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煤矿采动覆岩离层水害致灾因素勘查与预测评价
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作者 乔伟 刘梦楠 +4 位作者 孟祥胜 程香港 冯培超 李小琴 李文平 《煤炭学报》 EI CAS CSCD 北大核心 2024年第4期2031-2044,共14页
采动覆岩离层突水在我国各地矿区均较为常见且危害性较大,现有的规范中鲜有针对离层水害的具体工程地质和水文地质勘查方法。探索煤矿离层水害工程地质水文地质勘查与评价方法,能够推动我国矿井水害防治水平进一步提升。首先从煤矿采动... 采动覆岩离层突水在我国各地矿区均较为常见且危害性较大,现有的规范中鲜有针对离层水害的具体工程地质和水文地质勘查方法。探索煤矿离层水害工程地质水文地质勘查与评价方法,能够推动我国矿井水害防治水平进一步提升。首先从煤矿采动覆岩高位离层水害孕灾机制出发,分析了离层水害从孕灾到致灾的工程地质条件,将我国现有的离层水害归纳为3种典型类型:离层动力突水、离层静水压涌突水和离层携泥砂突水。然后,确定了“水源”“通道”“力源”和“物源”为控制离层水害类型与强度的关键隐蔽致灾因素,将位于传统导水裂隙带以上,可发生离层突水的复合层位称为采动覆岩“突水离层带”,并提出了煤矿采动覆岩“突水离层带”的判别流程,划分勘查阶段,指明勘查要点。煤矿离层水害采前勘查应包括2个阶段:①开展覆岩基本工程地质和水文地质条件勘探,评估勘探区离层水害的可能性并确定潜在“突水离层带”的层位;②将“突水离层带”和“物源”层作为勘查目标层,开展离层水害致灾因素专项勘查,评定离层水害类型和强度。回采期间对水动力条件和覆岩裂隙演化进行探查。最后,基于离层水害致灾因素互馈演化致灾机制,建立了适用于采动覆岩离层水害的矿井区域预测综合评价模型,提出了全矿井/采区尺度的区域危险性分区、采前工作面突水位置判定及涌水量预计的煤矿采动覆岩离层水害预测评价方法。 展开更多
关键词 离层水害 致灾因素 覆岩“水离层带” 工程地质勘查 预测评价
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断层采动型突水自组织临界特性研究 被引量:5
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作者 邱秀梅 王连国 《山东科技大学学报(自然科学版)》 CAS 2002年第1期59-61,共3页
利用重整化群方法研究了断层单元体破裂的随机性和关联性。在此基础上 ,对断层导水裂隙的扩展规律进行了分析。
关键词 断层 自组织 临界特性 重整化群方法 导水裂隙 分形树破坏模型
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当前夫妇冲突动因之分析
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作者 陈秀华 封淑珍 《道德与文明》 1987年第3期19-23,共5页
一 目的和方法 作为社会细胞,家庭的稳定与否直接关系到社会安定。一个家庭能否稳定,很大程度上取决于夫妻关系。而要研究夫妻关系却是一件十分困难的事情,因为它纯属私生活中最隐秘的部分。从这个意义上来说,夫妇与家庭是一个封闭的小... 一 目的和方法 作为社会细胞,家庭的稳定与否直接关系到社会安定。一个家庭能否稳定,很大程度上取决于夫妻关系。而要研究夫妻关系却是一件十分困难的事情,因为它纯属私生活中最隐秘的部分。从这个意义上来说,夫妇与家庭是一个封闭的小群体。尽管如此,人们还是从各个方面为巩固家庭这一社会细胞的稳定做了很多努力。本文试图在调查研究的基础上,从社会心理学和道德的角度,对当前夫妇的冲突动因作一分析。 展开更多
关键词 突动 婚姻家庭关系 离婚诉讼 婚后 夫妇关系 原告 个案 家庭经济 婚姻基础
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露天爆破地震动态模拟分析的一种新方法
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作者 张凤鹏 马万昌 +1 位作者 孙豁然 金校元 《中国矿业》 北大核心 2005年第9期49-52,共4页
以南芬露天铁矿生产爆破和主运输平硐为研究对象,依据现场测试的大量爆破振动数据,利用瞬态有限单元法对人工爆破过程进行模拟。提出了一种基于位移等效原则的突加动荷分析方法,通过该方法对平硐稳定性进行了分析,给出了系统的阻尼系数... 以南芬露天铁矿生产爆破和主运输平硐为研究对象,依据现场测试的大量爆破振动数据,利用瞬态有限单元法对人工爆破过程进行模拟。提出了一种基于位移等效原则的突加动荷分析方法,通过该方法对平硐稳定性进行了分析,给出了系统的阻尼系数、极限抗震速度和临界单段药量。结果表明,该方法简便有效。 展开更多
关键词 露天爆破地震 态模拟 荷法 瞬态有限单元法
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Analysis of Smooth Cepstral Peak Prominence in Hypokinetic Dysarthria Associated With Parkinson’s Disease
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作者 Qiang LI Abigail WALLACE +4 位作者 Wesley DAVIS Beau ROTH Laura LANGHOFER Shalini NARAYANA Michael CANNITO 《Chinese Journal of Applied Linguistics》 2024年第4期657-669,688,共14页
Smoothed cepstral peak prominence(CPPs)is a measurement of the distance from the prominent cepstral peak to the linear regression line directly beneath it.Variations of CPPs data acquisition and analysis lead to the c... Smoothed cepstral peak prominence(CPPs)is a measurement of the distance from the prominent cepstral peak to the linear regression line directly beneath it.Variations of CPPs data acquisition and analysis lead to the complexity of the clinical cut-off values,and there are no agreeable values for a specific voice disorder,such as hypokinetic dysarthria associated with Parkinson’s disease(PD).This study examined the CPPs in people with hypokinetic dysarthria associated with PD compared with healthy participants.Results demonstrated significant differences in speech tasks of sustained vowel and connected speech,with CPPs of connected speech more sensitive to dysphonia and gender difference in PD participants.Males in PD participants presented higher CPPs for sustained vowels and lower CPPs for connected speech than females.It is implied that a consistent clinical application protocol is necessary,and multiple acoustic measures are needed to ensure the accuracy of clinical decisions. 展开更多
