维普中文期刊产品整合服务
897篇 您的检索式:作者名="SHEN Chang"
    题名 作者 年代 出处 被引量
1The Chinese Society of Clinical Oncology(CSCO):Clinical guidelines for the diagnosis and treatment of gastric cancer,2021显示文摘There exist differences in the epidemiological characteristics,clinicopathological features,tumor biological characteristics,treatment patterns,and drug selections between gastric cancer patients from the Eastern and Western countries.The Chinese Society of Clinical Oncology(CSCO)has organized a panel of senior experts specializing in all sub-specialties of gastric cancer to compile a clinical guideline for the diagnosis and treatment of gastric cancer since 2016 and renews it annually.Taking into account regional differences,giving full consideration to the accessibility of diagnosis and treatment resources,these experts have conducted expert consensus judgment on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes in China.The 2021 CSCO Clinical Practice Guidelines for Gastric Cancer covers the diagnosis,treatment,follow-up,and screening of gastric cancer.Based on the 2020 version of the CSCO Chinese Gastric Cancer guidelines,this updated guideline integrates the results ofmajor clinical studies from China and overseas for the past year,focused on the inclusion of research data from the Chinese population for more personalized and clinically relevant recommendations.For the comprehensive treatment of non-metastatic gastric cancer,attentions were paid to neoadjuvant treatment.The value of perioperative chemotherapy is gradually becoming clearer and its recommendation level has been updated.For the comprehensive treatment of metastatic gastric cancer,recommendations for immunotherapy were included,and immune checkpoint inhibitors fromthird-line to the first-line of treatment for different patient groups with detailed notes are provided.Feng-Hua Wang Xiao-Tian Zhang Yuan-Fang Li Lei Tang Xiu-Juan Qu Jie-Er Ying Jun Zhang Ling-Yu Sun Rong-Bo Lin Hong Qiu Chang Wang Miao-Zhen Qiu Mu-Yan Cai QiWu Hao Liu Wen-Long Guan Ai-Ping Zhou Yu-Jing Zhang Tian-Shu Liu Feng Bi Xiang-Lin Yuan Sheng-Xiang Rao Yan Xin Wei-Qi Sheng Hui-Mian Xu Guo-Xin Li Jia-Fu Ji Zhi-Wei Zhou Han Liang Yan-Qiao Zhang Jing Jin Lin Shen Jin Li Rui-Hua Xu 2021Cancer Communications2021,41,8:97
2Evaluation of the effect of partial splenic embolization on platelet values for liver cirrhosis patients with thrombocytopenia显示文摘AIM: To investigate the effect of partial splenic embolization (PSE) on platelet values in liver cirrhosis patients with thrombocytopenia and to determine the effective embolization area for platelet values improvement. METHODS: Blood parameters and liver function indicators were measured on 10 liver cirrhosis patients (6 in Child-Pugh grade A and 4 in grade B) with thrombocytopenia (platelet values < 80 × 103/μL) before embolization. Computed tomography scan was also needed in advance to acquire the splenic baseline. After 2 to 3 d, angiography and splenic embolization were performed. A second computed tomography scan was made to confirm the embolization area after 2 to 3 wk of embolization. The blood parameters of patients were also examined biweekly during the 1 year follow-up period. RESULTS: According to the computed tomography images after partial splenic embolization, we divided all patients into two groups: low (< 30%), and high (≥ 30%) embolization area groups. The platelet values were increased by 3 times compared to baseline levels after 2 wk of embolization in high embolization area group. In addition, there were significant differences in platelet values between low and high embolization area groups. GPT values decreased significantly in all patients after 2 wk of