检索结果-南通市图书馆

Thermal effects on prediction accuracy of dense granite mechanical behaviors using modified maximum tangential stress criterion

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2023年第7期15卷 1734-1748页

作者： Gan feng Chun zhu Xiaochuan Wang Shibin Tang College of Water Resource and Hydropower Sichuan UniversityChengdu610065China Key Laboratory of Deep Earth Science and Engineering(Sichuan University) Ministry of EducationChengdu610065China Hubei Key Laboratory of Waterjet Theory and New Technology Wuhan UniversityWuhan430072China School of Earth Sciences and Engineering Hohai UniversityNanjing210098China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian116024China

Thermally-induced changes in the fracture properties of geological reservoir rocks can influence their stability,transport characteristics,and performance related to various deep subsurface energy *** modified maximum tangential stress(MMTS)criterion is a classical theory for predicting the fracture instability of ***,there is a lack of research on the accuracy of MMTS theory when rocks are subjected to different *** this study,mechanical theoretical analysis and failure and fracture mechanics experiments of granite under the influence of temperatures ranging from 20℃to 600℃are carried *** results showed that the theoretical estimated value of MMTS differs significantly from the experimental data at 20℃-600℃.The Keff/KIC ratio is less than the experimental test value due to the critical crack growth radius(rc)estimated by the conventional method being larger than the critical crack growth radius(rce)derived from the experimental *** temperatures affect the fracture process zone size of fine-grained,compact granite,and the MMTS theoretical estimation ***,it is essential to modify the critical crack growth radius for MMTS theory to accurately predict the fracture characteristics of thermally damaged *** addition,the variation of the rock’s me-chanical properties with temperature and its causes are *** 20℃and 600℃,the mode-Ⅰ,mode-Ⅱ,and mixed-mode(a-30℃and 45℃)fracture toughness and Brazilian splitting strength of the granite decrease by 80%and 73%,*** the rock is heated above 400℃,its deterioration is mainly caused by a widening of its original cracks.

关键词： Underground geotechnical engineering Hot dry rock(HDR) Geothermal temperature Fracture behavior

Study on the Total Synthesis of Ecteinascidin 743 and Its Analogues--Construction of A Pentacyclic Intermediate

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

Chinese Chemical Letters 2003年第1期14卷 1-2页

作者： Ye feng TANG Zhan zhu LIU 等 InstituteofMatcriaMcdica ChineseAcademyofMedicalSciences&PekingUnionMedicalCollegeBeijing100050 InstituteofMatcriaMcdica ChineseAcademyofMedicalSciences&PekingUnionMedicalC

A concise and efficient synthesis of the pentacyclic intermediate 1, as a simple model compound of Ecteinascidin 743 and its analogues, is described.

关键词： Pentacyclic intermediate ecteinascidin 743 L-dopa.

Multiple input self-organizing-map ResNet model for optimization of petroleum refinery conversion units

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2023年第6期17卷 759-771页

作者： Jiannan zhu Vladimir Mahalec Chen Fan Minglei Yang feng Qian Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China Department of Chemical Engineering McMaster UniversityHamiltonOntario L8S 4L8Canada Engineering Research Center of Process System Engineering Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

This work introduces a deep-learning network,i.e.,multi-input self-organizing-map ResNet(MISR),for modeling refining units comprised of two reactors and a separation *** model is comprised of self-organizing-map and the neural network *** self-organizing-map part maps the input data into multiple two-dimensional planes and sends them to the neural network *** the neural network part,residual blocks enhance the convergence and accuracy,ensuring that the structure will not be overfitted *** of the MISR model of hydrocracking unit also benefits from the utilization of prior knowledge of the importance of the input variables for predicting properties of the *** results show that the proposed MISR structure predicts more accurately the product yields and properties than the previously introduced self-organizing-map convolutional neural network model,thus leading to more accurate optimization of the hydrocracker ***,the MISR model has smoother error convergence than the previous *** operating conditions have been determined via multi-round-particle-swarm and differential evolution *** experiments show that the MISR model is suitable for modeling nonlinear conversion units which are often encountered in refining and petrochemical plants.