关键词 cepstral peak prominence hypokinetic dysarthria VOICE Parkinson’s disease motor speech disorders
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采动影响下黏土隔水层失效过程的数值模拟研究 被引量:1
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作者 张星宇 刘世奇 +1 位作者 王海成 蒋裕华 《煤炭科学技术》 CAS 北大核心 2016年第S2期39-43,共5页
为研究黏土隔水层在采动影响下阻隔水性的变化规律,利用有限元分析软件Midas/GTS建立了近松散含水层开采工作面的流固耦合数值计算模型,分析了在多场耦合效应下,黏土隔水层中应力、位移、孔压等参数在其隔水性改变过程中的变化规律,进... 为研究黏土隔水层在采动影响下阻隔水性的变化规律,利用有限元分析软件Midas/GTS建立了近松散含水层开采工作面的流固耦合数值计算模型,分析了在多场耦合效应下,黏土隔水层中应力、位移、孔压等参数在其隔水性改变过程中的变化规律,进而探讨了黏土隔水层隔水性的变化规律及其所引起的顶板突水规律。结果表明:松散层能够阻止导水断裂带的向上发育,深厚黏土层具有明显的阻隔水作用;当地层达到一定的采动程度,黏土隔水层发生破坏,开采影响范围内的黏土隔水层中部容易且先发生破坏;隔水层在破坏前其底部会产生负孔隙压力,随着隔水性的失去负孔隙压力消散;黏土层的隔水性能并非因为其完整性的破坏而立即丧失,而是存在一个非单调的渐变过程。 展开更多
关键词 黏土隔水层 隔水性变化 数值模拟
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微地震监测在特厚煤层底板突水评价中的应用
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作者 秦九天 姜福兴 +2 位作者 王存文 梁兴旺 师克勐 《现代矿业》 CAS 2015年第2期108-112,119,共6页
特厚煤层综放开采对底板扰动大,在底板下方有承压含水层时,存在原生裂隙导水、采动裂隙导水、构造活化导水等底板突水灾害,动态监测底板裂隙的萌生、发展、贯通直至破坏过程是底板突水灾害有效预测、预警的关键。以平朔地区特厚煤层综... 特厚煤层综放开采对底板扰动大,在底板下方有承压含水层时,存在原生裂隙导水、采动裂隙导水、构造活化导水等底板突水灾害,动态监测底板裂隙的萌生、发展、贯通直至破坏过程是底板突水灾害有效预测、预警的关键。以平朔地区特厚煤层综放工作面回采过程中底板突水问题为研究背景,在工作面建立了一套自主研发的高精度微地震监测系统,实时获取采动过程中采场围岩破裂的三维特征,采用动突水系数法,对该工作面底板突水可能性进行了分析。研究表明:工作面向斜轴部以西90 m突水危险性增大,动突水系数达到峰值,但小于带压开采突水危险标准,认为工作面回采期间无突水危险。通过对比,动突水系数峰值位置与底板最大破裂深度位置具有明显的时空差异,且底板破裂深度峰值超前于动突水系数峰值,为通过底板破裂深度进行突水危险的实时预警提供了依据。 展开更多
关键词 特厚煤层 微地震监测 底板 水系数
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Influence range of emergency under special events based on CTM 被引量:6
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作者 陈茜 李文权 《Journal of Southeast University(English Edition)》 EI CAS 2009年第2期257-261,共5页
To determine the dynamic influence range of emergencies under special events, the spacial and temporal characteristics of the traffic flow are studied by simulation based on the cell transmission model (CTM). Based ... To determine the dynamic influence range of emergencies under special events, the spacial and temporal characteristics of the traffic flow are studied by simulation based on the cell transmission model (CTM). Based on the traffic management measures used under special events, a semi-dynamic assignment algorithm is proposed, which is combined with an algorithm for logit multi-path traffic assignment and the CTM. In a simple calculation network, the spacial and temporal characteristics of traffic flows which vary with different traffic management schemes are studied, and a method to obtain the influence range of emergency is proposed by computing the jam time of the intersections. By contrasting the average delay of each vehicle, the dissipation effect is studied under two different traffic management schemes. The example shows that the spatial and temporal variety of the traffic flow can be easily simulated and the influence range of emergency can be confirmed by the method based on the CTM. The proposed method provides a new idea for decision-making on traffic management under emergency under special events. 展开更多
关键词 traffic management special event EMERGENCY influence range cell transmission model (CTM)
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煤层下伏岩层采动变形规律及承压水突水机理研究
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作者 顾秀根 王家臣 刘玉德 《湖南科技大学学报(自然科学版)》 CAS 北大核心 2010年第2期1-5,共5页
