检索结果-南通市图书馆

Petroleum Science 2020年第3期17卷 658-670页

作者： Xin-Peng Pan guang-Zhi zhang Jiao-Jiao Chen School of Geoscience and Info-Physics Central South UniversityChangsha 410082HunanChina School of Geoscience China University of Petroleum(East China)Qingdao 266580ShandongChina

Due to the huge differences between the unconventional shale and conventional sand reservoirs in many aspects such as the types and the characteristics of minerals,matrix pores and fluids,the construction of shale rock physics model is significant for the exploration and development of shale *** make a better characterization of shale gas-bearing reservoirs,we first propose a new but more suitable rock physics model to characterize the *** then use a well A to demonstrate the feasibility and reliability of the proposed rock physics model of shale gas-bearing ***,we propose a new brittleness indicator for the high-porosity and organic-rich shale gas-bearing *** on the parameter analysis using the constructed rock physics model,we finally compare the new brittleness indicator with the commonly used Young’s modulus in the content of quartz and organic matter,the matrix porosity,and the types of filled *** also propose a new shale brittleness index by integrating the proposed new brittleness indicator and the Poisson’s *** on real data sets demonstrate that the new brittleness indicator and index are more sensitive than the commonly used Young’s modulus and brittleness index for the high-porosity and high-brittleness shale gas-bearing reservoirs.

关键词： Shale gas Rock physics model Brittleness prediction

Tribological properties of FeCoCrNiAlB_x high-entropy alloys coating prepared by laser cladding

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2017年第2期24卷 184-189页

作者： Dan-yang Lin Nan-nan zhang Bin He guang-wei zhang Yue zhang De-yuan Li Department of Material Science and Engineering Shenyang University of Technology Hardface Technology Institute Dalian Huarui Heavy Industrial Special Spare Parts Co.Ltd.

FeCoCrNiA1Bx（x=0, 0.25, 0.50, 0.75） coatings were prepared by laser cladding to study the effects of boron on the structure and properties of high-entropy alloys coatings. The microstructure, microhardness, and wear resistance properties of the samples were investigated by scanning electron microscopy, X-ray diffraction, metallographic micro-hardness test, and friction wear test, respectively, and the mechanism of the wear behavior was also analyzed. The results showed that the high-entropy alloys consisted of BCC phase and eutectic structure, which contained FCC phase and M2B. With boron addition, the content of BCC phase increased while that of eutectic structure decreased. The wear resistance of the high-entropy coatings was considerably improved with increasing addition of horon, and accordingly, the FeCoCrNiAlB0.75 coating showed the best wear resistance.

关键词： Laser cladding High-entropy alloys coating Tribological property FeCoCrNiAlBx

Insertion of Supramolecular Segments into Covalently Crosslinked Polyurethane Networks towards the Fabrication of Recyclable Elastomers

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2022年第3期40卷 321-330,I0009页

作者： Lu-Ping Wang Ming-guang zhang Jing-Cheng Hao Xu Wang National Engineering Research Center for Colloidal Materials School of Chemistry and Chemical EngineeringShandong UniversityJinan 250100China Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education School of Chemistry and Chemical EngineeringShandong UniversityJinan 250100China

Thermoset plastics have become one of the most important chemical products in the world. The consequent problem is that although the thermosets possess excellent performance in mechanical strength, they cannot be reprocessed because of the internal permanent network structures. Optimizing the molecular design of thermosets is one of the most feasible ways to improve their recyclability. Here we present a facile and robust strategy to engineer the reprocessability of thermoset polyurethanes without compromising their mechanical toughness and chemical resistance via adding supramolecular additives during the polymer synthesis process. By using a multiple hydrogen bonding moiety as the model supramolecular additive, we demonstrate that the mechanical properties, recyclability, and chemical resistance of the crosslinked polyurethanes can be precisely controlled by adjusting the contents of the supramolecular additive. Systematic studies on the relations between molecular design and material properties are performed, and the optimized polyurethane network with a moderate amount of the supramolecular additive achieves the right balance between the robustness and recyclability. This work provides a cost-effective and practical way to chemically engineer thermoset plastics, aiming to enable the recycling of mechanically tough and chemically stable polymer materials.

关键词： Thermoset plastics Recyclability Polyurethane Supramolecular additives Chemical resistance

Wearing prediction of stellite alloys based on opposite degree algorithm

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2015年第2期34卷 125-132页

作者： Xiao-guang Yue guang zhang Qu Wu Fei Li Xian-Feng Chen Gao-Feng Ren Mei Li School of Resources and Environmental Engineering Wuhan University of Technology School of Materials Science and Engineering Shanghai University

In order to predict the wearing of stellite alloys, the related methods of rare metals data processing were discussed. The method of opposite degree （OD） algorithm was put forward to predict the wearing of stellite alloys. OD algorithm is based on prior numerical data, posterior numerical data and the opposite degree between numerical forecast data. To compare the performance of predicted results based on different algorithms, the back propagation （BP） and radial basis function （RBF） neural network methods were introduced. Predicted results show that the relative error of OD algorithm is smaller than those of BP and RBF neural network methods. OD algorithm is an effective method to predict the wearing of stellite alloys and it can be applied in practice.

