期刊文献+
共找到12篇文章
< 1 >
每页显示 20 50 100
海上试验系统定位点迹外推算法设计
1
作者 李旭 《数字技术与应用》 2017年第7期144-145,共2页
针对海上试验平台位置点迹丢失问题,介绍了一种基于α-β-γ滤波的外推方法,使用导航信号跟踪失锁前序点迹对无效定位时刻坐标进行预测,计算复杂度低,并使用实际采集点迹对算法进行了仿真分析。仿真结果表明,除匀变速运动外,该方法对于... 针对海上试验平台位置点迹丢失问题,介绍了一种基于α-β-γ滤波的外推方法,使用导航信号跟踪失锁前序点迹对无效定位时刻坐标进行预测,计算复杂度低,并使用实际采集点迹对算法进行了仿真分析。仿真结果表明,除匀变速运动外,该方法对于缓变加速平台运动同样具有较好的外推结果,具有较高的工程实用价值。 展开更多
关键词 运动建模 Α-Β-Γ滤波 失锁
下载PDF
Non-cooperative Space Target Estimation Algorithm Without Prior Information Dependence Based on Temporal Line of Sight Constraint
2
作者 XIAO Hui ZHU Chongrui +3 位作者 LIU Xinqi YU Yifan SHENG Qinghong YANG Rui 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第4期526-540,共15页
Under single-satellite observation,the parameter estimation of the boost phase of high-precision space noncooperative targets requires prior information.To improve the accuracy without prior information,we propose a p... Under single-satellite observation,the parameter estimation of the boost phase of high-precision space noncooperative targets requires prior information.To improve the accuracy without prior information,we propose a parameter estimation model of the boost phase based on trajectory plane parametric cutting.The use of the plane passing through the geo-center and the cutting sequence line of sight(LOS)generates the trajectory-cutting plane.With the coefficient of the trajectory cutting plane directly used as the parameter to be estimated,a motion parameter estimation model in space non-cooperative targets is established,and the Gauss-Newton iteration method is used to solve the flight parameters.The experimental results show that the estimation algorithm proposed in this paper weakly relies on prior information and has higher estimation accuracy,providing a practical new idea and method for the parameter estimation of space non-cooperative targets under single-satellite warning. 展开更多
关键词 motion parameter estimation estimation of impact point infrared early warning boost phase modeling trajectory database construction
下载PDF
BESⅢ主漂移室径迹的外推和径迹匹配 被引量:1
3
作者 王亮亮 苑长征 +25 位作者 马秋梅 马想 王大勇 邓子艳 尤郑昀 毛泽普 文硕频 孙永昭 刘怀民 刘春秀 李卫东 伍灵慧 张长春 邱进发 何康林 何苗 张学尧 张瑶 季晓斌 郑直 冒亚军 俞国威 袁野 蒋林立 谢宇广 臧石磊 《高能物理与核物理》 CSCD 北大核心 2007年第2期183-188,共6页
BESⅢ主漂移室重建径迹的外推算法采用面向对象的设计方法,利用GEANT4部分代码开发实现,它提供主漂移室带电径迹外推到外部其他子探测器上的预期径迹信息.该算法的外推过程考虑了带电径迹在磁场中的偏转以及与探测器物质相互作用造成... BESⅢ主漂移室重建径迹的外推算法采用面向对象的设计方法,利用GEANT4部分代码开发实现,它提供主漂移室带电径迹外推到外部其他子探测器上的预期径迹信息.该算法的外推过程考虑了带电径迹在磁场中的偏转以及与探测器物质相互作用造成的电离能损,并为径迹参数计算考虑了库仑多次散射效应影响在内的参数误差矩阵.经检查,主漂移室径迹的外推结果和完全模拟结果一致,并且径迹外推的结果能够成功用于各个子探测器测量径迹间的匹配,这些工作为分析实验数据作了必要的准备,能够满足BESⅢ实验的使用要求. 展开更多
关键词 GEANT4 多次散射 匹配
原文传递
Influence of layout of scanners on intelligent mine scanning trails
4
作者 李大勇 赵俊利 +1 位作者 王妍 王立君 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第3期229-234,共6页
To expand scanning area and attack range without changing the inner structure of intelligent warhead, a new arrangement mode of the scanner for intelligent mine is proposed. The required coordinate systems are es... To expand scanning area and attack range without changing the inner structure of intelligent warhead, a new arrangement mode of the scanner for intelligent mine is proposed. The required coordinate systems are established firstly on the basis of advanced dynamics principle. and the exterior ballistics equations are deduced. Then the equations of scanning trails are established by the method of space analytic geometry. To get the scanning trails. the differential equations are transformed into discrete simulation model using the algorithm of fourth order Runge-Kutta and then are simulated using Matlab. Compared with the scanning trails obtained by the traditional layout of scanner, the scanning trails obtained by the proposed layout of scanner has larger horizontal range of scanning circle and bigger trarget acquisition probability. Therefore, the new arrangement mode of the scanner for intelligent mine can increase attack range. 展开更多
