检索结果-南通市图书馆

Ballistic performance of spherical fragments penetrating PCrNi3MoV target plates

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第3期33卷 295-307页

作者： Dou Hong Wenbin Li Yu Zheng yiming Li Ning jiang Kebin Zhang Ministerial Key Laboratory of ZNDY Nanjing University of Science and TechnologyNanjingChina

PCrNi3MoV steel is a medium-carbon,low-alloy quenched and tempered steel that finds its applications in military gun barrels due to the high wear resistance and ablation resistance.To study the penetration and failure modes of PCrNi3MoV plates impacted by tungsten spheres,tungsten spheres of various diameters(5 mm,8 mm,and 10 mm)were used to impact PCrNi3MoV steel plates with thicknesses of 6 mm,9 mm,and 14 mm.The penetration performance of the spheres was analyzed for different velocities,and the ultimate penetration velocity of the plate was obtained.It was found that the primary failure modes of the PCrNi3MoV plate were compression pitting failure and shear failure.Using the dimensional analysis method,a relationship between the bulge height of the steel plate and the fragment velocity,an equation for the ultimate penetration velocity,and a relationship between the target penetration energy and the fragment velocity were obtained.Then,a projectile-target action index was proposed to describe the process of tungsten spheres with different velocities impacting target plates.The results suggested that under the same thickness of the target plate,a larger-diameter fragment required more kinetic energy to obtain the same ultimate penetration effect as a smaller-diameter fragment.The equations obtained through dimensional analysis predicted values that agreed well with experimental values,indicating that these equations can be applied to engineering applications.

关键词： Impact damage Ultimate penetration velocity Bulge height Target penetration energy Failure modes

Bio-inspired Design and Inverse Kinematics Solution of an Omnidirectional Humanoid Robotic Arm with Geometric and Load Capacity Constraints

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第2期21卷 778-802页

作者： Zhichao Zhu Zirong Luo yiming Zhu Tao jiang Minghai Xia Shanjun Chen Boyu Jin College of Intelligence Science and Technology National University of Defense TechnologyChangshaChina

Inspired by the driving muscles of the human arm,a 4-Degree of Freedom(DOF)concentrated driving humanoid robotic arm is proposed based on a spatial double parallel four-bar mechanism.The four-bar mechanism design reduces the inertia of the elbow-driving unit and the torque by 76.65%and 57.81%,respectively.Mimicking the human pose regulation strategy that the human arm picks up a heavy object by adjusting its posture naturally without complicated control,the robotic arm features an integrated position-level closed-form inverse solution method considering both geometric and load capacity limitations.This method consists of a geometric constraint model incorporating the arm angle(φ)and the Global Configuration(GC)to avoid joint limits and singularities,and a load capacity model to constrain the feasible domain of the arm angle.Further,trajectory tracking simulations and experiments are conducted to validate the feasibility of the proposed inverse solution method.The simulated maximum output torque,maximum output power and total energy consumption of the robotic arm are reduced by up to 2.0%,13.3%,and 33.3%,respectively.The experimental results demonstrate that the robotic arm can bear heavy loads in a human-like posture,effectively reducing the maximum output torque and energy consumption of the robotic arm by 1.83%and 5.03%,respectively,while avoiding joints beyond geometric and load capacity limitations.The proposed design provides a high payload–weight ratio and an efficient pose control solution for robotic arms,which can potentially broaden the application spectrum of humanoid robots.

