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A new model for predicting hydraulic fracture penetration or termination at an orthogonal interface between dissimilar formations

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Petroleum Science 2022年第6期19卷 2810-2829页

作者： Yu Zhao Yong-Fa Zhang Guo-dong Tian Chao-Lin Wang Jing bi College of Civil Engineering Guizhou UniversityGuiyang550025GuizhouChina Guizhou Provincial Key Laboratory of Rock and Soil Mechanics and Engineering Safety(Guizhou University) Guiyang550025GuizhouChina School of Civil Engineering Chongqing UniversityChongqing400045China

Vertical height growth of hydraulic fractures(HFs)can unexpectedly penetrate a stratigraphic interface and propagate into neighboring layers,thereby resulting in low gas-production efficiency and high risk of groundwater contamination or fault *** of hydraulic fracture behavior at the interface is of pivotal importance for the successful development of layered *** this paper,a twodimensional analytical model was developed to examine HF penetration and termination behavior at an orthogonal interface between two dissimilar *** model involves changes in the stress singularity ahead of the HF tip,which may alter at the formation interface due to material *** critical stress conditions were considered to assess possible fracture behavior(i.e.,crossing,slippage,and opening)at the ***,this model was verified by comparing its theoretical predictions to numerical simulations and three independent *** agreement with the simulation results and experimental data was observed,which shows the validity and reliability of this ***,a parametric study was conducted to investigate the effects of key formation parameters(elastic modulus,Poisson’s ratio,and fracture toughness)between adjacent *** results indicate that the variation in the introduced parameters can limit or promote vertical HF growth by redistributing the induced normal and shear stresses at the *** the three studied parameters,Poisson’s ratio has the least influence on the formation *** the fracture toughness and elastic modulus of the bounding layer are larger than those of the pay zone layer,the influence of fracture toughness will dominate the HF behavior at the interface;otherwise,the HF behavior will more likely be influenced by elastic modulus.

关键词： Analytical model Hydraulic fracture Interface of dissimilar materials Vertical propagation behavior Parametric sensitivity analysis

Existence of Classical Solutions to a Stationary Simplified Quantum Energy-Transport Model in 1-Dimensional Space

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Chinese Annals of Mathematics,Series B 2013年第5期34卷 691-696页

作者： Jianwei dong Youlin ZHANG Shaohua cheng Department of Mathematics and Physics Zhengzhou Institute of Aeronautical Industry Management Library Zhengzhou Institute of Aeronautical Industry Management

The existence of classical solutions to a stationary simplified quantum energytransport model for semiconductor devices in 1-dimensional space is *** model consists of a nonlinear elliptic third-order equation for the electron density,including a temperature derivative,an elliptic nonlinear heat equation for the electron temperature,and the Poisson equation for the electric *** proof is based on an exponential variable transformation and the Leray-Schauder fixed-point theorem.

关键词： Quantum energy-transport model Stationary solutions Existence

Development of the readout system for waveguide multilayer optical card

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Optoelectronics Letters 2008年第2期4卷 150-152页

作者： GU Min-fen LIANG Zhong-cheng WANG Ren-zhou dong Xiang-mei ZHANG Pei-ming CHEN Jia-bi College of Mathematics ＆ Physics Nanjing University of Posts ＆ Telecommunications Nanjing 210003 China Jiangsu Key Lab. of Optoelectronic Technology Nanjing Normal University Nanjing 210097 China College of Optics and Electronics Information Engineering Shanghai University for Science and Technology Shanghai 200093 China

Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.

