检索结果-南通市图书馆

Performance of soft-hard-soft （SHS） cement based composite subjected to blast loading with consideration of interface properties

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2015年第3期9卷 323-340页

作者： Jun WU xuemei liu College of Urban Railway Transportation Shanghai University of Engineering Science Shanghai 201620 China Department of Civil and Environmental Engineering National University of Singapore Singapore 119077 Singapore School of Civil Engineering and Built Environment Queensland University of Technology Brisbane QLD 4072 Australia

This paper presents a combined experimental and numerical study on the damage and performance of a soft-hard-soft （SHS） multi-layer cement based composite subjected to blast loading which can be used for protective structures and infrastructures to resist extreme loadings, and the composite consists of three layers of construction materials including asphalt concrete （AC） on the top, high strength concrete （HSC） in the middle, and engineered cementitious composites （ECC） at the bottom. To better characterize the material properties under dynamic loading, interface properties of the composite were investigated through direct shear test and also used to validate the interface model. Strain rate effects of the asphalt concrete were also studied and both compressive and tensile dynamic increase factor （DIF） curves were improved based on split Hopkinson pressure bar （SHPB） test. A full-scale field blast test investigated the blast behavior of the composite materials. The numerical model was established by taking into account the strain rate effect of all concrete materials. Furthermore, the interface properties were also considered into the model. The numerical simulation using nonlinear finite element Both the numerical and field blast test indicated that the software LS-DYNA agrees closely with the experimental data SHS composite exhibited high resistance against blast loading

关键词： high strength concrete (SHS) engineered cementitious composite interface blast test strain rate effect

Optimization of Line Configuration and Balancing for Flexible Machining Lines

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2016年第3期29卷 579-587页

作者： liu xuemei LI Aiping CHEN Zurui College of Mechanical Engineering Tongji University

Line configuration and balancing is to select the type of line and allot a given set of operations as well as machines to a sequence of workstations to realize high-efficiency production. Most of the current researches for machining line configuration and balancing problems are related to dedicated transfer lines with dedicated machine workstations. With growing trends towards great product variety and fluctuations in market demand, dedicated transfer lines are being replaced with flexible machining line composed of identical CNC machines. This paper deals with the line configuration and balancing problem for flexible machining lines. The objective is to assign operations to workstations and find the sequence of execution, specify the number of machines in each workstation while minimizing the line cycle time and total number of machines. This problem is subject to precedence, clustering, accessibility and capacity constraints among the features, operations, setups and workstations. The mathematical model and heuristic algorithm based on feature group strategy and polychromatic sets theory are presented to find an optimal solution. The feature group strategy and polychromatic sets theory are used to establish constraint model. A heuristic operations sequencing and assignment algorithm is given. An industrial case study is carried out, and multiple optimal solutions in different line configurations are obtained. The case studying results show that the solutions with shorter cycle time and higher line balancing rate demonstrate the feasibility and effectiveness of the proposed algorithm. This research proposes a heuristic line configuration and balancing algorithm based on feature group strategy and polychromatic sets theory which is able to provide better solutions while achieving an improvement in computing time.

关键词： flexible machining line line balancing line configuration constraints model optimization

Recent advances in understanding of the epigenetic regulation of plant regeneration

在线全文

学校读者我要写书评

暂无评论

aBIOTECH 2023年第1期4卷 31-46页

作者： xuemei liu Kehui Zhu Jun Xiao Key Laboratory of Plant Cell and Chromosome Engineering Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China CAS-JIC Centre of Excellence for Plant and Microbial Science(CEPAMS) Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China

Ever since the concept of"plant cell totipotency"was first proposed in the early twentieth century,plant regeneration has been a major focus of ***-mediated organogenesis and genetic transformation are important topics in both basic research and modern *** studies in the model plant Arabidopsis thaliana and other species have expanded our understanding of the molecular regulation of plant *** hierarchy of transcriptional regulation driven by phytohormone signaling during regeneration is associated with changes in chromatin dynamics and DNA ***,we summarize how various aspects of epigenetic regulation,including histone modifications and variants,chromatin accessibility dynamics,DNA methylation,and microRNAs,modulate plant *** the mechanisms of epigenetic regulation are conserved in many plants,research in this field has potential applications in boosting crop breeding,especially if coupled with emerging single-cell omics technologies.

