检索结果-南通市图书馆

A novel box-counting method for quantitative fractal analysis of threedimensional pore characteristics in sandstone

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2024年第4期34卷 479-489页

作者： huiqing Liu Heping Xie Fei Wu Cunbao Li Renbo Gao State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China School of Resources and Safety Engineering Chongqing UniversityChongqing 400030China Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Shenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Deep Underground Engineering Sciences and Green Energy College of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518060China

Fractal theory offers a powerful tool for the precise description and quantification of the complex pore structures in reservoir rocks,crucial for understanding the storage and migration characteristics of media within these *** with the challenge of calculating the three-dimensional fractal dimensions of rock porosity,this study proposes an innovative computational process that directly calculates the three-dimensional fractal dimensions from a geometric *** employing a composite denoising approach that integrates Fourier transform(FT)and wavelet transform(WT),coupled with multimodal pore extraction techniques such as threshold segmentation,top-hat transformation,and membrane enhancement,we successfully crafted accurate digital rock *** improved box-counting method was then applied to analyze the voxel data of these digital rocks,accurately calculating the fractal dimensions of the rock pore *** numerical simulations of permeability experiments were conducted to explore the physical correlations between the rock pore fractal dimensions,porosity,and absolute *** results reveal that rocks with higher fractal dimensions exhibit more complex pore connectivity pathways and a wider,more uneven pore distribution,suggesting that the ideal rock samples should possess lower fractal dimensions and higher effective porosity rates to achieve optimal fluid transmission *** methodology and conclusions of this study provide new tools and insights for the quantitative analysis of complex pores in rocks and contribute to the exploration of the fractal transport properties of media within rocks.

关键词： 3D fractal analysis Fractal dimension Rock pore structure Box-counting method Permeability simulation Computational geosciences

Training Generative Adversarial Networks with Adaptive Composite Gradient

在线全文

学校读者我要写书评

暂无评论

Data Intelligence 2024年第1期6卷 120-157页

作者： huiqing Qi Fang Li Shengli Tan Xiangyun Zhang School of Mathematical Sciences East China Normal UniversityShanghai 200241China

The wide applications of Generative adversarial networks benefit from the successful training methods,guaranteeing that an object function converges to the local ***,designing an efficient and competitive training method is still a challenging task due to the cyclic behaviors of some gradient-based ways and the expensive computational cost of acquiring the Hessian *** address this problem,we proposed the Adaptive Composite Gradients(ACG)method,linearly convergent in bilinear games under suitable *** analysis and toy-function experiments both suggest that our approach alleviates the cyclic behaviors and converges faster than recently proposed SOTA *** convergence speed of the ACG is improved by 33%than other *** ACG method is a novel Semi-Gradient-Free algorithm that can reduce the computational cost of gradient and Hessian by utilizing the predictive information in future *** mixture of Gaussians experiments and real-world digital image generative experiments show that our ACG method outperforms several existing technologies,illustrating the superiority and efficacy of our method.

关键词： Generative adversarial networks adaptive composite gradient semi-gradient free game theory bilinear game

Reevaluation by the CRISPR/Cas9 knockout approach revealed that multiple pluripotency-associated lncRNAs are dispensable for pluripotency maintenance while Snora73a/b is essential for pluripotency exit

在线全文

学校读者我要写书评

暂无评论

Science China Life Sciences 2024年第10期67卷 2198-2212页

作者： Zhen Li Xuefei Li Jingxia Lin Yangming Wang huiqing Cao Jiajian Zhou Institute of Molecular Medicine College of Future TechnologyPeking University Dermatology Hospital Southern Medical University Beijing Advanced Center of RNA Biology (BEACON) Peking University

