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Observer-based dynamic event-triggered control for distributed parameter systems over mobile sensor-plus-actuator networks
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作者 穆文英 庄波 邱芳 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期237-243,共7页
We develop a policy of observer-based dynamic event-triggered state feedback control for distributed parameter systems over a mobile sensor-plus-actuator network.It is assumed that the mobile sensing devices that prov... We develop a policy of observer-based dynamic event-triggered state feedback control for distributed parameter systems over a mobile sensor-plus-actuator network.It is assumed that the mobile sensing devices that provide spatially averaged state measurements can be used to improve state estimation in the network.For the purpose of decreasing the update frequency of controller and unnecessary sampled data transmission, an efficient dynamic event-triggered control policy is constructed.In an event-triggered system, when an error signal exceeds a specified time-varying threshold, it indicates the occurrence of a typical event.The global asymptotic stability of the event-triggered closed-loop system and the boundedness of the minimum inter-event time can be guaranteed.Based on the linear quadratic optimal regulator, the actuator selects the optimal displacement only when an event occurs.A simulation example is finally used to verify that the effectiveness of such a control strategy can enhance the system performance. 展开更多
关键词 distributed parameter systems event-triggered control mobile sensors mobile actuators
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Effects of sphincter of Oddi motility on the formation of cholesterol gallstones 被引量:12
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作者 Zhong-Hou Rong Hong-Yuan Chen +5 位作者 Xin-Xing Wang Zhi-Yi Wang Guo-Zhe Xian Bang-Zhen Ma Cheng-Kun Qin Zhen-Hai Zhang 《World Journal of Gastroenterology》 SCIE CAS 2016年第24期5540-5547,共8页
AIM: To investigate the mechanisms and effects of sphincter of Oddi(SO) motility on cholesterol gallbladder stone formation in guinea pigs.METHODS: Thirty-four adult male Hartley guinea pigs were divided randomly into... AIM: To investigate the mechanisms and effects of sphincter of Oddi(SO) motility on cholesterol gallbladder stone formation in guinea pigs.METHODS: Thirty-four adult male Hartley guinea pigs were divided randomly into two groups, the control group(n = 10) and the cholesterol gallstone group(n = 24), which was sequentially divided into four subgroups with six guinea pigs each according to time of sacrifice. The guinea pigs in the cholesterol gallstone group were fed a cholesterol lithogenic diet and sacrificed after 3, 6, 9, and 12 wk. SO manometry and recording of myoelectric activity were obtained by a multifunctional physiograph at each stage. Cholecystokinin-A receptor(CCKAR) expression levels in SO smooth muscle were detected by quantitative real-time PCR(q RT-PCR) and serum vasoactive intestinal peptide(VIP), gastrin, and cholecystokinin octapeptide(CCK-8) were detected by enzyme-linked immunosorbent assay at each stage in the process of cholesterol gallstone formation.RESULTS: The gallstone formation rate was 0%, 0%, 16.7%, and 83.3% in the 3, 6, 9, and 12 wk groups, respectively. The frequency of myoelectric activity in the 9 wk group, the amplitude of myoelectric activity in the 9 and 12 wk groups, and the amplitude and the frequency of SO in the 9 wk group were all significantly decreased compared to the control group. The SO basal pressure and common bile duct pressure increased markedly in the 12 wk group, and the CCKAR expression levels increased in the 6 and 12 wk groups compared to the control group. Serum VIP was elevated significantly in the 9 and 12 wk groups and gastrin decreased significantly in the 3 and 9 wk groups. There was no difference in serum CCK-8 between the groups.CONCLUSION: A cholesterol gallstone-causing diet can induce SO dysfunction. The increasing tension of the SO along with its decreasing activity may play an important role in cholesterol gallstone formation. Expression changes of CCKAR in SO smooth muscle and serum VIP and CCK-8 may be important causes of SO dysfunction. 展开更多
关键词 Cholesterol GALLSTONE SPHINCTER of ODDI MANOMETRY MYOELECTRIC activity Cholecystokinin-A receptor
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Roles of sphincter of Oddi motility and serum vasoactive intestinal peptide,gastrin and cholecystokinin octapeptide 被引量:12
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作者 Zhen-Hai Zhang Cheng-Kun Qin +4 位作者 Shuo-Dong Wu Jian Xu Xian-Ping Cui Zhi-Yi Wang Guo-Zhe Xian 《World Journal of Gastroenterology》 SCIE CAS 2014年第16期4730-4736,共7页
AIM: To investigate roles of sphincter of Oddi (SO) motility played in pigment gallbladder stone formation in model of guinea pigs.
