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A numerical study of non-Darcy flow in EGS heat reservoirs during heat extraction

Frontiers in Energy 2019年第3期13卷 439-449页

作者： Wenjiong CAO Wenbo HUANG Guoling wei Yunlong JIN Fangming jiang Laboratory of Advanced Energy Systems Guangdong Key Laboratory of New and Renewable Energy Research and DevelopmentCAS Key Laboratory of Renewable EnergyGuangzhou Institute of Energy ConversionChinese Academy of SciencesGuangzhou 510640China Guangdong Hydrogeology Battalion Guangzhou 510510China

Underground non-Darcy fluid flow has been observed and investigated for decades in the petroleum industry. It is deduced by analogy that the fluid flow in enhanced geothermal system (EGS) heat reservoirs may also be in the non-Darcy regime under some conditions. In this paper, a transient 3D model was presented, taking into consideration the non-Darcy fluid flow in EGS heat reservoirs, to simulate the EGS long-term heat extraction process. Then, the non-Darcy flow behavior in water- and supercritical CO2 (SCCO2)-based EGSs was simulated and discussed. It is found that non-Darcy effects decrease the mass flow rate of the fluid injected and reduce the heat extraction rate of EGS as a flow resistance in addition to the Darcy resistance which is imposed to the seepage flow in EGS heat reservoirs. Compared with the water-EGS, the SCCO2-EGS are more prone to experiencing much stronger non-Darcy flow due to the much larger mobility of the SCCO2. The non-Darcy flow in SCCO2- EGSs may thus greatly reduce their heat extraction performance. Further, a criterion was analyzed and proposed to judge the onset of the non-Darcy flow in EGS heat reservoirs. The fluid flow rate and the initial thermal state of the reservoir were taken and the characteristic Forchheimer number of an EGS was calculated. If the calculated Forchheimer number is larger than 0.2, the fluid flow in EGS heat reservoirs experiences non-negligible non-Darcy flow characteristic.

关键词： enhanced geothermal system non-Darcy flow heat extraction Reynolds number Forchheimer number

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“含蓄”的化育:穿梭在革命叙事与日常哲学之间——《粤海风》对话《潜伏》导演、编剧姜伟

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粤海风 2022年第5期 105-112页

作者：姜伟卢瑜北京电影学院导演系不详

一、《潜伏》的“幸运”来源于中国电视剧的高光时代卢:14年后重谈作品《潜伏》,有三方面原因:一是近来社交媒体上似乎呈现出一种电视剧的“考古”热潮,《甄媛传》《武林外传》等经典作品屡出场,甚至有观众开始进行细致的文本分析和再解... 详细信息

一、《潜伏》的“幸运”来源于中国电视剧的高光时代卢:14年后重谈作品《潜伏》,有三方面原因:一是近来社交媒体上似乎呈现出一种电视剧的“考古”热潮,《甄媛传》《武林外传》等经典作品屡出场,甚至有观众开始进行细致的文本分析和再解读,《潜伏》也是“老剧新聊”的代表作品;二是中国艺术研究院推荐了“讲话”精神照耀下的百部文艺作品榜单.

关键词：《潜伏》中国艺术研究院革命叙事《武林外传》社交媒体文本分析电视剧文艺作品

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A combined denoising method of empirical mode decomposition and singular spectrum analysis applied to Jason altimeter waveforms: A case of the Caspian Sea

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Geodesy and Geodynamics 2022年第4期13卷 327-342页

作者： Wenguan jiang wei You Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China Third Geodetic Team of the Department of Natural Resources Chengdu 610100China State-Province Joint Engineering Laboratory of Spatial Information Technology for High-Speed Railway Safety Chengdu 610031China

During the satellite pulse propagation and reception, the altimeter waveform is inevitably affected by noise. To reduce the noise level in Jason altimeter waveforms, we used singular spectrum analysis(SSA),empirical mode decomposition(EMD), and the combination of SSA and EMD to obtain the denoised waveforms. The advantages of the combined method were verified and the accuracy of the mean sea surface height(MSSH) model was improved. Comparing the denoising effect of the three methods, the results show that the signal-to-noise ratio(SNR), correlation coefficient and root-mean-square error are effectively improved by the combination of SSA and EMD. The sea surface heights(SSHs) were remeasured with a 50% threshold retracker of denoised waveforms, and the MSSH model of the Caspian Sea with a grid of 1’× 1’was established from the retracked SSHs of Jason-1/2/3. Taking the mean value of the four models as a control, it is found that the model calculated by the combined denoising method has the highest accuracy. This indicates that using the combined denoising method to reduce the noise level is beneficial to improve the accuracy of the MSSH model.