关键词： hydrocracking convolutional neural networks self-organizing map deep learning data-driven optimization

Improved observation of colonized roots reveals the regulation of arbuscule development and senescence by drought stress in the arbuscular mycorrhizae of citrus

在线全文

学校读者我要写书评

暂无评论

Horticultural Plant Journal 2024年第2期10卷 425-436页

作者： Xilong Yin Wei Zhang Zengwei feng Guangda feng Honghui zhu Qing Yao College of Horticulture South China Agricultural UniversityKey Laboratory of Biology and Genetic Improvement of Horticultural Crops(South China)Ministry of Agriculture and Rural AffairsGuangdong Province Key Laboratory of Microbial Signals and Disease ControlGuangzhouGuangdong 510642China Key Laboratory of Agricultural Microbiomics and Precision Application Ministry of Agriculture and Rural AffairsGuangdong Provincial Key Laboratory of Microbial Culture Collection and ApplicationKey Laboratory of Agricultural MicrobiomicsState Key Laboratory of Applied Microbiology Southern ChinaGuangdong Microbial Culture Collection Center(GDMCC)Institute of MicrobiologyGuangdong Academy of SciencesGuangzhouGuangdong 510070China

Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to drought stress, remain unclear, which is mainly due to the difficulty in clearing and staining lignified roots with the conventional method. Here, we improved the observation of colonized roots of citrus plants with the sectioning method, which enabled the clear observation of AM fungal structures. Furthermore, we investigated the effects of one week of drought stress on arbuscule development and senescence with the sectioning method. Microscopy observations indicated that drought stress significantly decreased mycorrhizal colonization (F%and M%) although it did not affect plant growth performance. Fluorescence probes (WGA 488 and/or Nile red) revealed that drought stress inhibited arbuscule development by increasing the percentage of arbuscules at the early stage and decreasing the percentages of arbuscules at the midterm and mature stages. Meanwhile, drought stress accelerated arbuscule senescence, which was characterized by the increased accumulation of neutral lipids. Overall, the sectioning method developed in this study enables the in-depth investigation of arbuscule status, and drought stress can inhibit arbuscule development but accelerate arbuscule senescence in the colonized roots of citrus plants. This study paves the way to elaborately dissecting the arbuscule dynamics in the roots of fruit tree species in response to diverse abiotic stresses.

关键词： Arbuscular mycorrhizae Citrus Drought stress Arbuscule development Arbuscule senescence Fruit tree species

Conditional Random Field Tracking Model Based on a Visual Long Short Term Memory Network

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology 2020年第4期18卷 308-319页

作者： Pei-Xin Liu Zhao-Sheng zhu Xiao-feng Ye Xiao-feng Li School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731

In dense pedestrian tracking,frequent object occlusions and close distances between objects cause difficulty when accurately estimating object *** this study,a conditional random field tracking model is established by using a visual long short term memory network in the three-dimensional(3D)space and the motion estimations jointly performed on object trajectory *** visual field information is added to the long short term memory network to improve the accuracy of the motion related object pair selection and motion *** address the uncertainty of the length and interval of trajectory segments,a multimode long short term memory network is proposed for the object motion *** tracking performance is evaluated using the PETS2009 *** experimental results show that the proposed method achieves better performance than the tracking methods based on the independent motion estimation.

关键词： Conditional random field(CRF) long short term memory network(LSTM) motion estimation multiple object tracking(MOT)

Shining in the dark:the big world of small peptides in plants

在线全文

学校读者我要写书评

暂无评论

aBIOTECH 2023年第3期4卷 238-256页

作者： Yan-Zhao feng Qing-feng zhu Jiao Xue Pei Chen Yang Yu Guangdong Key Laboratory of Crop Germplasm Resources Preservation and Utilization Key Laboratory of South China Modern Biological Seed IndustryMinistry of Agriculture and Rural AffairsAgro-Biological Gene Research CenterGuangdong Academy of Agricultural SciencesGuangzhou 510640China

Small peptides represent a subset of dark matter in plant *** differential expression patterns and modes of action,small peptides act as important regulators of plant growth and devel*** the past 20 years,many small peptides have been identified due to technical advances in genome sequencing,bioinformatics,and chemical *** this article,we summarize the classifi-cation of plant small peptides and experimental strategies used to identify them as well as their potential use in agronomic *** review the biological functions and molecular mechanisms of small peptides in plants,discuss current problems in small peptide research and highlight future research directions in this *** review provides crucial insight into small peptides in plants and will contribute to a better understanding of their potential roles in biotechnology and agriculture.

