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粉煤热解气化过程颗粒大小变化的影响因素 被引量:3
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作者 旷戈 张济宇 +2 位作者 林诚 翁开昀 韦居权 《燃烧科学与技术》 EI CAS CSCD 北大核心 2006年第4期289-294,共6页
在900℃固定床热解装置中,考察了诸多因素(水分、挥发分、热应力、热解时间以及介质氛围)对粒径为0.61~6.0mm的粉煤颗粒的颗粒大小的影响.结果表明,低挥发分福建无烟粉煤的热解过程仅发生一次碎裂,热解过程中煤粒大小的变化在1 min... 在900℃固定床热解装置中,考察了诸多因素(水分、挥发分、热应力、热解时间以及介质氛围)对粒径为0.61~6.0mm的粉煤颗粒的颗粒大小的影响.结果表明,低挥发分福建无烟粉煤的热解过程仅发生一次碎裂,热解过程中煤粒大小的变化在1 min内即可完成,热应力对煤颗粒大小变化起主要作用,有5%~20%的煤颗粒爆裂为更小的颗粒,而水分与挥发分的挥发对煤粒大小变化的影响不明显;煤样高湿含量(15%)时对大煤粒(>2.5 mm)在热解过程中粒径大小的变化有一定影响,但对小煤粒(<1.6mm)几乎没有影响;热解过程中介质氛围对煤粒变化的影响很大,水蒸气对煤粒大小变化的影响要比空气大,而混合气介质(空气/水蒸气)介于这两者之间. 展开更多
关键词 粉煤 热解 气化 煤粒大小变化
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An Econometric Analysis on the Effect of Climate Change on Wheat Cropping Area in China 被引量:3
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作者 侯麟科 张同龙 +1 位作者 蔡颖萍 崔永伟 《Agricultural Science & Technology》 CAS 2012年第3期686-688,共3页
[Objective] This study aimed to explore the impact of climate change on wheat cropping by using province-specific historical data during 1996-2007. [Method] We established a panel data econometric model with lagged wh... [Objective] This study aimed to explore the impact of climate change on wheat cropping by using province-specific historical data during 1996-2007. [Method] We established a panel data econometric model with lagged wheat cropping area and province-specific fixed-effects model to control the unobserved factors. [Result] The results showed that the temperature positively affects wheat cropping area, while precipitation does not have such impact. [Conclusion] The study provided empirical evidence for analysis of the determinants of wheat cropping area in China. 展开更多
关键词 Climate change Wheat cropping area Fixed-effects model
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Morphological Change of Starch Grain Based on Simulated Experiment and its Significance of Agricultural Archaeology——Taking Wheat as an Example 被引量:2
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作者 万智巍 杨晓燕 +1 位作者 马志坤 刘光旭 《Agricultural Science & Technology》 CAS 2011年第11期1621-1624,共4页
[Objective] The aim was to research and identify starch grain microfossil found in archaeological sites in China, and to find appropriate procedures for the starch grain analysis experiment.[Method] Wheat starch grain... [Objective] The aim was to research and identify starch grain microfossil found in archaeological sites in China, and to find appropriate procedures for the starch grain analysis experiment.[Method] Wheat starch grain size distribution was analyzed, and some simulated experiments were carried out, like mortar grinding, ultrasonic treatment, hydrochloric acid and hydrogen peroxide immersion, drying treatment, and so on. [Result] The mean size of wheat starch grains had increased in the growth process. Mortar grinding would make wheat starch grains larger than untreated sample. Long time of ultrasonic treatment can also make the starch grain size larger. 10% HCl and 6% H2O2 would have little effects on morphological feature of wheat starch grains. Low temperature heating did not cause starch grains to be gelatinized. [Conclusion] These experiment results can improve the accuracy of starch grain microfossil identification in the archaeological site. Starch grain analysis may be a utility and effective analytical tool in studying the origin of agriculture and the dispersal of crops in China. 展开更多
关键词 Starch grain analysis WHEAT Morphological change Agricultural archaeology
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Effect of Source-sink Change on Photosynthesis and Yield of Wheat 被引量:2
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作者 陈旭 刘佳音 江晓东 《Agricultural Science & Technology》 CAS 2010年第7期59-61,共3页