关键词：读出系统波导光学卡存贮器

Effects of nitrogen addition on plant biomass and tissue elemental content in different degradation stages of temperate steppe in northern China

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Journal of Plant Ecology 2018年第5期11卷 730-739页

作者： Jin-bin Chen cheng-cheng dong Xiao-dong Yao Wei Wang Department of Ecology College of Urban and Environmental Sciences and Key Laboratory for Earth Surface ProcessesPeking UniversityNo.5 Yiheyuan RoadHaidian DistrictBeijing 100871China School of Urban Planning and Design Peking University Shenzhen Graduate SchoolLishui RoadXili TownNanshan DistrictShenzhen 518055China

Aims Grassland degradation has become a common problem *** studies have analyzed the effects of nitrogen(N)addition on plant growth in grasslands,but few have considered its effects on plant growth in degraded *** aim of this study was to evaluate the effects of N addition on plant growth in grasslands with different levels of degradation in Inner Mongolia,*** A 2-year field experiment was conducted to evaluate plant growth response to N addition in degraded grasslands on the Inner Mongolian *** with four levels of degradation were selected for N-addition treatments(0,10,20,30,40,50 g N m−2 year−1).Important Findings Aboveground biomass was increased by N fertilization in degraded grasslands,and N addition was significantly related to increased biomass in grasslands with severe ***,N fertilization did not significantly affect belowground *** effects of N addition on foliar nutrient concentrations in the same species differed among grasslands with different degradation *** was an inconsistent response to N addition between Sanguisorba officinalis and Vicia sepium in non-degraded *** was a significant positive correlation between foliar N content and aboveground biomass in grasslands with different levels of *** results indicate that the effects of N addition on plant growth in grasslands differ according to the severity of *** conclude that N fertilization may be an effective management technique for degraded grasslands in this area and may improve for-age productivity in the short term.

关键词： nitrogen addition degraded grassland aboveground biomass belowground biomass foliar nitrogen concentrations root nitrogen concentrations

Soil Microbial and Enzymatic Activities Across a Chronosequence of Chinese Pine Plantation Development on the Loess Plateau of China

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Pedosphere 2012年第1期22卷 1-12页

作者： YUAN bing-cheng YUE dong-Xia School of Real Estate Beijing Normal University Zhuhai CampusZhuhai 519087(China) MOE Key Laboratory of Western China's Environmental System Lanzhou UniversityLanzhou 730000(China)

Successional and seasonal effects on soil microbial and enzymatic properties were studied in Chinese pine （Pinus tabulaeformis） plantations in an age sequence of 3-, 7-, 13-, 21- and 28-year-old in northern Ziwuling region in the middle of Loess Plateau, China. The results indicated that plantation age and season affected soil microbial and enzymatic parameters significantly. Soil organic C, total N, microbial biomass C, microbial quotient, basal respiration, dehydrogenase, N-α-benzoyl-L-argininamide （BAA）-protease, urease and β-glucosidase increased quickly and tended to be highest at PF21 （21-year plantation）, thereafter they remained nearly at a constant level, whereas the metabolic quotient （qCO2） showed an initial increase and then decreased gradually. Measures of these soil properties showed significant seasonal fluctuations except for organic C and total N, which were found to be relatively stable throughout the study period, and the seasonal distributions were autumn 〉 spring 〉 summer 〉 winter for microbial biomass C, microbial quotient, dehydrogenase, and β-glucosidase; autumn 〉 summer 〉 spring 〉 winter for BAA-protease and urease; and summer 〉 autumn 〉 spring 〉 winter for basal respiration and qCO2. Significant season x age interaction was observed for biomass C, basal respiration, dehydrogenase and BAA-protease.

关键词： dehydrogenase metabolic quotient microbial biomass seasonality soil basal respiration

Numerical analysis of shell-side flow-induced vibration of elastic tube bundle in heat exchanger

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Journal of Hydrodynamics 2018年第2期30卷 249-257页

作者： Jia-dong Ji Pei-qi Ge Wen-bo bi School of Mechanical Engineering Anhui University of Science and Technology Huainan 232001 China School of Mechanical Engineering Shandong University Jinan 250061 China

The responses of the flow-induced vibration of an elastic tube bundle subjected to the shell-side cross flow are investigated in this paper. The weak coupling method and the fluid solid interface are used to solve the fluid-structure interaction problem with consideration of the geometry and physical natures. The effects of the shell-side fluid flow velocity and the structural parameters on the flow-induced vibration are discussed. Numerical results demonstrate that the vibration frequency and amplitude at the monitor points increase with the increase of the shell-side water inlet velocity in all directions. The wall thickness and the external diameter of the elastic tube bundle have significant effects on the responses of the flow-induced vibration. The structural parameters affect the vibration frequency and amplitude, and the vibration equilibrium position in the water flow direction. The vibration frequency decreases with the increase of the tube external diameter. In addition, the vibration in the water flow direction has a lower equilibrium position when the elastic tube bundle has a larger wall thickness or smaller external diameter.