关键词 Pigment gallstone Sphincter of Oddi MANOMETRY Myoelectric activity Guinea pig Vasoactive intestinal peptide GASTRIN Cholecystokinin octapeptide
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An attribute recognition model for safe thickness assessment between concealed karst cave and tunnel 被引量:12
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作者 HUANG Xin LI Shu-cai +5 位作者 XU Zhen-hao GUO Ming SHI Xue-song GAO Bin ZHANG Bo LIU Lang 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第4期955-969,共15页
An attribute recognition model for safe thickness assessment between a concealed karst cave and a tunnel is established based on the attribute mathematic theory.The model can be applied to carrying out risk classifica... An attribute recognition model for safe thickness assessment between a concealed karst cave and a tunnel is established based on the attribute mathematic theory.The model can be applied to carrying out risk classification of the safe thickness between a concealed karst cave and a tunnel and to guarantee construction’s safety in tunnel engineering.Firstly,the assessment indicators and classification standard of safe thickness between a concealed karst cave and a tunnel are studied based on the perturbation method.Then some attribute measurement functions are constructed to compute the attribute measurement of each single index and synthetic attribute measurement.Finally,the identification and classification of risk assessment of safe thickness between a concealed karst cave and a tunnel are recognized by the confidence criterion.The results of two engineering application show that the evaluation results agree well with the site situations in construction.The results provide a good guidance for the tunnel construction. 展开更多
关键词 concealed karst cave karst tunnel safe thickness attribute recognition method
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Influence of dynamic pressure on deep underground soft rock roadway support and its application 被引量:4
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作者 Meng Qingbin Han Lijun +4 位作者 Chen Yanlong Fan Jiadong Wen Shengyong Yu Liyuan Li Hao 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第5期903-912,共10页
Due to high ground stress and mining disturbance, the deformation and failure of deep soft rock roadway is serious, and invalidation of the anchor net-anchor cable supporting structure occurs. The failure characterist... Due to high ground stress and mining disturbance, the deformation and failure of deep soft rock roadway is serious, and invalidation of the anchor net-anchor cable supporting structure occurs. The failure characteristics of roadways revealed with the help of the ground pressure monitoring. Theoretical analysis was adopted to analyze the influence of mining disturbance on stress distribution in surrounding rock,and the change of stress was also calculated. Considering the change of stress in surrounding rock of bottom extraction roadway, the displacement, plastic zone and distribution law of principal stress difference under different support schemes were studied by means of FLAC3D. The supporting scheme of U-shaped steel was proposed for bottom extraction roadway that underwent mining disturbance. We carried out a similarity model test to verify the effect of support in dynamic pressure. Monitoring results demonstrated the change rules of deformation and stress of surrounding rock in different supporting schemes. The supporting scheme of U-shaped steel had an effective control on deformation of surrounding rock. The scheme was successfully applied in underground engineering practice, and achieved good technical and economic benefits. 展开更多
关键词 Deep soft rock roadway Dynamic pressure impact Similarity model test Combined support Ground pressure monitoring
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A new triterpenoid saponin from the roots of Platycodon grandiflorum 被引量:6
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作者 Wei Li Lan Xiang +3 位作者 Jing Zhang Yi Nan Zheng Li Kun HAN Masato Saito 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第3期306-308,共3页
A new triterpenoid saponin, 3-O-β-D-glucopyranosyl 16-oxo-platycodigenin 28-O-β-D-apiofuranosyl-(1 → 3)-β-D-xylopyra- nosyl-(1→4)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyra-nosyl ester, was isolated fro... A new triterpenoid saponin, 3-O-β-D-glucopyranosyl 16-oxo-platycodigenin 28-O-β-D-apiofuranosyl-(1 → 3)-β-D-xylopyra- nosyl-(1→4)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyra-nosyl ester, was isolated from the roots of Platycodon grandiflorum, together with three known saponins, including platycodin D, deapio platycoside E and platycoside E. The structure of the new compound, named 16-oxo-platycodin D, was elucidated on the basis of spectroscopic data. 展开更多
