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| 1 | Visualization of the complex structure and stress field inside rock by means of 3D printing technology显示文摘Accurate characterization and visualization of the complex inner structure and stress distribution of rocks are of vital significance to solve a variety of underground engineering problems. In this paper, we incorporate several advanced technologies, such as CT scan, three-dimensional(3D) reconstruction, and 3D printing, to produce a physical model representing the natural coal rock that inherently contains complex fractures or joints. We employ 3D frozen stress and photoelastic technologies to characterize and visualize the stress distribution within the fractured rock under uniaxial compression. The 3D printed model presents the fracture structures identical to those of the natural prototype. The mechanical properties of the printed model,including uniaxial compression strength, elastic modulus,and Poisson's ratio, are testified to be similar to those of the prototype coal rock. The frozen stress and photoelastic tests show that the location of stress concentration and the stress gradient around the discontinuous fractures are in good agreement with the numerical predictions of the real coalsample. The proposed method appears to be capable of visually quantifying the influences of discontinuous,irregular fractures on the strength, deformation, and stress concentration of coal rock. The method of incorporating3 D printing and frozen stress technologies shows a promising way to quantify and visualize the complex fracture structures and their influences on 3D stress distribution of underground rocks, which can also be used to verify numerical simulations. | Yang Ju Heping Xie Zemin Zheng Jinbo Lu Lingtao Mao Feng Gao Ruidong Peng | 2014 | Chinese Science Bulletin2014,59,36: | 41 |
| 2 | Influence of pore structures on the mechanical behavior of low-permeability sandstones:numerical reconstruction and analysis显示文摘The research of rock properties based on its inherent microscopic to mesoscopic porous structure has drawn great attention for its potential in predicting the macroscopic behavior of rocks.An accurate reconstruction of the threedimensional porous structure is a premise for the related studies of hydraulic and mechanical properties of rocks,such as the transport properties and mechanical responses under pressures.In this paper,we present a computer procedure for reconstructing the 3D porous structure of low-permeability sandstone.Two large-size 3D models are reconstructed based on the information of a reference model which is established from computed tomography(CT)images.A self-developed finite element method is applied to analyze the nonlinear mechanical behavior of the sandstone based on its reconstructed model and to compare the results with those based on the reference model.The good consistency of the obtained mechanical responses indicates the potential of using reconstruction models to predict the influences of porous structure on the mechanical properties of low-permeability sandstone. | Jiangtao Zheng Yang Ju Xi Zhao | 2014 | International Journal of Coal Science & Technology2014,1,3: | 34 |
| 3 | Visual representation and characterization of three-dimensional hydrofracturing cracks within heterogeneous rock through 3D printing and transparent models显示文摘 | Peng Liu Yang Ju Pathegama G. Ranjith Zemin Zheng Li Wang Ayai Wanniarachchi | 2016 | International Journal of Coal Science & Technology2016,3,3: | 21 |
| 4 | Arpin contributes to bacterial translocation and development of severe acute pancreatitis显示文摘AIM: To assess the impact of Arpin protein and tight junction(TJ) proteins in the intestinal mucosa onbacterial translocation in patients with severe acute pancreatitis(SAP).METHODS: Fifty SAP patients were identified as study objects and then classified into two groups according to the presence of bacterial translocation(BT) in the blood [i.e., BT(+) and BT(-)].Twenty healthy individuals were included in the control group.BT was analyzed by polymerase chain reaction, colonic mucosal tissue was obtained by endoscopy and the expression of TJ proteins and Arpin protein was determined using immunofluorescence and western blotting.RESULTS: Bacterial DNA was detected in the