08 July 2012, Volume 30 Issue 19

    

Spescial Issues
Articles
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Spescial Issues
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  Regionalization Study on Dry-hot Windy Days in the North China Plain Using CAST Model

  WU Dingrong;LIU Jiandong;LIU Ling;JIANG Chaoyang

  . 2012, 30(19): 19-23. https://doi.org/10.3981/j.issn.1000-7857.2012.19.001

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  Dry-hot wind day is one of the main argometeorological disasters which impact the development and yield of winter wheat in the North China Plain (NCP). Using daily meteorological data of 48 weather stations from the year of 1961 to 2008 in the NCP, the dry-hot windy days, that include two types, type one is high temperature and low humidity and type two is immature death after rain, are analyzed. Then by using dry-hot windy days and Cluster Analysis of Statistic Test (CAST), which is a newly developed regionalization method, the dry-hot windy days regionalization is carried out in the NCP. Results show that spatially speaking, both types of dry-hot windy days all present higher in the middle and lower in the south and north; temporally speaking, type one is slightly decrease in the last nearly fifty years, except the individual stations in the south part of the plain. Although type two of dry-hot windy days is also generally decrease in the past, however, the exceptional stations are higher than type one. Results of CAST indicate that for the type one, five regions are divided and for the type two, four regions are divided. Those regionalization results are reasonably reflecting the spatial and temporal changes of dry-hot windy days in those load centers, and CAST is more powerful than conventional regionalization methods. The results could provide the scientific and practical base for developing the monitor and forecast system of dry-hot wind days, and is also able to provide realistic instructions for the decision making on the agricultural managements of the local farmers.
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  Temporal and Spatial Variations of Dry-hot Windy Days in the North China Under the Condition of Climatic Change in the Future

  LIU Ling;LIU Jiandong;WU Dingrong;XU Yinlong;JIANG Chaoyang

  . 2012, 30(19): 24-27. https://doi.org/10.3981/j.issn.1000-7857.2012.19.002

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  Dry Hot Windy Day (DHWD) is one of the main agrometeorological disasters happend in the north China area which could cause the serious yield loss of winter wheat. Using daily weather data created by RPECIS, which is the one of most widely used regional climate models developed by Hadley Center, DHWD in the future SRES A2 and B2 climate change scenarios is analyzed. Results show that PRECIS predicts DHWD for A2 scenario is 6.5 days/year, and is lower in coastal, north, and south areas, but higher in the middle west area. DHWD is increase in most areas except the far southern area, the maximum increase rate is 0.145 day/year; for B2 scenario, DHWD is 6.0 day/year, with similar regional distribution trend of A2, i.e., higher in the middle area and lower in the other areas. DHWD is slightly decrease in southwest area and a little increase in northeast area; however increase rate is much lower than that for A2. The trends and variations of DHWD in the future for both SRES A2 and B2 scenarios are analyzed. Results are able to serve as the argometeorological disaster prevention and reduction, and make the contribution to the relative policy making.
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  Evaluation Technique for Crop Drought Losses in the Context of Climate Change in Northwest of China —Taking Spring Corn in the Gansu Province of China as an Example

  BAI Yueming;LIU Ling;WANG Yusha

  . 2012, 30(19): 28-33. https://doi.org/10.3981/j.issn.1000-7857.2012.19.003

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  In order to quantitatively evaluate the crop disaster losses caused by drought in northwest of China in the context of climate change, a Bio-meteorological Index-DI, that is used to quantitatively evaluate the drought loss of spring corn in Gansu Province, China, is built. The DI index consists of CI index and water fitness. The former reflects the role of the medium- and long-term precipitation and heat condition; the latter represents the relationship between the water supply and physiological water demand of corp. According to the drought-reduced and growing season precipitations, the DI index is divided into four degrees, that is, mild drought, moderate drought, serious drought, and particular heavy drought, respectively based on the verification analysis and feasibility evaluation of the DI index. The historical daily DI index and accumulated DI index are backward calculated by using the materials of daily precipitation and temperatures collected from the meteorological stations, the corn yields and total productions, developmental and physiological water demand. The temporal and spatial variations of spring corn DI index for the representative stations in the growing areas have some practical significance on the agricultural crop system adjustment, crop allocation, and disaster prevention and mitigation.
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  Temporal and Spatial Dynamic Distribution of Drought Risk over the Northwest of Liaoning Province Based on Remote Sensing Data

