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排序方式: 共有2287条查询结果,搜索用时 8 毫秒
21.
对BIM国际前沿文献进行跟踪研究,梳理BIM在建设工程项目中的主要应用模式。在分析建设工程创新特性的基础上,指出BIM为建设工程项目各参与组织构建了合作创新的工作环境。依据建设工程创新类别,分析BIM应用模式的创新定位,探索BIM在建设工程创新中的价值。  相似文献   
22.
沉积微相约束条件下的随机地质建模方法及应用研究   总被引:12,自引:0,他引:12  
以地质建模为主要研究对象,根据油田开发地质研究需要完善的方法技术,以建模方法研究为基础,进行了沉积微相约束地质建模综合研究.在分析目前国内外研究现状的基础上,针对我国开发地质研究工作的特点,提出根据测井解释成果,应用随机模拟的方法定量地开展沉积微相研究.应用沉积微相研究成果约束测井储层参数的分布,形成油藏数值模拟研究所需要的准确的储层三维地质模型,解决了常规油田开发地质研究过程中沉积相研究成果与储层参数分布无法有效结合的缺陷.应用与该方法相适应的IRMS软件成功实现了山东胜利油区孤东油田第七开发区西部上第三系馆陶组油藏精确的沉积微相模型,由此微相约束形成的油藏储层三维地质模型数据体直接应用于油藏数值模拟研究,应用效果及现场实施的效果良好.  相似文献   
23.
Research and development activities are regarded as one of the most influencing factors of the future of a country. Large investments in research can yield a tremendous outcome in terms of a country’s overall wealth and strength. However, public financial resources of countries are often limited which calls for a wise and targeted investment. Scientific publications are considered as one of the main outputs of research investment. Although the general trend of scientific publications is increasing, a detailed analysis is required to monitor the research trends and assess whether they are in line with the top research priorities of the country. Such focused monitoring can shed light on scientific activities evolution as well as the formation of new research areas, thus helping governments to adjust priorities, if required. But monitoring the output of the funded research manually is not only very expensive and difficult, it is also subjective. Using structural topic models, in this paper we evaluated the trends in academic research performed by federally funded Canadian researchers during the time-frame of 2000–2018, covering more than 140,000 research publications. The proposed approach makes it possible to objectively and systematically monitor research projects, or any other set of documents related to research activities such as funding proposals, at large-scale. Our results confirm the accordance between the performed federally funded research projects and the top research priorities of Canada.  相似文献   
24.
Objective: To study the effect of halo substitution on disubstituted aryl semicarbazones on the anticonvulsant potential and model the activity based on quantum mechanics. Methods: A series of twenty-six compounds of N^4-(4-bromo-3-methylphenyl) semicarbazones were synthesized and evaluated for the anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure threshold tests. Some potential compounds were also tested in the subcutaneous strychnine (scSTY) and subcutaneous picrotoxin (scPIC) seizure threshold tests. The synthesized compounds were tested for behavioral impairment and CNS (central nervous system) depression in mice. Quantum mechanical modelling was carried out on these compounds to gain understanding on the structural features essential for activity. Results: Some compounds possessed broad spectrum anticonvulsant activity as indicated by their effect in pentylenetetrazole, strychnine, picrotoxin and maximal electroshock seizures models in resemblance to other aryl semicarbazone derivatives reported earlier. The higher the difference in HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy levels was, the greater was the activity profile. Conclusion: The pharmacophoric requirements for compounds to exhibit anticonvulsant activity that includes one aryl unit in proximity to a hydrogen donor-acceptor domain and an electron donor have been justified with the molecular orbital surface analysis of the synthesized compounds.  相似文献   
25.
设计制作了"旋风除尘器操作试验台",该装置能调节风量、进灰量等各种试验参数,可观察除尘器内部的气流运动、除尘效果和灰分收集情况,为"大气污染控制工程"和"锅炉原理"等课程的教学提供了实验手段。通过对旋风除尘器的工作原理及结构进行分析,建立以除尘效率、压力损失为目标函数的双目标数学模型。考虑了设计变量和约束条件后,经过优化设计,寻找出旋风除尘器的最优化结构参数,绘制试验平台结构图,并制作了旋风除尘器操作试验台。  相似文献   
26.
通过对滚柱式超越离合器的工作原理及结构进行分析,运用SolidWorks软件实现三维实体建模及装配,并结合SolidWorks_COSMOSMotion模块对超越离合器的单向转动、反向空转和超越转动进行运动仿真分析。  相似文献   
27.
从符号与数值的转化、同余映射中的周期长度及分阶段执行程序等3个方面,以实际例子研究了如何在实践中运用数学原理来优化程序设计、节约运行时间,达到利于解决数学建模问题的目标。  相似文献   
28.
The Technology Acceptance Model (TAM) is a key model describing teachers' intentions to use technology. This meta-analysis clarifies some of the contradictory findings surrounding the relations within the TAM for a sample of 45 studies comprising 300 correlations. We evaluate the overall fit of the TAM and its structural parameters, and quantify the between-sample variation through meta-analytic structural equation modeling. The TAM fitted the data well, and all structural parameters were statistically significant. On average, the TAM variables explained 39.2% of the variance in teachers' intentions to use technology. Several sample, measurement, and publication characteristics, including teachers’ experience and the representation of the TAM variables, moderated the relations within the TAM. Overall, the TAM represents a valid model explaining technology acceptance—however, the degree of explanation and the relative importance of predictors vary across samples. Implications for further research, in particular the generalizability of the TAM, are discussed.  相似文献   
29.
数学建模的思想已经渗入理科各个学科,而数学建模真正走进课堂还需要认真探讨与实践。分析了高等数学教学中结合数学建模思想的重要性与可行性,联系高等数学教学中的一个内容即微分方程问题,探讨了高等数学教学与数学建模的有机结合.  相似文献   
30.
大学生创新能力的培养是数学建模活动的重要目的,要在双师型、复合型教师团队带领下,以教师科研子课题、时事热点和已就业学生求助问题等立项实行招标,引入企业机制对数学建模创新实验室进行引导和管理,对入驻项目实施流程化、规范化管理。对项目成果实行多目标提取。  相似文献   
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