peripheral blood of 62.0% of patients(31/50) with SAP.The expression of TJ proteins in SAP patients was lower than that in healthy controls.In contrast, Arpin protein expression in SAP patients was higher than in healthy controls(0.38 ± 0.19 vs 0.28 ± 0.16, P < 0.05).Among SAP patients, those positive for BT showed a higher level of claudin-2 expression(0.64 ± 0.27 vs 0.32 ± 0.21, P < 0.05) and a lower level of occludin(OC)(0.61 ± 0.28 vs 0.73 ± 0.32, P < 0.05) and zonula occludens-1(0.42 ± 0.26 vs 0.58 ± 0.17, P = 0.038) expression in comparison with BT(-) patients.Moreover, the level of Arpin expression in BT(+) patients was higher than in BT(-) patients(0.61 ± 0.28 vs 0.31 ± 0.24, P < 0.05).CONCLUSION: Arpin protein affects the expression of tight junction proteins and may have an impact on BT.These results contribute to a better understanding of the factors involved in bacterial translocation during acute pancreatitis. | Wen-Sheng Deng Jian Zhang Hui Ju Hong-Mei Zheng Jiang Wang Su Wang Dian-Liang Zhang | 2015 | World Journal of Gastroenterology2015,21,14: | 20 |
| 5 | Spectral clustering based on matrix perturbation theory显示文摘This paper exposes some intrinsic characteristics of the spectral clustering method by using the tools from the matrix perturbation theory. We construct a weight ma- trix of a graph and study its eigenvalues and eigenvectors. It shows that the num- ber of clusters is equal to the number of eigenvalues that are larger than 1, and the number of points in each of the clusters can be approximated by the associated eigenvalue. It also shows that the eigenvector of the weight matrix can be used directly to perform clustering; that is, the directional angle between the two-row vectors of the matrix derived from the eigenvectors is a suitable distance measure for clustering. As a result, an unsupervised spectral clustering algorithm based on weight matrix (USCAWM) is developed. The experimental results on a number of artificial and real-world data sets show the correctness of the theoretical analysis. | TIAN Zheng LI XiaoBin JU YanWei | 2007 | Science in China(Series F)2007,50,1: | 19 |
| 6 | The development and function of follicular helper T cells in immune responses显示文摘小囊的助手 T 房间(Tfh ) 作为提供帮助让 B 房间增殖并且在幼芽的中心经历抗体亲密关系成熟的一个系被提交了。证据支持了那个 Tfh 子集开发象另外的系一样,依赖于一个特别 transcriptional 节目被开始的微型环境。它为 Tfh 房间的开发和函数作为主人管理者被看了那 Bcl-6 和 IL-21 行为。Tfh dysregulation 涉及自体免疫的病理的发展,例如全身的豺狼座 erythematosus,风湿性关节炎和另外的自体免疫的疾病。现在的评论在在他们的开发和函数的 Tfh 房间和焦点的域里加亮最近的进展。 | Maogen Chen Zhiyong Guo Weiqiang Ju Bernhard Ryffel Xiaoshun He Song Guo Zheng | 2012 | Cellular & Molecular Immunology2012,9,5: | 18 |
| 7 | Numerical analysis of the failure process of soil-rock mixtures through computed tomography and PFC3D models显示文摘 | Yang Ju Huafei Sun Mingxu Xing Xiaofei Wang Jiangtao Zheng | 2018 | International Journal of Coal Science & Technology2018,5,2: | 17 |
| 8 | Cancer statistics in Chinese older people,2022:current burden,time trends,and comparisons with the US,Japan,and the Republic of Korea显示文摘Largely due to population ageing,the cancer burden from older people has been rising,which imposed considerable pressure on current Chinese healthcare system.We provide comprehensive information about cancer burden of Chinese older people based on the most recent data from National Central Cancer Registry of China.The logarithmic linear regression was used to project the current cancer burden in 2022,and Joinpoint regression was used for temporal trend analysis from 2000 to 2017.We also estimated cancer statistics of older people in the US,Japan and the Republic of Korea for comparisons.It is estimated that 2.79 million cases and 1.94 million deaths occur for Chinese older people,representing 55.8%and 68.2%of cases and deaths in all population in 2022.The overall cancer incidence rate gradually increased among older women,while the mortality rates declined for both sexes.Notably,approximately 10.0%of all cases and 17.7%of all deaths are from people aged over 80 years,and cancer incidence and mortality in this age group showed upward trends for women.Lung cancer and digestive cancers are the leading cancer types for Chinese older people.Compared with other countries,China has lower incidence rates but higher mortality rates for older people.The rapidly growing burden of prostate cancer,breast cancer,colorectal cancer,and declines in esophageal cancer,stomach cancer,and liver cancer among older people indicate the cancer pattern in China is being in a transition stage to that in developed countries.Our findings imply that it should be the national health priority to meet the growing demands for cancer diagnosis,treatment and care services from the older people as the rapid population ageing in next few decades. | Wen Ju Rongshou Zheng Siwei Zhang Hongmei Zeng Kexin Sun Shaoming Wang Ru Chen Li Li Wenqiang Wei Jie He | 2023 | Science China(Life Sciences)2023,66,5: | 15 |