embolization. The improvement in platelet and GPT values still persisted until 1 year after PSE. In addition, 3 of 4 (75%) Child-Pugh grade B patients progressed to grade A after 2 mo of PSE. The complicationrate in < 30% and ≥ 30% embolization area groups was 50% and 100%, respectively. CONCLUSION: Partial splenic embolization is an effective method to improve platelet values and GPT values in liver cirrhosis patients with thrombocytopenia and the ≥ 30% embolization area is meaningful for platelet values improvement. The relationship between the complication rate and embolization area needs further studies.Chi-Ming Lee Ting-Kai Leung Hung-Jung Wang Wei-Hsing Lee Li-Kuo Shen Jean-Dean Liu Chun-Chao Chang Ya-Yen Chen 2007World Journal of Gastroenterology2007,13,4:56
3The Inhibitory Effect of Oridonin on the Growth of Fifteen Human Cancer Cell Lines显示文摘OBJECTIVE To study the inhibitory effect of oridonin on the growth of cancer cells. METHODS Fifteen human cancer cell lines were subjected to various concentrations of oridonin in culture medium. The inhibitory rate of cell growth was measured by the MTT assay, and compared with a negative con- trol and 5-Fu-positive control. RESULTS The 50% inhibiting concentration (IC50) and maximal inhibition (Imax) of oridonin shown by studying the growth of the cancer cell lines were as follows: leukemias (HL60 cells: 3.9 μg/ml and 73.8%, K562 cells: 4.3 μg/ml and 76.2%); esophageal cancers(SHEEC cells: 15.4 μg/ml and 99.2%, Eca109 cells: 15.1 μg/ml and 84.6%, TE1 cells: 4.0 μg/ml and 70.2%); gastric cancers (BGC823 cells: 7.6 μg/ml and 98.7%, SGC7901 cells: 12.3 μg/ml and 85.7%); colon cancers (HT29 cells: 13.6 μg/ml and 97.2%, HCT cells: 14.5 μg/ml and 96.5%); liver cancers (Bel7402 cells: 15.2 μg/ml and 89.2%, HepG2 cells: 7.1 μg/ml and 88.3%); pancreatic cancer (PC3 cells: 11.3 μg/ml and 68.4%); lung cancer (A549 cells: 18.6 μg/ml and 98.0% ); breast cancer (MCF7 cells: 18.4 μg/ml and 84.7%); uterine cervix cancer (Hela cells: 13.7 μg/ml and 98.5%). CONCLUSION Oridonin had a relatively wide anti-tumor spectrum, and a relatively strong inhibitory effect on the growth of the 15 human cancer cells. Inhibitory effects were concentration dependent.Junhui Chen Shaobin Wang Dongyang Chen Guisheng Chang Qingfeng Xin Shoujun Yuan Zhongying Shen 2007Chinese Journal of Clinical Oncology2007,4,1:32
4Shortened Basal Internodes Encodes a Gibberellin 2-Oxidase and Contributes to Lodging Resistance in Rice显示文摘改进住宿抵抗的繁殖半矮子变化被证明了在自从绿 revolution.?However 的来临,增加谷物产量极其成功,在亚洲繁殖半矮子米饭变化的多数主要依赖于 SD1 的变异的等位基因的基因介绍,它编码赤霉素( GA ) 20-oxidase , OsGA20ox2 ,为催化 GA 生合成。这里,我们报导新米饭住宿抵抗基因,弄短的基础 Internodes (SBI ) ,它编码赤霉素 ? 2-oxidase 并且明确地控制灰煤杆的延伸通过撤销的基础 internodes GA 活动。SBI 主要在灰煤杆被表示基础 internodes。基因分析显示 SBI 是影响米饭高度和住宿抵抗的半主导的基因。SBI 突变而产生之遗传的变体显示不同活动并且与米饭变化的高度被联系。与 SBI 等位基因的更高的活动繁殖与改进住宿抵抗和增加的产量产生新米饭变化。SBI 的发现为生产半矮子米饭显型提供一个理想的基因资源并且为与提高的住宿抵抗和高产量引起米饭变化提供有效策略。Chang Liu Jinshan Gui Chenjian Fu Hasi Yu Dongliang Song Junhui Shen Peng Qin Xuanming Liu Bin Han Yuanzhu Yang Laigeng Li 2018Molecular Plant2018,11,2:33
5Terrestrial carbon sinks in China and around the world and their contribution to carbon neutrality显示文摘Enhancing the terrestrial ecosystem carbon sink(referred to as terrestrial C sink) is an important way to slow down the continuous increase in atmospheric carbon dioxide(CO_(2)) concentration and to achieve carbon neutrality target.To better understand the characteristics of terrestrial C sinks and their contribution to carbon neutrality,this review summarizes major progress in terrestrial C budget researches during the past decades,clarifies spatial patterns and drivers of terrestrial C sources and sinks in China and around the world,and examines