Many long noncoding RNAs(lncRNAs) have been identified through siRNA-based screening as essential regulators of embryonic stem cell(ESC) pluripotency. However, the biological and molecular functions of most lncRNAs remain unclear. Here, we employed CRISPR/Cas9-mediated knockout technology to explore the functions of 8 lncRNAs previously reported to promote pluripotency in mouse ESCs. Unexpectedly, all of these lncRNAs were dispensable for pluripotency maintenance and proliferation in mouse ESCs when disrupted individually or in combination. Single-cell transcriptomic analysis also showed that the knockout of these lncRNAs has a minimal impact on pluripotency gene expression and cell identity. We further showed that several small hairpin RNAs(shRNAs) previously used to knock down lncRNAs caused the downregulation of pluripotency genes in the corresponding lncRNA-knockout ESCs, indicating that off-target effects likely responsible for the pluripotency defects caused by these shRNAs. Interestingly, linc1343-knockout and linc1343-knockdown ESCs failed to form cystic structures and exhibited high expression of pluripotency genes during embryoid body(EB) differentiation. By reintroducing RNA products generated from the linc1343 locus, we found that two snoRNAs, Snora73a and Snora73b, but not lncRNAs, could rescue pluripotency silencing defects during EB differentiation of linc1343 knockout ESCs. Our results suggest that the 8 previously annotated pluripotency-regulating lncRNAs have no overt functions in conventional ESC culture; however, we identified snoRNA products derived from an annotated lncRNA locus as essential regulators for silencing pluripotency genes.

关键词： long noncoding RNAs embryonic stem cells CRISPR/Cas9 snoRNAs stem cell differentiation

同方期刊数据库

Research on the Loss Model and Junction Temperature of IGBT for Electric Vehicles using PSPICE

在线全文

学校读者我要写书评

暂无评论

Research on the Loss Model and Junction Temperature of IGBT ...

Conversion of LiPSs Accelerated by Pt-Doped Biomass-Derived Hyphae Carbon Nanobelts as Self-Supporting Hosts for Long-Lifespan Li-S Batteries

11th International Conference on Electrical Machines and Systems

作者： Wei Hu~1 Xuhui wen~1 huiqing wen~2 Jun Liu~1 1 Institute of Electrical Engineering Chinese Academy of Sciences Beijing P.R.China 100080 2 Graduate School of Chinese Academy of Science Beijing P.R.China 100080

＜正＞IGBT is one of the key components of motor driving system for electric vehicles,and its reliability directly affects the reliability of the electric *** the reliability of the IGBT is affected by the loss and the junction temperature in working condition. To predict the IGBT’s loss and thermal response,especially in the case of adverse dynamic conditions,the dynamic loss model based on physics and the junction temperature of power IGBT are studied in this *** model is then applied to simulation the loss of Eupec’s power IGBT FS450RKE3 used in a motor driving system for electric vehicles developed by the Institute of Electrical Engineering Chinese Academy of *** results accurately match the *** work can be extended to evaluate power IGBTs in other automotive application such as DC/DC conversion,EPAS and so on.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第3期7卷 53-62页

作者： Fengfeng Han Liwen Fan Xinzhi Ma huiqing Lu Lu Li Xitian Zhang Lili Wu Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of EducationSchool of Physics and Electronic EngineeringHarbin Normal University Key Laboratory of Molecular Cytogenetics and Genetic Breeding of Heilongjiang Province School of Life Science and TechnologyHarbin Normal University

Rechargeable Li-S batteries （LSBs） are emerging as an important alternative to lithium-ion batteries （LIBs）,owing to their high energy densities and low cost; yet sluggish redox kinetics of LiPSs results in inferior cycle ***,we prepared multifunctional self-supporting hyphae carbon nanobelt （HCNB）as hosts by carbonization of hyphae balls of Rhizopus,which could increase the S loading of the cathode without sacrificing reaction *** platinum （Pt） nanoparticles were introduced into HCNBs （PtHCNBs） by ionbeam sputtering *** on the X-ray photoelectron spectroscopy analyses,the introduced trace Pt regulated the local electronic states of heteroatoms in *** kinetics investigation combined with operando Raman measurements revealed the accelerated reaction mechanics of sulfur *** from the synergistic catalytic effect and the unique structures,the as-prepared PtHCNB/MWNCT/S cathodes delivered a stable capacity retention of 77%for 400 cycles at 0.5℃with a sulfur loading of 4.6 mg *** importantly,remarkable cycling performance was achieved with an high areal S loading of 7.6 mg *** finding offers a new strategy to prolong the cycle life of LSBs.