关键词： Humanoid robotic arm Bio-inspired design Inverse kinematics solution Load capacity constraint Geometric constraint

Insights into the mechanism of the deterioration of mainstream partial nitritation/anammox under low residual ammonium

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第4期126卷 29-39页

作者： Yandong Yang yiming jiang Yanan Long Jiarui Xu Changqing Liu Liang Zhang Yongzhen Peng School of Environmental and Municipal Engineering Qingdao University of TechnologyQingdao 266033China National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery EngineeringBeijing University of TechnologyBeijing 100124China

Residual ammonium is a critical parameter affecting the stability of mainstream partial nitritation/anammox(PN/A), but the underlying mechanism remains unclear. In this study,mainstream PN/A was established and operated with progressively decreasing residual ammonium. PN/A deteriorated as the residual ammonium decreased to below 5 mg/L, and this was paralleled by a significant loss in anammox activity in situ and an increasing nitrite oxidation rate. Further analysis revealed that the low-ammonium condition directly decreased anammox activity in situ via two distinct mechanisms. First, anammox bacteria were located in the inner layer of the granular sludge, and thus were disadvantageous when competing for ammonium with ammonium-oxidizing bacteria(AOB) in the outer layer. Second, the complete ammonia oxidizer(comammox) was enriched at low residual ammonium concentrations because of its high ammonium affinity. Both AOB and comammox presented kinetic advantages over anammox bacteria. At high residual ammonium concentrations,nitrite-oxidizing bacteria(NOB) were effectively suppressed, even when their maximum activity was high due to competition for nitrite with anammox bacteria. At low residual ammonium concentrations, the decrease in anammox activity in situ led to an increase in nitrite availability for nitrite oxidation, facilitating the activation of NOB despite the dissolved oxygen limitation(0.15–0.35 mg/L) for NOB persisting throughout the operation. Therefore, the deterioration of mainstream PN/A at low residual ammonium was primarily triggered by a decline in anammox activity in situ. This study provides novel insights into the optimized design of mainstream PN/As in engineering applications.

关键词： Mainstream partial nitritation/anammox Residual ammonium Granular sludge Comammox

Topological reorganization and functional alteration of distinct genomic components in gallbladder cancer

在线全文

学校读者我要写书评

暂无评论

Frontiers of Medicine 2024年第1期18卷 109-127页

作者： Guoqiang Li Peng Pu Mengqiao Pan Xiaoling Weng Shimei Qiu yiming Li Sk Jahir Abbas Lu Zou Ke Liu Zheng Wang Ziyu Shao Lin jiang Wenguang Wu Yun Liu Rong Shao Fatao Liu Yingbin Liu Department of Biliary-Pancreatic Surgery Renji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200127China State Key Laboratory of Oncogenes and Related Genes Shanghai Cancer InstituteShanghai200127China Shanghai Key Laboratory of Biliary Tract Disease Shanghai200082China Department of Health Science and Engineering University of Shanghai for Science and TechnologyShanghai200082China Shanghai Tenth People’s Hospital of Tongji University Shanghai200072China Department of General Surgery Xinhua HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200082China Department of Pharmacology Shanghai Jiao Tong University School of MedicineShanghai200025China

Altered three-dimensional architecture of chromatin influences various genomic regulators and subsequent gene expression in human cancer.However,knowledge of the topological rearrangement of genomic hierarchical layers in cancer is largely limited.Here,by taking advantage of in situ Hi-C,RNA-sequencing,and chromatin immunoprecipitation sequencing(ChIP-seq),we investigated structural reorganization and functional changes in chromosomal compartments,topologically associated domains(TADs),and CCCTC binding factor(CTCF)-mediated loops in gallbladder cancer(GBC)tissues and cell lines.We observed that the chromosomal compartment A/B switch was correlated with CTCF binding levels and gene expression changes.Increased inter-TAD interactions with weaker TAD boundaries were identified in cancer cell lines relative to normal controls.Furthermore,the chromatin short loops and cancer unique loops associated with chromatin remodeling and epithelial–mesenchymal transition activation were enriched in cancer compared with their control counterparts.Cancer-specific enhancer–promoter loops,which contain multiple transcription factor binding motifs,acted as a central element to regulate aberrant gene expression.Depletion of individual enhancers in each loop anchor that connects with promoters led to the inhibition of their corresponding gene expressions.Collectively,our data offer the landscape of hierarchical layers of cancer genome and functional alterations that contribute to the development of GBC.