关键词 Platycodon grandiflorum Triterpenoid saponin 16-oxo-Platycodin D
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Provenance Study of Fe–Ti Oxide Minerals in the Quaternary Sediments in Yichang Area and Its Implication of Formation Time of the Yangtze Three Gorges, China 被引量:4
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作者 XIANG Fang DU Wen +3 位作者 HUANG Henxu KANG Dongya ZHU Hongbo FENG Qin 《Acta Geologica Sinica(English Edition)》 CAS CSCD 2018年第4期1598-1608,共11页
The Three Gorges are considered to be critical to understand the formation of Yangtze River. Recent research results suggest that the Yangtze Three Gorges was created during the Quaternary but the exact time is debata... The Three Gorges are considered to be critical to understand the formation of Yangtze River. Recent research results suggest that the Yangtze Three Gorges was created during the Quaternary but the exact time is debatable. Fe-Ti oxide minerals are seldom used to study sediment provenance, expecially using scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). In this study, the provenance of Quaternary sediments in Yichang area, which is located to the east of the Yangtze Three Gorges, was investigated by using SEM and EDS to research Fe-Ti oxides. The Panzhihua vanadium titanomagnetite and Emeishan basalt outcrop are located to the west of the Three Gorges. Further, the materials from them are observed in the Quaternary sediments of Yichang area. Fe-Ti oxide minerals from the Huangling granite are observed in the Yunchi and Shanxiyao Formations, which were formed before 0.75 Ma B.P., whereas Fe-Ti oxide minerals from the Huangling granite, Panzhihua vanadium titanomagnetite, and Emeishan basalt are observed in the riverbed and fifth-terrace sediments of the Yangtze River, which were formed after 0.73 Ma B.P.. Thus, we can infer that the Three Gorges formed after the deposition of the Shanxi Formation and before the fifth-terrace; i.e., 0.75-0.73 Ma B.P.. 展开更多
关键词 Yangtze Three Gorges Yichang area Quaternary sediments Fe-Ti oxide minerals China
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ON THE RENEWAL RISK MODEL WITH INTEREST AND DIVIDEND 被引量:3
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作者 房莹 吴荣 《Acta Mathematica Scientia》 SCIE CSCD 2010年第5期1730-1738,共9页
We consider that the reserve of an insurance company follows a renewal risk process with interest and dividend. For this risk process, we derive integral equations and exact infinite series expressions for the Cerber-... We consider that the reserve of an insurance company follows a renewal risk process with interest and dividend. For this risk process, we derive integral equations and exact infinite series expressions for the Cerber-Shiu discounted penalty function. Then we give lower and upper bounds for the ruin probability. Finally, we present exact expressions for the ruin probability in a special case of renewal risk processes. 展开更多
关键词 Gerber-Shiu discounted penalty function ruin probability DIVIDEND INTEREST
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Gastric ulcer treated using an elastic traction ring combined with clip: A case report 被引量:2
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作者 Fei Pang Yan-Jun Song +3 位作者 Yin-He Sikong Ai-Jun Zhang Xiu-Li Zuo Ru-Yuan Li 《World Journal of Clinical Cases》 SCIE 2022年第31期11574-11578,共5页
BACKGROUND There is a high annual incidence of acute,nonvariceal upper gastrointestinal bleeding in Chinese adults.Early endoscopic intervention can reduce rates of rebleeding,surgery,and mortality.The metal clip is t... BACKGROUND There is a high annual incidence of acute,nonvariceal upper gastrointestinal bleeding in Chinese adults.Early endoscopic intervention can reduce rates of rebleeding,surgery,and mortality.The metal clip is the most common method for establishing homeostasis;however,it possesses several limitations.In patients with bleeding secondary to large gastric ulcers,the clip will often fail to stop the bleeding.This article highlights the use of an elastic traction ring as a novel hemostatic method for patients with upper gastrointestinal bleeding.CASE SUMMARY An elderly male presented to the emergency room with complaints of hematemesis and melena.Endoscopic examination revealed an ulcer(Forrest IIa)in the lesser curvature of the gastric antrum.Six tissue clips and one elastic traction ring were inserted into the stomach cavity to suture the ulcer.The patient recovered quickly without postoperative gastrointestinal bleeding.Two months later,the patient's ulcer was significantly healed.CONCLUSION To our best knowledge,this is the first report to demonstrate the safety and efficacy of elastic traction rings for upper gastrointestinal bleeding.Elastic traction rings should be considered a routine therapeutic modality for patients with upper gastrointestinal bleeds. 展开更多
