Computation of elastic properties of 3D digital cores from the Longmaxi shale

The dependence of elastic moduli of shales on the mineralogy and microstructure of shales is important for the prediction of sweet spots and shale gas production. Based on 3D digital images of the microstructure of Longmaxi black shale samples using X-ray CT, we built detailed 3D digital images of cores with porosity properties and mineral contents. Next, we used finite-element （FE） methods to derive the elastic properties of the samples. The FE method can accurately model the shale mineralogy. Particular attention is paid to the derived elastic properties and their dependence on porosity and kerogen. The elastic moduli generally decrease with increasing porosity and kerogen, and there is a critical porosity （0.75） and kerogen content （ca. ≤3%） over which the elastic moduli decrease rapidly and slowly, respectively. The derived elastic moduli of gas- and oil-saturated digital cores differ little probably because of the low porosity （4.5%） of the Longmaxi black shale. Clearly, the numerical experiments demonstrated the feasibility of combining microstructure images of shale samples with elastic moduli calculations to predict shale properties.

中国古代建筑龙壁的艺术特点

龙文化在中国具有很不寻常的文化符号意义，并在人们的生活中以不同的形式予以物化。本文通过对中国古代建筑元素一龙壁的起源，龙壁的艺术特色，及由龙壁本体所反映出来的中国传统的文化内涵的分析和描述，以展示我国古代龙壁建筑的艺术和文化特色的无穷魅力。

Characteristics of natural Japanese yew population in Muling Nature Reserve of Heilongjiang Province,China

The scalar of Japanese yew （Taxus cuspidata） population and the relationship between individual distribution and site factors were analyzed according to investigating data in 74 sample belts with a total sampled area of 436.872 hm2 in Muling Nature Reserve. The result showed that the distribution rules of Japanese yew population were correlated to elevation, slope position, slope aspect and slope gradient. The optimal distribution range in elevation for the natural Japanese yew population is at the attitudes of 700-800 m. The amounts of Japanese yew individuals on shady slope were more than those on sunny slope. On top slope and mid-slope, the individual amounts of Japanese yew are more than those on toe slope. Most of Japanese yew individuals occurred on slope gradient of less than 15. The scalar of the population was decreased with the slope gradient increasing.

A Numerical Method for Calculating Transmission Coefficients Across Arbitrary Potential Barriers with High Accuracy

We report a new method for calculating transmission coefficients across arbitrary potential barriers based on the Runge-Kutta method. A numerical solution of the Schrodinger equation is calculated using the Runge-Kutta method,and a new model is established to analyze the numerical results to find the transmission coefficient. This technique is applied to various cases, such as parabolic potential barrier and double-barrier structures. Transmission probability with high precision is obtained and discussed. The tunnelling current density through a MOS structure is also explored and the result coincides with the Fowler-Nordheim model,which indicates the applicability of our method.

Genetic Parameters for Yields and Reproductive Traits of Chinese Holstein Cows in Heilongjiang Province

[Objective] This study aimed to estimate the genetic parameters for milk yield, fat percentage, fat yield and age at first freshening of Chinese Holsteins first lactation cows in Heilongjiang under frigid-temperature and temperature zone. [Method] Records of yield and reproduction from 8 868 Chinese Holstein first lacta- tion cows from 21 herds were utilized to evaluate genetic parameters for Hei- Iongjiangs＇ Chinese Holsteins. Restricted maximum likelihood （REML） method was used with an animal model. [Result] The heritabilities were 0.16 to 0.34 for yields and fat percentage, 0.38 for reproduction （age at the first freshening）, which were similar to estimates for temperate areas from similar methods, except for constituent percentage. Also, the estimates of genetic correlation were high between milk yield and fat yield （0.97）, but were low between milk yield and fat percentage （-0.24）, age at the first freshening （-0.29） and generally antagonistic. [Conclusion] Thus, es- timates of genetic parameters in this frigid and frigid-temperate environment did not differ appreciably from those that occur in temperate dairy areas.

Comparative analysis of fracture identification methods based on gravity anomaly in Heilongjiang

The identification of fractures is of great importance in gravity and magnetic data processing and interpretation.In this study,four fracture identification methods are applied,and widely used in processing and analysis of the gravity anomaly,including vertical second derivative method,tilt derivative method,theta map method and normalized differential method,for gravity data acquired in a given area in Heilongjiang.By comparing the distribution of the zero contour or maximum contour,we summarize the application effects,and both advantages and disadvantages of each method.It is found that tilt derivative method and normalized differential method provide better effects than other two methods:the narrower anomaly gradient belt and higher identification precision of fracture or geological boundary.The inferred fractures and geological boundaries have a great match with the results obtained from geologic map and remote sensing data interpretation.Those study results have definitely provided the theoretical foundation for identifying faults and the geological boundaries.

