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Visualization of hydraulic fracture interacting with pre-existing fracture

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Petroleum Science 2023年第6期20卷 3723-3735页

作者： Zi-xiao Xie xiao-guang wu Teng-Da Long Zhong-Wei Huang Gen-Sheng Li Wen-Chao Zou Zhao-Wei Sun State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum-BeijingBeijing102249China

Hydraulic fracturing is considered the main stimulation method to develop shale gas reservoirs. Due to its strong heterogeneity, the shale gas formation is typically embedded with geological discontinuities such as bedding planes and natural fractures. Many researchers realized that the interaction between natural fractures and hydraulic fractures plays a crucial role in generating a complex fracture network. In this paper, true tri-axial hydraulic fracturing tests were performed on polymethyl methacrylate (PMMA), on which pre-existing fracture was pre-manufactured to simulate natural fracture. A cohesive model has been developed to verify the results of the experimental tests. The key findings demonstrate that the experimental results agreed well with the numerical simulation outcomes where three main interaction modes were observed: crossing;being arrested by opening the pre-existing fracture;being arrested without dilating the pre-existing fracture. Crossing behavior is more likely to occur with the approaching angle, horizontal stress difference, and injection rate increase. Furthermore, the higher flow rate might assist in reactivating the natural fractures where both sides of the pre-existing fractures were reactivated as the injection rate increased from 5 to 20 mL/min. Additionally, hydraulic fractures show a tendency to extend vertically rather than along the direction of maximum horizontal stress when they are first terminated at the interface. This research may contribute to the field application of hydraulic fracturing in shale gas formation.

关键词： Hydraulic fracturing Natural fracture Fracture propagation Interaction mode PMMA

Simulation study of supercritical carbon dioxide jet fracturing for carbonate geothermal reservoir based on fluid-thermo-mechanical coupling model

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Petroleum Science 2023年第3期20卷 1750-1767页

作者： Jian-Xiang Chen Rui-Yue Yang Zhong-Wei Huang xiao-guang wu Shi-Kun Zhang Hai-Zhu Wang Feng Ma State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China Sinopec Research Institute of Petroleum Engineering Beijing102206China The Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological SciencesShijiazhuang050061HebeiChina Technology Innovation Center of Geothermal&Hot Dry Rock Exploration and Development Ministry of Natural ResourcesShijiazhuang050061HebeiChina

Geothermal energy is a kind of renewable,sustainable and clean energy *** energy is abundant in carbonate ***,low matrix permeability limits its *** super-critical carbon dioxide(SC-CO_(2))jet fracturing is expected to efficiently stimulate the carbonate geothermal reservoirs and achieve the storage of CO_(2) *** this paper,we established a transient seepage and fluid-thermo-mechanical coupled model to analyze the impact performance of sc-CO_(2) jet *** mesh-based parallel code coupling interface was employed to couple the fluid and solid domains by exchanging the data through the mesh *** physical properties change of sC-CO_(2) with temperature were considered in the numerical *** showed that SC-CO_(2) jet frac-turing is superior to water-jet fracturing with respect to jetting velocity,particle trajectory and ***,stress distribution on the carbonate rock showed that the tensile and shear failure would more easily occur by SC-CO_(2) jet than that by water ***,pressure and temperature control the jet field and seepage field of sC-CO_(2) *** the jet temperature can effectively enhance the impingement effect and seepage process by decreasing the viscosity and density of SC-CO_(2).The key findings are expected to provide a theoretical basis and design reference for applying SC-CO_(2) jet fracturing in carbonate geothermal reservoirs.