关键词 Gastric ulcer Elastic traction ring Acute nonvariceal upper gastrointestinal bleeding Endoscopic hemostasia Tissue clips Case report
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Effects of Tidal Channels and Roads on Landscape Dynamic Distribution in the Yellow River Delta, China 被引量:2
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作者 YU Xiaojuan ZHANG Zhongsheng +2 位作者 XUE Zhenshan WU Haitao ZHANG Hongri 《Chinese Geographical Science》 SCIE CSCD 2020年第1期170-179,共10页
Landscape characters in estuarine regions generally controlled by tidal regimes and human activities like road construction.In this work,tidal channels and road construction in the Yellow River Delta(YRD)were extracte... Landscape characters in estuarine regions generally controlled by tidal regimes and human activities like road construction.In this work,tidal channels and road construction in the Yellow River Delta(YRD)were extracted by visual interpretation methods so as to decipher impacts of tidal channel development and road construction on landscape patch change during 1989–2016.Spatial distribution history of three wetlands,which covered by Phragmites australis(freshwater marsh,FM),Suaeda salsa(salt marsh,SM),and mudflats(MD)were also established.Results indicated that tidal channel,number,frequency,and fractal dimension were all the maximum in 2003,and the minimum in 1998,respectively.Road length,number,and density showed increasing trend during 1989–2016.MD were the predominant landscape type,followed by FM and SM during 1989-2016.Principal component analysis implied two extracted factors,F1 and F2,which could represent 91.93% of the total variations.F1 mainly proxied tidal channel development,while F2 represented road construction.A multiple linear regression analysis showed positive effects of both F1 and F2 on FM patch numbers and negative impacts on SM patch areaes with R^2 values of 0.416 and 0.599,respectively.Tidal channels were negatively related to MD patch numbers,while roads were positively related to that.In any case,road construction showed larger impacts on landscape type shifting than that of tidal channel development in the YRD. 展开更多
关键词 tidal channel development road construction principal component analysis multiple linear regression analysis the Yellow River Delta
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Novel weigh-in-motion system based on FBGs 被引量:2
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作者 LIU Quan-jie JIANG Ming-shun +2 位作者 LI Yan-hua YANG Hong-mei ZENG Li 《重庆邮电大学学报(自然科学版)》 北大核心 2009年第2期196-199,共4页
In this weigh-in-motion(WIM)research,a novel fiber Bragg grating(FBG)-based weigh-in-motion(WIM)system was introduced.The design derived from the idea using in-service bridge abutments as the weigh scale.The bridge be... In this weigh-in-motion(WIM)research,a novel fiber Bragg grating(FBG)-based weigh-in-motion(WIM)system was introduced.The design derived from the idea using in-service bridge abutments as the weigh scale.The bridge beam was replaced by a piece of steel plate which supports the weight of the traveling vehicle.All weights would be finally transferred into the tubes where four FBGs were attached and could record the weight-induced strains by shifting their Bragg wavelengths.The system identification algorithm based on parameters estimation was initiated.Over 40-ton load had been applied on the system and the experimental results showed a good repeatability and linearity.The system resolution had been achieved as low as 10 kg.Compared with other designs of fiber-optic WIM systems,this design is easy and reliable. 展开更多
关键词 动态称重系统 光纤光栅 布拉格波长 参数估计 识别算法 设计 重量 线性度
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Numerical simulation study of the failure evolution process and failure mode of surrounding rock in deep soft rock roadways 被引量:15
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作者 Meng Qingbin Han Lijun +3 位作者 Xiao Yu Li Hao Wen Shengyong Zhang Jian 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第2期209-221,共13页
