检索结果-南通市图书馆

Acta Mechanica Sinica 2021年第4期37卷 570-588,I0001页

作者： Zhiqiang Yang Yi Sun yizhi liu Junzhi Cui Department of Astronautic Science and Mechanics Harbin Institute of TechnologyHarbin 150001China Academy of Mathematics and Systems Science LSECICMSECChinese Academy of SciencesBeijing 100190China

A novel statistical second-order reduced multiscale(SSRM)approach is established for nonlinear composite materials with random distribution of *** these composites considered in this work,the complex microstructure of grains,including their shape,orientation,size,spatial distribution,volume fraction and so on,results in changing of the macroscopic mechanical *** first-and second-order unit cell functions based on two-scale asymptotic expressions are constructed at ***,the expected homogenized parameters are defined,and the nonlinear homogenization equation on global structure is established,***,an effective reduced model format for analyzing second-order nonlinear unit cell problem with less computation cost is introduced in ***,some numerical examples for the materials with varying distribution models are evaluated and compared with the data by theoretical models and experimental *** examples illustrate that the proposed SSRM approaches are effective for predicting the macroscopic properties of the random composite materials and supply a potential application in actual engineering computation.

关键词： SSRM algorithms Reduced order homogenization Homogenization Random composites

Simulator of pyroshock environment and effect rules of its adjustable parameters

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 Journal of Aeronautics 2020年第2期33卷 609-620页

作者： Hongda ZHAO Jifeng DING Wei liu Zhiwei HAO Yi SUN Qiuhua ZHANG yizhi liu School of Astronautics Harbin Institute of TechnologyHarbin 150001China Institute of Spacecraft System Engineering China Academy of Space TechnologyBeijing 100094China

During the launching of spacecraft,the on-board devices will undergo a series of pyroshock *** order to verify the reliability of these devices under these pyroshock environments,all of them are needed to take the shock test before *** paper has carried out an in-depth research on the simulation method of the pyroshock based on the true explosive *** this study,a simulator containing multiple adjustment parameters is presented and the safety is considered by the design of the protective *** the working process of this setup is simulated with the explicit dynamic codes *** more,the effects of the adjustment parameters on the three factors of shock Response Spectrum(SRS)of the resonant board are explored *** rules achieved in this paper are verified by a typical *** results indicate that the improved simulator can avoid the danger of explosive and make full use of the advantage of actual explosive *** the test condition can be quickly realized at the simulator according to the effect rules of the three adjustable parameters.

关键词： Adjustable parameters Maximum Expected Flight Environment(MEFE) Protective cover Pyroshock Shock Response Spectrum(SRS)

Fast approximate matching of binary codes with distinctive bits

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2015年第5期9卷 741-750页

作者： Chenggang Clarence YAN Hongtao XIE Bing ZHANG Yanping MA Qiong DAI yizhi liu Institute of Information Engineering Chinese Academy of Sciences National Engineering Laboratory for Information Security Technologies Beijing 100093 China Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China Department of Automation Tsinghua University Beijing 100083 China School of Physics Beijing Institute of Technology Beijing 100081 China School of Information Science and Engineering Ocean University of China Qingdao 266100 China School of Computer Science and Engineering Hunan University of Science and Technology Xiangtan 411201 China

Although the distance between binary codes can be computed fast in Hamming space, linear search is not practical for large scale datasets. Therefore attention has been paid to the efficiency of performing approximate nearest neighbor search, in which hierarchical clustering trees （HCT） are widely used. However, HCT select cluster centers randomly and build indexes with the entire binary code, this degrades search performance. In this paper, we first propose a new clustering algorithm, which chooses cluster centers on the basis of relative distances and uses a more homogeneous partition of the dataset than HCT has to build the hierarchical clustering trees. Then, we present an algorithm to compress binary codes by extracting distinctive bits according to the standard deviation of each bit. Consequently, a new index is proposed using compressed binary codes based on hierarchical decomposition of binary spaces. Experiments conducted on reference datasets and a dataset of one billion binary codes demonstrate the effectiveness and efficiency of our method.

