This paper studies the petrologic characteristics of the dawsonite- bearing sandstone reservoirs of the Cretaceous in southern Songliao Basin,the diagenetic sequence of the dawsonite-bearing sandstone, and the occurrence and the origin of the dawsonite based on the principles and the methods of the petrology and the isotope geochemistry. The petrologic study shows that the dawsonite-bearing sandstones are mainly composed of the arkoses and the feldspathic litharenite. The diagenetic sequence is shown to be the clay coating cementation-secondary feldspar overgrowth-secondary quartz overgrowth, authigenic quartz, kaolinite-calcitehydrocarbon charging-CO₂ charging-dawsonite-ankerite. The analysis of the carbon and oxygen isotope composition indicates that the dawsonite δ¹³C_PDB values range from -0.342% to 0.329%, and δ¹⁸O_PDB values range from -1.922% to -0.954%, as is similar to the proved dawsonite formed in the organic background and related to the magmatic activity. The calculated δ¹³C_PDB values of CO₂ gas in the isotope equilibrium with the dawsonite ranging from -0.992% to -0.423%, are consistent with the δ¹³C_PDB values of the inorganic CO₂ in the southern Songliao Basin. These values indicate that the CO₂ that forms the dawsonite and that from the gas reservoir have the same source, which is the mantle-sourced origin.

Ultra-low permeability sandstone reservoirs are significantly influenced by development of natural fractures. Based on laboratory experiments, fractured ultra- low permeability sandstone reservoirs were detailedly characterized in terms of porositypermeability relationship, micro-pore structure, stress sensitivity, and oil-water two-phase flow. The results show that permeability of fractured reservoir was higher than that of non-fractured one under equal reservoir porosity. When the reservoir porosity ranged from 10% to 20%, the permeability of fractured reservoir was approximately 2-4 times higher than that of non-fractured one. Compared with experiments on non-fractured reservoir, fractured reservoir is featured by larger throat radius span, higher proportion of largeradius throats, larger radius of dominant throats, and major contribution of large-radius throats to permeability under equal permeability. Fractured reservoir is more stress-sensitive, and the corresponding permeability loss of effective stress increase was 1-2 times higher than that of non-fractured one. Oil-water two-phase flow in fractured reservoir is featured by higher bound water and residual oil saturations, shorter common-flow interval, rapid oil relative permeability decline and water relative permeability increase with the increase of water saturation, short water-free production period, rapid water-cut increase after water break-through and low ultimate recovery factor.

One hundred and nineteen samples were collected and measured to study the pollution degree and distribution characteristics of total petroleum hydrocarbon (TPH) in vadose zone and water-bearing medium in a petroleum contaminated site. The method of cumulative frequency was used to identify the background threshold by solving the intersection point of the linear regression lines. This method has solved the inaccurate problem in identifying the background threshold caused by difference in drawing of the cumulative frequency curve. The contamination status was analyzed and evaluated by method of single factor index. The results show that the site background threshold of TPH was 36.7 mg·kg^-1. In the south of the contaminated site (pollution source), the TPH pollution level of medium in vadose zone gradually decreased with the increase of depth. That of water-bearing medium increased first, decreased after stability, and finally stabilized at the secondary pollution level. As for the central area of the site, the contaminated characteristics in vadose zone were similar to that in the southern area. The water-bearing medium was polluted by petroleum hydrocarbons only in the shallow part. In the north of the site, there was no or low TPH contamination. The pollution degree of medium in vadose zone was higher than that of water-bearing medium.

To obtain an accurate size of mine goaf is an important criterion of resource exploitation surrounding mine goaf region. What is more, it is also important groundwork of mine goaf treatment and disaster monitoring. In view of the traditional goaf triangulation model tetrahedron algorithm which is prone to cause the overlap computation problem, this paper takes the original data of three-dimensional laser system CMS acquisition as the standard criterion, and puts forward a tetrahedron cumulative sum algorithm that takes laser probe as the center point to connect all the triangulation. Thus, the accurate solution of the goaf's volumes is determined. On the basis of the goaf triangulation network model generated by self-developed products-3D modeling software of goaf detection, the traditional tetrahedron algorithm of mining goaf triangulation model is improved. First of all, the center point of tetrahedral solution is determined by the algorithm, then a tetrahedron is formed through the connection of the center point and triptychs of the triangle network model. Finally, the mining goaf's volume is calculated by summing up the tetrahedral directed volumes. Actual application shows that the improved tetrahedron algorithm of mining goaf tetrahedral volume has the advantages of high precision and wide application range.