煤层底板突水是华北区域煤矿事故的最主要原因.基于肥城矿区地质条件,应用FLAC3D软件和岩石力学电液伺服系统分别对开采煤层下伏岩层移动变形规律、岩体的渗透特性、岩体在渗流场作用下的变形破坏特征等方面进行了深入研究,分析了水体... 煤层底板突水是华北区域煤矿事故的最主要原因.基于肥城矿区地质条件,应用FLAC3D软件和岩石力学电液伺服系统分别对开采煤层下伏岩层移动变形规律、岩体的渗透特性、岩体在渗流场作用下的变形破坏特征等方面进行了深入研究,分析了水体上煤层开采突水机理,为确定高突危险水体上煤层的安全开采技术与工艺奠定了理论基础,具有十分重要和深远的意义. 展开更多
关键词 水体上 下伏岩层 FLAC 电液伺服
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Structural changes and volatility correlation in nonferrous metal market 被引量:1
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作者 吴丹 胡振华 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第10期2784-2792,共9页
The GARCH and DCC-GARCH models are used to study the volatility aggregation and dynamic relevance of China’s three kinds of nonferrous metals (copper, aluminum and zinc) pricesincorporating structural changes. The ... The GARCH and DCC-GARCH models are used to study the volatility aggregation and dynamic relevance of China’s three kinds of nonferrous metals (copper, aluminum and zinc) pricesincorporating structural changes. The results show that copper, aluminum and zinc returns have many structure breaks points, and nonferrous metals have the greatvolatilityrisk during financial crisis. From the resultsof GARCH with and without structural changes,it isfoundthat the volatility clustering of single nonferrous metal is overvalued when ignoring the structural mutation, and the return of aluminum isthe most overvalued, indicating that aluminum market is more susceptible to external shock.Furthermore,it is also foundthatdynamic volatility correlation exists in the three prices of nonferrous metals, and the structural changes have no significant effect on the volatility correlation of thethree nonferrous metals. 展开更多
关键词 copper ZINC ALUMINUM nonferrous metals price structural changes DCC-GARCH model volatilitydynamic correlation
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诗词四首
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作者 王浴海 《作文成功之路》 2004年第Z2期96-96,共1页
爵江月·怀乡一丛香蒲,几点芦花;一串鸟啭,几处鸣蛙,都能逗起我对故乡长长的思念。野泊荒塘,几户错落草房,绿柳白杨。鸡鸣犬吠,炊烟直,丛中一花翘望。白鹤兀立,在水一方,倒影留天上。长空望断,几番梦回故乡。小院柴扉柳墙,叶底莺藏... 爵江月·怀乡一丛香蒲,几点芦花;一串鸟啭,几处鸣蛙,都能逗起我对故乡长长的思念。野泊荒塘,几户错落草房,绿柳白杨。鸡鸣犬吠,炊烟直,丛中一花翘望。白鹤兀立,在水一方,倒影留天上。长空望断,几番梦回故乡。小院柴扉柳墙,叶底莺藏,瓣上蜂忙。雄鸡漫踱,鸭点首,门畔花猪半躺。麻雀忽起,犬叫骤响,有贵客来访。一蝶突动,款款越过柳墙。 展开更多
关键词 突动 香蒲 白杨 麻雀 鸡鸣 犬吠 芦花 白鹤 大开发 成功之路
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Spatial-temporal Evolution and Driving Force of Cultivated Land Quality in Henan Province
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作者 宋艳华 《Agricultural Science & Technology》 CAS 2017年第11期2106-2112,2126,共8页
The purpose of this study was to find out the spatial-temporal rules and driving force of cultivated land quality in Henan Province in the last ten years. Agricultural land grading factor evaluation was used to evalua... The purpose of this study was to find out the spatial-temporal rules and driving force of cultivated land quality in Henan Province in the last ten years. Agricultural land grading factor evaluation was used to evaluate the cultivated land quality of 2002 and 2012 in Henan Province, and to research the change laws. Method of correlation coefficient was employed to select the driving forces affecting cultivated land quality evolution. The results indicated that the cultivated land quality in Henan Province increased slightly in the last ten years in general, and in spatial there were unchanged regions, increased regions and decreased regions. The cultivated land quality in spatial presented the trend of good becoming better, bad becoming worse, which should be highly valued in cultivated land quality protection and management. Land development and consolidation projects had significant contributions to increasing the cultivated land quality. Driving forces between the sudden change regions and gradual change regions were significantly different. The paper concluded that the research on the spatial-temporal evolution and driving force of cultivated land quality based on cultivated land quality evolution had important academic significance and practical value. 展开更多