the role of terrestrial C sinks in achieving carbon neutrality target.According to recent studies,the global terrestrial C sink has been increasing from a source of (-0.2±0.9) Pg C yr^(-1)(1 Pg=1015g)in the 1960s to a sink of (1.9±1.1) Pg C yr^(-1) in the 2010s.By synthesizing the published data,we estimate terrestrial C sink of 0.20–0.25 Pg C yr^(-1) in China during the past decades,and predict it to be 0.15–0.52 Pg C yr^(-1) by 2060.The terrestrial C sinks are mainly located in the mid-and high latitudes of the Northern Hemisphere,while tropical regions act as a weak C sink or source.The C balance differs much among ecosystem types:forest is the major C sink;shrubland,wetland and farmland soil act as C sinks;and whether the grassland functions as C sink or source remains unclear.Desert might be a C sink,but the magnitude and the associated mechanisms are still controversial.Elevated atmospheric CO_(2) concentration,nitrogen deposition,climate change,and land cover change are the main drivers of terrestrial C sinks,while other factors such as fires and aerosols would also affect ecosystem C balance.The driving factors of terrestrial C sink differ among regions.Elevated CO_(2) concentration and climate change are major drivers of the C sinks in North America and Europe,while afforestation and ecological restoration are additionally important forcing factors of terrestrial C sinks in China.For future studies,we recommend the necessity for intensive and long-term ecosystem C monitoring over broad geographic scale to improve terrestrial biosphere models for accurately evaluating terrestrial C budget and its dynamics under various climate change and policy scenarios.Yuanhe Yang Yue Shi Wenjuan Sun Jinfeng Chang Jianxiao Zhu Leiyi Chen Xin Wang Yanpei Guo Hongtu Zhang Lingfei Yu Shuqing Zhao Kang Xu Jiangling Zhu Haihua Shen Yuanyuan Wang Yunfeng Peng Xia Zhao Xiangping Wang Huifeng Hu Shiping Chen Mei Huang Xuefa Wen Shaopeng Wang Biao Zhu Shuli Niu Zhiyao Tang Lingli Liu Jingyun Fang 2022Science China(Life Sciences)2022,65,5:32
6Ratios of T-helper 2 Cells to T-helper 1 Cells and Cytokine Levels in Patients with Hepatitis B显示文摘Ming-Hui Li Dan Zhang Lu Zhang Xiao-Jing Qu Yao Lu Ge Shen Shu-Ling Wu Min Chang Ru-Yu Liu Lei-Ping Hu Hong-Xiao Hao Wen-Hao Hua Shu-Jing Song Gang Wan Shun-Ai Liu Yao Xie 2017Chinese Medical Journal2017,,15:21
7Coordinated flight control of miniature fixed-wing UAV swarms: methods and experiments显示文摘In this paper,we present our recent advances in both theoretical methods and field experiments for the coordinated control of miniature fixed-wing unmanned aerial vehicle(UAV)swarms.We propose a multi-layered group-based architecture,which is modularized,mission-oriented,and can implement large-scale swarms.To accomplish the desired coordinated formation flight,we present a novel distributed coordinated-control scheme comprising a consensus-based circling rendezvous,a coordinated path-following control for the leader UAVs,and a leader-follower coordinated control for the follower UAVs.The current framework embeds a formation pattern reconfiguration technique.Moreover,we discuss two security solutions(inter-UAV collision avoidance and obstacle avoidance)in the swarm flight problem.The effectiveness of the proposed coordinated control methods was demonstrated in field experiments by deploying up to 21 fixed-wing UAVs.Xiangke WANG Lincheng SHEN Zhihong LIU Shulong ZHAO Yirui CONG Zhongkui LI Shengde JIA Hao CHEN Yangguan YU Yuan CHANG Yajing WANG 2019Science China(Information Sciences)2019,62,11:21
