目的探讨胃镜检查在无警告症状的消化不良患者中的临床诊断价值.方法以问卷调查形式,收集因消化不良进行门诊胃镜检查患者的资料,包括人口学资料、症状,并结合胃镜及病理组织学检查结果进行分析.结果共纳入521例患者,胃镜检查表现为主...目的探讨胃镜检查在无警告症状的消化不良患者中的临床诊断价值.方法以问卷调查形式,收集因消化不良进行门诊胃镜检查患者的资料,包括人口学资料、症状,并结合胃镜及病理组织学检查结果进行分析.结果共纳入521例患者,胃镜检查表现为主要病变的有163例(31.3%),包括糜烂性食管炎95例(18.2%)、消化性溃疡65例(12.5%)、上消化道恶性肿瘤3例(0.58%).多因素Logistic回归分析显示,男性、上腹痛、幽门螺杆菌(Helicobacter pylori, H. pylori)感染是胃镜检查结果为主要病变的独立危险因素.结论消化不良是消化科门诊患者主要就诊原因之一,对于这部分病人即使没有任何警告症状仍应行胃镜检查,特别是男性、有上腹痛症状以及H. pylori感染患者,以防遗漏消化性溃疡、反流性食管炎甚至恶性肿瘤等器质性疾病.展开更多
In this paper,a theoretical solution of vertical buckling is proposed with regard to the typical initial imperfection cases of submarine pipelines.Analytical tools are applied to predicting the occurrence and conseque...In this paper,a theoretical solution of vertical buckling is proposed with regard to the typical initial imperfection cases of submarine pipelines.Analytical tools are applied to predicting the occurrence and consequence of inservice buckling of a buried heated pipeline in Bohai Gulf.An evaluation is performed to ensure the pipeline structural integrity during operation under loading conditions.Different protection measures are proposed and their validities are analyzed.Analyses show that for the same magnitude of initial imperfection,the upheaval buckling of pipeline with isolated prop model is the most likely to occur.The empathetic model represents a special sub-case of continuous prop model,and the calculated buckle temperature is between the first stage and the second stage of post-upheaval buckling of continuous prop model.And the larger the initial imperfection,the less the axial force required for the upheaval buckling.Meanwhile,it can be seen that a peak point appears on the curves of temperature difference against buckling amplitude for small initial imperfection.Besides,trenching-burial is one kind of protection measures preventing the pipeline from thermal upheaval.The covered depth-to-diameter ratio depends on the design conditions and subsoil properties.For the given pipeline in this paper,the covered depth-to-diameter ratio is recommended to be 5.展开更多
The key technologies of precision blasting were put forward based on the characteristics of urban via- duct blasting demolition in complicated surroundings. Initial bending instability mechanics model of reinforcing s...The key technologies of precision blasting were put forward based on the characteristics of urban via- duct blasting demolition in complicated surroundings. Initial bending instability mechanics model of reinforcing steel bar frame of blasting fragmented pier and sequenced collapsed dynamic model were established for quanti- tative blasting design. Technologies of water pressure blasting were applied in multi-cell box girder fragmenta- tion. The detonating network of non-electric duplication crossover was adopted for the safety and reliability of ultra-long delay. The rationality of blasting scheme and parameters were validated by physical model test. Harm- ful effects were forecasted and controlled by integrated protective technologies. Specialization, cooperation, pre- cision, execution （SCPE） project management method was put forward for precision management. The key tech- nologies of precision demolition blasting can provide reference for similar proiects.展开更多
At present,water pollutant emission trading plays an increasingly important role in pollution control in many foreign countries,and its pilot studies and demonstration have also been started in China.In order to solve...At present,water pollutant emission trading plays an increasingly important role in pollution control in many foreign countries,and its pilot studies and demonstration have also been started in China.In order to solve the problem of initial allocation of emission permits:premise and basis of emission trading in a river basin,basic principles on initial allocation of actual emission permits in China are put forward.And it is thought that local development stage of industry should be taken into full account for initial allocation model of emission permits.There are five different allocation models in different development stages of industry,including models like distribution according to needs,improved same-rate reduction,performance,integration and environmental capacity,etc.The initial allocation of emission permits in various basins should choose a suitable model in accordance with their respective development stages.It is suggested in this article that integrated allocation model should be a main choice for current development stage of industry in China.展开更多