关键词： Altimetry waveforms Jason-1/2/3 Combined method Waveform retracking Mean sea surface height

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Design of a combined magnetic negative stiffness mechanism with high linearity in a wide working region

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Science China(Technological Sciences) 2022年第9期65卷 2127-2142页

作者： WU JiuLin CHE JiXing CHEN XueDong JIANG Wei State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Combining magnetic negative stiffness mechanism(NSM) in parallel with positive stiffness has been considered to be an effective approach to realize the quasi-zero stiffness(QZS) characteristic,thus resolving the contradiction between high load capacity and(ultra-) low-frequency vibration isolation capability.However,the remarkable stiffness nonlinearity of common magnetic NSMs restricts the displacement region with reliable negative stiffness,resulting in considerable nonlinear behavior,poor vibration attenuation performance,and probable instability under large amplitude vibrations.A novel combined negative stiffness mechanism(CNSM) with attractive magnetic NSM(ANSM) and repulsive magnetic NSM(RNSM) in parallel is proposed in this paper.The stiffness nonlinearities of the ANSM and RNSM in the CNSM are counteracted through the parallel configuration such that the displacement region with reliable linear stiffness of the CNSM is widened by several times.An analytical model of the CNSM is established by the magnetic charge model and verified by simulation on ANSYS Maxwell.Parametric studies are then conducted to investigate the effects of design parameters on the stiffness characteristic,providing guidelines for the optimal design of the CNSM.Meanwhile,the stiffness and nonlinearity of the CNSM are compared with that of a single ANSM and RNSM.Static and dynamic experiments are finally conducted on the proposed test prototypes.Experimental results demonstrated the validity of the established model and the effectiveness of the CNSM in generating high linear stiffness within a wide displacement region and lowering the resonance frequency.Thus,the proposed CNSM can be applied in(ultra-) low-frequency vibration isolation under large amplitude excitations.

关键词： vibration isolation quasi-zero stiffness combined negative stiffness mechanism high linearity

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Research on emotional space for movie and TV drama videos

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The Journal of China Universities of Posts and Telecommunications 2022年第5期29卷 73-82页

作者： Li Yujie Zhang Jingjing JIANG Wei Wang Chunxiao Key Laboratory of Acoustic Visual Technology and Intelligent Control System Communication University of ChinaBeijing 100024China Beijing Key Laboratory of Modern Entertainment Technology Communication University of ChinaBeijing 100024China School of Information and Communication Engineering Communication University of ChinaBeijing 100024China School of Computer and Cyber Sciences Communication University of ChinaBeijing 100024China

Emotional space refers to a multi-dimensional emotional model that describes a group of subjective feelings or emotions. Since the existing discrete emotional space is mainly aimed at human’s primary emotions, it cannot describe the complex emotions evoked when watching movies. In order to solve this problem, an emotional fusion space for videos was constructed by selecting movies and TV dramas with rich emotional semantics as the research objects. Firstly, emotional words based on movie and TV drama videos are acquired and analyzed by using subjective evaluation and semantic analysis methods. Then, the emotional word vectors obtained from the above analysis are fused, reduced dimension by t-distributed stochastic neighbor embedding(t-SNE) algorithm, and clustered by bisecting K-means clustering algorithm to get a discrete emotional space for movie and TV drama videos. This emotional fusion space can obtain different categories by changing the value of the emotion classification number without re-labeling and calculation.

关键词： emotional space movie and TV drama videos subjective evaluation words semantic analysis fusion space

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Effective Responses to Public Emergencies at the Urban Community Level:A Perspective of COVID-19 Prevention and Control

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Chinese Journal of Urban and Environmental Studies 2022年第3期10卷 112-123页

作者： LIU Ziqi JIANG Wei LI Jiahui School of Philosophy and Religions Minzu University of China The Institute of Ethnology and Anthropology Chinese Academy of Social Sciences School of Sociology and Ethnology University of Chinese Academy of Social Sciences

Community is directly responsible for implementing the policy measures against public emergencies such as extreme weather, earthquake, flash flood and pandemic diseases. Summarizing the experience at the urban community level can help promote the global emergency management.This paper, from the perspective of COVID-19 prevention and control, selects three communities with different features to explore an effective response system for public emergency management at the urban community level. It demonstrates that based on a centralized leadership, the multilevel governance(MLG) network combined with information technology has mobilized their participation in combating COVID-19 and ensured the effective and timely response to the public emergencies, which blocked the spread of epidemic to the greatest extent, proving worthy of being promoted as one of the Chinese approaches and Chinese wisdom.