  LIU Xiaojing;ZHANG Jiquan;WANG Chunyi;YAN Denghua;LIU Xingpeng;MA Donglai;BAO Yulong

  . 2012, 30(19): 34-39. https://doi.org/10.3981/j.issn.1000-7857.2012.19.004

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  Normalized Difference Vegetation Index (NDVI) is an indicator which is able to measure the growth status and coverage of vegetation on the surface. It has been widely used at home and abroad for the quantitative identification and monitor of drought. Thus against the background of meteorological drought, NDVI in drought period is calculated in order to establish the drought risk diagnosis model of maize which is able to reflect the agricultural drought risk by the response of drought from crops. The NDVI under meteorological drought is used to build the drought risk diagnosis model of maize for assessing the drought risk of maize during the typical drought period of typical years in the study area. K-Mean method is used to divide risks into three levels, namely, low, moderate, and high. Then the grade maps of risk are drawn by GIS and RS. And the temporal and spatial distribution of drought risk of maize is dynamically analyzed. The analysis result shows that based on the time changes of maize drought risk, because of water effect on soil, precipitation anomaly percentage at drought period in typical years is not completely inverse proportional to the drought risk of maize; based on the drought spatial distribution features of maize, drought risk, which is affected by the latitude, altitude, and drought control ability, has a large differences between the north and south. The study on the temporal and spatial dynamic distribution of the drought risk of maize could provide a scientific basis for learning the occurrence and development of drought and making defense strategies based on local conditions for government departments and the farmers.
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  Response of Agronomic Characteristics to Water Stress for the Winter Wheat Before Flowering Stage

  BI Jianjie;LIU Lianying;TAN Xiushan;WANG Jinhua;WANG Chao;LIU Xinghai;LIU Jiandong

  . 2012, 30(19): 40-44. https://doi.org/10.3981/j.issn.1000-7857.2012.19.005

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  In order to study the response of winter wheat to the water stress before flowering stage, the winter wheat of Jimai20 is taken as the research object by measuring agronomic characteristics under three different water stresses in the field conditions. The result shows that under water stress, the spike rate increases while spike per hectare reduces. Leaf area, height and, matter accumulation are all blocked. The decrease of length rather than the width is mainly caused by the changes in the area of the fourth leaf. The response from flag leaf is less sensible than that from the leafs in lower positions. The height decrease is due to the length decrease between modal Ⅳ and Ⅴ. As water stress increases, all the agronomic characters mentioned above decline. Comparing with leaves and intermodal, the change for root system is more complicated. The number of secondary roots reduces, however the lengths increase. Matter accumulation delays by water stress, and the distribution of matter increases toward root causing root-shoot ratio increase. The plants decrease drought damage though reducing the root density, leaf area, intermodal length, and increasing root length.
Articles
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  Relationship between KRAS, BRAF' and PIK3CA Mutations and Metastatic Colorectal Cancer