关键词 intelligent mine SCANNER scanning trails exterior ballistics
下载PDF
引进智力
5
作者 徐敦 《中国储运》 1995年第Z1期44-44,共1页
改革开放十余载,引资风盛。外资借我国政策春风蜂拥而入,极大地促进了经济的发展。外资的异彩也深深地辐射到千百万寻常百姓家。蓬勃发展的合资、独资公司,拔地而起的一幢幢写字楼。外资的活力已经让我们感受的真真切切。
关键词 引进智力 独资公司 外迹 部智力 最大限度 两厢情愿 改革开放 蓬勃发展 市场经济
下载PDF
Molecular and in vitro Characterization of Field Isolates of Bovine Herpesvirus-1 被引量:4
6
作者 Julian Ruiz-Saenz Jairo Jaime +1 位作者 Gloria Ramirez Victor Vera 《Virologica Sinica》 SCIE CAS CSCD 2012年第1期26-37,共12页
Bovine Herpesvirus-1 (BoHV-1) is distributed worldwide and is a major pathogen in cattle, being the causal agent of a variety of clinical syndromes. The aim of this study was to isolate and to characterize (molecular ... Bovine Herpesvirus-1 (BoHV-1) is distributed worldwide and is a major pathogen in cattle, being the causal agent of a variety of clinical syndromes. The aim of this study was to isolate and to characterize (molecular and biological characterization) BoHV-1 from 29 immunosuppressed animals. It was possible to obtain 18 isolates, each from a different animal, such as from the respiratory and reproductive tracts. In some cases the cytopathic effect was visible 12 hours post-inoculation, and became characteristic after 36-48 hours. Biological characteristics were evaluated and compared with Iowa and Colorado-1 reference strains, and differences were found in plaque size, virus titer measured by TCID50 and PFU/mL, and one step virus curves. These results showed that some isolates had a highly virulent-like behavior in vitro, compared to the reference strains, with shorter eclipse periods, faster release of virus into the supernatants, and higher burst size and viral titer. There were no differences in glycoprotein expression of BoHV-1 isolates, measured by Western blot on monolayers. Moreover, using restriction endonucleases analysis, most of the viruses were confirmed as BoHV-1.1 and just one of them was confirmed as BoHV-1.2a subtype. These findings suggest that some wild-type BoHV-1 isolates could be useful as seeds to develop new monovalent vaccines. 展开更多
关键词 Bovine herpesvirus 1 Genital infection Respiratory infection Latent infection
下载PDF
Effects of sargentgloryvine stem extracts on HepG-2 cellsin vitro andin vivo 被引量:3
7
作者 Ming-Hua Wang Min Long Bao-Yi Zhu Shu-Hui Yang Ji-Hong Ren Hui-Zhong Zhang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第23期2848-2854,共7页
AIM:To observe the effects of sargentgloryvine stem extracts (SSE) on the hepatoma cell line HepG-2 in vitro andin vivo and determine its mechanisms of action.METHODS:Cultured HepG-2 cells treated with SSE were analys... AIM:To observe the effects of sargentgloryvine stem extracts (SSE) on the hepatoma cell line HepG-2 in vitro andin vivo and determine its mechanisms of action.METHODS:Cultured HepG-2 cells treated with SSE were analysed by 3-(4,5-Dimethyl-thiazol-2-yl)-2,5Diphenyltetrazolium bromide and clone formation assay.The cell cycle and apoptosis analysis were conducted by flow cytometric,TdT-Mediated dUTP Nick End Labeling and acridine orange/ethidium bromide staining methods,and protein expression was examined by both reverse transcriptase-polymerase chain reaction and Western blotting.The pathological changes of the tumor cells were observed by haematoxylin and eosin staining.Tumor growth inhibition and side effects were determined in a xenograft mouse model.RESULTS:SSE treatment could not only inhibit HepG-2 cell proliferation in a doseand time-dependent manner but also induce apoptosis and cell cycle arrest at the S phase.The number of colonies formed by SSEtreated tumor cells was fewer than that of the controls (P<0.05).SSE induced caspase-dependent apoptosis accompanied by a significant decrease in Bcl-xl and Mcl-1 and elevation of Bak expression (P<0.05).Tumor necrosis factor α in the xenograft tumor tissue and the liver functions of SSE-treated mice showed no significant changes at week 8 compared with the control group (P>0.05).Systemic administration of SSE could inhibit the HepG-2 xenograft tumor growth with no obvious toxic side effects on normal tissues.CONCLUSION:SSE can induce apoptosis of HepG-2 cells in vitro and in vivo through decreasing expression of Bcl-xl and Mcl-1 and increasing expression of Bax. 展开更多