| 9 | Study on protecting effects of Baicalin and Octreotide on hepatic injury in rats with severe acute pancreatitis显示文摘AIM: To investigate the protective effects and mechanisms of Baicalin and Octreotide on hepatic injury in rats with severe acute pancreatitis (SAP). METHODS: The SAP rat models were prepared and randomly assigned to the model control group, Baicalin treated group, and Octreotide treated group while other healthy rats were assigned to the sham-operated group. Rat mortality, levels of ALT, AST, liver and pancreas pathological changes in all groups were observed at 3, 6 and 12 h after operation. Tissue microarray (TMA) sections of hepatic tissue were prepared to observe expression levels of Bax, Bcl-2 protein and Caspase-3, and changes of apoptotic indexes.RESULTS: Rat survival at 12 h, expression levels of Bax, Caspase-3 protein and apoptotic indexes of liver were all significantly higher in treated groups than in model control group. While the liver and pancreas pathological scores, contents of ALT, AST, and expression levels of Bcl-2 protein were all lower in treated groups than in the model control group. CONCLUSION: Both Baicalin and Octreotide can protect rats with SAP by decreasing the contents of ALT, AST and expression levels of Bcl-2 protein, and improving the expression levels of Bax protein, Caspase-3 protein, and inducing apoptosis. | Xi-Ping Zhang Guang-Hua Feng Wei Zhu Yang Cai Qi-Jun Yang Tong-Fa Ju Qi xie Wen-Qin Yuan Jie Zhang Zheng Ren | 2008 | World Journal of Gastroenterology2008,14,42: | 13 |
| 10 | MicroRNAs in tomato plants显示文摘MicroRNAs (miRNAs) are a specialized class of small silencing RNAs that regulate gene expression in eukaryotes.In plants,miRNAs negatively regulate target mRNAs containing a highly complementary sequence by either mRNA cleavage or translational repression.As a model plant to study fleshy fruit ripening,miRNA studies in tomato have made great progress recently.MiRNAs were predicted to be involved in nearly all biological processes in tomato,particularly development,differentiation,and biotic and abiotic stress responses.Surprisingly,several miRNAs were verified to be involved in tomato fruit ripening and senescence.Recent studies suggest that miRNAs are related to host-virus interactions,which raises the possibility that miRNAs can be used as diagnostic markers for response to virus infection in tomato plants.In this review,we summarize our current knowledge systematically and advance future directions for miRNA research in tomato. | ZUO JinHua WANG YunXiang LIU HaiPing MA YuanZheng JU Zheng ZHAI BaiQiang FU DaQi ZHU Yi LUO YunBo ZHU BenZhong | 2011 | Science China(Life Sciences)2011,54,7: | 13 |
| 11 | Development of a Hand Exoskeleton System for Index Finger Rehabilitation显示文摘In order to overcome the drawbacks of traditional rehabilitation method,the robot-aided rehabilitation has been widely investigated for the recent years.And the hand rehabilitation robot,as one of the hot research fields,remains many challenging issues to be investigated.This paper presents a new hand exoskeleton system with some novel characteristics.Firstly,both active and passive rehabilitative motions are realized.Secondly,the device is elaborately designed and brings advantages in many aspects.For example,joint motion is accomplished by a parallelogram mechanism and high level motion control is therefore made very simple without the need of complicated kinematics.The adjustable joint limit design ensures that the actual joint angles don't exceed the joint range of motion(ROM) and thus the patient safety is guaranteed.This design can fit to the different patients with different joint ROM as well as to the