[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 (D1) and 320 plant/m2(D2) were adopted,then cutting flag leaf (L1),the secon... [Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 (D1) and 320 plant/m2(D2) were adopted,then cutting flag leaf (L1),the second last leaf (L2),removing upper part of spike (L3) and controlling (CK) were used to conduct field experiment.[Result] The results showed that both of the two densities of wheat's 1 000-grain weight and grain filling rate after anthesis in a decreasing order of L3〉CK〉L2〉L1,and the grain weight per spike and dry matter amount translated after anthesis turned to be CK〉L2〉L1 〉L3.[Conclusion].Both of leaf-cutting and spikelet removing decreased the grain weight per spike and dry matter amount translated after anthesis.Removing upper part of spike increased wheat's 1 000-grain weight.But the decreasing of the sink and dry matter amount translated contributed to the decreasing of the yield of wheat. 展开更多
关键词 Source-sink change WHEAT YIELD Rate of grouting Dry matter transferred yield
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LINEAR ULTRASONIC MOTOR USING LONGITUDINAL VIBRATION 被引量:5
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作者 王寅 黄卫清 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第1期40-45,共6页
A linear ultrasonic motor using longitudinal vibration of bar with varying section is proposed. The lin- ear ultrasonic motor has two varying section bars connected by semi-circumferential structure. Elliptical trajec... A linear ultrasonic motor using longitudinal vibration of bar with varying section is proposed. The lin- ear ultrasonic motor has two varying section bars connected by semi-circumferential structure. Elliptical trajecto- ries of particles are formed on top of the semi-circumferential structure outer surface where a driving foot is locat- ed. And a mover is pushed to move linearly when the driving foot is pressed onto it. Finite element model of sta- tor is built and results of harmonic analysis verify its principle. Moreover, design requirements of the motor are analyzed through finite element analysis and the results of sensitive analysis provide an efficient way to design the type of linear ultrasonic motor. Prototype test shows that the motor can afford load of 10 N at the speed of 100 mm/s. 展开更多
关键词 linear ultrasonic motor varying section longitudinal vibration MINIMIZATION
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A study of wavelet transforms applied for fracture identification and fracture density evaluation 被引量:3
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作者 张晓峰 潘保芝 +1 位作者 王飞 韩雪 《Applied Geophysics》 SCIE CSCD 2011年第2期164-169,178,179,共8页
Combining wavelet transforms with conventional log differential curves is used to identify fractured sections is a new idea.In this paper,we first compute the mother wavelet transform of conventional logs and the wave... Combining wavelet transforms with conventional log differential curves is used to identify fractured sections is a new idea.In this paper,we first compute the mother wavelet transform of conventional logs and the wavelet decomposed signals are compared with fractures identified from image logs to determine the fracture-matched mother wavelet.Then the mother wavelet-based decomposed signal combined with the differential curves of conventional well logs create a fracture indicator curve,identifying the fractured zone.Finally the fracture density can be precisely evaluated by the linear relationship of the indicator curve and image log fracture density.This method has been successfully used to evaluate igneous reservoir fractures in the southern Songnan basin and the calculated density from the indicator curve and density from image logs are both basically consistent. 展开更多
关键词 Wavelet transform fracture identification differential curves fracture density
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“名数化聚”的弥补教学 被引量:1
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作者 冯丁兰 《广西教育》 1996年第11期26-26,共1页
“名数化聚”的弥补教学凌云县一小冯丁兰在连续几届的高年级教学中,均发现学生对名数的化聚方法掌握得不牢。究其原因,关键在于学生对计量单位的实际大小认识模糊,对“把高级单位名数化成低级单位名数要乘进率,把低级单位名数聚成... “名数化聚”的弥补教学凌云县一小冯丁兰在连续几届的高年级教学中,均发现学生对名数的化聚方法掌握得不牢。究其原因,关键在于学生对计量单位的实际大小认识模糊,对“把高级单位名数化成低级单位名数要乘进率,把低级单位名数聚成高级单位名数要除以进率”这一方法没... 展开更多
关键词 计量单位 变化的方向 换算率 弥补教学 单名数 分析方法 “乘” 教学效果 引导学生 小变化
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Impact of marsh changes on breeding cranes in Sanjiang Plain,northeastern China 被引量:1
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作者 江红星 钱法文 +5 位作者 刘春悦 李晓民 侯韵秋 张国钢 戴铭 刘冬平 《Chinese Birds》 2012年第3期165-179,共15页