关键词： Opposite degree algorithm Stellite alloyswearing Back propagation neural network Radial basisfunction neural network

Multi-Bernoulli Filter for Tracking Multiple Targets Using Sensor Array

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2020年第2期34卷 245-256页

作者： zhang guang-pu ZHENG Ce QIU Long-hao SUN Si-bo Acoustic Science and Technology Laboratory Harbin Engineering UniversityHarbin 150001China College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001China Qindao Haina Underwater Information Technology Co. Ltd.Qindao 266500China

This paper presents a multi-Bernoulli filter for tracking the direction of arrival(DOAs)of time-varying number of targets using sensor *** method operates directly on the measurements of sensor array and does not require any ***,more information is reserved and compared with the after-detection measurements using a finite set of detected *** can significantly improve the tracking performance,especially in low signal-to-noise ***,it inherits the advantages of the multi-Bernoulli approximation which models each of the targets *** allows more accurate multi-target state estimation,especially when targets *** proposed filter does not need clustering step and simulation results showcase the improved performance of the proposed filter.

关键词： multiple target tracking multi-Bernoulli filter direction of arrival estimation random finite set track-before-detect

Effects and Mechanism of Action of Artemisinin on Mitochondria of Plasmodium berghei

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2020年第4期26卷 277-282页

作者： HOU Hong-ping zhang guang-ping MA Li-na SU Ping zhang Zhong-xiu DAI Bao-qiang YE Zu-guang Institute of Chinese Materia Medica China Academy of Chinese Medical SciencesBeijing(100700)China

Objective:To study the antimalarial effects and mechanisms of artemisinin(Qinghaosu in Chinese,QHS)on mitochondria in mice infected with Plasmodium ***:A total of 108 C57 mice infected with Plasmodium berghei were randomly divided into 3 groups by weight:the control group,200 and 400 mg/kg QHS *** two QHS treatment groups were further divided into 4 sub-groups with 12 animals each time according to the treatment time,0.5,1,2,and 4 *** saline was intragastrically(i.g.)administered to the control *** other two groups received different doses of QHS by *** were treated once with QHS for different detection time as follows:0.5,1,2,and 4 *** mitochondrial energy metabolism,oxidative damage,membrane potential,and membrane permeability and other indexes were ***:After administration of 200 and 400 mg/kg QHS,adenosine triphosphate(ATP)levels in Plasmodium and its mitochondria were reduced(P<0.05),the levels of reactive oxygen species(ROS)and malondialdehyde(MDA)were in creased(P<0.05),and the activity of superoxide dismutase(SOD)was also increased(P<0.05).At the same time,the membrane potential of the mitochondria was reduced and the degree to which the membrane permeability transition pore was ope ned was irreversibly in creased(P<0.05).Conclusions:Mitoch on dria in Plasmodium were the targets of QHS,which can adversely affect mitochondrial energy metabolism,oxidative damage,membrane potential,and membrane opening,and ultimately exert an antimalarial effect.

关键词： Qinghaosu Clinese medicine Plasmodium mitochondria antimalarial effect

Unified analytical solutions for a circular opening based on non-linear unified failure criterion

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第2期11卷 71-79页

作者： Chang-guang zhang Qing-he zhang Jun-hai ZHAO Fei XU Chuang-zhou WU MOE Key Laboratory of Geotechnical and Underground Engineering Tongji University Shanghai 200092 China Department of Geotechnical Engineering Tongji University Shanghai 200092 China School of Civil Engineering Chang'an University Xi'an 710061 China Shanghai No. 1 Municipal Engineering Co. Ltd. Shanghai 200083 China

Unified analytical solutions are presented for the predictions of the stresses and displacements around a circular opening based on nonqinear unified failure criterion and the elastic-brittle-plastic softening model. Unified analytical solutions not only involve generally traditional solutions which are based on the Hock-Brown （H-B） failure criterion or the non-linear twin-shear failure criterion, but also involve other new results. The results of the radius of plastic zone, radial displacements and stresses are obviously different using three rock masses when different values of the unified failure criterion parameter or different material behavior models are used. For a given condition, the radius of plastic zone and radial displacements are reduced by increasing the unified failure criterion parameter. The latent potentialities of rock mass result from considering the effect of intermediate principal stress. It is shown that proper choices of the failure criterion and the material behavior model for rock mass are significant in the tunnel design.