关键词： high areal capacity high S loading hyphae carbon nanobelt lithium–sulfur battery operando Raman

Non-diffracting integer-order and half-integer-order carpet beams obtained by even-type sinusoidal amplitude radial gratings

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Optics Letters 2024年第7期22卷 86-92页

作者： Yefeng Liu huiqing Li Rijian Chen Changjiang Fan Yile Shi Zhijun Ren Key Laboratory of Optical Information Detecting and Display Technology Zhejiang Normal UniversityJinhua 321004China

In this work,we introduce a kind of new structured radial grating,which is named the even-type sinusoidal amplitude radial(ETASR)*** on diffraction theory and the principle of stationary phase,a comprehensive theoretical investigation on the diffraction patterns of ETASR gratings is *** results show that novel carpet beams with beautiful optical structures and distinctive characteristics have been constructed on the basics of the ETASR *** diffraction patterns are independent of propagation distance,that is,the new carpet beams have diffraction-free propagating *** non-diffracting carpet beams are divided into two types by beam characteristics:non-diffracting integer-order and half-integer-order carpet ***,we experimentally generate these carpet beams using the ETASR ***,their particularly interesting optical morphology and features are explored through numerical simulations and experiments.

关键词： even-type sinusoidal amplitude radial gratings principle of stationary phase non-diffracting integer-order carpet beams non-diffracting half-integer-order carpet beams.

Impact of effective stress on permeability for carbonate fractured-vuggy rocks

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 942-960页

作者： Ke Sun huiqing Liu Juliana Y.Leung Jing Wang Yabin Feng Renjie Liu Zhijiang Kang Yun Zhang State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China School of Mining&Petroleum Engineering University of AlbertaEdmontonT6G 1H9Canada SINOPEC Petroleum Exploration and Production Research Institute Beijing100083China

To gain insight into the flow mechanisms and stress sensitivity for fractured-vuggy reservoirs,several core models with different structural characteristics were designed and fabricated to investigate the impact of effective stress on permeability for carbonate fractured-vuggy rocks(CFVR).It shows that the permeability performance curves under different pore and confining pressures(*** stress conditions)for the fractured core models and the vuggy core models have similar change *** ranges of permeability variation are significantly wider at high pore pressures,indicating that permeability reduction is the most significant during the early stage of development for fractured-vuggy *** each obtained effective stress coefficient for permeability(ESCP)varies with the changes in confining pressure and pore pressure,the effective stresses for permeability of four representative CFVR show obvious nonlinear characteristics,and the variation ranges of ESCP are all between 0 and ***,a comprehensive ESCP mathematical model considering triple media,including matrix pores,fractures,and dissolved vugs,was *** is proved theoretically that the ESCP of CFVR generally varies between 0 and ***,the regression results showed that the power model ranked highest among the four empirical models mainly applied in stress sensitivity characterization,followed by the logarithmic model,exponential model,and binomial *** concept of“permeability decline rate”was introduced to better evaluate the stress sensitivity performance for CFVR,in which the one-fracture rock is the strongest,followed by the fracture-vug rock and two-horizontalfracture rock;the through-hole rock is the *** general,this study provides a theoretical basis to guide the design of development and adjustment programs for carbonate fractured-vuggy reservoirs.