关键词： Carbonate Carbon capture utilization and storage(CCUS) Jet fracturing Coupled model Geothermal reservoir

A large area ^(3)He tube array detector with vacuum operation capacity for the SANS instrument at the CSNS

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Nuclear Science and Techniques 2022年第7期33卷 83-92页

作者： Xing-Fen Jiang Jian-Rong Zhou Hong Luo Liang xiao xiao-Juan Zhou Hong Xu Yuan-guang Xia xiao-guang wu Lin Zhu Wen-Qing Yang Gui-An Yang Bei-Ju Guan Hong-Yu Zhang Yu-Bin Zhao Zhi-Jia Sun Yuan-Bo Chen State Key Laboratory of Particle Detection and Electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing100049China Spallation Neutron Source Science Center Dongguan523803China University of Chinese Academy of Sciences Beijing100049China

The small-angle neutron scattering(SANS)instrument,one of the first three instruments of the China Spallation Neutron Source(CSNS),is designed to probe the microscopic and mesoscopic structures of materials in the scale range 1–100 nm.A large-area ^(3)He tube array detector has been constructed and operates at the CSNS SANS instrument since August *** consists of 120 linear position-sensitive detector tubes,each 1 m in length and 8 mm in diameter,and filled with ^(3)He gas at 20 bar to obtain a high detection *** ^(3)He tubes were divided into ten modules,providing an overall area of 1000 mm×1020 mm with a high count rate *** each tube is installed independently,the detector can be quickly repaired in situ by replacing damaged *** reduce air scattering,the SANS detector must operate in a vacuum environment(0.1 mbar).An all-metal sealing technique was adopted to avoid high-voltage breakdown by ensuring a high-voltage connection and an electronic system working in an atmospheric environment.A position resolution of 7.8±0.1 mm(full width at maximum)is measured along the length of the tubes,with a high detection efficiency of 81±2% at *** over the past four years,the detector appears to perform well and with a high stability,which supports the SANS instrument to finish approximately 200 user scientific programs.

关键词： Neutron detectors ^(3)He tubes Gaseous detectors Small-angle neutron scattering

Homocysteine, hypertension, and risks of cardiovascular events and all-cause death in the Chinese elderly population: a prospective study

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Journal of Geriatric Cardiology 2021年第10期18卷 796-808页

作者： Zhong-Ying ZHANG Xiang GU Zhe TANG Shao-Chen GUAN Hong-Jun LIU xiao-guang wu Yan ZHAO Xiang-Hua FANG Geriatric Department Xuanwu HospitalCapital Medical UniversityBeijingChina Evidence-based Medical Center Xuanwu HospitalCapital Medical UniversityBeijingChina Medical Affair Department Beijing Friendship HospitalCapital Medical UniversityBeijingChina Beijing Geriatric Healthcare Center Xuanwu HospitalCapital Medical UniversityBeijingChina Education Department Xuanwu HospitalCapital Medical UniversityBeijingChina

BACKGROUND Increased homocysteine levels are associated with the risk of cardiovascular disease(CVD)and ***,their prevention has not been effective in decreasing CVD *** study investigated the individual and combined associations of hyperhomocysteinemia and hypertension with incident CVD events and all-cause death in the Chinese elderly population without a history of *** This prospective study was conducted among 1,257 elderly participants(mean age:69 years).A questionnaire survey,physical examinations,and laboratory tests were conducted to collect baseline *** was defined as homocysteine level≥15μmol/L.H-type hypertension was defined as concomitant hypertension and *** Cox regression analysis was used to evaluate individual and combined associations of hyperhomocysteinemia and hypertension with the risks of incident CVD events and all-cause *** Over a median of 4.84-year follow-up,hyperhomocysteinemia was independently associated with incident CVD events and all-cause *** hazard ratios(HRs)were 1.45(95%CI:1.01−2.08)for incident CVD events and 1.55(95%CI:1.04−2.30)for all-cause *** adjustment for confounding factors,H-type hypertension had the highest HRs for incident CVD events and all-cause *** fully adjusted HRs were 2.44 for incident CVD events(95%CI:1.28−4.65),2.07 for stroke events(95%CI:1.01−4.29),8.33 for coronary events(95%CI:1.10−63.11),and 2.31 for all-cause death(95%CI:1.15−4.62).CONCLUSIONS Hyperhomocysteinemia was an independent risk factor,and when accompanied by hypertension,it contrib-uted to incident CVD events and all-cause death in the Chinese elderly population without a history of CVD.