In order to measure the impact of changes in the marsh on breeding Red-crowned Cranes (Grus japonensis) and White-naped Cranes (G.vipio) in the Sanjiang Plain,we conducted a complete crane súrvey in each of the s... In order to measure the impact of changes in the marsh on breeding Red-crowned Cranes (Grus japonensis) and White-naped Cranes (G.vipio) in the Sanjiang Plain,we conducted a complete crane súrvey in each of the summers of 2007 and 2008,and obtained information on the changes in its marsh through interpretation of satellite images in 1986,1995,2000 and 2005.A comparison between the 1984 and 2008 census shows that:1) the number of Red-crowned Cranes remained stable at about 300 birds,while the number of White-naped Cranes increased markedly; 2) the estimates of nests of Red-crowned cranes are close to the numbers of 1984,while approximately 90% of the nests of these two crane species were distributed over five national nature reserves (NNRs); 3) the two crane species became more concentrated in three regions,i.e.,the Fuyuan Delta,the middle reaches of the Naoli and Qixing rivers,and the Xingkai Lake wetlands,rather as formerly in six regions.The area of the marsh decreased by 45% within the 20-year period from 1986 to 2005.The major loss of the marsh area was in the form of a conversion to paddy fields and dry land,which can be primarily attributed to direct human activity under various economic and policy drivers.The disappearance of cranes in the Dulu and Abuqin rivers was induced by large-scale agricultural development.The fragmentation into and isolation of small areas of the marsh became increasingly more serious,which resulted in unsuitable condtions for crane breeding in small patches of the marsh.The number of cranes declined from 1984-1995 but had recovered remarkably by 2008,which may be due to theestablishment of a system of nature reserves,in place since 2000.The land ownership of the reserve plays a key role in maintaining the integrity of the wetland ecosystem,especially in Sanjiang,Honghe,Naolihe and Qixinghe NNRs,which together accommodated approximately 80% of the population of cranes.However,we did not discover any nests at all in the provincial and municipal reserves,which may be attributed to high human disturbances in these areas.In the end,we propose some recommendations on reserve management. 展开更多
关键词 Red-crowned Crane White-naped Crane BREEDING population size marsh change habitat loss Sanjiang Plain
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不妨多一点机智
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作者 丁一 《青海教育》 北大核心 1995年第6期15-15,共1页
不妨多一点机智丁一我们在教育教学工作中,不妨多一些机智:一、机智地“引入”。机智的引人来自机智的设计。即不仅能抓住矛盾、设立悬念,而且能够设计出既富有魅力又符合学生实际的问题。这源于认真的思考、比较、选择和实践。二、... 不妨多一点机智丁一我们在教育教学工作中,不妨多一些机智:一、机智地“引入”。机智的引人来自机智的设计。即不仅能抓住矛盾、设立悬念,而且能够设计出既富有魅力又符合学生实际的问题。这源于认真的思考、比较、选择和实践。二、机智地传授。即教学中诸法皆备,且运... 展开更多
关键词 教育教学过程 突发事件 现代化手段 化难为易 教育技巧 地应变 偶发事件 题海战术 学生实际 小变化
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Available parking space occupancy change characteristics and short-term forecasting model 被引量:5
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作者 季彦婕 王炜 邓卫 《Journal of Southeast University(English Edition)》 EI CAS 2007年第4期604-608,共5页
Based on an available parking space occupancy (APSO) survey conducted in Nanjing, China, an APSO forecasting model is proposed. The APSO survey results indicate that the time series of APSO with different time-secti... Based on an available parking space occupancy (APSO) survey conducted in Nanjing, China, an APSO forecasting model is proposed. The APSO survey results indicate that the time series of APSO with different time-sections are periodical and self-similar, and the fluctuation of the APSO increases with the decrease in time-sections. Taking the short-time change behavior into account, an APSO forecasting model combined wavelet analysis and a weighted Markov chain is presented. In this model, an original APSO time series is first decomposed by wavelet analysis, and the results include low frequency signals representing the basic trends of APSO and several high frequency signals representing disturbances of the APSO. Then different Markov models are used to forecast the changes of low and high frequency signals, respectively. Finally, integrating the predicted results induces the final forecasted APSO. A case study verifies the applicability of the proposed model. The comparisons between measured and forecasted results show that the model is a competent model and its accuracy relies on real-time update of the APSO database. 展开更多