文摘目的探讨胃镜检查在无警告症状的消化不良患者中的临床诊断价值.方法以问卷调查形式,收集因消化不良进行门诊胃镜检查患者的资料,包括人口学资料、症状,并结合胃镜及病理组织学检查结果进行分析.结果共纳入521例患者,胃镜检查表现为主要病变的有163例(31.3%),包括糜烂性食管炎95例(18.2%)、消化性溃疡65例(12.5%)、上消化道恶性肿瘤3例(0.58%).多因素Logistic回归分析显示,男性、上腹痛、幽门螺杆菌(Helicobacter pylori, H. pylori)感染是胃镜检查结果为主要病变的独立危险因素.结论消化不良是消化科门诊患者主要就诊原因之一,对于这部分病人即使没有任何警告症状仍应行胃镜检查,特别是男性、有上腹痛症状以及H. pylori感染患者,以防遗漏消化性溃疡、反流性食管炎甚至恶性肿瘤等器质性疾病.
基金Supported by National Natural Science Foundation of China (No.40776055)
文摘In this paper,a theoretical solution of vertical buckling is proposed with regard to the typical initial imperfection cases of submarine pipelines.Analytical tools are applied to predicting the occurrence and consequence of inservice buckling of a buried heated pipeline in Bohai Gulf.An evaluation is performed to ensure the pipeline structural integrity during operation under loading conditions.Different protection measures are proposed and their validities are analyzed.Analyses show that for the same magnitude of initial imperfection,the upheaval buckling of pipeline with isolated prop model is the most likely to occur.The empathetic model represents a special sub-case of continuous prop model,and the calculated buckle temperature is between the first stage and the second stage of post-upheaval buckling of continuous prop model.And the larger the initial imperfection,the less the axial force required for the upheaval buckling.Meanwhile,it can be seen that a peak point appears on the curves of temperature difference against buckling amplitude for small initial imperfection.Besides,trenching-burial is one kind of protection measures preventing the pipeline from thermal upheaval.The covered depth-to-diameter ratio depends on the design conditions and subsoil properties.For the given pipeline in this paper,the covered depth-to-diameter ratio is recommended to be 5.
文摘The key technologies of precision blasting were put forward based on the characteristics of urban via- duct blasting demolition in complicated surroundings. Initial bending instability mechanics model of reinforcing steel bar frame of blasting fragmented pier and sequenced collapsed dynamic model were established for quanti- tative blasting design. Technologies of water pressure blasting were applied in multi-cell box girder fragmenta- tion. The detonating network of non-electric duplication crossover was adopted for the safety and reliability of ultra-long delay. The rationality of blasting scheme and parameters were validated by physical model test. Harm- ful effects were forecasted and controlled by integrated protective technologies. Specialization, cooperation, pre- cision, execution （SCPE） project management method was put forward for precision management. The key tech- nologies of precision demolition blasting can provide reference for similar proiects.
基金Research sponsored by the Major Project of National Science and Technology of China(Grant no.2009ZX07210)
文摘At present,water pollutant emission trading plays an increasingly important role in pollution control in many foreign countries,and its pilot studies and demonstration have also been started in China.In order to solve the problem of initial allocation of emission permits:premise and basis of emission trading in a river basin,basic principles on initial allocation of actual emission permits in China are put forward.And it is thought that local development stage of industry should be taken into full account for initial allocation model of emission permits.There are five different allocation models in different development stages of industry,including models like distribution according to needs,improved same-rate reduction,performance,integration and environmental capacity,etc.The initial allocation of emission permits in various basins should choose a suitable model in accordance with their respective development stages.It is suggested in this article that integrated allocation model should be a main choice for current development stage of industry in China.