关键词： Effective stress Permeability Carbonate fractured-vuggy rocks Structure characteristics Stress sensitivity

An amorphous FeMoO_(4) nanorod array enabled high-efficiency oxygen evolution electrocatalysis in alkaline seawater

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2270-2275页

作者： Jie Tang Shengjun Sun Xun He Hui Zhang Chaoxin Yang Min Zhang Meng Yue Hefeng Wang Yuntong Sun Yonglan Luo Sulaiman Alfaifi Asmaa Farouk Mohamed S.Hamdy Xuping Sun huiqing Wang Binwu Ying Department of Laboratory Medicine West China HospitalSichuan UniversityChengdu 610041China College of Chemistry Chemical Engineering and Materials ScienceShandong Normal UniversityJinan 250014China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China Chemistry Department Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia Department of Chemistry College of ScienceKing Khalid UniversityAbha 61413Saudi Arabia Medical Simulation Centre West China Second University HospitalSichuan UniversityChengdu 610041China

The development of highly efficient and durable oxygen evolution reaction(OER)catalysts for seawater electrolysis is of great importance for ***,an amorphous FeMoO_(4) nanorod array on Ni foam is reported as a highly active OER electrocatalyst in alkaline seawater,requiring only overpotentials of 303 and 332 mV to achieve 100 and 300 mA·cm^(-2),***,it shows strong long-term electrochemical durability for at least 50 h.

关键词： amorphous material FeMoO_(4) nanorod array electrocatalyst seawater electrolysis oxygen evolution reaction

钢-UHPC轻型组合结构短栓钉抗剪性能试验研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

天津大学学报（自然科学与工程技术版） 2024年第1期57卷 42-52页

作者：邓宗才黄松薛会青北京工业大学城市与工程安全减灾教育部重点实验室北京100124 北京市政工程研究院北京100037

通过6个钢-超高性能混凝土(ultra-high performance concrete,UHPC)轻型组合结构短栓钉推出试验,对其抗剪承载力、破坏形态、栓钉应变及荷载-滑移曲线进行了研究,探讨了栓钉直径、长度、数量以及界面黏结对短栓钉抗剪性能的影响规律.结... 详细信息

通过6个钢-超高性能混凝土(ultra-high performance concrete,UHPC)轻型组合结构短栓钉推出试验,对其抗剪承载力、破坏形态、栓钉应变及荷载-滑移曲线进行了研究,探讨了栓钉直径、长度、数量以及界面黏结对短栓钉抗剪性能的影响规律.结果表明:所有试件均为栓钉根部剪切破坏,UHPC板除栓钉根部沿承压方向部分UHPC压碎外,其余部分保持完好,UHPC可以抵抗栓钉传递的高压应力;栓钉根部截面屈服后应力强化阶段明显,栓钉发生剪切破坏时,栓钉根部上侧应变超过3500με;长径比为2.0的短栓钉在UHPC中也能发挥全部强度;所有试件的荷载-滑移曲线分为弹性、弹塑性和塑性3个阶段,所有短栓钉的最大滑移量均小于4 mm,工程应用时应按照弹性剪力连接件进行设计;栓钉直径对栓钉抗剪性能提高最显著,直径16 mm的栓钉比直径13 mm的栓钉的抗剪承载力和极限滑移分别提高了46.4%和11%,弹性刚度和塑性刚度分别提高了35.8%和59.1%,增加栓钉长度和界面黏结能有效提高栓钉的剪切刚度,长径比为3.0的栓钉比长径比为2.5的栓钉的弹性刚度提高了12.3%,界面有黏结试件比界面无黏结试件的弹性刚度提高了17.4%;相同间距内,合理增加更多栓钉有利于提高整体抗剪强度,但会降低延性变形能力.最后,结合实验数据和国内外UHPC中栓钉推出试验结果,建立了UHPC中栓钉荷载-滑移曲线和抗剪承载力预测表达式,计算值与试验值吻合良好.

关键词：超高性能混凝土短栓钉推出试验抗剪性能荷载-滑移曲线抗剪承载力