关键词： Analytical solution Elastic-brittle-plastic rock Non-linear unified failure criterion Intermediate principal stress Dilatancy

Recovery of alkali and alumina from Bayer red mud by the calcification–carbonation method

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第3期23卷 257-268页

作者： xiao-feng zhu ting-an zhang yan-xiu wang guo-zhi lü wei-guang zhang Key Laboratory of Ecological Utilization of Multi-metal Intergrown Ores of the Ministry of Education School of Materials and MetallurgyNortheastern UniversityShenyang 110819China

Red mud produced in the Bayer process is a hazardous solid waste because of its high alkalinity; however, it is rich in valuable components such as titanium, iron, and aluminum. In this study, a novel calcification-carbonation method was developed to recover alkali and alumina from Bayer red mud under mild reaction conditions. Batch experiments were performed to evaluate the potential effects of im- portant parameters such as temperature, amount of CaO added, and CO2 partial pressure on the recovery of alkali and alumina. The results showed that 95.2% alkali and 75.0% alumina were recovered from red mud with decreases in the mass ratios of Na2O to Fe2O3 and of Al2O3 to Fe2O3 from 0.42 and 0.89 to 0.02 and 0.22, respectively. The processed red mud with less than 0.5wt% Na2O can potentially be used as a construction material.

关键词： waste utilization red mud calcification carbonation alumina alkali recovery

在线全文

学校读者我要写书评

暂无评论

微生物菌群调控人畜共患结核病的研究进展

动物医学进展 2025年第1期46卷 91-96页

作者：许霄峰张广智鑫婷叶建新张建伟贾丽钱佳豪温贺飞吴慧光蒋卉丁家波中国农业科学院北京畜牧兽医研究所北京100097 农业农村部动物生物安全风险预警及防控重点实验室(北方) 北京100193 扬州大学兽医学院江苏扬州225009 北京市畜牧总站北京100193 河北农业大学动物医学院河北保定071000 河北省遵化市农业农村局河北唐山064200

目前,人畜共患结核病(zTB)仍是世界上最重要的细菌传染性疫病之一,严重威胁人和动物健康以及公共卫生安全。机体数量庞大的微生物菌群积极参与着机体的发育、免疫调控、代谢等。研究发现微生物菌群和zTB的发生、发展、治疗、疫苗免疫具... 详细信息

目前,人畜共患结核病(zTB)仍是世界上最重要的细菌传染性疫病之一,严重威胁人和动物健康以及公共卫生安全。机体数量庞大的微生物菌群积极参与着机体的发育、免疫调控、代谢等。研究发现微生物菌群和zTB的发生、发展、治疗、疫苗免疫具有紧密的相关性,现已成为诸多领域中的研究热点。菌群对zTB进程的调控可通过诸多途径直接或间接地进行,如菌群稳态、代谢物及对免疫的调控等。基于此,论文综述了目前微生物菌群与zTB相关研究的最新进展,重点讨论了肠道菌群和肺部菌群与zTB的关联及调节机制,分析了肠-肺轴相互作用、菌群代谢产物对zTB的影响,探讨了通过调节宿主的菌群组成和功能对预防和辅助治疗结核病的潜在价值,旨在为zTB防控提供理论基础和借鉴。

关键词：人畜共患结核病肠道微生物菌群肠-肺轴益生菌

Hydrophobicity and tribological properties of Al_(2)O_(3)/PTFE composite coating

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2023年第11期42卷 3870-3876页

作者： Ruo-Nan Ji Chen-Xu Liu Jin zhang Shu-guang zhang Le zhang Yong Lian Institute of Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory for Corrosion Erosion and Surface Technology Beijing100083China

Al_(2)O_(3)/polytetrafluoroethylene(PTFE)composite coating was prepared on titanium alloy by cathode plasma electrolytic deposition(CPED)and impregnation method,to improve the hydrophobicity and tribological *** electron microscopy(SEM)and energy-dispersive spectroscopy(EDS)analysis of the coating indicate that PTFE penetrates into the interior of the coating and is well bonded to titanium alloy substrate by cross-linking with Al_(2)O_(3) ceramic *** contact angles were measured by contact angle measurement,and the tribological properties of the composite coating were evaluated by sliding wear *** surface of the composite coating is found to possess good hydrophobicity with a water contact angle of 140°.The results also indicate an improved tribological properties of Al_(2)O_(3)/PTFE composite coating at room temperature with a steady friction coefficient as low as *** self-lubricating anti-wear composite coating is expected to solve fouling problems and poor wear resistance of titanium alloys.

关键词： Titanium alloy Al_(2)O_(3) Cathode plasma electrolytic deposition PTFE Hydrophobicity Wear resistance