  LI Hongtao;LIU Hongbin;ZHAO Qingchuan;HAN Xiaopeng;ZHU Wankun;SU Lin

  . 2012, 30(19): 45-49. https://doi.org/10.3981/j.issn.1000-7857.2012.19.006

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  In order to investigate the molecular occurrence of KRAS, BRAF, and PIK3CA mutations in the colorectal cancer patients and to study the association of these events with clinicopathological parameters. Two hundred paraffn-embedded tumor specimens were collected from 150 colorectal cancer patients who underwent resection of primary tumors at Xijing Hospital of Digestive Diseases and General Hospital of Lanzhou Military Region of PLA from the year of 2008 to 2009. The DNAs are extracted from 200 cases of human colorectal cancer tissue samples. KRAS, BRAF, and PIK3CA mutations analysis is performed by PCR and pyrosequencing. Using statistical methods, the relationships between the gene mutations and clinicopathological parameters are analyzed. The KRAS point mutation rate is 32% (48/150); The V600e mutation rate of BRAF is 8% (12/150); PIK3CA point mutation rate is 12% (18/150), among them, exon 9 mutation rate is 6% (9/150) and exon 20 mutation rate is 6% (9/150). The study indicates that the mutational status of BRAF is not correlated with Dukes' staging, histological type, age, and gender of patients. However, strong connections are found between KRAS, PIK3CA mutations and Dukes' staging (staging D, 48% (9/150)).
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  Relationship of Cervical Cancer of Uighur Women and HPV Infection with the Up-regulation of Multiple Gene Expression

  ABABAIKELI Anaguli;TUERXUN Hankiz;ABUDULA Abulizi;SUZUKE Lalai;MAITISIDIKE Ayinuer

  . 2012, 30(19): 50-54. https://doi.org/10.3981/j.issn.1000-7857.2012.19.007

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  Previous studies suggest that the profiles of over-expressed genes in cervical carcinoma are very different among populations. The aim of this study is to identify the early warning molecular markers specific to Uighur women by screening the cervical lesions for candidate over-expressed genes. 85 cases of fresh cervical tissues were collected from Uighur women with cervical squamous cell carcinoma (CSSC) and chronic cervicitis as well as the normal tissue specimens from the surgical excision of uterus. After preparation of the tissue, the total DNA and RNA, HPV positivity and genotypes were screened by the HPV specific primer PCR, and the transcription level of 7 candidate genes was analyzed by the semi-quantitative RT-PCR. The positive rates of the mRNA expressions of the SPP1, TK1 and ARP2/3 genes are found to be relative low in the chronic cervicitis and the normal periphery of the tumor (25%—28%), and are markedly increased in the CSSC (62%—66%), with a significant difference (P<0.05), but with no significant difference in the expressions of ANX8, HSPAIP, S100-A9 and S100-P genes. In case of the HPV infection, the rates of TK1 and ARP2/3 gene expressions are very low in the HPV negative cases (50.0% and 44.2%), relatively high in the HPV positive cases (82.9% and 74.2%), and with a significant difference (P<0.05). The up regulation of SPP1, TK1 and ARP2/3 gene expressions might serve as an important mark of the cervical cancer progression in Uighur women, and the alteration of TK1 and SPP1 gene expressions may be related with the HPV infection.
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  Application and Prospect of Random Walk in 3D Reservoir Modeling

  SHI Shuyuan;FENG Wenjie;YIN Yanshu;YANG Rui;JIANG Ren;HU Hao

  . 2012, 30(19): 55-59. https://doi.org/10.3981/j.issn.1000-7857.2012.19.008

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  This paper reviews the basic principles of the random walk, and proposes two modifications for the technology, related with the random influencing factor and the widening channel methods. First, in the calculation of the transition probability, the Monto Carlo factor is added to increase the stochastic extent and to make the model more deterministic. Second, the circling filling approach is used to reconstruct the width of the channel along the channel mainstream, so that the channel will not vary sharply in the high curvature points. The real data from the eastern oilfield is used to test the modified algorithm. It is shown that it is similar to drawing picture by a geologist and the results agree with the real geological phenomenon, with a coincidence rate of 76.5%. Furthermore, the results of the modified algorithm using the sparsing testing agree with the results before the sparsing, with a rate of matching of 77.3%. Finally, some problems in using the random walk are analyzed and related solving schemes are proposed.
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  Application of Non-contact Video Extensometer in Mechanical Properties Test