关键词： Flow-induced vibration heat exchanger elastic tube bundle fluid-structure interaction shell-side fluid weak coupling method

Uniform Homeomorphisms of Unit Spheres and Property H of Lebesgue–Bochner Function Spaces

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Acta Mathematica Sinica,English Series 2017年第5期33卷 681-690页

作者： Qing Jin cheng Yun Bai dong School of Mathematical Sciences Xiamen University School of Mathematics and Computer Wuhan Textile University

Assume that the unit spheres of Banach spaces X and Y are uniformly *** we prove that all unit spheres of the Lebesgue–Bochner function spaces Lp(μ, X) and Lq(μ, Y)are mutually uniformly homeomorphic where 1 ≤ p, q < ∞. As its application, we show that if a Banach space X has Property H introduced by Kasparov and Yu, then the space Lp(μ, X), 1 ≤ p < ∞,also has Property H.

关键词： Banach space uniform classification Property H Novikov conjecture

CNTs-promoted Co-Cu Catalyst for Efficient Synthesis of Cinnamyl Alcohol from Hydrogenation of Cinnamaldehyde

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Chemical Research in Chinese Universities 2024年第6期40卷 1082-1087页

作者： dong Xin LIU cheng ZHOU Zhaohui Gulei Innovation Institute Xiamen UniversityZhangzhou 363200P.R.China College of Chemistry and Chemical Engineering Xiamen UniversityXiamen 361005P.R.China

With types of in-house-synthesized multi-walled carbon nanotubes (CNTs);highly active CNT-promoted Co-Cu catalysts,symbolized as CoiCuj-x%CNTs (mass fraction) were prepared by the co-precipitation method from nitrate salts of the corresponding metallic *** catalytic performances for the cinnamyl alcohol synthesis from the hydrogenation of cinnamaldehyde were studied and compared with the corresponding CNT-free coprecipitated catalyst of CoiCuj mixed *** was shown that the appropriate incorporation of a minor amount of the CNTs into CoiCuj oxide could significantly increase the catalytic activity for cinnamyl alcohol *** the pressure of 5.0 MPa,the highest yield of cinnamyl alcohol reaches 94.4% with selectivity of 98.7% for the catalyst Co_(2)-Cu1-10.0%*** addition of an appropriate amount of CNT can promote the highly dispersed catalyst and promote the recovery of the *** results show that carbon nanotube is an excellent accelerator,and its properties for unique hydrogen absorption play important roles in promoting the synthesis of cinnamyl alcohol.

关键词： Cinnamaldehyde Cinnamyl alcohol Carbon nanotube Co-Cu catalyst

Preparation and Characterization of In_2O_3 Nanorods

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稀有金属材料与工程 2006年第A03期35卷 572-574页

作者： Qingyi Pan Xiangbing dong Zhixuan cheng Xiaowen dong Department of Chemistry Shanghai University Shanghai 200444 China

In_2O_3 nanorods were prepared by sol-gel technique with nonionic surfactant controlling their morphology,and were characterized by TEM,TG-DSC and *** results indicated that In_2O_3 nanorods had the length of about 120 nm and diameter of 20 *** In_2O(OH)_4 dried gelatin was formed by partial dehydrating of In(OH)_3 *** factors influencing the morphology of In_2O_3 nanorods and their growth mechanism were *** geometry array parameter P of the nonionic surfactant was between 1/3～1/2 through calculation,which confirmed that the shape of the micelle was claviform.

关键词： nanorods In2O3 sol-gel nonionic surfactant