dynamically changing ROM for individual patient.The device can also accommodate to some extent variety of hand sizes.Thirdly,the proposed control strategy simultaneously realizes the position control and force control with the motor driver which only works in force control mode.Meanwhile,the system resistance compensation is preliminary realized and the resisting force is effectively reduced.Some experiments were conducted to verify the proposed system.Experimentally collected data show that the achieved ROM is close to that of a healthy hand and the range of phalange length(ROPL) covers the size of a typical hand,satisfying the size need of regular hand rehabilitation.In order to evaluate the performance when it works as a haptic device in active mode,the equivalent moment of inertia(MOI) of the device was calculated.The results prove that the device has low inertia which is critical in order to obtain good backdrivability.The experiments also show that in the active mode the virtual interactive force is successfully feedback to the finger and the resistance is reduced by one-third;for the passive control mode,the desired trajectory is realized satisfactorily. | LI Jiting WANG Shuang WANG Ju ZHENG Ruoyin ZHANG Yuru CHEN Zhongyuan | 2012 | Chinese Journal of Mechanical Engineering2012,25,2: | 12 |
| 12 | Insight-HXMT observations of the first binary neutron star merger GW170817显示文摘Finding the electromagnetic(EM) counterpart of binary compact star merger, especially the binary neutron star(BNS) merger,is critically important for gravitational wave(GW) astronomy, cosmology and fundamental physics. On Aug. 17, 2017,Advanced LIGO and Fermi/GBM independently triggered the first BNS merger, GW170817, and its high energy EM counterpart,GRB 170817 A, respectively, resulting in a global observation campaign covering gamma-ray, X-ray, UV, optical, IR, radio as well as neutrinos. The High Energy X-ray telescope(HE) onboard Insight-HXMT(Hard X-ray Modulation Telescope) is the unique high-energy gamma-ray telescope that monitored the entire GW localization area and especially the optical counterpart(SSS17 a/AT2017 gfo) with very large collection area(~1000 cm^2) and microsecond time resolution in 0.2-5 MeV. In addition,Insight-HXMT quickly implemented a Target of Opportunity(ToO) observation to scan the GW localization area for potential X-ray emission from the GW source. Although Insight-HXMT did not detect any significant high energy(0.2-5 MeV) radiation from GW170817, its observation helped to confirm the unexpected weak and soft nature of GRB 170817 A. Meanwhile,Insight-HXMT/HE provides one of the most stringent constraints(~10^(-7) to 10^(-6) erg/cm^2/s) for both GRB170817 A and any other possible precursor or extended emissions in 0.2-5 MeV, which help us to better understand the properties of EM radiation from this BNS merger. Therefore the observation of Insight-HXMT constitutes an important chapter in the full context of multi-wavelength and multi-messenger observation of this historical GW event. | TiPei Li ShaoLin Xiong ShuangNan Zhang FangJun Lu LiMing Song XueLei Cao Zhi Chang Gang Chen Li Chen TianXiang Chen Yong Chen YiBao Chen YuPeng Chen Wei Cui WeiWei Cui JingKang Deng YongWei Dong YuanYuan Du MinXue Fu GuanHua Gao He Gao Min Gao MingYu Ge YuDong Gu Ju Guan ChengCheng Guo DaWei Han Wei Hu Yue Huang Jia Huo ShuMei Jia LuHua Jiang WeiChun Jiang Jing Jin YongJie Jin Bing Li ChengKui Li Gang Li MaoShun Li Wei Li Xian Li XiaoBo Li XuFang Li YanGuo Li ZiJian Li ZhengWei Li XiaoHua Liang JinYuan Liao CongZhan Liu GuoQing Liu HongWei Liu ShaoZhen Liu XiaoJing Liu Yuan Liu YiNong Liu Bo Lu XueFeng Lu Tao Luo Xiang Ma Bin Meng Yi Nang JianYin Nie Ge OU JinLu Qu Na Sai Liang Sun Yin Tan Lian Tao WenHui Tao YouLi Tuo GuoFeng Wang HuanYu Wang Juan Wang WenShuai Wang YuSa Wang XiangYang Wen BoBing WU Mei Wu GuangCheng Xiao He Xu YuPeng Xu LinLi Yan JiaWei Yang Sheng Yang YanJi Yang AiMei Zhang ChunLei Zhang ChengMo Zhang Fan Zhang HongMei Zhang Juan Zhang Qiang Zhang Shu Zhang Tong Zhang Wei Zhang WanChang Zhang WenZhao Zhang Yi Zhang Yue Zhang YiFei Zhang YongJie Zhang Zhao Zhang ZiLiang Zhang HaiSheng Zhao JianLing Zhao XiaoFan Zhao ShiJie Zheng Yue Zhu YuXuan Zhu ChangLin Zou | 2018 | Science China(Physics,Mechanics & Astronomy)2018,61,3: | 12 |