8Anchoring mechanism and application of hydraulic expansion bolts used in soft rock roadway floor heave control显示文摘Comparing with the resin bolt, the hydraulic expansion bolt has different anchoring mechanism and application advantage. According to the working mechanism of the hydraulic expansion bolt, its anchoring force is expressed in four forms including support anchoring force, tension anchoring force, expansion anchoring force and tangent anchoring force, and their values can be obtained on the basis of each calculation formula. Among them, the expansion anchoring force, which is the unique anchoring force of the hydraulic expansion bolt, can provide confining pressure to increase the strength of rock. Aiming at solving the problem of stability control in the soft rock roadway in Jinbaotun Coal Mine which has a double layer of 40 U-type sheds and cannot provide enough resistance support to control floor heave, the study reveals the mechanism of floor heave in the soft rock roadway, and designs the reasonable support parameters of the hydraulic expansion bolts. The observed results of floor convergence indicate that the hydraulic expansion bolts can prevent the development and flow of the plastic zone in the floor rock to control floor heave. Research results enrich the control technology in the soft rock roadway.Chang Qingliang Zhou Huaqiang Xie Zhihong Shen Shiping 2013International Journal of Mining Science and Technology2013,23,3:20
9Kinetics of Hepatitis B Surface Antigen Level in Chronic Hepatitis B Patients who Achieved Hepatitis B Surface Antigen Loss during Pegylated Interferon Alpha-2a Treatment显示文摘Ming-Hui Li Lu Zhang Xiao-Jing Qu Yao Lu Ge Shen Shu-Ling Wu Min Chang Ru-Yu Liu Lei-Ping HU Zhen-Zhen Li Wen-Hao Hua Shu-Jing Song Yao Xie 2017Chinese Medical Journal2017,,5:18
10Moving object detection in aerial video based on spatiotemporal saliency显示文摘In this paper,the problem of moving object detection in aerial video is addressed.While motion cues have been extensively exploited in the literature,how to use spatial information is still an open problem.To deal with this issue,we propose a novel hierarchical moving target detection method based on spatiotemporal saliency.Temporal saliency is used to get a coarse segmentation,and spatial saliency is extracted to obtain the object's appearance details in candidate motion regions.Finally,by combining temporal and spatial saliency information,we can get refned detection results.Additionally,in order to give a full description of the object distribution,spatial saliency is detected in both pixel and region levels based on local contrast.Experiments conducted on the VIVID dataset show that the proposed method is effcient and accurate.Shen Hao Li Shuxiao Zhu Chengfei Chang Hongxing Zhang Jinglan 2013Chinese Journal of Aeronautics2013,26,5:18
11Association of Cytokines with Alanine Aminotransferase, Hepatitis B Virus Surface Antigen and Hepatitis B Envelope Antigen Levels in Chronic Hepatitis B显示文摘Ming-Hui Li Yao Lu Lu Zhang Xing-Yue Wang Chong-Ping Ran Hong-Xiao Hao Dan Zhang Xiao-Jing Qu Ge Shen Shu-Ling Wu Wei-Hua Cao Tian-Lin Qi Ru-Yu Liu Lei-Ping Hu Min Chang Wen-Hao Hua Shun-Ai Liu Gang Wan Yao Xie 2018Chinese Medical Journal2018,,15:17
12Plasmacytoid Dendritic Cell Function and Cytokine Network Profiles in Patients with Acute or Chronic Hepatitis B Virus Infection显示文摘Ming-Hui Li Lu Zhang Dan Zhang Wei-Hua Cao Tian-Lin Qi Hong-Xiao Hao Xing-Yue Wang Chong-Ping Ran Xiao-Jing Qu Shun-Ai Liu Yao Lu Ge Shen Shu-Ling Wu Min Chang Ru-Yu Liu Lei-Ping Hu Wen-Hao Hua Gang Wan Jun Cheng Yao Xie 2018Chinese Medical Journal2018,,1:16