关键词： binary codes approximate nearest neighbor search hierarchical clustering index

Fractional partial differential equation denoising models for texture image

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2014年第7期57卷 184-202页

作者： PU YiFei SIARRY Patrick ZHOU Jiliu liu YiGuang ZHANG Ni HUANG Guo liu yizhi School of Computer Science and Technology Sichuan University Universit de Paris 12 (LiSSi E.A.3956) 61 av.du Gnral de Gaulle94010 CRETEIL CedexFrance Library of Sichuan University Sichuan University Computer Science College Leshan Normal University Wu Yuzhang Honors College of Sichuan University

In this paper,a set of fractional partial differential equations based on fractional total variation and fractional steepest descent approach are proposed to address the problem of traditional drawbacks of PM and ROF multi-scale denoising for texture *** extending Green,Gauss,Stokes and Euler-Lagrange formulas to fractional field,we can find that the integer formulas are just their special case of fractional *** order to improve the denoising capability,we proposed 4 fractional partial differential equation based multiscale denoising models,and then discussed their stabilities and convergence *** deduction and experimental evaluation demonstrate the stability and astringency of fractional steepest descent approach,and fractional nonlinearly multi-scale denoising capability and best value of parameters are discussed *** experiments results prove that the ability for preserving high-frequency edge and complex texture information of the proposed denoising models are obviously superior to traditional integral based algorithms,especially for texture detail rich images.

关键词： fractional Green formula fractional Euler-Lagrange equation fractional steepest descent approach fractional extreme points fractional total variation fractional differential mask.

Biodistribution characteristics of ^(188)Re-TSC after TAE in rabbits bearing VX_2 liver tumor

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2009年第2期20卷 106-110页

作者： ZHANG Bin WU Yiwei JIN Yonghai liu yizhi LUO Xianwen FAN Wo School of Radiation Medicine and Public Health Soochow University Suzhou 215123 China Department of Nuclear Medicine the First Affiliated Hospital of Soochow University Suzhou 215006 China Department oflnterventional Radiology the First Affiliated Hospital of Soochow University Suzhou 215006 China

188Re-tin sulfur colloid(TSC) was prepared to compare its biodistribution characteristics with 188Re-macroaggregates album(MAA) after transhepatic arterial embolization(TAE) in rabbits bearing VX2 liver *** efficiencies of the 188Re-TSC and 188Re-MAA were 99.94%±0.04% and 99.95%±0.03%,respectively,and they were stable for 72 h in human *** and biodistribution in 31 rabbits bearing VX2 liver tumor after transcatherter hepatic arterial injection of the radiopharmaceuticals were performed,and relevant activity accumulated mostly in the *** percentage of the injected dose per gram of wet tissue(%ID/g) of 188Re-TSC and 188Re-MAA were *** uptake of 188Re-TSC at 1 h and 24 h were 24.32%±11.93% and 21.88%±18.29%,and the radioactive ratios of tumor/liver were 70.89±19.58 and 17.42±13.96,*** uptake of 188Re-MAA at 1 h and 24 h were 38.78%±30.23% and 15.98%±26.64%,and the radioactive ratio of tumor/liver of 188Re-MAA were 39.71±25.06 and 8.13±4.61,respectively.188Re-TSC is a potential radiopharmaceutical for the therapy of tumors.

关键词：肝肿瘤生物特征栓塞轴承甲基丙烯酸放射性药物铼糖

Fusing Spatio-Temporal Contexts into DeepFM for Taxi Pick-Up Area Recommendation

在线全文

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2023年第6期45卷 2505-2519页

作者： yizhi liu Rutian Qing Yijiang Zhao Xuesong Wang Zhuhua Liao Qinghua Li Buqing Cao School of Computer Science and Engineering Hunan University of Science and TechnologyXiangtan411201China Northwestern Institute on Complex Systems Northwestern UniversityEvanstonIL60208USA Key Laboratory of Knowledge Processing and Networked Manufacturing in Hunan Province Xiangtan411201China