| 13 | Imaging superoxide flash and metabolism-coupled mitochondrial permeability transition in living animals显示文摘线粒体为精力新陈代谢和反应的氧种类(ROS ) 的生产是必要的。在未经触动的房间,呼吸线粒体展览自发的 “ superoxide flashes”,对短暂 mitochondrial 渗透转变(tMPT ) 结果的 quantal 生产 ROS 事件。这里,我们在表示 superoxide 生物传感器 mt-cpYFP 的生活老鼠在 mitochondrial superoxide 闪光和 tMPT 活动的 vivo 成像执行第一,并且表明他们联合到整个身体的葡萄糖新陈代谢。柔韧的 tMPT/superoxide 闪光活动发生在骨胳的肌肉和 anesthetized 的臀部的神经转基因的老鼠。在骨胳的肌肉,成像 tMPT/superoxide 闪光揭示了线粒体的迷宫的三维的网络同时地操作。tMPT/superoxide 闪光活动响应全身的葡萄糖挑战或胰岛素刺激澎湃,以一种显然调制频率的方式并且也在 tMPT 的 gating 模式包含移动。因此,在 tMPT 依赖的 mitochondrial ROS 的 vivo 成像,信号和 metabolism-tMPT-superoxide 的发现闪光联合标记为 mitochondrial 功能并且 ROS 处于健康和疾病发信号的学习的重要工艺、概念的进展。 | Huaqiang Fang Min Chen Yi Ding Wei Shang Jiejia Xu Xing Zhang Wanrui Zhang Kaitao Li Yao Xiao Feng Gao Shujiang Shang Jing-Chao Li Xiao-Li Tian Shi-Qiang Wang Jingsong Zhou Noah Weisleder Jianjie Ma Kunfu Ouyang Ju Chen Xianhua Wang Ming Zheng Wang Wang Xiuqin Zhang Heping Cheng | 2011 | Cell Research2011,21,9: | 11 |
| 14 | Synchronous Dynamic Research on Respiratory and Intestinal Microflora of Chronic Bronchitis Rat Model显示文摘Objective: To investigate the mechanism of the Chinese medicine theory that Fei(Lung) and Dachang(Large Intestine) are exteriorly and interiorly related via synchronous observation on the dynamic changes of the respiratory and intestinal microflora. Methods: Forty specific pathogen free Sprague-Dawley rats were selected and randomly divided into blank(10 rats) and chronic bronchitis model groups(30 rats). The blank group rats were put into the smoke-free environment and the model group rats were put into the smoke environment in order to establish pulmonary disease(chronic bronchitis) model. Then the corresponding changes of the respiratory and intestinal microflora of the model on 20th, 50th and 70th days were synchronously observed. Results: The respiratory tract microflora showed an increase in the total aerobic and Staphylococcus aureus and reduced anaerobic amount significantly on 20th day in the respiratory tract microflora(P<0.05 or 0.01). On 50th day, total aerobic, total anaerobic amount and bifidobacterium significantly increased(P<0.05). On 70th day, Staphylococcus aureus reduced and lactobacillus increased significantly(P<0.01). The intestinal microflora showed an increase in the total aerobic, Clostridium perfringens, enterobacter and enterococcus significantly increased on 20th day(P<0.05 or 0.01). Staphylococcus aureus on 50th day increased significantly(P<0.05). Total aerobic and enterococcus increased, total anaerobic and Clostridium perfringens reduced significantly on 70th day(P<0.05 or 0.01). Conclusions: The microecosystem of respiratory tract and intestine of rat model during the pathological process showed a dynamic disorder, indicating an interaction between the lung and large intestine which may be one of the connotations as they exteriorly and interiorly related. | ZHENG Xiu-li YANG Yu WANG Bao-jia WANG Ju TANG Hong-qu | 2017 | Chinese Journal of Integrative Medicine2017,23,3: | 10 |
| 15 | Is graphite lithiophobic or lithiophilic?显示文摘Graphite and lithium metal are two classic anode materials and their composite has shown promising performance for rechargeable batteries.However,it is generally accepted that Li metal wets graphite poorly,causing its spreading and infiltration difficult.Here we show that graphite can either appear superlithiophilic or lithiophobic,depending on the local redox potential.By comparing the wetting performance of highly ordered pyrolytic graphite,porous carbon paper(PCP),lithiated PCP and graphite powder,we demonstrate that the surface contaminants that pin the contact-line motion and cause contact-angle hysteresis have their own electrochemical-stability windows.The surface contaminants can be either removed or reinforced in a time-dependent manner,depending on whether the reducing agents(C6→Li C6)or the oxidizing agents(air,moisture)dominate in the ambient environment,leading to bifurcating dynamics of either superfast or superslow wetting.Our findings enable new fabrication technology for Li–graphite composite with a controllable Li-metal/graphite ratio and present great promise for the mass production of Li-based anodes for use in high-energy-density batteries. | Jian Duan Yuheng Zheng Wei Luo Wangyan Wu Tengrui Wang Yong Xie Sa Li Ju Li Yunhui Huang | 2020 | National Science Review2020,7,7: | 8 |