关键词 Cultivated land quality Spatial-temporal evolution Driving force Sudden change region Gradual change region Henan Province
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颞下颌关节陈旧性前脱位手法复位
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作者 刘治忠 《青岛医药卫生》 1995年第11期57-57,共1页
颞厂颌关节陈旧性前脱位在临床较为少见,复位难度随脱位时间的延长而增加。临床上多采用切开复位固定方法来治疗。笔者临床采用单纯手法复位(未用全麻、局麻、针麻及穴位按摩等措施)治疗颞下颌关节陈旧性前脱位效果良好。现介绍如下。
关键词 前脱位 陈旧性 颞下颌关节 手法复位 关节结节 位时间 突动 切开复位 复位方法 侧关节窝
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Effects of sudden change in wind loads on running performance of trains on a highway-railway one-story bridge in crosswinds 被引量:1
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作者 HAN Yan LIU Ye +2 位作者 CAI Chun-sheng HU Peng HE Xu-hui 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第8期2621-2638,共18页
To investigate the effects of sudden change in wind loads on the running performance of trains on the bridge in crosswinds,a highway-railway one-story bridge was taken as the research object.Aerodynamic coefficients o... To investigate the effects of sudden change in wind loads on the running performance of trains on the bridge in crosswinds,a highway-railway one-story bridge was taken as the research object.Aerodynamic coefficients of the train and the bridge were measured in a series of train-bridge system segment models through wind tunnel tests when two trains passed each other on the bridge and when a train entered and left the wind barrier section of the bridge.Based on the improved SIMPACK and ANSYS rigid-flexible coupling simulation method,a wind-double train-track-bridge system coupled vibration model was established.The dynamic responses of the train were analyzed under the effects of sudden change in wind loads caused by two trains passing each other and a train entering and leaving the wind barrier section of the bridge.The results show that the effects of sudden wind load change caused by the trains passing each other had less effects on the running safety of the leeward-side train than the wind shielding effect caused by the windward-side train in the wind speed range of 10−25 m/s.With the decrease in the porosity of wind barriers,the effects of the sudden wind load change played an increasingly important role in the running safety and comfort of the train.With the increase in wind speed,the lateral response of the train increased obviously because of the effects of sudden wind load change,which affects both the lateral running stability and the comfort of the train. 展开更多
关键词 wind-train-track-bridge system two trains passing each other wind barrier sudden change in wind load dynamic response
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Hepatitis B virus subgenotypes and basal core promoter mutations in Indonesia 被引量:4
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作者 Andi Utama Sigit Purwantomo +16 位作者 Marlinang Diarta Siburian Rama Dhenni Rino Alvani Gani Irsan Hasan Andri Sanityoso Upik Anderiani Miskad Fardah Akil Irawan Yusuf Wenny Astuti Achwan Soewignjo Soemohardjo Syafruddin AR Lelosutan Ruswhandi Martamala Benyamin Lukito Unggul Budihusodo Laurentius Adrianus Lesmana Ali Sulaiman Susan Tai 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第32期4028-4036,共9页