Based on the safety coefficient method,which assigns rock failure criteria to calculate the rock mass unit,the safety coefficient contour of surrounding rock is plotted to judge the distribution form of the fractured ... Based on the safety coefficient method,which assigns rock failure criteria to calculate the rock mass unit,the safety coefficient contour of surrounding rock is plotted to judge the distribution form of the fractured zone in the roadway.This will provide the basis numerical simulation to calculate the surrounding rock fractured zone in a roadway.Using the single factor and multi-factor orthogonal test method,the evolution law of roadway surrounding rock displacements,plastic zone and stress distribution under different conditions is studied.It reveals the roadway surrounding rock burst evolution process,and obtains five kinds of failure modes in deep soft rock roadway.Using the fuzzy mathematics clustering analysis method,the deep soft surrounding rock failure model in Zhujixi mine can be classified and patterns recognized.Compared to the identification results and the results detected by geological radar of surrounding rock loose circle,the reliability of the results of the pattern recognition is verified and lays the foundations for the support design of deep soft rock roadways. 展开更多
关键词 Deep soft rock roadway Evolutionary process Failure model Numerical simulation Model recognition
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Severe acute cholangitis after endoscopic sphincterotomy induced by barium examination:A case report 被引量:2
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作者 Zhen-Hai Zhang Ya-Guang Wu +4 位作者 Cheng-Kun Qin Zhong-Xue Su Jian Xu Guo-Zhe Xian Shuo-Dong Wu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第39期5658-5660,共3页
Endoscopic sphincterotomy (EST) is considered as a possible etiological factor for severe cholangitis. We herein report a case of severe cholangitis after endo-scopic sphincterotomy induced by barium examination. An a... Endoscopic sphincterotomy (EST) is considered as a possible etiological factor for severe cholangitis. We herein report a case of severe cholangitis after endo-scopic sphincterotomy induced by barium examination. An adult male patient presented with epigastric pain was diagnosed as having choledocholithiasis by ultra-sonography. EST was performed and the stone was completely cleaned. Barium examination was done 3 d after EST and severe cholangitis appeared 4 h later. The patient was recovered after treated with tienam for 4 d. Barium examination may induce severe cholangitis in patients after EST, although rare, barium examination should be chosen cautiously. Cautions should be also used when EST is performed in patients younger than 50 years to avoid the damage to the sphincter of Oddi. 展开更多
关键词 Endoscopic sphincterotomy Severe cholan-gitis Barium examination Sphincter of Oddi
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Isolation and characterization of an enoyl-acyl carrier protein reductase gene from microalga Isochrysis galbana 被引量:2
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作者 郑明刚 梁科鹏 +4 位作者 王波 孙修勤 岳燕燕 万文文 郑立 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第2期398-406,共9页
In most bacteria, plants and algae, fatty acid biosynthesis is catalyzed by a group of freely dissociable proteins known as the type II fatty acid synthase (FAS II) system. In the FAS II system, enoyl- acyl carrier ... In most bacteria, plants and algae, fatty acid biosynthesis is catalyzed by a group of freely dissociable proteins known as the type II fatty acid synthase (FAS II) system. In the FAS II system, enoyl- acyl carrier protein reductase (ENR) acts as a determinant for completing the cycles of fatty acid elongation. In this study, the cDNA sequence of ENR, designated as IgENR, was isolated from the microalga lsochrysis galbana CCMM5001. RACE (rapid amplification of cDNA ends) was used to isolate the full-length cDNA oflgENR (1 503 bp), which contains an open reading frame (ORF) of 1 044 bp and encodes a protein of 347 amino acids. The genomic DNA sequence oflgENR is interrupted by four introns. The putative amino acid sequence is homologous to the ENRs of seed plants and algae, and they contain common coenzyme- binding sites and active site motifs. Under different stress conditions, real-time quantitative polymerase chain reaction (RT-qPCR) showed the expression oflgENR was upregulated by high temperature (35℃), and downregulated by depleted nitrogen (0 mol/L). To clarify the mechanism of lipids accumulating lipids, other genes involved in lipids accumulation should be studied. 展开更多
关键词 lsochrysis galbana enoyl-ACP reductase real-time quantitative PCR TEMPERATURE NITROGEN
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Synthesis and Field Emission of ZnO Nanostructures on CuO Catalyzed Porous Silicon Substrate 被引量:1
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作者 郁可 张永胜 +6 位作者 欧阳世翕 张清杰 罗来强 张秋香 常中坤 李立君 朱自强 《Chinese Physics Letters》 SCIE CAS CSCD 2005年第9期2411-2414,共4页