关键词 Sargentgloryvine stem extract Apoptosis Human hepatocellular carcinoma HEPG-2 Bcl-2 family
下载PDF
Suppression of esophageal cancer cell growth using curcumin,(-)-epigallocatechin-3-gallate and lovastatin 被引量:12
8
作者 Fei Ye Gui-Hong Zhang +1 位作者 Bao-Xiang Guan Xiao-Chun Xu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第2期126-135,共10页
AIM:To determine the effects of curcumin,(-)-epigallocatechin-3-gallate (EGCG),lovastatin,and their combinations on inhibition of esophageal cancer.METHODS:Esophageal cancer TE-8 and SKGT-4 cell lines were subjected t... AIM:To determine the effects of curcumin,(-)-epigallocatechin-3-gallate (EGCG),lovastatin,and their combinations on inhibition of esophageal cancer.METHODS:Esophageal cancer TE-8 and SKGT-4 cell lines were subjected to cell viability methyl thiazolyl tetrazolium and tumor cell invasion assays in vitro and tumor formation and growth in nude mouse xenografts with or without curcumin,EGCG and lovastatin treatment.Gene expression was detected using immunohistochemistry and Western blotting in tumor cell lines,tumor xenografts and human esophageal cancer tissues,respectively.RESULTS:These drugs individually or in combinations significantly reduced the viability and invasion capacity of esophageal cancer cells in vitro.Molecularly,these three agents reduced the expression of phosphorylated extracellular-signal-regulated kinases (Erk1/2),c-Jun and cyclooxygenase-2 (COX-2),but activated caspase 3 in esophageal cancer cells.The nude mouse xenograft assay showed that EGCG and the combinations of curcumin,EGCG and lovastatin suppressed esophageal cancer cell growth and reduced the expression of Ki67,phosphorylated Erk1/2 and COX-2.The expression of phosphorylated Erk1/2 and COX-2 in esophageal cancer tissue specimens was also analyzed using immunohistochemistry.The data demonstrated that 77 of 156 (49.4%) tumors expressed phosphorylated Erk1/2 and that 121 of 156 (77.6%) esophageal cancers expressed COX-2 protein.In particular,phosphorylated Erk1/2 was expressed in 23 of 50 (46%) cases of esophageal squamous cell carcinoma (SCC) and in 54 of 106 (50.9%) cases of adenocarcinoma,while COX-2 was expressed in 39 of 50 (78%) esophageal SCC and in 82 of 106 (77.4%) esophageal adenocarcinoma.CONCLUSION:The combinations of curcumin,EGCG and lovastatin were able to suppress esophageal cancer cell growth in vitro and in nude mouse xenografts,these drugs also inhibited phosphorylated Erk1/2,c-Jun and COX-2 expression. 展开更多
关键词 CHEMOPREVENTION CURCUMIN Cyclooxygen-ase-2 (-)-epigallocatechin-3-gallate Esophageal can-cer STATIN
下载PDF
Localization and Dynamic Expression of a 27.8kDa Receptor Protein for Lymphocystis Disease Virus Infection in Sea Bass(Lateolabrax japonicus) Tissues
9
作者 WU Ronghua SHENG Xiuzhen +2 位作者 TANG Xiaoqian XING Jing ZHAN Wenbin 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第5期889-896,共8页