关键词 available parking space occupancy change characteristics short-term forecasting wavelet analysis weighted Markov chain
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Dynamic Changes of Nitrate Reductase Activity within 24 Hours
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作者 杜瑛 王子龙 《Agricultural Science & Technology》 CAS 2012年第11期2284-2286,共3页
[Objective] The research aimed to study the circadian rhythm of nitrate re- ductase activity (NRA) in plant. [Method] The wheat plants at heading stage were used as the materials for the measurement of dynamic chang... [Objective] The research aimed to study the circadian rhythm of nitrate re- ductase activity (NRA) in plant. [Method] The wheat plants at heading stage were used as the materials for the measurement of dynamic changes of nitrate reductase activity (NRA) within 24 h under the conditions of constant high temperature. [Resulti The fluctuation of NRA in wheat changed greatly from 20:00 pm to 11:00 am. The enzyme activity remained constant, but at 14:00 the enzyme activity was the high- est, higher than all the other time points except the enzyme activity measured at11:00. The enzyme activity was the lowest of 17:00, which was lower than all the other time points except the enzyme activity measured at 2:00. [Conclusion] There were autonomous rhythm changes of NRA in wheat in a certain degree. 展开更多
关键词 WHEAT 24 h Nitrate reductase ACTIVITY Solution culture
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ANALYSIS OF TEMPERATURE CHANGES IN JANUARY AND JULY IN CHINA 被引量:2
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作者 刘莉红 郑祖光 《Journal of Tropical Meteorology》 SCIE 2004年第1期69-78,共10页
The temperature change trends in January and July are analyzed and the results show that the trends descend in July but ascend in January except in South China and Southwest China. The relation between the temperature... The temperature change trends in January and July are analyzed and the results show that the trends descend in July but ascend in January except in South China and Southwest China. The relation between the temperature in January and July are discussed by using the wavelet. The results show that the trend phase in July and January are nearly in-phase in Southwest and South China, but are out-of-phase in other regions. Reconstruction of original temperature series in each of the regions indicates that their change trends are consistent with the original temperature series. 展开更多
关键词 temperature in January temperature in July wavelet analysis
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Fulminant ulcerative colitis associated with steroid-resistant minimal change disease and psoriasis: A case report 被引量:1
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作者 Ka-Ho Lok Hiu-Gong Hung +3 位作者 Wai-Man Yip Kin-Kong Li Kam-Fu Li Ming-Leung Szeto 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第29期4022-4024,共3页
A 43-year-old Chinese patient with a history of psoriasis developed fulminant ulcerative colitis after immunosuppressive therapy for steroid-resistant minimal change disease was stopped. Minimal change disease in asso... A 43-year-old Chinese patient with a history of psoriasis developed fulminant ulcerative colitis after immunosuppressive therapy for steroid-resistant minimal change disease was stopped. Minimal change disease in association with inflammatory bowel disease is a rare condition. We here report a case showing an association between ulcerative colitis, minimal change disease, and psoriasis. The possible pathological link between 3 diseases is discussed. 展开更多
关键词 Ulcerative colitis Inflammatory bowel disease Minimal change disease
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CAS FGOALS-f3-H and CAS FGOALS-f3-L outputs for the high-resolution model intercomparison project simulation of CMIP6 被引量:4