关键词： 3D genome cancer TADs loop gene regulation

Id2 epigenetically controls CD8^(+)T-cell exhaustion by disrupting the assembly of the Tcf3-LSD1 complex

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2024年第3期21卷 292-308页

作者： yiming Li Mingwei Han Haolin Wei Wan Huang Zhinan Chen Tianjiao Zhang Meirui Qian Lin Jing Gang Nan Xiuxuan Sun Shuhui Dai Kun Wang Jianli jiang Ping Zhu Liang Chen Department of Cell Biology of National Translational Science Center for Molecular Medicine and Department of Clinical Immunology of Xijing Hospital Fourth Military Medical UniversityXi’anShaanxi 710032China State Key Laboratory of New Targets Discovery and Drug Development for Major Diseases GanzhouJiangxi341000Xi’anShaanxi 710032China School of Medicine Shanghai UniversityShanghai 200444China

CD8^(+)T-cell exhaustion is a state of dysfunction that promotes tumor progression and is marked by the generation of Slamf6^(+)progenitor exhausted(Tex^(prog))and Tim-^(3+)terminally exhausted(Tex^(term))subpopulations.Inhibitor of DNA binding protein 2(Id2)has been shown to play important roles in T-cell development and CD8^(+)T-cell immunity.However,the role of Id2 in CD8^(+)T-cell exhaustion is unclear.Here,we found that Id2 transcriptionally and epigenetically regulates the generation of Texprog cells and their conversion to Texterm cells.Genetic deletion of Id2 dampens CD8^(+)T-cell-mediated immune responses and the maintenance of stem-like CD8^(+)T-cell subpopulations,suppresses PD-1 blockade and increases tumor susceptibility.Mechanistically,through its HLH domain,Id2 binds and disrupts the assembly of the Tcf3-Tal1 transcriptional regulatory complex,and thus modulates chromatin accessibility at the Slamf6 promoter by preventing the interaction of Tcf3 with the histone lysine demethylase LSD1.Therefore,Id2 increases the abundance of the permissive H3K4me2 mark on the Tcf3-occupied E-boxes in the Slamf6 promoter,modulates chromatin accessibility at the Slamf6 promoter and epigenetically regulates the generation of Slamf6+Texprog cells.An LSD1 inhibitor GSK2879552 can rescue the Id2 knockout phenotype in tumor-bearing mice.Inhibition of LSD1 increases the abundance of Slamf6^(+)Tim-3^(−)Tex^(prog) cells in tumors and the expression level of Tcf1 in Id2-deleted CD8+T cells.This study demonstrates that Id2-mediated transcriptional and epigenetic modification drives hierarchical CD8^(+)T-cell exhaustion,and the mechanistic insights gained may have implications for therapeutic intervention with tumor immune evasion.

关键词： Id2 T-cell exhaustion Epigenetic modification Immune evasion

Stochastic partial differential equations with gradient driven by space-time fractional noises

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2021年第2期16卷 479-497页

作者： yiming jiang Xu YANG School of Mathematical Sciences and LPMC Nankai UniversityTianjin 300071China School of Mathematics and Information Science North Minzu UniversityYinchuan 750021China

We establish a class of stochastic partial differential equations (SPDEs) driven by space-time fractional noises, where we suppose that the drfit term contains a gradient and satisfies certain non-Lipschitz condition.... 详细信息

关键词： Stochastic partial differential equation(SPDE) fractional noise uniqueness strong solution Hölder continuity

Asymptotic analysis parabolic stochastic equations driven by of a kernel estimator for partial differential fractional noises

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2018年第1期13卷 187-201页

作者： Suxin WANG yiming jiang College of Sciences Civil Aviation University of China Tianjin 300300 China School of Mathematical Sciences and LPMC Nankai University Tianjin 300071 China

We study a strongly elliptic partial differential operator with time- varying coefficient in a parabolic diagonalizable stochastic equation driven by fractional noises. Based on the existence and uniqueness of the solution, we then obtain a kernel estimator of time-varying coefficient and the convergence rates. An example is given to illustrate the theorem.