关键词： hypertension prospective prevention

Lifetime measurements in 138Nd

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Nuclear Science and Techniques 2021年第10期32卷 72-78页

作者： Jian Zhong xiao-guang wu Shi-Peng Hu Ying-Jun Ma Yun Zheng Cong-Bo Li guang-Sheng Li Bao-Ji Zhu Tian-xiao Li Yan-Jun Jin Yan-Xiang Gao Qi-Wen Fan Ke-Yan Ma Dong Yang Hui-Bin Sun Hai-Ge Zhao Lin Gan Qi Luo Zheng-Xin wu College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China China Institute of Atomic Energy Beijing 102413China College of Physics Jilin UniversityChangchun 621010China

Lifetimes of the 2_(1)^(+),4_(1)^(+),7_(2)^(-),10_(2)^(+),12_(2)^(+),and 14_(1)^(+) states in 138 Nd populated via the 123 Sb(19 F,4n)138 Nd fusion–evaporation reaction were measured with the recoil distance Doppler shift technique in combination with the differential decay curve *** B(E2;2_(1)^(+)→0_(1)^(+))value fit well with the systematic trend in the Nd isotope chain and Grodzins rule,which proved that 138Nd is a transitional nucleus.

关键词： Lifetime measurement Recoil distance Doppler shift technique Differential decay curve method

A development of lifetime measurement based on the differential decay curve method

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Nuclear Science and Techniques 2018年第8期29卷 114-120页

作者： Jian Zhong xiao-guang wu Ying-Jun Ma Yun Zheng Cong-Bo Li guang-Sheng Li Bao-Ji Zhu Tian-xiao Li Yan-Jun Jin Yan-Xiang Gao Ke-Yan Ma Dong Yang Hao Guo Jia-Qi Wang Xian Guan Ji Sun China Institute of Atomic Energy Beijing 102413China College of Physics Jilin UniversityChangchun 621010China Shenyang Institute of Engineering Shenyang 110136China

A new development of indirect gating case in the differential decay curve method used for lifetime measurement has been *** gate region was extended from partial shifted peak to both shifted and unshifted *** statistics of flight and stop peaks in gating spectra was improved *** reliability of this change has been tested by reanalysing the lifetime of 2^+ state in^(134) *** result of 32.2(33) ps was fit well with the previous published values within the experimental *** developed method was also used to analyse the lifetime of 2_1^+ state in^(138) Nd.

关键词：线方法腐烂微分开发测量大小写可靠性试验性

Test of a ^(3)He neutron detector readout electronics prototype for CSNS multipurpose physics neutron diffractometer

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Radiation Detection Technology and Methods 2021年第2期5卷 200-206页

作者： xiao-guang wu Yu-bin Zhao Hong Luo Jian-rong Zhou Liang xiao xiao-juan Zhou Bei-ju Guan Xing-cheng Tian Lin Zhu Xing-fen Jiang Zhi-jia Sun State Key Laboratory of Particle Detection and Electronics Institute of High Energy PhysicsChinese Academy of Sciences(CAS)Beijing 100049China University of Chinese Academy of Sciences(UCAS) Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China

Background Large areas of 3He neutron detector array and corresponding readout electronics are used in the MPI built at China Spallation Neutron Source(CSNS)to measure the position and flight time of scattered neutrons,and MPI has a high requirement for the position resolution of 3He neutron detector.A 3He neutron detector readout electronics prototype composed of two front-end boards and one digital readout board is designed to meet the above *** Testing the whole readout electronics system before its mass production to ensure it can run correctly and fulfill the functional and performance *** The test of the readout electronics prototype is implemented in the laboratory,and a signal generator is used to generate electronic signals instead of actual neutron *** position resolution test of the readout electronics prototype with 3He tubes is carried out in the No.20 beamline measurement room of *** and Conclusion The functional and performance tests in the laboratory state that the readout electronics prototype can fulfill the readout *** typical value of charge resolution is 0.85 fC;the integral nonlinearity of charge is 0.094%in the input charge range from 100 to 800 *** position resolution test result of the prototype with 3He tubes is better than the design requirement of 10 mm and also quite good compared with that of some other commercial *** tests provide a reliable basis for the mass production of the readout electronics prototype.