Lymphocystis disease virus(LCDV) infects target cells by attaching to a 27.8 k Da receptor(27.8R) protein in flounder Paralichthys olivaceus, and anti-27.8R monoclonal antibodies(MAbs) have been developed. However, th... Lymphocystis disease virus(LCDV) infects target cells by attaching to a 27.8 k Da receptor(27.8R) protein in flounder Paralichthys olivaceus, and anti-27.8R monoclonal antibodies(MAbs) have been developed. However, the 27.8R existence in tissues of sea bass(Lateolabrax japonicus) and its role in LCDV infection have remained unclear. In this study, the results of western blotting demonstrated that the same 27.8R was shared by flounder and sea bass. LCDV-free sea bass individuals were intramuscularly injected with LCDV, and viral copies were detected in tissues from 3 h post infection and showed a time-dependent increase during 9 days infection. Distribution and synthesis of 27.8R in sea bass tissues were investigated by using anti-27.8R MAbs as probes. It was found that 27.8R was distributed in all the tested tissues. The levels of 27.8R protein were highest in gill and skin, then a bit lowly in stomach, head kidney and heart, followed by spleen, intestine, blood cells, gonad and liver, and least in kidney and brain in healthy sea bass. Upon LCDV infection, 27.8R synthesis was up-regulated in each tissue, and higher in the tissues with higher LCDV copies. The 27.8R and LCDV were detected in some peripheral blood leukocytes but not in red blood cells. These results suggested that 27.8R was widely distributed in sea bass tissues, and it served as a receptor and correlated with tissue tropism of LCDV infection. Furthermore, leukocytes had the potential of being a LCDV carrier and were responsible for a systemic infection of LCDV in sea bass. 展开更多
关键词 Lateolabrax Infection intestine stomach Paralichthys monoclonal probes unclear Receptor Scophthalmus
下载PDF
A young and booming approach:the extreme lateral supracerebellar infratentorial approach 被引量:1
10
作者 陈鑫 丰育功 +2 位作者 唐万忠 李环廷 李照建 《Neuroscience Bulletin》 SCIE CAS CSCD 2010年第6期479-485,共7页
Surgical accesses to lesions of the posterolateral pontomesencephalic junction(PMJ)region and the posterolateral tentorial gap remain a challenge in the field of neurosurgery.Since the first report of application of... Surgical accesses to lesions of the posterolateral pontomesencephalic junction(PMJ)region and the posterolateral tentorial gap remain a challenge in the field of neurosurgery.Since the first report of application of the extreme lateral supracerebellar infratentorial(ELSI)approach in resecting the PMJ lesions in 2000,a few articles concerning the ELSI approach have been published.The present review mainly provided an intimate introduction of the ELSI approach,and evalu- ated it in facets of patient position,skin incision,craniectomy,draining veins,retraction against the cerebellum,exposure limits,patient healing,as well as advantages and limitations compared with other approaches.The ELSI approach is proposed to be a very young and promising approach to access the lesions of posterolateral PMJ region and the posterolateral tentorial gap.Besides,it has several advantages such as having a shorter surgical pathway,causing less surgical complications,laborsaving,etc.Still,more studies are needed to improve this approach. 展开更多
关键词 extreme lateral supracerebellar infratentorial approach tentorial gap NEUROSURGERY
原文传递
Polyphyllin I inhibits proliferation and metastasis of ovarian cancer cell line HO-8910PM invitro 被引量:16
11
作者 Linhui Gu Jianguo Feng +2 位作者 Haiyan Xu Min Luo Dan Su 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2013年第3期325-333,共9页