13Hepatitis B surface antigen clearance in inactive hepatitis B surface antigen carriers treated with peginterferon alfa-2a显示文摘AIM: To examine the association between interferon(IFN) therapy and loss of hepatitis B surface antigen(HBs Ag) in inactive HBs Ag carriers. METHODS: This was a retrospective cohort study in inactive HBs Ag carriers, who were treatment-naive, with a serum HBs Ag level < 100 IU/m L and an undetectable hepatitis B virus(HBV) DNA level(< 100 IU/m L). All the 20 treated patients received subcutaneous PEG-IFN alfa-2a 180 μg/wk for 72 wk and were then followed for 24 wk. There were 40 untreated controls matched with 96 wk of observation. Serum HBs Ag, HBV DNA, and alanine aminotransferases were monitored every 3 mo in the treatment group and every 3-6 mo in the control group. RESULTS: Thirteen(65.0%) of 20 treated patients achieved HBs Ag loss, 12 of whom achieved HBs Ag seroconversion. Mean HBs Ag level in treated patients decreased to 6.69 ± 13.04 IU/m L after 24 wk of treatment from a baseline level of 26.22 ± 33.00 IU/m L. Serum HBV DNA level remained undetectable(< 100 IU/m L) in all treated patients during the study. HBs Ag level of the control group decreased from 25.72 ± 25.58 IU/m L at baseline to 17.11 ± 21.62 IU/m L at week 96(P = 0.108). In the control group, no patient experienced HBs Ag loss/seroconversion, and two(5.0%) developed HBV reactivation.CONCLUSION: IFN treatment results in HBs Ag loss and seroconversion in a considerable proportion of inactive HBs Ag carriers with low HBs Ag concentrations.Ming-Hui Li Yao Xie Lu Zhang Yao Lu Ge Shen Shu-Ling Wu Min Chang Cai-Qin Mu Lei-Ping Hu Wen-Hao Hua Shu-Jing Song Shu-Feng Zhang Jun Cheng Dao-Zhen Xu 2016World Journal of Hepatology2016,8,15:15
14Cleaning space debris with a space-based laser system显示文摘High-energy pulsed laser radiation may be the most feasible means to mitigate the threat of collision of a space station or other valuable space assets with orbital debris in the size range of 1–10 cm. Under laser irradiation, part of the debris material is ablated and provides an impulse to the debris particle. Proper direction of the impulse vector either deflects the object trajectory or forces the debris on a trajectory through the upper atmosphere, where it burns up. Most research concentrates on ground-based laser systems but pays little attention to space-based laser systems.There are drawbacks of a ground-based laser system in cleaning space debris. Therefore the placement of a laser system in space is proposed and investigated. Under assumed conditions,the elimination process of space debris is analyzed. Several factors such as laser repetition frequency, relative movement between the laser and debris, and inclination of debris particles which may exercise influence to the elimination effects are discussed. A project of a space-based laser system is proposed according to the numerical results of a computer study. The proposed laser system can eliminate debris of 1–10 cm and succeed in protecting a space station.Shen Shuangyan Jin Xing Chang Hao 2014Chinese Journal of Aeronautics2014,27,4:14
15The Predictive Value of Baseline HBs Ag Level and Early Response for HBs Ag Loss in Patients with HBe Ag-positive Chronic Hepatitis B during Pegylated Interferon Alpha-2a Treatment显示文摘Objective To explore the predictive value of baseline HBsAg level and early response for HBsAg loss in patients with HBeAg-positive chronic hepatitis B during pegylated interferon alpha-2a treatment. Methods A total of 121 patients with HBeAg-positive chronic hepatitis B who achieved HBsAg loss were enrolled; all patients were treated with PEG-IFNα-2a 180 μg/week. Serum HBV DNA and serological indicators(HBsAg, anti-HBs, HBeAg, and anti-HBe) were determined before and every 3 months during treatment. Results The median treatment time for HBsAg loss was 84 weeks(7-273 weeks), and 