AIM: To identify the distribution of hepatitis B virus (HBV) subgenotype and basal core promoter (BCP) mutations among patients with HBV-associated liver disease in Indonesia.METHODS: Patients with chronic hepat... AIM: To identify the distribution of hepatitis B virus (HBV) subgenotype and basal core promoter (BCP) mutations among patients with HBV-associated liver disease in Indonesia.METHODS: Patients with chronic hepatitis (CH, n =61), liver cirrhosis (LC, n = 62), and hepatocellular carcinoma (HCC, n = 48) were included in this study. HBV subgenotype was identified based on S or preS gene sequence, and mutations in the HBx gene including the overlapping BCP region were examined by direct sequencing.RESULTS: HBV genotype B (subgenotypes B2, B3, B4, 85 and B7) the major genotype in the samples, accounted for 75.4%, 71.0% and 75.0% of CH, LC and HCC patients, respectively, while the genotype C (subgenotypes C1, C2 and C3) was detected in 24.6%, 29.0%, and 25.0% of CH, LC, and HCC patients, respectively. Subgenotypes B3 (84.9%) and C1 (82.2%) were the main subgenotype in HBV genotype B and C, respectively. Serotype adw2 (84.9%) and adrq+ (89.4%) were the most prevalent in HBV genotype B and C, respectively. Double mutation (A1762T/G1764A) in the BCP was significantly higher in LC (59.7%) and HCC (54.2%) than in CH (19.7%), suggesting that this mutation was associated with severity of liver disease. The T1753V was also higher in LC (46.8%), but lower in HCC (22.9%) and CH (18.0%), suggesting that this mutation may be an indicator of cirrhosis.CONCLUSION: HBV genotype B/B3 and C/C1 are the major genotypes in Indonesia. Mutations in BCP, such as A1762T/G1764A and T1753V, might have an association with manifestations of liver disease. 展开更多
关键词 Basal core promoter mutation Hepatitis Bvirus Indonesia Liver disease SUBGENOTYPE
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A GIS-based Earthquake and Tsunami Emergency Command System for Seaside Cities 被引量:3
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作者 GUAN Youhai FENG Qimin JIA Jing 《Journal of Ocean University of China》 SCIE CAS 2006年第2期181-186,共6页
In this paper the geographical information system (GIS) is applied to earthquake and tsunami emergency work and an earthquake and tsunami emergency command system (ETECS) for seaside cities is developed which is c... In this paper the geographical information system (GIS) is applied to earthquake and tsunami emergency work and an earthquake and tsunami emergency command system (ETECS) for seaside cities is developed which is composed of a basic database and six subsystems. By employing this system, the responsible municipal departments can make rapid prediction before the occurrence of earthquake or tsunami, make commanding decisions concerning the disaster-fight during the disastrous event, and make rapid estimates of the casualties and economic losses. So that the government could conduct relief work in time and planning for future disaster reduction and prevention. 展开更多
关键词 EARTHQUAKE TSUNAMI seismic emergency command anti-seism and disaster-reduction geographical information system (GIS)
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Prone-positioned upside-done arch exercise, a kind of lumbodorsal muscles training, curbs the progression of lumbar disc bulge 被引量:1
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作者 Zeng-Jie Gao Jiu-Yi Chen Yang Liu 《TMR Non-Drug Therapy》 2018年第1期9-15,共7页