关键词： Plant regeneration Epigenetic regulation Arabidopsis Crop breeding

Mechanism of conductive powder microstructure evolution in the process of SPS

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

Science China(Technological Sciences) 2005年第3期48卷 258-269页

作者： SONG Xiaoyan liu xuemei ZHANG Jiuxing College of Materials Science and Engineering Key Laboratory of Advanced Functional Materials of Ministry of Education of ChinaBeijing University of TechnologyBeijing 100022China

Spark plasma sintering(SPS)is an advanced sintering technology that has been recently developed in the *** to many reports about experimental investigations on the methods of new materials preparation,there are very few systematic studies on the special sintering mechanism of SPS *** the present paper,by using the pure electrolytic copper powders as the raw material,a series of sintering experiments have been designed and carried *** evolution of the powder microstructures during SPS has been systematically studied,and for the first time a“self-adjusting mechanism”of the microstructure evolution is proposed,from which the essential for the advantages of materials preparation by SPS in the respects of high density,homogeneity and fine grain structure can be well *** addition,the changes of the relative density during SPS are quantitatively predicted by a theoretical model and confirmed by the experimental measurements.

关键词： spark plasma sintering microstructure evolution sintering mechanism

A 1G-cell floating-gate NOR flash memory in 65 nm technology with 100 ns random access time

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2015年第4期58卷 158-165页

作者： liu LiFang WU Dong liu xuemei HUO ZongLiang liu Ming PAN LiYang Institute of Microelectronics University of Tsinghua Tsinghua National Laboratory for Information Science and Technology Laboratory of Nano-Fabrication and Novel Devices Integrated Technology Institute of MicroelectronicsChinese Academy of Sciences

A 1G-cell NOR flash memory chip has been designed and fabricated successfully with 65 nm technology. To compromise the array efficiency and chip speed, the paper establishes an array model including parasitics of the whole array, and optimizes the sector structure as 512 wordlines(WLs) and 4096 bitlines(BLs).Furthermore, by adding other models of long and thin metal lines, we have analyzed the speed of critical circuit nodes. As a result, the agreement of WL delay between simulation and measurement verifies the accuracy of the array model and lines models. The test results indicate that the chip achieves random access time of 100 ns and page read time of 25 ns under 3.3 V voltage supply.

关键词： NOR flash memory giga-level 65 nm technology array efficiency high speed

Efficiency-first spraying mission arrangement optimization with multiple UAVs in heterogeneous farmland with varying pesticide requirements

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Information Processing in Agriculture 2024年第2期11卷 237-248页

作者： Yang Li Yanqiang Wu Xinyu Xue xuemei liu Yang Xu Xinghua liu Nanjing Institute of Agricultural Mechanization Ministry of Agriculture and Rural AffairsNanjing 210014PR China College of Mechanical&Electronic Engineering Shandong Agricultural UniversityTai'an 271018PR China Key Laboratory of Modern Agricultural Equipment Ministry of Agriculture and Rural AffairsNanjing 210014PR China Shandong Provincial Key Laboratory of Horticultural Machinery and Equipment Tai’an 271018PR China Shandong Provincial Engineering Laboratory of Agricultural Equipment Intellectualization Tai’an 271018PR China

Combining multiple crop protection Unmanned Aerial Vehicles(UAVs)as a team for a scheduled spraying mission over farmland now is a common way to significantly increase ***,given some issues such as different configurations,irregular borders,and especially varying pesticide requirements,it is more important and more complex than other multi-Agent Systems(MASs)in common *** this work,we focus on the mission arrangement of UAVs,which is the foundation of other high-level cooperations,systematically propose Efficiency-first Spraying Mission Arrangement Problem(ESMAP),and try to construct a united problem framework for the mission arrangement of crop protection ***,to characterise the differences in sub-areas,the varying pesticide requirement per unit is well considered based on Normalized Difference Vegetation Index(NDVI).Firstly,the mathematical model of multiple crop-protection UAVs is established and ESMAP is ***,an acquisition method of a farmland’s NDVI map is proposed,and the calculation method of pesticide volume based on NDVI is ***,an improved Genetic Algorithm(GA)is proposed to solve ESMAP,and a comparable combination algorithm is *** simulations for algorithm analysis are carried out within MATLAB,and it is determined that the proposed GA is more efficient and accurate than the ***,a mission arrangement tested with three UAVs was carried out to validate the effectiveness of the proposed GA in spraying *** results illustrated that it performed well,which took only 90.6%of the operation time taken by the combination algorithm.