关键词： CSNS MPI 3He tube Readout electronics prototype Functional and performance tests

Mechanism of the protective effects of noninvasive limbs preconditioning on myocardial ischemia-reperfusion injury

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Chinese Medical Journal 2005年第20期118卷 1723-1727页

作者： CHEN xiao-guang wu Bin-yang WANG Jun-ke BAI Tao Department of Anesthesiology First Affiliated Hospital ChinaMedical University Shenyang 110001 China

Background This study aimed at assessing the effect of noninvasive limb preconditioning on myocardial infarct size, and determining whether nitric oxide and neurogenic pathway play an important role in the mechanism of acute remote ischemic preconditioning （IPC）.Methods Forty Wistar rats were randomly divided into four experimental groups. In Group I , the rats underwent 30-minute occlusion of the left anterior descending coronary artery, and 120-minute reperfusion. In Group PL, the rats underwent four cycles of 5-minute occlusion and reperfusion of both hind limbs using a tourniquet before the experiment was continued as in Group I. In Group PL-N and Group PL-,, we administered L-nitro-arginine methyl ester （L-NAME） 10 mg/kg or hexamethonium chloride 20 mg,/kg intravenously, 10 minutes before IPC. Infarct size as a percentage of the area at risk was determined by triphenyhetrazolium chloride staining.Results There were no statistically significant differences in mean arterial pressure and heart rate among these groups at any time point during the experiment （ P〉0. 05 ）. The myocardial infarct size （IS） was decreased significantly in Group PL and Group PL-U compared with Group I , and the IS/AAR was 34. 5%± 7.6%, 35.9%±8.6% and58.5%±8.5%, respectively （P〈0.05）. The IS/AAR was 49.1%±6.5% in Group PEN, and there was no significant difference compared with Group I （P〉0. 05 ）.Conclusions Noninvasive limb IPC is effective in protecting the myocardium from ischemia reperfusion injury. Nitric oxide plays an important role in the mechanism of acute remote IPC, in which the neurogenic pathway is not involved.

关键词： limb preconditioning ·ischemia-reperfusion injury myocardial protection· nitric oxide·neurogenic pathway

Mechanism of the protective effects of noninvasive limbs preconditioning on myocardial ischemia-reperfusion injury

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中华医学杂志(英文版) 2005年第20期000卷 53-57页

作者： CHEN xiao-guang, wu Bin-yang, WANG Jun-ke and BAI Tao Department of Anesthesiology, First Affiliated Hospital, China Medical Unive rsity, Shenyang 110001, China Department of Anesthesiology First Affiliated Hospital China Medical University Shenyang 110001 China

Background This study aimed at assessing the effect of noninvasive limb preconditioning on myocardial infarct size, and deter mining whether nitric oxide and neurogenic pathway play an important role in the mechanism of acute remote ischemic preconditioning (IPC). Methods Forty Wistar rats were randomly divided into fo ur experimental groups. In Group Ⅰ, the rats underwent 30-minute occlusion of the left anterior descending coronary artery, and 120-minute reperfusion. In Group PL, the rats underwent four cycles of 5-minute occlusion and reperfusion of both h ind limbs using a tourniquet before the experiment was continued as in Group Ⅰ. In Group P L-N and Group P L-H, we administered L-nitro-arginine meth yl ester (L-NAME) 10 mg/kg or hexamethonium chloride 20 mg/kg intravenously, 10 minutes before IPC. Infarct size as a percentage of the area at risk was deter mine d by triphenyltetrazolium chloride staining. Results There were no statistically significant differences in mean arterial pressure and heart rate amo ng these groups at any time point during the experiment (P>0.05). The myo cardial infarct size (IS) was decreased significantly in Group PL and Group P  L-H compared with Group Ⅰ, and the IS/AAR was 34.5%±7.6%, 35.9%±8. 6 % and 58.5%±8.5%, respectively (P0.05). Conclusions Noninvasive limb IPC is effective in protecting the myocardium from ischemia reperfusion injury. Nitric oxide plays an important r ole in the mechanism of acute remote IPC, in which the neurogenic pathway is not involved .

关键词： limb preconditioning · ischemia-reperfusion injury · myocardial protection · nitric oxide · neurogenic pathway