| 16 | The modified temperature term on Johnson-Cook constitutive model of AZ31 magnesium alloy with {0002} texture显示文摘The dynamic compression experiments with Split-Hopkinson Pressure Bar(SHPB)were performed on AZ31 magnesium alloy rolled sheet specimens in the normal direction(AZ31-ND)with{0002}texture at the temperature of 293-523 K and the strain rate of 0.001-2200 s^−1.The temperature term in Johnson-Cook(JC)constitutive model had been reasonably modified.This advantage made constitutive model promising for decribing the dynamic deformation behavior of AZ31-ND with{0002}texture more accurately.The obtained true stress-true plastic strain curves agreed well with the measured results in a wide range of strain rates and temperatures.The thermal softeninging,strain and strain rate hardening effect on the AZ31-ND with{0002}texture were discussed.The adiabatic shear band(ASB)of AZ31-ND with{0002}texture hat shaped specimen was successfully predicted by combining modified JC constitutive model and numerical simulation,which was also validated by Electron Back-Scattered Diffraction(EBSD)map under the same boundary condition. | Feng Zhang Zheng Liu Yue Wang Pingli Mao Xinwen Kuang Zhenglai Zhang Yingdong Ju Xiaozhong Xu | 2020 | Journal of Magnesium and Alloys2020,8,1: | 8 |
| 17 | Long-term bone and lung consequences associated with hospital-acquired severe acute respiratory syndrome:a 15-year follow-up from a prospective cohort study显示文摘The most severe sequelae after rehabilitation from SARS are femoral head necrosis and pulmonary fibrosis. We performed a 15-year follow-up on the lung and bone conditions of SARS patients. We evaluated the recovery from lung damage and femoral head necrosis in an observational cohort study of SARS patients using pulmonary CT scans, hip joint MRI examinations, pulmonary function tests and hip joint function questionnaires. Eighty medical staff contracted SARS in 2003. Two patients died of SARS, and78 were enrolled in this study from August 2003 to March 2018. Seventy-one patients completed the 15-year follow-up. The percentage of pulmonary lesions on CT scans diminished from 2003(9.40 ± 7.83)% to 2004(3.20 ± 4.78)%(P < 0.001) and remained stable thereafter until 2018(4.60 ± 6.37)%. Between 2006 and 2018, the proportion of patients with interstitial changes who had improved pulmonary function was lower than that of patients without lesions, as demonstrated by the one-second ratio(FEV1/FVC%, t = 2.21, P = 0.04) and mid-flow of maximum expiration(FEF25%–75%, t = 2.76, P = 0.01). The volume of femoral head necrosis decreased significantly from 2003(38.83 ± 21.01)% to 2005(30.38 ± 20.23)%(P = 0.000 2), then declined slowly from 2005 to 2013(28.99 ± 20.59)% and plateaued until 2018(25.52 ± 15.51)%. Pulmonary interstitial damage and functional decline caused by SARS mostly recovered, with a greater extent of recovery within 2 years after rehabilitation. Femoral head necrosis induced by large doses of steroid pulse therapy in SARS patients was not progressive and was partially reversible. | Peixun Zhang Jia Li Huixin Liu Na Han Jiabao Ju Yuhui Kou Lei Chen Mengxi Jiang Feng Pan Yali Zheng Zhancheng Gao Baoguo Jiang | 2020 | Bone Research2020,8,1: | 8 |
| 18 | CO_2 permeability of fractured coal subject to confining pressures and elevated temperature: Experiments and modeling显示文摘The CO_2 permeability of fractured coal is of great significance to both coalbed gas extraction and CO_2 storage in coal seams, but the effects of high confining pressure, high injection pressure and elevated temperature on the CO_2 permeability of fractured coal with different fracture extents have not been investigated thoroughly. In this paper, the CO_2 permeability of fractured coals sampled from a Pingdingshan coal mine in China and artificially fractured to a certain extent is investigated through undrained triaxial tests. The CO_2 permeability is measured under the confining pressure with a range of 10–25 MPa, injection pressure with a range of 6–12 MPa and elevated temperature with a range of 25–70°C. A mechanistic model is then proposed to characterize the CO_2 permeability of the fractured coals. The effects of thermal expansion, temperature-induced reduction