Short-term GPS data based taxi pick-up area recommendation can improve the efficiency and reduce the *** how to alleviate sparsity and further enhance accuracy is still *** at these issues,we propose to fuse spatio-temporal contexts into deep factorization machine(STC_DeepFM)offline for pick-up area recommendation,and within the area to recommend pick-up points online using factorization machine(FM).Firstly,we divide the urban area into several grids with equal ***-temporal contexts are destilled from pick-up points or points-of-interest(POIs)belonged to the preceding ***,the contexts are integrated into deep factorization machine(DeepFM)to mine high-order interaction relationships from *** a novel algorithm named STC_DeepFM is presented for offline pick-up area ***,we devise the architecture of offline-to-online(O2O)recommendation respectively based on DeepFM and FM model in order to tradeoff the accuracy and *** experiments are designed on the DiDi dataset to evaluate step by step the performance of spatio-temporal contexts,different recommendation models,and the O2O *** results show that the proposed STC_DeepFM algorithm exceeds several state-of-the-art methods,and the O2O architecture achieves excellent real-time performance.

关键词： Location-based service(LBS) trajectory data mining offline-toonline(O2O)recommendation deep factorization machine(DeepFM) spatiotemporal context

Pigment Epithelium-derived Factor in Cataractous Aqueous Humor and Lens Epithelial Cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

眼科学报 2006年第1期22卷 40-46,53页

作者： Tian liu yizhi liu Mingxing Wu Zhongshan Ophthalmic Center Sun Yat-sen University Guangzhou China 510060

Purpose: To study the characteristics of PEDF in cataractous aqueous humor and its expression in human lens epithelium. Methods: The PEDF concentration in the aqueous humor was measured by enzyme -linked immunosorbent assay in senile (130cases) and congenital (18cases) cataract patients who underwent cataract phacoemulsification extraction surgery. Anterior lens capsular specimens were obtained from these patients to count lens epithelial cells (LEC) density. The Lens Opacities Classification System Ⅲ was used to classify the senile cataracts as cortical, nuclear, posterior subcapsular and mixed types of opacity, and quantitative analysis of the nuclear opacities was performed by Pentacam Scheimpflug imaging system. Anterior lens capsular specimens from another senile (10cases) and congenital (10cases) cataract were collected for immunofluorescence with polyclonal antibodies specific to human pigment epithelium -derived factor (PEDF). Results:The mean aqueous level of PEDF was(178. 9±87. 5)ng/ml, and there was negative linear correlation of PEDF level and age (r=0. 811, P<0. 001). In senile cases, the aqueous PEDF concentration decreased with increasing nuclear opacities (r=0. 447, P < 0.01) , and the mean PEDF level in nuclear cataract was significantly lower than that in posterior subcapsular opacity (P < 0.01) . PEDF immunostaining was detected in LEC of all capsular specimens. Conclusion : The PEDF level in human aqueous humor is related to age, types of cataracts and lens opacity. PEDF also express in human LEC. The study results suggest PEDF may regulate and/or protect LEC by paracrine and autocrine, and lack of PEDF may play a role in cataractogenesis.

关键词：色素上皮液体上皮细胞眼科

D609 protects retinal pigmented epithelium as a potential therapy for age-related macular degeneration

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2020年第1期5卷 2280-2291页

作者： Bowen Wang Li Wang Sijie Gu Yankun Yu Huaxing Huang Kunlun Mo He Xu Fanzhu Zeng Yichen Xiao Lulu Peng Chunqiao liu Nan Cao yizhi liu Jin Yuan Hong Ouyang State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangzhou 510623China Program of Stem Cells and Regenerative Medicine Fifth Affiliated HospitalZhongshan School of MedicineSun Yat-Sen UniversityGuangdong 510080China

Accumulated oxidative damage may lead to irreversible retinal pigmented epithelium(RPE)cell death,which is considered to be the primary cause of dry age-related macular degeneration(AMD),leading to blindness in the ***,an effective therapy for this disease is ***,we described a robust high-content screening procedure with a library of 814 protective compounds and found that D609 strongly protected RPE cells from sodium iodate(SI)-induced oxidative cell death and prolonged their healthy survival.D609 effectively attenuated excessive reactive oxygen species(ROS)and prevented severe mitochondrial loss due to oxidative stress in the RPE ***,the potent antioxidative effects of D609 were not achieved through its own reducibility but were primarily dependent on its ability to increase the expression of *** injection of this small water-soluble molecule also showed an explicit protective effect of the RPE layer in an SI-induced AMD mouse *** findings suggested that D609 could serve as a novel antioxidative protector of RPE cells both in vitro and in vivo and unveiled a novel antioxidative mechanism of D609,which may ultimately have clinical applications for the treatment of AMD.