关键词： Small peptide Biological function Regulatory mechanism Crop improvement

Power and efficiency optimizations of Maisotsenko-Atkinson,Dual and Miller cycles and performance comparisons with corresponding traditional cycles

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) 2023年第12期66卷 3393-3411页

作者： CHEN LinGen zhu FuLi SHI ShuangShuang GE YanLin feng HuiJun Institute of Thermal Science and Power Engineering Wuhan Institute of TechnologyWuhan 430205China Fute Technology Hangzhou 310012China Hubei Provincial Engineering Technology Research Center of Green Chemical Equipment Wuhan 430205China School of Mechanical&Electrical Engineering Wuhan Institute of TechnologyWuhan 430205China

Maisotsenko cycle(M-cycle)has been combined with some cooling and power cycles,and behaves important thermodynamic ***-time thermodynamics(FTT)is applied to establish three endoreversible models of M-Atkinson,M-Dual and M-Miller *** are performed based on models of endoreversible Atkinson,Dual and Miller cycles by combing FTT model with M-cycle *** output(POW)and thermal efficiency(TEF)of those M-cycles are studied and optimized by numerical *** maximum power output(MPO)and the corresponding pressure ratio and TEF,the maximum TEF and the corresponding pressure ratio and POW,as well as optimal ranges of pressure ratio are *** of mass flow rate of circulating water injection,initial cycle temperature and maximum cycle temperature on cycle POW,TEF and optimal pressure ratio range are *** optimal performances of the three M-cycles are compared with those of traditional Atkinson,Dual and Miller cycles under the same *** results show that for the three M-cycles,end temperature of adiabatic expansion process of M-cycle is less than that of the corresponding traditional cycle,POW and TEF at arbitrary pressure ratio of M-cycle are much higher than those of the corresponding traditional cycle,and performance characteristics of M-cycles are superior to those of the corresponding traditional cycles.

关键词： Maisotsenko-Atkinson cycle Maisotsenko-Dual cycle Maisotsenko-Miller cycle power efficiency finite time thermodynamic optimization

A general strategy towards improving the strength and thermal shock resistance of glass-ceramics through microstructure regulation

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第25期120卷 139-149页

作者： Min feng Chengyang Jiang Minghui Chen Shenglong zhu Fuhui Wang Shenyang National Laboratory for Materials Science Northeastern UniversityShenyang 110819China Chinese Academy of Sciences Institute of Metal ResearchShenyang 110016China

Glass-ceramics are usually obtained through controlled *** this work,we propose a new strategy to add an appropriate amount of oxide particles to the parent glass to improve the performance of *** amounts of Al_(2)O_(3) or/and CeO_(2) particles were added into a SiO_(2)-Al_(2)O_(3)-ZnOCaO-ZrO_(2)-TiO_(2)based glass,and crystallization behavior,fracture strength,and thermal shock behavior were systematically *** results indicate that with the addition of Al_(2)O_(3) or/and CeO_(2) particles of moderate amount,the unfavorable needle-like ZrSiO_(4),Zn 2 SiO_(4),and CaTiSiO_(5) crystals were largely inhibited when annealed at 900℃ .Accordingly,fracture strength is maintained high after heating at high *** thermal shock resistance is also enhanced *** additive Al_(2)O_(3) is thermodynamically favorable to react with the glass,forming particulate ZnAl_(2)O_(4) instead of precipitating the needle-like crystals of Zn_(2)SiO_(4) and CaTiSiO_(5);while CeO_(2) will combine with ZrO_(2) to form a solid solution and promote the precipitation of primary crystal CaZrTi_(2)O_(7) that will not transform to ZrSiO_(4) with prolonging thermal exposure.

关键词： Non-metallic glasses(silicates) Crystallization Microstructure Mechanical property High-temperature oxidation

Straightforward Guess and Determine Analysis Based on Genetic Algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2022年第5期35卷 1988-2003页

作者： CAO Chunping CEN Zhe feng Xiutao WANG Zhangyi zhu Yamin Department of Computer Science and Technology University of Shanghai for Science and TechnologyShang-hai 200093China Key Laboratory of Mathematics Mechanization Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Cyber Science and Engineering Wuhan UniversityWuhan 430072China School of Science Xi'an Technological UniversityXi'an 710021China

With the development of artificial intelligence,the genetic algorithm has been widely used in many *** cryptography,the authors find it is natural to code an individual and design its fitness in a genetic algorithm for a straightforward guess and determine analysis(SGDA,in short).Based on this observation,the authors propose an SGDA based on genetic *** it with the other three SGDAs based on exhaustive search,MILP method and CPP method respectively,the authors illustrate its effectiveness by three stream ciphers:Small scale SNOW 2.0,medium scale Enocoro-128v2 and large scale *** results show our method is significantly superior to them,especially for Trivium,the method can find a solution of 165 variables in less than one hour,while the other three methods are not applicable due to its enormous search space of size 2^(619.37).As far as we know,it is a best solution in an SGDA for Trivium so far.

关键词： Enocoro-128v2 genetic algorithm guess and determine analysis SNOW 2.0 trivium