of adsorption capacity, and thermal micro-cracking on the CO_2 permeability are explored. The test results show that the CO_2 permeability of naturally fractured coal saliently increases with increasing injection pressure. The increase of confining pressure reduces the permeability of both naturally fractured coal and secondarily fractured coal. It is also observed that initial fracturing by external loads can enhance the permeability, but further fracturing reduces the permeability. The CO_2 permeability decreases with the elevation of temperature if the temperature is lower than 44°C, but the permeability increases with temperature once the temperature is beyond 44°C. The mechanistic model well describes these compaction mechanisms induced by confining pressure, injection pressure and the complex effects induced by elevated temperature. | JU Yang WANG JianGuo WANG HuiJie ZHENG JiangTao RANJITH Pathegama G GAO Feng | 2016 | Science China(Technological Sciences)2016,59,12: | 8 |
| 19 | First-principles calculations of structural,elastic and electronic properties of AB_(2)type intermetallics in Mg–Zn–Ca–Cu alloy显示文摘Electronic structure and elastic properties of MgCu_(2),Mg_(2)Ca and MgZn_(2)phases were investigated by means of first-principles calculations from CASTEP program based on density functional theory(DFT).The calculated lattice parameters were in good agreement with the experimental and literature values.The calculated heats of formation and cohesive energies shown that MgCu_(2)has the strongest alloying ability and structural stability.The elastic constants of MgCu_(2),Mg_(2)Ca and MgZn_(2)phases were calculated,the bulk moduli,shear moduli,Young's moduli and Poisson's ratio were derived.The calculated results shown that MgCu_(2),Mg_(2)Ca and MgZn_(2)are all ductile phases.Among the three phases,MgCu_(2)has the strongest stiffness and the plasticity of MgZn_(2)phase is the best.The density of states(DOS),Mulliken electron occupation number and charge density difference of MgCu_(2),Mg_(2)Ca and MgZn_(2)phases were discussed to analyze the mechanism of structural stability and mechanical properties. | Pingli Mao Bo Yu Zheng Liu Feng Wang Yang Ju | 2013 | Journal of Magnesium and Alloys2013,1,3: | 7 |
| 20 | A more consistent intraluminal rhesus monkey model of ischemic stroke显示文摘Endovascular surgery is advantageous in experimentally induced ischemic stroke because it causes fewer cranial traumatic lesions than invasive surgery and can closely mimic the pathophysiology in stroke patients. However, the outcomes are highly variable, which limits the accuracy of evaluations of ischemic stroke studies. In this study, eight healthy adult rhesus monkeys were randomized into two groups with four monkeys in each group: middle cerebral artery occlusion at origin segment(M1) and middle cerebral artery occlusion at M2 segment. The blood flow in the middle cerebral artery was blocked completely for 2 hours using the endovascular microcoil placement technique(1 mm × 10 cm)(undetachable), to establish a model of cerebral ischemia. The microcoil was withdrawn and the middle cerebral artery blood flow was restored. A reversible middle cerebral artery occlusion model was identified by hematoxylin-eosin staining, digital subtraction angiography, magnetic resonance angiography, magnetic resonance imaging, and neurological evaluation. The results showed that the middle cerebral artery occlusion model was successfully established in eight adult healthy rhesus monkeys, and ischemic lesions were apparent in the brain tissue of rhesus monkeys at 24 hours after occlusion. The rhesus monkeys had symptoms of neurological deficits. Compared with the M1 occlusion group, the M2 occlusion group had lower infarction volume and higher neurological scores. These experimental findings indicate that reversible middle cerebral artery occlusion can be produced with the endovascular microcoil technique in rhesus monkeys. The M2 occluded model had less infarction and less neurological impairment, which offers the potential for application in the field of brain injury research. | Bo Zhao Guowei Shang Jian Chen Xiaokun Geng Xin Ye Guoxun Xu Ju Wang Jiasheng Zheng Hongjun Li Fauzia Akbary Shengli Li Jing Lu Feng Ling Xunming Ji | 2014 | Neural Regeneration Research2014,9,23: | 6 |