74.38%(90 cases) of the patients needed extended treatment(> 48 weeks). The correlation between baseline HBsAg levels and the treatment time of HBsAg loss was significant(B = 14.465, t = 2.342, P = 0.021). Baseline HBsAg levels together with the decline range of HBsAg at 24 weeks significantly correlated with the treatment time of HBsAg loss(B = 29.862, t = 4.890, P = 0.000 and B = 27.993, t = 27.993, P = 0.005). Conclusion Baseline HBsAg levels and extended therapy are critical steps toward HBsAg loss. Baseline HBsAg levels together with early response determined the treatment time of HBsAg loss in patients with HBeAg-positive chronic hepatitis B during pegylated interferon alpha-2a treatment.LI Ming Hui ZHANG Lu QU Xiao Jing LU Yao SHEN Ge LI Zhen Zhen WU Shu Ling LIU Ru Yu CHANG Min HU Lei Ping HUA Wen Hao SONG Shu Jing WAN Gang XIE Yao 2017Biomedical and Environmental Sciences2017,30,3:14
16Binding Activity Difference of Anti-CD20 scFv-Fc Fusion Protein Derived from Variable Domain Exchange显示文摘Two novel engineered antibody fragments binding to antigen CD20 were generated by fusing a murine IgM-type anti-CD20 single-chain Fv fragment (scFv) to the human IgG1 CH2 (i.e., Cγ2) and CH3 (i.e., Cγ3) domains with the human IgG1 hinge (i.e. Hγ). Given the relationship between structure and function of protein, the 3-D structures of the two engineered antibody fragments were modeled using computer-aided homology modeling method. Furthermore, the relationship between 3-D conformation and their binding activity was evaluated theoretically. Due to the change of active pocket formed by CDRs, the HL23 (VH-Linker-VL-Hγ-Cγ2-Cγ3) remained its activity because of its preserved conformation, while the binding activity of the LH23 (VL-Linker-VH-Hγ-Cγ2-Cγ3) was impaired severely. Experimental studies by flow cytometry and fluorescence microscopy showed that HL23 possessed significantly superior binding activity to CD20-expressing target cells than LH23. That is to say, the order of variable regions could influence the binding activity of the fusion protein to CD20+ cell lines, which was in accordance with the theoretical results. The study highlights the potential relationship between the antibody binding activity and their 3-D conformation, which appears to be worthwhile in providing direction for future antibody design of recombinant antibody.Shusheng Geng Jiannan Feng Yan Li Yingxun Sun Xin Gu Ying Huang Yugang Wang Xianjiang Kang Hong Chang Beifen Shen 2006Cellular & Molecular Immunology2006,3,6:13
17Depletion of activated hepatic stellate cell correlates with severe liver damage and abnormal liver regeneration in acetaminophen-induced liver injury显示文摘肝的星形的房间(HSC ) 是为肝的祖先房间(HPC ) 和 hepatocytes 的本地干细胞壁龛的重要部分。然而,它至于激活的 HSC 的产品是否被要求稀释 hepatocyte 损害是不清楚的,提高肝新生,或两个。在这研究,我们由弄空执行了功能研究的损失有 gliotoxin 的激活的 HSC。显著地严重的肝损坏和拒绝的幸存率与激活的 HSC 的弄空被相关,这被表明。而且,减少 HSC 激活导致了增殖的 hepatocytes 的数字的 hepatocyte apoptosis 和 66% 减少的 3 褶层增加。这被戏剧的减少在知道在 hepatocyte 复制期间起来调整的五基因的表示层次伴随。特别地,激活的 HSC 的弄空禁止了被 Pank 积极的房间的减少的数字在道和降低的基因表示 cytokeratin 铺平的门附近证实的卵形的房间反应,这被发现 19 (CK19 ) 在对待 gliotoxin 的肝。这些数据提供激活的 HSC 涉及 hepatocyte 死亡和 hepatocytes 的增长,在 acetaminophen (APAP ) 的 HPC 导致了尖锐的肝损害的清楚的证据。Kuntang Shen Wenju Chang Xiaodong Gao Hongshan Wang Weixin Niu Lujun Song Xinyu Qin 2011Acta Biochimica et Biophysica Sinica2011,43,4:13