Mass production of ZnO nanobelts and hexagonal nanorods has been successfully synthesized on CuO catalyzed porous silicon (PS) using a simple vapour-solid (VS) growth method. A comparison of their morphologies is ... Mass production of ZnO nanobelts and hexagonal nanorods has been successfully synthesized on CuO catalyzed porous silicon (PS) using a simple vapour-solid (VS) growth method. A comparison of their morphologies is investigated by scanning electron microscopy (SEM). The transmission electron microscopy (TEM) confirms that ZnO nanobelts and nanorods are single crystalline with the growth direction of (0110) and (0001), respectively. Field emission tests indicate that the ZnO nanostructures on porous silicon have low turn-on field of about 3.6 V/μm (at 1.0μA/cm^2) and the threshold field of about 8.3 V/μm (at 1.0mA/cm^2), high emission site density (ESD) of approximately 104 cm^-2. 展开更多
关键词 ZINC-OXIDE NANOWIRES ROOM-TEMPERATURE GROWTH PHOTOLUMINESCENCE NANORODS FILMS
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OsSRK1,an Atypical S-Receptor-Like Kinase Positively Regulates Leaf Width and Salt Tolerance in Rice 被引量:2
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作者 ZHOU Jinjun JU Peina +6 位作者 ZHANG Fang ZHENG Chongke BAI Bo LI Yaping WANG Haifeng CHEN Fan XIE Xianzhi 《Rice science》 SCIE CSCD 2020年第2期133-142,共10页
Receptor-like kinases(RLKs)are important for plant growth,development and defense responses.The S-receptor protein kinases(SRKs),which represent an RLK subfamily,control the selfincompatibility among Brassica species.... Receptor-like kinases(RLKs)are important for plant growth,development and defense responses.The S-receptor protein kinases(SRKs),which represent an RLK subfamily,control the selfincompatibility among Brassica species.However,little information is available regarding SRK functions in rice.We identified a gene OsSRK1 encoding an atypical SRK.The transcript of OsSRK1 was induced by abscisic acid(ABA),salt and polyethylene glycol.OsSRK1 localized to the plasma membrane and cytoplasm.Leaf width was increased in OsSRK1-overexpression(OsSRK1-OX)transgenic rice plants,likely because of an increase in cell number per leaf.Furthermore,the expression levels of OsCYCA3-1 and OsCYCD2-1,which encode positive regulators of cell division,were up-regulated in leaf primordium of OsSRK1-OX rice plants relative to those in wild type.Meanwhile,the expression level of OsKRP1,which encodes cell cycle inhibitor,was down-regulated in the OsSRK1-OX plants.Therefore,it is deduced that OsSRK1 regulates leaf width by promoting cell division in the leaf primordium.Additionally,OsSRK1-OX plants exhibited enhanced ABA sensitivity and salt tolerance compared with wild type.These results suggest that OsSRK1 plays important roles in leaf development and salt responses in rice. 展开更多
关键词 RICE S-receptor-like protein KINASE OsSRK1 salt tolerance LEAF width cell division
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Dynamic Pathology and Antigen Location Study on Broiler Breeders with Coinfection of Marek's Disease Virus and Reticuloendotheliosis Virus 被引量:1
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作者 DIAO Xiu-guo ZHU Guo CHENG Zi-qiang WANG Gui-hua MENG Xiang-kai GAO Ting-ting CUI Zhi-zhong 《Agricultural Sciences in China》 CAS CSCD 2008年第11期1387-1393,共7页
To further understand the generation and development of coinfection of Marek's disease virus (MDV) and reticuloendotheliosis virus (REV) in broiler breeders, and then find the method and optimal time of different... To further understand the generation and development of coinfection of Marek's disease virus (MDV) and reticuloendotheliosis virus (REV) in broiler breeders, and then find the method and optimal time of differential diagnosis for complex clinic multiple infection, the authors studied the pathohistological changes, apoptosis, immunohistochemistry (immunofluorescence), and ultrastructure of tumor tissues of broiler breeders inoculated with MDV and REV. The study showed that proliferation of small lymphocytes was seen in the main organs at the age of 1 week, then immature lymphocytes, all kinds of lymphocytes, primitive reticulum cells, and Marek's disease cells (MDCs) were observed at 2-9 weeks. Apoptosis of lymphocytes could not be seen until the age of 10 weeks in the immune system. Immunohistochemistry detection showed that the positive signs of MDV and REV antigen were observed in the main organs at 2 weeks of age. Multi-morphology lymphocytes, MDV, and REV, mitotic figures and apoptosis of lymphocytes were observed with the help of transmission electron microscopy. MDV cooperating with REV promotes the course of disease of coinfection. Differential diagnosis can be done by immunohistochemistry in the early stage (before 2 weeks), and histopathology in the late stage (post 4 weeks). MDCs, primitive reticulum cells, immature lymphocytes, and two kinds of virions can serve as a basis for bistopathology differential diagnosis. 展开更多
关键词 Marek's disease virus reticuloendotheliosis virus COINFECTION dynamic pathology antigen location