关键词： Efficiency-first optimization Mission arrangement Multi-UAVs Heterogeneous farmland

Complex regulatory network of Betula BplSPL8 in planta

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

Journal of Forestry Research 2017年第5期28卷 881-890页

作者： Chuang liu Minxiao Guan Xiaoqing Hu Jing Tian xuemei liu College of Life Science Northeast Forestry University Suzhou Micro Diag Biomedicine Co. LtdJiangsu Engineering Research Center for Tumor Molecular Diagnostics

SQUAMOSA-promoter binding protein-like (SPL) proteins are plant-specific transcription factors and participate in different pathways, including the vegetative to reproductive transition, male sterility, biosynthesis of gibberellic acid (GA), plant morphogenesis and response to environmental stress. In this study, we generated transgenic Arabidopsis that overexpressed Betula BplSPL8 and confirmed that BplSPL8 is a transcription factor with transcriptional activation activity and is located in the nucleus. Functional analysis of BplSPL8 showed that it is involved in regulating different development processes: (1) BplSPL8 can delay flowering by reducing sensitivity to GA under short days; (2) BplSPL8 controls the number and morphogenesis of leaves, including up-rolling leaves under long days and folded leaves mediated by GA under short days; (3) BplSPL8 can promote root elongation during late development of roots and inhibit lateral root formation; (4) BplSPL8 may be involved in regulating carotenoid biosynthesis and secretion metabolism. These results show that there is a complex regulatory network for the SPL family genes that is mediated by other components and may provide a new insights for the functional research of SPL genes.

关键词： Birch Root SQUAMOSA-promoter binding protein-like Transgenic Carotenoid

Dissecting the novel abilities of aripiprazole: The generation of anti-colorectal cancer effects by targeting Gαq via HTR2B

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2023年第8期13卷 3400-3413页

作者： Haowei liu Qiuming Huang Yunqi Fan Bo Li xuemei liu Changhua Hu College of Pharmaceutical Sciences Southwest UniversityChongqing 400715China NMPA Key Laboratory for Quality Monitoring of Narcotic Drugs and Psychotropic Substances Chongqing Institute for Food and Drug ControlChongqing 401121China

Colorectal cancer(CRC)is a type of malignant tumor that seriously threatens human health and life,and its treatment has always been a difficulty and hotspot in ***,this study for the first time reports that antipsychotic aripiprazole(Ari)against the proliferation of CRC cells both in vitro and in vivo,but with less damage in normal colon ***,the results showed that5-hydroxytryptamine 2B receptor(HTR2B)and its coupling protein G protein subunit alpha q(Gaq)were highly distributed in CRC *** had a strong affinity with HTR2B and inhibited HTR2B downstream *** of HTR2B signaling suppressed the growth of CRC cells,but HTR2B was not found to have independent anticancer ***,the binding of Gaq to HTR2B was decreased after Ari *** of Gaq not only restricted CRC cell growth,but also directly affected the antiCRC efficacy of ***,an interaction between Ari and Gaq was found in that the mutation at amino acid 190 of Gaq reduced the efficacy of ***,these results confirm that Gaq coupled to HTR2B was a potential target of Ari in mediating CRC ***,this study provides a novel effective strategy for CRC therapy and favorable evidence for promoting Ari as an anticancer agent.

关键词： Aripiprazole 5-Hydroxytryptamine receptor 5-Hydroxytryptamine 2B receptor G protein subunit alpha q Colorectal cancer Phosphoinositide 3-kinase/theserine threoninekinaseAKT Extracellularregulated protein kinases

SEMI-FRAGILE WATERMARKING ALGORITHM FOR IMAGE TAMPERS LOCALIZATION AND RECOVERY

在线全文

学校读者我要写书评

暂无评论

Journal of Electronics(China) 2008年第3期25卷 343-351页

作者： Jiang xuemei liu Quan School of Information Engineering Wuhan University of Technology Wuhan 430070 China

Two watermarks are embedded into the original image. One is the authentication watermark generated by secret key, which is embedded into the sub-LSB （Least Significant Bit） of the original image for tamper localization; the other is the recovery watermark for tamper recovering. The original image is divided into 8 x 8 blocks and each block is transformed by Discrete Cosine Transform （DCT）. For each block, some lower frequency DCT coefficients are chosen to be quantized and binary encoded so as to gain the recovery watermark of each block, and the recovery watermark is embedded into the LSB of another block by chaos encryption and authentication chain technology. After the two watermarks being detected, the location of any minute changes in image can be detected, and the tampered image data can be recovered effectively. In the paper, the number of coefficients and their bit lengths are carefully chosen in order to satisfy with the payload of each block and gain the capability of self-recovering. The proposed algorithm can well resist against possible forged attacks. Experimental results show that the watermark generated by the proposed algorithm is sensitive to tiny changes in images, and it has higher accuracy of tamper localization and good capability of the tamper recovery.

关键词： Image authentication Tamper localization Image recovery Semi-fragile watermark