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作者 BAO Qing LIU Yimin +8 位作者 WU Guoxiong HE Bian LI Jinxiao WANG Lei WU Xiaofei CHEN Kangjun WANG Xiaocong YANG Jing ZHANG Xiaoqi 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第6期576-581,共6页
The High Resolution Model Intercomparison Project(HighResMIP)is a unique model intercomparison project in phase 6 of the Coupled Model Intercomparison Project(CMIP6),which is focused on the impact of horizontal resolu... The High Resolution Model Intercomparison Project(HighResMIP)is a unique model intercomparison project in phase 6 of the Coupled Model Intercomparison Project(CMIP6),which is focused on the impact of horizontal resolutions.The outputs of the high-and low-resolution versions of CAS FGOALS-f3-H and CAS FGOALS-f3-L for the experiments of the HighResMIP simulations in CMIP6 are described in this paper.The models and their configurations,experimental settings,and postprocessing methods are all introduced.CAS FGOALS-f3-H,with a 0.25°horizontal resolution,and CAS FGOALS-f3-L,with a 1°horizontal resolution,were forced by the standard external conditions,and two coordinated sets of simulations were conducted for 1950–2014 and 2015–50 with the Experiment IDs of‘highresSST-present’and‘highresSST-future’,respectively.The model outputs contain multiple time scales including the required hourly mean,three-hourly mean,six-hourly transient,daily mean,and monthly mean datasets.It is reported that the 0.25°CAS FGOALS-f3-H successfully simulates some of the key challenges in climate modeling,including the average lifetime of tropical cyclones,particularly in the western parts of the northern Pacific Ocean,and the diurnal cycle of hourly precipitation.These datasets will contribute to the benchmarking of current models for CMIP,and studies of the impacts of horizontal resolutions on climate modeling issues. 展开更多
关键词 CMIP6 HighResMIP FGOALS-f3-H FGOALS-f3-L tropical cyclone diurnal cycle hourly precipitation
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Method of Edge Extraction Based on Wavelet Transform for the Image of Mechanical Engineering Drawings
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作者 吴林瑞 陈炯柏 袁曾凤 《Journal of Beijing Institute of Technology》 EI CAS 2000年第3期335-340,共6页
A method, by which the broken edge of mechanical engineering drawings being binarised can be eliminated and the whole edge of mechanical engineering drawing can be got, is given. To all points of a connected area on t... A method, by which the broken edge of mechanical engineering drawings being binarised can be eliminated and the whole edge of mechanical engineering drawing can be got, is given. To all points of a connected area on the image of the modular maximum value of wavelet transform at scale 2 2, the averaging grey value method is used to their grey values, then the edge of the dim place is continuous after the maximum variance threshold method is used. All these methods are fast, they can be used for all linear graphics having nothing to do with the grey value, its application scope is wide. 展开更多
关键词 wavelet transform CONNECT FILTERING BINARIZATION
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A new extension algorithm for cubic B-splines based on minimal strain energy 被引量:8
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作者 MO Guo-liang ZHAO Ya-nan 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第12期2043-2049,共7页
Extension of a B-spline curve or surface is a useful function in a CAD system. This paper presents an algorithm for extending cubic B-spline curves or surfaces to one or more target points. To keep the extension curve... Extension of a B-spline curve or surface is a useful function in a CAD system. This paper presents an algorithm for extending cubic B-spline curves or surfaces to one or more target points. To keep the extension curve segment GC^2-continuous with the original one, a family of cubic polynomial interpolation curves can be constructed. One curve is chosen as the solution from a sub-class of such a family by setting one GC^2 parameter to be zero and determining the second GC^2 parameter by minimizing the strain energy. To simplify the final curve representation, the extension segment is reparameterized to achieve C-continuity with the given B-spline curve, and then knot removal from the curve is done. As a result, a sub-optimized solution subject to the given constraints and criteria is obtained. Additionally, new control points of the extension B-spline segment can be determined by solving lower triangular linear equations. Some computing examples for comparing our method and other methods are given. 展开更多