The panel roadway in a coal mine in Shanxi province was in high stress state by the influence of stress concentration with dynamic pressure phenomena appearing, such as supporting difficulty, spalling, floor heaving, U-steel support pushed and threatened by burst. Microseismic monitoring technology was used for monitoring the roadway roof strata breaking. Two sets of sub-stations and 18 measuring points were installed to monitor and warning the burst disasters. Monitoring results showed that microseismic events occurred 0-4 times per day in the monitoring area with less energy. The microseismic events were concentrated in two areas, and were closely related to the extractive activities. More attention should be taken to these areas, monitoring of densely populated areas with microseismic events should be strengthened, and measures should be taken immediately to cope with abnormal events.

A large-scale visual fracture simulation system and experimental schedule have been designed with consideration of fiber adding method, fiber concentration, and temperature to study the effect of fiber on fiber fracturing. Experimental results show that fracturing fluid carrying capacity was the best through adding fiber, then crosslinking agent, and finally proppant. In a certain temperature range, the higher the fiber concentration, the more stable the network, and the carrying capacity was better, but it became worse when the temperature exceeded 80℃. With increasing of fiber concentration, the sand bank became flat, and the amount of proppant in deep fracture increased, leading to increase of the effective length of the fracture. This study may provide reference for the design of fiber sand fracturing.

This paper studies the fracturing characteristics of hard overlying strata and its control of the strata pressure behavior of the working face based on working face 8015 of coal seam 3-5 of the carboniferous system in Tongxin mine. The critical layer of the working face was determined as well as the initial and cycle fault displacement using critical layer theory. The relationship between critical layer facture and support pressure of the working face was derived based on theory of mechanics of materials to analyze the influence of critical layer facture on the strata pressure behavior of the working face. The results show that the working face of the hard overlying strata had sub-critical layer I, sub-critical layer II, and a main critical layer, the fracture of which led to generation of cycle pressure and complex pressure at the working face, and fracture of the main critical layer led to a relatively large range of pressure. These strata pressure behaviors derived by theoretical analysis are consistent with practical pressure monitoring.

To study the borehole stability problem of oil and gas drilling and geothermal drilling in deep formations, a basic differential equation of plane strain problem for borehole stability in deep formation is proposed on the basis of the continuum mechanics of elasticity, and a BEM calculation method of stress and displacement distribution around the wellbore is derived by using the BEM theory. To test the correctness of the BEM method, a physical model and the boundary elements of borehole stability problem are established, then the stress solution around the wellbore is compared with the analytical solution. By analyzing the borehole stability problem of deep formation in a certain oilfield of Sichuan, it is shown that the stress distribution with the BEM method is in good agreement with analytical solution, and its error is less than 0.82%. The borehole stability analysis results are basically in accord with the actual situation at 2500-3500 m in the example well, the actual drilling fluid density is lower than the equivalent density of the collapse pressure, and the hole expanding rate is above 20%. Increasing the density of drilling fluid can maintain wellbore stability, thus the accuracy of the BEM method is further verified. This method provides a new means for wellbore stability analysis.

In the design of the image guided bomb, the frame angle varies in a limited range in order to avoid hitting the frame of the miniaturization seeker. Therefore the guidance with a limited frame angle range of the image guided aircraft should be studied. The frame angle increases with the decrease of the line-of-sight distance in the three-point guidance, but it is the other way round using the proportional guidance. Therefore, the maximum frame angle is reached when changing the guidance law from the three-point guidance to the proportional guidance. In this paper, a modified proportional navigation is put forward to decrease the frame angle when following a curve escaping target. The frame angle can thus be limited in a small range according to the simulation results.

