HTML (1 KB)  PDF   (0 KB)  ( 174 )
Abstract ( 445 )
Focus

Science & Technology Review. 2010, 28 (08): 118-119. ;  doi:
Full text: HTML (1 KB)  PDF  (179 KB)  ( 438 )
Abstract ( 424 )
主编心语

Science & Technology Review. 2010, 28 (08): 125-125. ;  doi:
Full text: HTML (1 KB)  PDF  (916 KB)  ( 328 )
Abstract ( 402 )
走向职场

Science & Technology Review. 2010, 28 (08): 126-126. ;  doi:
Full text: HTML (1 KB)  PDF  (228 KB)  ( 257 )
Abstract ( 419 )

Science & Technology Review. 2010, 28 (08): 127-127. ;  doi:
Full text: HTML (1 KB)  PDF  (156 KB)  ( 239 )
Abstract ( 416 )

Science & Technology Review. 2010, 28 (08): 128-132. ;  doi:
Full text: HTML (1 KB)  PDF  (463 KB)  ( 201 )
Abstract ( 445 )

Science & Technology Review. 2010, 28 (08): 133-137. ;  doi:
Full text: HTML (1 KB)  PDF  (1043 KB)  ( 197 )
Abstract ( 435 )

Copyright © Editorial office of Science & Technology Review
Tel: +86-10-62138113 Fax: +86-10-62138113 E-mail: jdbbjb@cast.org.cn
京ICP备14028469号-1