关键词： Fractional white noise elliptic partial differential operator kernelestimator

Early Cenozoic paleontological assemblages and provenance evolution of the Lishui Sag,East China Sea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2023年第3期42卷 113-122页

作者： Yingzhao Zhang yiming jiang Zhenghua Liu Shuai Li Ning Li Jinshui Liu Peijun Qiao Kai Zhong Shuhui Chen Thian Lai Goh Shanghai Branch of China National Offshore Oil Corporation(CNOOC)Co. Ltd.Shanghai 200335China Shanghai Natural History Museum(Branch of Shanghai Science&Technology Museum) Shanghai 200041China State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China Shenzhen Branch of China National Offshore Oil Corporation(CNOOC)Co. Ltd.Shenzheng 518000China Department of Earth Sciences and Environment Faculty of Science and TechnologyUniversity Kebangsaan MalaysiaBangi 43600SelangorMalaysia

The East China Sea Shelf Basin generated a series of back-arc basins with thick successions of marine-and terrestrial-facies sediments during Cenozoic.It is enriched with abundant oil and gas resources and is of great significance to the petroleum exploration undertakings.Therein,the Lishui Sag formed fan delta,fluvial delta and littoral-to-neritic facies sediments during Paleocene–Eocene,and the research on its sedimentary environment and sediment source was controversial.This study analyzed the paleontological combination characteristics,and conducted a source-to-sink comparative analysis to restore the sedimentary environment and provenance evolution of the Lishui Sag during Paleocene–Eocene based on the integration of detrital zircon U-Pb age spectra patterns with paleontological assemblages.The results indicated that Lishui Sag was dominated by littoral and neritic-facies environment during time corroborated by large abundance of foraminifera,calcareous nannofossils and dinoflagellates.Chronological analysis of detrital zircon U-Pb revealed that there were significant differences in sediment sources between the east and west area of the Lishui Sag.The western area was featured by deeper water depths in the Paleocene–Eocene,and the sediment was characterized by a single Yanshanian peak of zircon U-Pb age spectra,and mainly influenced from Yanshanian magmatic rocks of South China Coast and the surrounding paleo-uplifts.However,its eastern area partly showed Indosinian populations.In particular,the upper Eocene Wenzhou sediments were featured by increasingly plentiful Precambrian zircons in addition to the large Indosinian-Yanshanian peaks,indicating a possible impact from the Yushan Low Uplift to the east.Therefore,it is likely that the eastern Lishui Sag generated large river systems as well as deltas during time.Due to the Yuquan Movement,the Lishui Sag experienced uplifting and exhumation in the late stage of the late Eocene and was not deposited with sediments until Miocene.Featured by transitional-facies

关键词： East China Sea Lishui Sag paleontological assemblages sedimentary provenance hydrocarbon exploration

Evaluation of Pitting Behavior on Solution Treated Duplex Stainless Steel UNS S31803

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2014年第2期30卷 179-183页

作者： yiming jiang Tao Sun Jin Li Jie Xu Department of Materials Science Fudan University School of Information and Electrical Engineering Zhejiang University City College

The pitting corrosion resistance of duplex stainless steels UNS S31803 annealed at different temperatures ranging from 1050 ℃ to 1200 ℃ for 24 h has been investigated by means of potentiostatic critical pitting temperature （CPT）. The microstructural evolution and pit morphologies of the specimens were studied through optical microscopy and scanning electron microscopy. The potentiostatic CPT measurements show that the CPT was elevated with the annealing temperature increased from 1050 ℃ to 1150℃ and decreased as the temperature further increased to 1200 ℃. The specimens annealed at 1150 ℃ exhibited the highest CPTand the best pitting corrosion resistance. The pit morphologies show that the pit initiation sites transfer from austenite phase to ferrite phase as the annealing temperature increases. The results were explained by the variation of pitting resistance equivalent number （PREN） of ferrite and austenite phases as the annealing temperature was varied.

关键词： Duplex stainless steel Solution treatment Pitting corrosion Critical pitting temperature Pitting resistance equivalent number