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The Development Trend of Developed Countries to Invest in Education of Disadvantaged Groups and the Enlightenment to Our Country 被引量:1
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作者 Ruan Ting Song Zhanmei 《学术界》 CSSCI 北大核心 2013年第9期288-297,共10页
Educational investment is the material basis for developing intelligence and educational cause and also an important factor for the development of economic and society.This paper argues that educational investment is ... Educational investment is the material basis for developing intelligence and educational cause and also an important factor for the development of economic and society.This paper argues that educational investment is an important strategy to solve the problem of disadvantaged groups in our country,and hopes that through the analysis of the structure and the trend for educational investment in developed countries,and it can provide reference and valuable suggestions for our country. 展开更多
关键词 教育投资 弱势群体 发达国家 发展趋势 物质基础 社会发展
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Influence of New Compound Admixture on Shotcrete Performance
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作者 商岩冬 郭艳培 +2 位作者 ZHANG Wenquan ZHAO Wenbin TAN Yunzhen 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第6期1392-1396,共5页
To analyze the influence of new compound admixture on shotcrete performance, the ordinary Portland cement pr425 was used as matrix components. The optimum proportion of admixture was obtained by analyzing the influenc... To analyze the influence of new compound admixture on shotcrete performance, the ordinary Portland cement pr425 was used as matrix components. The optimum proportion of admixture was obtained by analyzing the influence of content on cement setting time and compressive strength. The microstructure of cement test block and the mechanism of reducing dust of composite macromolecule admixture were analyzed by scanning electron microscopy and infrared spectroscopy. It was shown that the ratio of polyacrylic acid was 0.02%. The ratio of J85 accelerator was 5%. The ratio of bentonite was 4.5% in composite admixture. The most optimal content of admixture in the slurry was 7%. The compound coagulant formed by additive together with C3A, C4AF which provided nucleation for hydration and crystallization of C3S and C3S, and played an active role to promote the activity of the mineral admixture in cement, and increased the elastic modulus of C-S-H gel and accelerated the hydration process of portland cement. Bentonite and polyacrylic acid promote the wettability, cohesiveness and workability of cement paste in the process of hydration. The formation of cement test block gel was even. The interface between the matrix phase and the aggregate phase was not obvious which ensured the matching between the matrix and the aggregate phase. The addition of bentonite formed hydrogen bonds in cement paste and improved the cohesiveness of the system. The J-85 accelerator promoted the combination of aluminate and gypsum which hindered the formation of calcium carbide around the cement particles which made cement rapid condensation. Polyacrylic acid mainly changed the strength of hydroxyl absorption peak in cement paste to improve the initial strength of cement test block. The addition of new admixtures promoted the process of cement hydration to be more thorough and affected the later strength development of concrete by affecting the formation of calcium carbonate stone. 展开更多
关键词 SHOTCRETE compound admixture optimum proportion microstructure HYDRATION
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The Strengthening and Toughening Mechanism of Fe-Al/Al_2O_3 Composite Material
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作者 孙康宁 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2006年第2期10-13,共4页
By means of different checks and measures, we obserced and analysed the microstructure of Fe-Al/ Al2O3 composite material, We found that not only intragranular nanostructure grains and rod-like crystals but also fine-... By means of different checks and measures, we obserced and analysed the microstructure of Fe-Al/ Al2O3 composite material, We found that not only intragranular nanostructure grains and rod-like crystals but also fine-grained structure of the composite material as well as the bridging of the Fe-Al intermetallics compound contribute to the material's strength and toughness, It is shoun that the strengthening and toughening of the Fe- Al/ Al2O3 composite is the joint effect of a multiplicute strengthening and tougheniug mechanism. 展开更多
关键词 ceramic-base composite strengthening and toughness microstructure intermetallics compound
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