18Ionic liquid based dispersive liquid-liquid microextraction of aromatic amines in water samples显示文摘In this work,a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction(IL-DLLME) was demonstrated for the extraction of 2-methylaniline,4-chloroaniline,1-naphthylamine and 4-aminobiphenyl in aqueous matrices.After extraction the ionic liquid(IL)phase was injected directly into the high performance liquid chromatography(HPLC) system for determination.Some parameters that might affect the extraction efficiency were optimized.Under the optimum conditions,good linear relationship,sensitivity and reproducibility were obtained.The limits of detection(LOD,S/N=3)for the four analytes were in the range of 0.45-2.6μg L^(-1).The relative standard deviations(R.S.D.,n=6)were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples.The recoveries ranged from 93.4 to 106.4%.The main advantages of the method are high speed,high recovery,good repeatability and volatile organic solvent-free.Yun Chang Fan Zheng Liang Hu Mei Lan Chen Chao Shen Tu Yan Zhu 2008Chinese Chemical Letters2008,19,8:13
19Emodin induces human T cell apoptosis in vitro by ROS-mediated endoplasmic reticulum stress and mitochondrial dysfunction显示文摘Kai Qu Nai-ying Shen Xin-sen Xu Hai-bo Su Ji-chao Wei Ming-hui Tai Fan-di Meng Lei Zhou Yue-lang Zhang Chang Liu 2013Acta Pharmacologica Sinica2013,34,9:11
20Clearance Influence on Dynamic Response of Intermittent Roller Chain Drive显示文摘The clearances appear in chain link hinges induced by manufacturing tolerance or wear of components are the most important factor that influences the dynamic performance of the intermittent roller chain drives.Due to the existence of the clearances in chain link hinges,the serious impact vibration phenomenon which influences the stability and the position accuracy of the chain drive system would be caused in the intermittent motion.But,the problem may be that a reasonable modeling on the chain with clearances is difficult due to the large clearance's number in chain system and the fact that the clearance' size are different.Currently,the studies on the dynamics of the intermittent roller chain considering the multi-clearance' joints are rare.Most research works have only focused on the constant moving chains.Taking the intermittent roller chain system as an object,this paper designs and builds the experimental device of this kind of mechanical system.The Longitudinal vibration response of the intermittent chain under the different motion laws was tested.The experimental study shows that the clearances presented in chain link hinges can cause severe impact vibration in the intermittent motion of chain.In subsequent work,the dynamic model of the intermittent roller chain system with the multi-clearance' joints was established.By calculating the dynamic response of this kind of mechanical system under the different motion laws,the effect of the clearances on the dynamic response of the intermittent chain drive system was analyzed.The theoretical simulation shows that the serious impact vibration phenomenon of the chain system can be caused by the clearances at the start accelerating period,and the chain drive system is often accompanied by the severe shock and vibration at the moment that the chain moves from the acceleration period to deceleration period.The research conclusions made by the experimental and theoretical studies indicate that the use of motion laws with small and continuous jerk at conversion point can effectively suppress the impact vibration at this point caused by clearances' effect.Additionally,the use of nonsymmetrical motion laws with small jerk approaching the end of the indexing period can obtain a smaller residual vibration.The presented motion law can provide an important reference for the improvement of the dynamic performance of the intermittent chain drive systems.XU Lixin YANG Yuhu CHANG Zongyu SHEN Zhaoguang LIU Jianping 2010Chinese Journal of Mechanical Engineering2010,23,6:11
返回顶部 每页显示:
共45页 首页 上一页 第1页 下一页 末页 /45 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费