关键词： Urban community response system for public emergencies COVID-19 Chinese approaches and Chinese wisdom

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Advances in the construction of diverse SuFEx linkers

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National Science Review 2023年第6期10卷 226-244页

作者： Daming Zeng wei-Ping Deng Xuefeng jiang Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism School of Pharmacy East China University of Science and Technology Shanghai Key Laboratory of Green Chemistry and Chemical Process School of Chemistry and Molecular Engineering East China Normal University

Sulfur fluoride exchange(SuFEx),a new generation of click chemistry,was first presented by Sharpless,Dong and co-workers in 2014.Owing to the high stability and yet efficient reactivity of the SⅥ-F bond,SuFEx has found widespread applications in organic synthesis,materials science,chemical biology and drug discovery.A diverse collection of SuFEx linkers has emerged,involving gaseous SO2F2and SOF4hubs;SOF4-derived iminosulfur oxydifluorides;O-,N-and C-attached sulfonyl fluorides and sulfonimidoyl fluorides;and novel sulfondiimidoyl fluorides.This review summarizes the progress of these SuFEx connectors,with an emphasis on analysing the advantages and disadvantages of synthetic strategies of these connectors based on the SuFEx concept,and it is expected to be beneficial to researchers to rapidly and correctly understand this field,thus inspiring further development in SuFEx chemistry.

关键词： SuFEx SuFEx linker SVI–F bond synthetic strategy

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Is Pain Representation？

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Frontiers of Philosophy in China 2017年第4期12卷 648-665页

作者： JIANG Wei School of Marxism Xi'an University of Architecture and Technology Xi'an 710055 China

The argument given by strong representationalists about phenomenal consciousness usually has two steps. The first is to identify all phenomenal consciousness with representation. The second is to identify all phenomenal aspects of phenomenal consciousness with certain representational content. Pain is often thought to be a counterexample torepresentationalism. However, current objections from this perspective mostly focus on the second step and try to show that pains have some special qualities that representational content cannot explain. This paper objects to representationalism with regard to pain （that pain is not representation） by way of a focus on the first step. First, it shows that by borrowing the notion of ＂representation＂ from the causal co-variation theory of representation, representationalists are not able to demonstrate that pain is representation. Second, by laying out some well-accepted criteria for what counts as representation, it argues that pains do not satisfy them. Thus, pain is not representation.

关键词： representationalism pain representation veridicality conditions,causal co-variation

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Trajectory and attitude deviations for internal store separation due to unsteady and quasi-steady test method

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Chinese Journal of Aeronautics 2022年第2期35卷 74-81页

作者： wei SONG Jingang DONG wei LU Zenghui jiang Aerodynamic Science Center China Academy of Aerospace AerodynamicsBeijing 100074China

The deviations of trajectory and attitude angle for internal store separation are evaluated by two wind tunnel test methods.One is the Freedrop Test(FDT),which is known as unsteady and time-dependent method of scaled model.The other is the Captive Trajectory System(CTS)test,which is usually regarded as a quasi-steady and time-averaged test technology.The result shows that there is a streamwise adverse pressure gradient on the cavity resulting in a nose-up pitching moment coefficient(>0)acting on the store model.When the initial pitch angular velocity is 0,the store exits the shear-layer with a nose-up pitch attitude causing the store to climb back towards and collide with the aircraft.However,the store passes through the shear-layer into the freestream with a nose-down pitch,which causes a successful separation event when the initial pitch angular velocity<0.The pitch angle obtained by unsteady test method is different from that by quasisteady test method.The time-dependent test includes the aerodynamic force induced by pitch angular velocity whereas the time-averaged method(CTS)cannot reflect the effect of unsteady aerodynamic force.The deviation of vertical displacement is not obvious for FDT and CTS test since the store has an initial vertical velocity,which is dominant for the vertical displacement.This means that the highly unsteady flow can create unpredictability in aerodynamic pitching moment of the store,which can lead to the deviation of pitch angle for internal store separation.

关键词： Captive trajectory system Freedrop test Internal weapons Store separation Unsteady test method

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Stepwise differentiation of functional pancreatic β cells from human pluripotent stem cells

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Cell Regeneration 2022年第1期11卷 227-245页

作者： Wenwen Jin wei jiang Department of Biological Repositories Frontier Science Center for Immunology and MetabolismMedical Research InstituteZhongnan Hospital of Wuhan UniversityWuhan 430071China Human Genetics Resource Preservation Center of Wuhan University Wuhan 430071China

Pancreaticβcells differentiated from stem cells provide promise for cell replacement therapy of diabetes.Human pluripotent stem cells could be differentiated into definitive endoderm,followed by pancreatic progenitors,and then subjected to endocrinal differentiation and maturation in a stepwise fashion.Many achievements have been made in making pancreaticβcells from human pluripotent stem cells in last two decades,and a couple of phase I/II clinical trials have just been initiated.Here,we overview the major progresses in differentiating pancreaticβcells from human pluripotent stem cells with the focus on recent technical advances in each differentiation stage,and briefly discuss the current limitations as well.

关键词： Pancreaticβcell Human pluripotent stem cells Stepwise differentiation Diabetes mellitus

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