Objective: To study the effects of prone-positioned upside-done arch exercise, a kind of lumbodorsal muscles training originated from Yoga, on curbing the progression of lumbar disc bulge. Methods: A total of 120 ou... Objective: To study the effects of prone-positioned upside-done arch exercise, a kind of lumbodorsal muscles training originated from Yoga, on curbing the progression of lumbar disc bulge. Methods: A total of 120 out-patients, diagnosed with lumbar disc bulge by CT and/or MRI, were randomly divided into the observation group and the control group, with 60 patients in each group. Patients in the observation group received the prone-positioned upside-done arch exercise combined with traction and acupuncture for two months and followed with a two-year treatment with prone-positioned upside-done arch exercise while the patients in the control group only received traction and acupuncture for two months. After two years, patients in both groups were investigated for the visual analogue score, MR image and straight leg raise tests. Results: Compared to the control group, prone-positioned upside-done arch exercise combined with traction and acupuncture showed significant decrease in patients’ visual analogue score, bulge size and the positive ratio of straight leg raise test (P = 0.001, P = 0.001 and P = 0.02 respectively), suggesting the inhibitory effect on the progression of lumber disc bulge. Conclusion: Prone-positioned upside-done arch has the potentials to protect patients with lumbar disc bulge from nerve root compression syndrome. 展开更多
关键词 Prone-positioned upside-done arch YOGA Lumbar disc bulge EXERCISE
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Numerical simulation on fault water-inrush based on fluid-solid coupling theory 被引量:3
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作者 HUANG Han-fu MAO Xian-biao +1 位作者 YAO Bang-hua PU Hai 《Journal of Coal Science & Engineering(China)》 2012年第3期291-296,共6页
About 75% water-inrush accidents in China are caused by geological structure such as faults, therefore, it is necessary to investigate the water-inrush mechanism of faults to provide references for the mining activity... About 75% water-inrush accidents in China are caused by geological structure such as faults, therefore, it is necessary to investigate the water-inrush mechanism of faults to provide references for the mining activity above confined water. In this paper, based on the fluid-solid coupling theory, we built the stress-seepage coupling model for rock, then we combined with an example of water-inrush caused by fault, studied the water-inrush mechanism by using the numerical software COMSOL Mutiphysics, analyzed the change rule of shear stress, vertical stress, plastic area and water pressure for stope with a fault, and estimated the water-inrush risk at the different distances between working faces and the fault. The numerical simula- tion results indicate that: (1) the water-inrush risk will grow as the decrease of the distance between working face and the fault; (2) the failure mode of the rock in floor with fault is shear failure; (3) the rock between water-containing fault and working face failure is the reason for water-inrush. 展开更多
关键词 FAULT fluid-solid coupling water inrush numerical simulation
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Nonlinear Mechanism of Bed Load Transport 被引量:1
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作者 徐海珏 白玉川 吴朝安 《Transactions of Tianjin University》 EI CAS 2009年第2期126-129,共4页