关键词 GC^2-continuous EXTENSION Minimal strain energy Knot removal Reparametrization
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Multiple malignant extragastrointestinal stromal tumors of the greater omentum and results of immunohistochemistry and mutation analysis:A case report 被引量:5
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作者 Jong-Han Kim Yoon-Jung Boo +6 位作者 Cheol-Woong Jung Sung-Soo Park Seung-Joo Kim Young-Jae Mok Sang-Dae Kim Yang-Suk Chae Chong-Suk Kim 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第24期3392-3395,共4页
To report an extragastrointestinal stromal tumor (EGIST) that occurs outside the gastrointestinal tract and shows unique clinicopathologic and immunohistochemical features. In our case, we experienced multiple soft ... To report an extragastrointestinal stromal tumor (EGIST) that occurs outside the gastrointestinal tract and shows unique clinicopathologic and immunohistochemical features. In our case, we experienced multiple soft tissue tumors that originate primarily in the greater omentum, and in immunohistochemical analysis, the tumors showed features that correspond to malignant EGIST. Two large omental masses measured 15 cm×10 cm and 5 cm×4 cm sized and several small ovoid fragments were attached to small intestine, mesentery and peritoneum. On histologic findings, the masses were separated from small bowel serosa and had high mitotic count (115/50 HPFs). In the results of immunohistochemical stains, the tumor showed CDl17 (c-kit) positive reactivity and high Ki-67 labeling index. On mutation analysis, the c-kit gene mutation was found in the juxtamembrane domain (exon 11)and it was heterozygote. Platelet-derived growth factor receptor (PDGFR) gene mutation was also found in the juxtamemembrane (exon 12) and it was polymorphism. From above findings, we proposed that there may be several mutational pathways to malignant EGIST, so further investigations could be needed to approach this unfavorable disease entity. 展开更多
关键词 Extragastrointestinal stromal tumor Greater omentum C-KIT Platelet-derived growth factor receptor MUTATION
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Impact of remote ischemic preconditioning on wound healing in small bowel anastomoses 被引量:2
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作者 Philipp Anton Holzner Birte Kulemann +4 位作者 Simon Kuesters Sylvia Timme Jens Hoeppner Ulrich Theodor Hopt Goran Marjanovic 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第10期1308-1316,共9页
AIM: To investigate the influence of remote ischemic preconditioning (RIPC) on anastomotic integrity. METHODS: Sixty male Wistar rats were randomized to six groups. The control group (n = 10) had an end- to-end ... AIM: To investigate the influence of remote ischemic preconditioning (RIPC) on anastomotic integrity. METHODS: Sixty male Wistar rats were randomized to six groups. The control group (n = 10) had an end- to-end ileal anastomosis without RIPC. The preconditioned groups (n = 34) varied in time of ischemia and time of reperfusion. One group received the amino acid L-arginine before constructing the anastomosis (n = 9). On postoperative day 4, the rats were re-laparotomized, and bursting pressure, hydroxyproline concentration, intra-abdominal adhesions, and a histological score concerning the mucosat ischemic injury were collected. The data are given as median (range).RESULTS: On postoperative day 4, median bursting pressure was 124 mmHg (60-146 mmHg) in the control group. The experimental groups did not show a statistically significant difference (P 〉 0.05). Regarding the hydroxyproline concentration, we did not find any significant variation in the experimental groups. We detected significantly less mucosal injury in the RIPC groups. Furthermore, we assessed more extensive intra-abdominal adhesions in the preconditioned groups than in the control group. CONCLUSION: RIPC directly before performing small bowel anastomosis does not affect anastomotic stability in the early period, as seen in ischemic preconditioning. 展开更多