Isothermal and nonisothermal crystallization kinetics of bio-sourced nylon 69

Bio-sourced nylon 69,one of promising engineering plastics,has a great potential in developing sustainable technology and various commercial applications.Isothermal and nonisothermal crystallization kinetics of nylon 69 is a base to optimize the process conditions and establish the structure–property correlations for nylon 69,and it is also highly bene ficial for successful applications of nylon products in industry.Isothermal and nonisothermal crystallization kinetics has been investigated by differential scanning calorimetry for nylon 69,bio-sourced even–odd nylon.The isothermal crystallization kinetics has been analyzed by the Avrami equation,the calculated Avrami exponent at various crystallization temperatures falls into the range of 2.28 and 2.86.In addition,the Avrami equation modi fied by Jeziorny and the equation suggested by Mo have been adopted to study the nonisothermal crystallization.The activation energies for isothermal and nonisothermal crystallization have also been determined.The study demonstrates that the crystallization model of nylon 69 might be a twodimensional(circular)growth at both isothermal and nonisothermal crystallization conditions.Furthermore,the value of the crystallization rate parameter(K)decreases signi ficantly but the crystallization half-time(t1/2)increases with the increase of the isothermal crystallization temperature.To nonisothermal crystallization,the crystallization rate increases as the cooling rate increases according to the analysis of Jeziorny's theory.The results of Mo's theory suggest that a faster cooling rate is required to reach a higher relative degree of crystallinity in a unit of time,and crystallization rate decreases when the relative degree of crystallinity increases at nonisothermal crystallization conditions.

Early Cretaceous dinosaur and other tetrapod tracks of southwestern China

In recent years the Lower Cretaceous red beds of southwestern China have yielded more than 20 significant dinosaur-dominated tracksites. More than half occur in the Jiaguan Formation with the remainder in the Feitianshan and Xiaoba formations. Collectively these sites provide evidence of at least 13 distinct dinosaurian trackmaker morphotypes, in addition to two avian theropod(bird)morphotypes and pterosaur and turtle tracks. Together these total 17 morphotypes provide a data base of 479 potential trackmakers, probably representing the same number of individuals. Such an ichnological database provides a useful proxy paleoecological census of tetrapod communities in the area during the Early Cretaceous, and is especially significant given the complete absence or scarcity of skeletal remains reported from these formations.The composition of ichnofaunas in all three formations is heavily saurischian(theropod and sauropod) dominated with a high diversity of distinctive theropod morphotypes,mostly assignable to known ichnogenera. Moreover, ichnofaunal data from multiple sites are generally consistent between sites and an indication of the reliability and repeatability of track census data. Such regionally-widespread data are rapidly superseding the information available from the skeletal record in the corresponding area, and must therefore be considered of high paleontological value.

Effects of Wuwei Dilong Decoction on Inflammatory Cells and Cytokines in Asthma Model Guinea Pigs

Objective： To explore the effects and the mechanism of Wuwei Dilong Decoction （五味地龙汤 Schisandra Fruit and Earthworm Decoction） for treatment of asthma. Methods： The asthma guinea pig model was established with spray of ovalbumin （OVA）. Fifteen days later, the guinea pigs were administered by intra-gastric perfusion of Wuwei Dilong Decoction once a day for 8 consecutive days. Blood samples were taken for testing the total leucocytes, eosinophil （EOS）, lymphocytes, interferon-γ （IFN-γ） and leukotriene B4 （LTB4）. Results： In the asthma model group, the total leucocytes, EOS and lymphocytes were all increased, with significant differences as compared with the different dosage Wuwei Dilong Decoction groups （P〈0.01 or P〈0.05）. The serum LTB4 in the asthma model group was significantly increased and IFN-γ decreased. After administration of Wuwei Dilong Decoction of the large, medium and small dosages, LTB4 decreased, while IFN-7 increased （P〈0.05 or P〈0.01）. Conclusion： Wuwei Dilong Decoction can inhibit infiltration and diffusion of the inflammatory cells in the asthma model guinea pigs, and regulate LTB4 and IFN-γ, which is probably one of the important mechanisms of Wuwei Dilong Decoction for relieving asthma.