This paper studies the carrying capacity and cushioning performance of multi- layer corrugated pallets with different structures to improve their cushioning performance. The bending resistance, compressive strength and cushioning performance of different structures of multi-layer corrugated pallets were analyzed by means of bending test, pressure test and compression test. The results show that multi- layer corrugated fiberboards have the maximum bending resistance when the corrugation is in parallel direction and the fiberboards are in longitudinal lamination, which is consistent with the linear relation between the maximum bending resistance and layer numbers. Vertical compressive strength of multi-layer corrugated fiberboards was greater than parallel compressive strength, which was greater than plane compressive strength, and vertical compressive strength and parallel compressive strength increased with the increase of layers, but plane compressive strength decreased. Vertical carrying capacity of foot piers was high, but their cushioning performance was unsatisfactory. Multi- layer corrugated fiberboards and EVA foam were combined to improve the cushioning performance. When the EVA foam accounted for 3/5 and the multi-layer corrugated fiberboard accounted for 2/5 of the total thickness of a foot pier, the cushioning efficiency and compressive strength of feet piers reached optimal. This paper may provide references for production of multi-layer corrugated pallets.

As a treatment for the industrial dye wastewater, this paper proposes a novel method of the microwave catalytic oxidation degradation (MCOD) using CuO/AC catalyst, and this novel method is used for the treatment of the crystal violet contaminant as a model wastewater in the aqueous solution without adding oxidant. The activated carbon-supported copper oxide (CuO/AC) is prepared by using the impregnation method and is characterized by using the XRD and the FT-IR. The effects of the metal loadings, the microwave catalyst dosage, the microwave power, the irradiation time and the initial crystal violet concentration on the degradation are investigated. It is shown that the removal rate of the crystal violet reaches up to 99.48%, with the removal rate of TOC being 90.4% under the optimized conditions: 0.8% of the CuO loading, 400 W of the MW power, 0.6 g of the dosage of the microwave catalyst, 6 min of the reaction time, and 100 mg/L of the initial concentration. The experiment of adding several different radical scavengers shows that the hydroxyl radicals (·OH) exist in the reaction process. The results indicate that the microwave catalytic oxidation degradation method could degrade the crystal violet wastewater effectively.

To reduce wind-induced vibration of power transmission tower, several wind-induced vibration reduction schemes with different SAM damper layouts are designed and compared. Firstly, the finite element models of dump-type transmission tower and SMA damper are built with ANSYS software, the wind load is simulated with Matlab software, and the time history samples of random fluctuating wind load are obtained using the linear auto-regressive filter law. Then, six layouts are proposed based on the working principle of damper and the structure of the tower. Finally, wind-induced vibration transient response simulation is performed for each different scheme. The responses of SMA dampers on the displacement and the acceleration of the controlled nodes are compared with each other. The results indicate that the SMA damper can suppress wind-induced vibration, and that different layouts have different control effects. Installing dampers at the tower head can reduce the top node displacement by more than 28% while installing dampers on the tower can reduce the top node acceleration by more than 66%. Through comparison and analysis, the optimal scheme is obtained.

The female reproductive system structures and ovary developmental traits of two parasitoids, Encarsia sophia (Girault & Dodd) and Eretmocerus hayati (Zolnerowich & Rose), of whitefly Bemisia tabaci (Gennadius) were studied to explain the differences of host handling strategies between these two parasitoid species. The female reproductive system of both En. sophia and Er. hayati each consisted of a pair of ovaries and lateral oviducts, common oviduct, spermatheca, ovipositor and ovipositor sheath. The ovipositor of En. sophia is straight and has an apparently hard and sharply pointed upper valve, while that of Er. hayati is curved, thick-walled, but has a blunt and apparently flexible tip. These features correlated well with the oviposition mechanisms of En. sophia and Er. hayati. Significant difference was found in the number of mature ova between En. sophia and Er. hayati when they emerged. The number of mature ova of both parasitoids increased with the age of adult female when the available nutrition was enough. Both En. sophia and Er. hayati are synovigenic.