关键词： D609 degeneration protective

Application of communication program between atomic absorption spectrometer and electronic balance for iron content determination of the galvanneal coating

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Baosteel Technical Research 2021年第3期15卷 38-41页

作者： WANG Jingjing ZHAO Bo liu yizhi Products&Technique Management Department Baoshan Iron&Steel Co.Ltd.Shanghai 201900China

At present,iron content in a galvanneal coating is determined by an atomic absorption spectrometer(AAS)in *** mass of a sample is recorded by operators two times on paper,then the mass of the coating is manually calculated and input in a *** the aid of a communication program between an AAS and an electronic balance(EB),the above process can be ***,the mass of a sample is sent to a computer by the ***,the mass of the coating is calculated by the computer ***,the iron mass is uploaded to the communication program,and the iron content can also be calculated *** such,the modified process is more efficient.

关键词： galvanneal steel sheet iron content automation communication program

Effects of acupuncture on serotonin, histamine, substance P, and tryptase levels at sensitized points in model rats with knee osteoarthritis

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medical Sciences 2024年第4期11卷 500-512页

作者： Yang, Jiayi Wang, Zidong Jiang, Jing Tian, Huiling Wang, Shun liu, yizhi Cao, Zumao Yang, Changqing Joseph Li, Zhigang School of Acupuncture Moxibustion and Tuina Beijing University of Chinese Medicine School of Nursing Beijing University of Chinese Medicine School of Traditional Chinese Medicine Capital Medical University Third Affiliated Hospital of Beijing University of Chinese Medicine Dongzhimen Hospital Key Laboratory Beijing University of Chinese Medicine American Institute of Mental Health in Traditional Chinese Medicine

Objective: To elucidate the differences in manual acupuncture effectiveness at sensitized points by investigating the mechanisms of local skin action at different sensitization points in rats with knee osteoarthritis (KOA). Methods: Forty Sprague–Dawley rats were equally divided into control, model (1 mg of monoiodoacetate into the right knee joint cavity), sham operation, manual acupuncture at right Tianjing acupoint (MAR-SJ 10), and left SJ 10 groups. Safranine-O and fast green staining were used to assess the modeling. The morphological and functional changes in mast cells (MCs) were assessed during acupoint sensitization using toluidine blue and immunofluorescence staining. The levels of serotonin, histamine, substance P (SP), and tryptase at skin acupoints and serum levels of IL-β, IL-6, and TNF-α were detected using ELISA. Results: After 14 days of treatment, the number of MCs and their degranulation rates were statistically higher in the model group than in the control group (both P < .001). After applying acupuncture, the levels of 5-HT, HA, and SP at skin acupoints were lower than those in the model group (all P < .05), and tryptase level was higher (both P < .05). Tryptase level was higher on the skin at the MAL-SJ 10 acupoint than that on the MAR-SJ 10 acupoint (P = .004). Compared with the model group, the serum levels of IL-1β, IL-6, and TNF-α in the MAR-SJ 10 and MAL-SJ 10 groups were lower (all P < .05). Conclusion: Acupuncture at KOA-sensitized acupoints mitigates joint injury in KOA rats and may bidirectionally regulate local MCs of these acupoints. This finding not only enhances the reference value of sensitizing points in clinical diagnosis and treatment, but also contributes to the understanding of the biological mechanisms underlying acupuncture intervention at sensitizing points. © 2024 Beijing University of Chinese Medicine

关键词： Acupoint sensitization Acupuncture Histamine Knee osteoarthritis Mast cells Serotonin Substance P Tryptase