OBJECTIVE: To study the anticancer mechanism of polyphyllin I (PPI), a Traditional Chinese Medicine, on the ovarian cancer cell line HO-8910PM in vitro. METHODS: Transwell chamber invasive assays were used to inve... OBJECTIVE: To study the anticancer mechanism of polyphyllin I (PPI), a Traditional Chinese Medicine, on the ovarian cancer cell line HO-8910PM in vitro. METHODS: Transwell chamber invasive assays were used to investigate the inhibitory capacity of PPI on HO-8910PM metastasis. Gene expression profiling chips was used to screen differentially ex- pressed genes between experiment group and con- trol group. Reverse transcription PCR and Western blotting were used to determine mRNA and pro- tein levels. RESULTS: With increasing PPI concentration, the metastatic capacity of cells decreased, with signifi- cance differences between the experimental and control groups (P〈0.01) as well as between two concentration groups. Gene expression profiling identified 123 differentially expressed genes, of which 70 were downregulated and 53 were upregu- lated. The genes were involved in multiple signal transduction pathways, including apoptosis, prolif- eration and metastasis. Real-time PCR (RT-PCR) showed that differential genes PIK3C2B, Caspase 9and WntSA were downregulated with increasing PPI, showing an evident dose-effect relationship. The c-Jun was an exception. As the PPI dosage in- creased and the exposure time was extended, c-Jun relative expression showed an upward trend. There were significant differences between the ex- periment and control (P〈0.05). Western blot analy- ses showed that PPI treatment decreased levels of Caspase 9, WntSA and PIK3C2B and increased acti- vated Caspase 9,c-Jun and p-c-Jun expression levels. CONCLUSION" PPI has strong antitumor and anti transfer activity. It can activate c-Jun expression and the JNK signaling pathway, elicit cell apoptosis via the mitochondrial-mediated Caspase activation pathway, and finally inhibit tumor growth and mi- gration in vitro. The downregulation of PIK3C2B and Wnt5A jointly inhibit the proliferation and me- tastasis of HO-8910PM. PPI may be a novel treat- ment for ovarian cancer. 展开更多
关键词 Chonglou Saponin I Ovarian Neo-plasms Apoptosis Cell Movement
原文传递
The in vitro and in vivo anti-tumor effects of MTX-Fe_3O_4-PLLA-PEG-PLLA microspheres prepared by suspension-enhanced dispersion by supercritical CO_2 被引量:1
12
作者 CHEN AiZheng DANG TingTing +3 位作者 WANG ShiBin TANG Na LIU YuanGang WU WenGuo 《Science China(Life Sciences)》 SCIE CAS 2014年第7期698-709,共12页
The in vitro and in vivo anti-tumor efficacy of methotrexate-loaded Fe3O4-poly-L-lactide-poly(ethylene glycol)-poly-L-lactide magnetic composite microspheres(MTX-Fe3O4-PLLA-PEG-PLLA MCMs,MMCMs),which were produced by ... The in vitro and in vivo anti-tumor efficacy of methotrexate-loaded Fe3O4-poly-L-lactide-poly(ethylene glycol)-poly-L-lactide magnetic composite microspheres(MTX-Fe3O4-PLLA-PEG-PLLA MCMs,MMCMs),which were produced by co-precipitation(C)and microencapsulation(M)in a supercritical process,was evaluated at various levels:cellular,molecular,and integrated.The results at the cellular level indicate that MMCMs(M)show a better anti-proliferation activity than raw MTX and could induce morphological changes of cells undergoing apoptosis.At the molecular level,MMCMs(M)lead to a significantly higher relative mRNA expression of bax/bcl-2 and caspase-3 than MMCMs(C)at 10μg mL-1(P<0.01);and the pro-caspase-3protein expression measured by Western blot analysis also demonstrates that MMCMs(M)can effectively activate pro-caspase-3.At the integrated level,mice bearing a sarcoma-180 tumor are used;in vivo anti-tumor activity tests reveal that MMCMs(M)with magnetic induction display a much higher tumor suppression rate and lower toxicity than raw MTX.Pharmacokinetic studies show that MMCMs(M)with magnetic induction significantly increase the accumulation of MTX in the tumor tissue compared with the other treatments.These results suggest that the MMCMs(M)prepared by the SpEDS process have great potential to play a positive role in the magnetic targeted therapy field. 展开更多
关键词 METHOTREXATE magnetic microsphere ANTI-TUMOR biological effectiveness
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部