The recombinant inbred lines (RILs) between Ningchun 4 and Ningchun 27 are used as the donors for the construction of the spring wheat genetic linkage map by different SSR markers. It is revealed that 307 pairs of the SSR markers in total are available to show the SSR polymorphism differences between the two parents among 1001 pairs of SSR markers originally selected. The polymorphism frequency is 30.7%. The 307 pairs of the SSR primers with the polymorphisms between Ningchun 4 and Ningchun 27 are applied to further analyze the RIL population, and 266 loci with polymorphism are detected by the primers mentioned above. The χ² test (P<0.05) shows that 147 SSR markers see a significant segregation distortion of 55.3%, mostly distributed on the B and D genomes. Among them, the segregated distortions of 129 SSR markers are resulted from the female parent of Ningchun 4. By using the software of Mapmaker 3.0 and Mapdraw 2.1, 266 SSR markers are assigned on the linkage genetic map of the wheat, which covers about 2187.79 cM of the wheat genome with an average distance of 8.22 cM between markers.

This paper studies the effect of Helicobacter pylori (Hp) infection on gut microbiota using fresh stool specimens collected from normal persons (Hp negative) and patients with Hp infection. Hp, E. coli O157, Lactobacillus, Enterococcus and Bifidobacterium were amplified by PCR. The expression of Hp was not found in Hp negative group, consistent with the ¹³C breath test. The expression of Lactobacillus, Enterococcus and Bifidobacterium in Hp negative group was higher than that in Hp infection group. There was no E. coli O157 in Hp negative group. The numbers of Lactobacillus, Enterococcus and Bifidobacterium were changed by Hp infection.

This paper aims to investigate the dynamic change and antioxidant activity of water soluble phenolic substances in mulberry leaves and Eurotium cristatum solid bi-directional fermentation process. The contents of the water soluble total flavonoids and total phenolics were measured by using AlCl₃ method and Folin-Ciocalteu method. At the same time, the antioxidant activity changes of the solid bi-directional fermentation process were evaluated by three in vitro experiments including DPPH assay, ABTS⁺ assay and ferric-reducing power assay. The results showed that during the fermentation process, the water soluble total flavonoids and total phenolics decreased after the initial increase. The water soluble flavonoid content after 14 days' fermentation was the highest, being 2.16 mg/g, and the water soluble phenolics content after 20 days' fermentation was the highest, being 1.48 mg/g. The antioxidant activity displayed an order of 14 d>7 d>11 d>20 d>40 d.

The design and synthesis of novel microporous materials are topics of current interest and of great challenge in materials science, not only because of their rich structural chemistry but also owing to their potential applications in the fields of separation, adsorption, photochemistry and catalysis. Metal phosphate is one of the most important inorganic framework materials in application. As an extension of metal phosphate, much attention has been paid to metal phosphite. In recent years, a series of metal phosphites with novel structures have been synthesized, such as large channels and helical and chiral open-framework. Syntheses of these new compounds with open-framework open a new field for microporous compounds. The study of metal phosphite has involved most metal elements in the periodic table and various synthetic methods and templates. This review introduces different metal phosphites, summarizing their structural features and the role of templates in synthesis and discussing recent research progress.

Plant cytoplasm fossil appears intangible for many palaeontologists. The palaeobotanical practice in the past decades has indicated that plant cytoplasm fossil is a truthful existence. With the improvement of observing technologies, many ultrastructures comparable to those in living plants are being revealed. Sometimes the study on fossil plant cytoplasm can lend critical help to modern biologists on some headache problems. High temperature and wild fire play a key role in the fossilization of plant cytoplasm, and a formerly frequently ignored phenomenon, lightning, is of special importance for the fixation of some ultrastructure in fossil plant cells. The study on plant cytoplasm fossils helps lead palaeobotany onto a new level, promotes its fusion with other scientific disciplines, and also introduces new technologies into palaeontology. This paper reviews the history of plant cytoplasm fossil study, summarizes the achievement and knowledge accumulated so far, and depicts the future development in this field.

In some particular flight environment, ice is easy to adhere to the airfoil and change the aerodynamic configuration of the airfoil. Icing will influence the aerodynamic characteristics and flight performance of the airfoil. Thus it is very important to carry out the research on anti-icing and de-icing technologies of airfoil. The major parts of icing, representative ice types on the airfoil and the damage of icing are introduced respectively in this paper. The aerodynamic characteristics of airfoils NACA23012 and NACA0012 before and after icing are analyzed using the software of FLUENT. Based on them, the principle, advantage, disadvantage and research advances of airfoil anti-icing and de-icing technologies are expounded; The development of the airfoil anti-icing and de-icing technologies is also prospected.