  HU Shijun;ZHANG Hongxiang;ZHANG Dailu;YANG Li

  . 2012, 30(19): 60-62. https://doi.org/10.3981/j.issn.1000-7857.2012.19.009

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  In order to promote and apply non-contact video extensometer to the mechanical test of materials, the tensile testing of 2A12T4 aluminum alloy profile sample is conducted on the 20kN electronic universal testing machine by automatically measuring elongation and width of the deformation for the alloy in non-contact video extensometer. At the same time, electronic strain extensometer is installed in the length direction for tracking measurement, with keeping in the corresponding force value, cut deformation in the width direction is measured by means of micrometer measurement . After the sample cracks, the tool microscope is used to measure the deformation in both length and the width directions. The deformations measured by two groups of measuring tools are compared with each other, and the average value curves in the absolute deviation for the vertical and horizontal deformations are drawn. The analytic results indicate that using non-contact video extensometer to measure mechanical properties of materials is able to completely meet the needs of production and test.
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  Comparison of Softwares Used for Predicting Partition Coefficient (n-Octanol/Water) of Organic Contaminants

  SHANG Zhaocong;HE Shaopeng

  . 2012, 30(19): 63-69. https://doi.org/10.3981/j.issn.1000-7857.2012.19.010

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  Ten kinds of general partition coefficient (octanol/water) prediction software (ALOGPs, AC logP, AB/LogP, COSMOFraq, miLogP, ALOGP, MLOGP, KOWWIN, XLOGP2, and XLOGP3) provided by Virtual Computational Chemistry Laboratory is introduced. Using 105 kinds of organic pollutants listing in the National Recommended Water Quality Criteria of USEPA as a test set, paired t-test and liner regression method are performed on the predictive values and experimental values. The paired t-test results show that there is no significant difference between predictive values and experimental values for ALOGPs, AC logP, AB/LogP, and KOWWIN. The corresponding p-values are 0.26517, 0.08149, 0.43717, and 0.89145, respectively. The results of liner regression method indicate that the ALOGPs and KOWWIN are more accurate predictors than other software. For ALOGPs, the correlation coefficient between predictive values and experimental values is 0.9919. The slope and the intercept of the fitting curve are 0.9765 and 0.0564, respectively. For KOWWIN, the correlation coefficient is 0.9884. The slope and the intercept of the fitting curve are 0.9982 and 0.0102, respectively. Since the ALOGPs has a more user friendly interface, more convenient operation, more methods for entering input data, is able to free online perform, and provides the average lgP value of 10 kinds of software, therefore the ALOGPS has advantage over KOWWIN.
Reviews
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  CO₂ Sequestration and Utilization in Deep Saline Aquifers

  LI Yiman;PANG Zhonghe;LI Jie;KONG Yanlong;

  . 2012, 30(19): 70-79. https://doi.org/10.3981/j.issn.1000-7857.2012.19.011

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  CO₂ sequestration in deep saline aquifers is one of the most effective and promising choices to mitigate anthropogenic CO₂ emissions. Commercial scale CO₂ injection projects and pilot scale field tests have demonstrated that it is technologically feasible. The state of the art and future challenges including CO₂ trapping mechanism, capacity assessment technology, monitoring technology, safety assessment technology, and utilization technology are discussed based on the review of existing literatures. Hydrothermal experiment and numerical simulation in particular have proven to be very important methods to study the water-rock-CO₂ interaction process and mechanism supported by field tests. Geophysical methods, seismic monitoring methods, in particular 4D, cross well and vertical seismic, could effectively detect the CO₂ plume in reservoirs. However, they are unable to be widely applied due to the high cost, meanwhile geochemical methods (e.g. water chemistry and isotopes) could reflect reservoir responses in time after CO₂ injection which is simple with low cost, and numerical simulation could provide the basis for CO₂ plume migration. It is suggested that a set of multi-methods monitoring technology with easy operations should be established. Safe assessment technology includes numerical simulation, mechanical parameters testing, and establishment of various models; and further consideration of public acceptance and practical experience from large-scale CO₂ storage projects need to be integrated for the improvement. Considering the high cost of CCS implementation, CO₂ utilization should be encouraged and in particular, the CO₂-EATER technology needs to be further discussed in order to improve waste geothermal water injectivity and sustainable development of geothermal resources. Technologies and methods of CO₂ sequestration in marine saline formations develop very fast abroad, in the meantime most of the sedimentary basins in China that are suitable for CO₂ sequestration are continental deposition with great differences in formation water and reservoir rock compositions and in this way, it is important and necessary to emphasis our specialty and focus when learning from experiences abroad.