关键词 Anastomotic healing HYDROXYPROLINE Bursting pressure Mucosal injury index Wound healing Remote ischemic preconditioning
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Shrinking and Drying up of Baiyangdian Lake Wetland:A Natural or Human Cause? 被引量:11
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作者 LIU Chunlan XIE Gaodi HUANG Heqing 《Chinese Geographical Science》 SCIE CSCD 2006年第4期314-319,共6页
The shrinking and drying up of wetlands in arid and semiarid areas of China have been widely observed in the recent years, but there has been no consensus on whether the aggravation is caused by human activities or by... The shrinking and drying up of wetlands in arid and semiarid areas of China have been widely observed in the recent years, but there has been no consensus on whether the aggravation is caused by human activities or by global climate warming. For a better understanding of the cause, this study investigates the dynamic changes of Baiyangdian Lake wetland over the last 40 years. It is shown that since the 1980s, Baiyangdian Lake has suffered from an insufficient water input and shrunk considerably. By using SPSS 11.0, this study urines a detailed Analysis on the signifficance of the effects of the possible driving factors for the degradation. It is identified that the North China Plain has been warrnin~ up significantly in recent years, which causes a significant reduction in the precipitation and inflow to the lake. Although human disturbances such as the irrigation and storage of water in reservoirs do not play a decisive role, they accelerate the degradation and their effects should be minimized. 展开更多
关键词 climate change human activities Baiyangdian Lake wetland hydrologic process North China Plain
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Wavelet Analysis and Nonparametric Test for Climate Change in Tarim River Basin of Xinjiang During 1959-2006 被引量:14
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作者 XU Jianhua CHEN Yaning +3 位作者 LI Weihong JI Minhe DONG Shan HONG Yulian 《Chinese Geographical Science》 SCIE CSCD 2009年第4期306-313,共8页
Using wavelet analysis,regression analysis and the Mann-Kendall test,this paper analyzed time-series(1959-2006) weather data from 23 meteorological stations in an attempt to characterize the climate change in the Tari... Using wavelet analysis,regression analysis and the Mann-Kendall test,this paper analyzed time-series(1959-2006) weather data from 23 meteorological stations in an attempt to characterize the climate change in the Tarim River Basin of Xinjiang Uygur Autonomous Region,China.Major findings are as follows:1) In the 48-year study period,average annual temperature,annual precipitation and average annual relative humidity all presented nonlinear trends.2) At the 16-year time scale,all three climate indices unanimously showed a rather flat before 1964 and a detectable pickup thereafter.At the 8-year time scale,an S-shaped nonlinear and uprising trend was revealed with slight fluctuations in the entire process for all three indices.Incidentally,they all showed similar pattern of a slight increase before 1980 and a noticeable up-swing afterwards.The 4-year time scale provided a highly fluctuating pattern of periodical oscillations and spiral increases.3) Average annual relative humidity presented a negative correlation with average annual temperature and a positive correlation with annual precipitation at each time scale,which revealed a close dynamic relationship among them at the confidence level of 0.001.4) The Mann-Kendall test at the 0.05 confidence level demonstrated that the climate warming trend,as represented by the rising average annual temperature,was remarkable,but the climate wetting trend,as indicated by the rising annual precipitation and average annual relative humidity,was not obvious. 展开更多
关键词 climate change nonlinear trend wavelet analysis Mann-Kendall test Tarim River Basin
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