From the group movement of the bed load within the bottom layer,details of the nonlinear dynamic characteristics of bed load movement are discussed in this paper.Whether the sediment is initiated into motion correspon... From the group movement of the bed load within the bottom layer,details of the nonlinear dynamic characteristics of bed load movement are discussed in this paper.Whether the sediment is initiated into motion corresponds to whether the constant term in the equation is equal to zero.If constant term is zero and no dispersive force is considered,the equation represents the traditional Shields initiation curve,and if constant term is zero without the dispersive force being considered,then a new Shields curve which is much lower than the traditional one is got.The fixed point of the equation corresponds to the equilibrium sediment transport of bed load.In the mutation analysis,we have found that the inflection point is the demarcation point of breaking.In theory,the breaking point corresponds to the dividing boundary line,across which the bed form changes from flat bed to sand ripple or sand dune.Compared with the experimental data of Chatou Hydraulic Lab in France,the conclusions are verified. 展开更多
关键词 sediment transport open channel flow dynamic mechanical analysis
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Germline mutation analysis of MLH1 and MSH2 in Malaysian Lynch syndrome patients 被引量:3
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作者 Mohd Nizam Zahary Ravindran Ankathi +4 位作者 Human Genome Centre Gurjeet Kaur Muhammad Radzi Abu Hassan Harjinder Singh Venkatesh R Naik 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第8期814-820,共7页
AIM: To investigate the protein expression profi le of mismatch repair (MMR) genes in suspected cases of Lynch syndrome and to characterize the associated germline mutations. METHODS: Immunohistochemical analysis of t... AIM: To investigate the protein expression profi le of mismatch repair (MMR) genes in suspected cases of Lynch syndrome and to characterize the associated germline mutations. METHODS: Immunohistochemical analysis of tumor samples was performed to determine the protein expression profile of MMR protein. Germline mutation screening was carried out on peripheral blood samples. The entire exon regions of MLH1 and MSH2 geneswere amplifi ed by polymerase chain reaction, screened by denaturing high performance liquid chromatography (dHPLC) and analyzed by DNA sequencing to characterize the germline mutations. RESULTS: Three out of 34 tissue samples (8.8%) and four out of 34 tissue samples (11.8%) showed loss of nuclear staining by immunohistochemistry, indicating the absence of MLH1 and MSH2 protein expression in carcinoma cells, respectively. dHPLC analysis followed by DNA sequencing showed these samples to have germline mutations of MSH2 gene. However, no deleterious mutations were identifi ed in any of the 19 exons or coding regions of MLH1 gene, but we were able to identify MLH1 promoter polymorphism, -93G > A (rs1800734), in 21 out of 34 patients (61.8%). We identified one novel mutation, transversion mutation c.2005G > C, which resulted in a missense mutation (Gly669Arg), a transversion mutation in exon 1, c.142G > T, which resulted in a nonsense mutation (Glu48Stop) and splice-site mutation, c.2006-6T > C, which was adjacent to exon 13 of MSH2 gene. CONCLUSION: Germline mutations were identified in four Malaysian Lynch syndrome patients. Immunohistochemical analysis of tumor tissue proved to be a good pre-screening test before proceeding to germline mutation analysis of DNA MMR genes. 展开更多
关键词 Denaturing high performance liquid chromatography DNA sequencing Germline mutation Mismatch repair genes IMMUNOHISTOCHEMISTRY Lynchsyndrome
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