Meta-分析中的统计学过程

从应用的角度出发,介绍Meta-分析的目的、意义、主要统计内容、两种统计模型、统计指标。最后引入了一个实例用Revman4.1软件处理,并对该分析结果进行了临床意义的解释。着重于Meta-分析的思路介绍,回避了统计学的数学公式,有助于临床医生对Meta-分析的认识和理解。

近红外光谱法和统计学过程控制方法对亚叶酸钙药品对照品水分进行质量控制的研究

目的应用近红外光谱技术对化学药品对照品水分质量控制和警戒方法开展研究,结合统计学方法和多元校正方法建立质量控制图,开发对化学药品对照品水分测定和质量监控的方法。方法以亚叶酸钙对照品为研究对象,应用近红外光谱技术对分装后的对照品水分进行测定;以卡氏水分测定结果为参考,建立近红外光谱法水分测定定量模型;结合统计学控制图确定亚叶酸钙化学药品对照品水分测定值的上下限,进而实现近红外光谱对水分的无损检测和质量控制。结果本研究建立的近红外光谱水分测定定量模型稳健准确,可实现亚叶酸钙对照品水分的无损测定,同时可实现化学对照品在分装过程中水分均匀性和稳定性的质量控制。结论将近红外光谱法与统计学质量控制原理相结合,可作为化学药品对照品水分质量控制的新方法,实现在线、无损测定和质量监控。

Multivariate Statistical Process Monitoring and Control: Recent Developments and Applications to Chemical Industry

Multivariate statistical process monitoring and control (MSPM&C) methods for chemical process monitoring with statistical projection techniques such as principal component analysis (PCA) and partial least squares (PLS) are surveyed in this paper. The four-step procedure of performing MSPM&C for chemical process, modeling of processes, detecting abnormal events or faults, identifying the variable(s) responsible for the faults and diagnosing the source cause for the abnormal behavior, is analyzed. Several main research directions of MSPM&C reported in the literature are discussed, such as multi-way principal component analysis (MPCA) for batch process, statistical monitoring and control for nonlinear process, dynamic PCA and dynamic PLS, and on-line quality control by inferential models. Industrial applications of MSPM&C to several typical chemical processes, such as chemical reactor, distillation column, polymerization process, petroleum refinery units, are summarized. Finally, some concluding remarks and future considerations are made.

An efficient latent variable optimization approach with stochastic constraints for complex industrial process

For complex chemical processes,process optimization is usually performed on causal models from first principle models.When the mechanism models cannot be obtained easily,restricted model built by process data is used for dynamic process optimization.A new strategy is proposed for complex process optimization,in which latent variables are used as decision variables and statistics is used to describe constraints.As the constraint condition will be more complex by projecting the original variable to latent space,Hotelling T^2 statistics is introduced for constraint formulation in latent space.In this way,the constraint is simplified when the optimization is solved in low-dimensional space of latent variable.The validity of the methodology is illustrated in pH-level optimal control process and practical polypropylene grade transition process.

Mirizzi Syndrome: Our Experience with 27 Cases in PUMC Hospital

Objective To retrospectively evaluate the diagnosis and treatment of Mirizzi syndrome （MS）. Methods Patients who received elective or emergency cholecystectomies in our center during 23 years were retrospectively evaluated. The data reviewed included demography, clinical presentations, diagnostic methods, surgical procedures, postoperative complications, and follow-up.

The Use of Task-Based Activities to Improve Listening and Speaking Skills in EFL Context

The aim of this study was to improve EFL learners＇ English listening and speaking skills at a State University in Turkey, School of Foreign Languages, Department of Basic English B1 and BI＋ groups through task-based activities. The participants were 56 in total, studying in the academic year of 2014-2015 Spring Fall. The instruments used for collecting data were 16 lesson plans and the speaking and listening quiz results as post-tests. The data were statistically analyzed by mean, max, and min values of the scores. Teaching process and the lesson plans were recorded by researcher then presented in essay form. After the implementation and the post-tests, the participants＇ opinions about the task were collected as an interview. The results of the study showed that B1 groups did not get significant results from listening test and get nearly significant scores from speaking test while the listening and speaking results of BI＋ groups through task-based learning after the implementations were highly significant, which shows that their participation in the task-based activities in the classroom reflected the results positively. Also the students＇ opinions about task-based learning and teaching activities were respectively positive. As a result, it can be said that task-based activities play a significant role in improving listening and speaking skills in EFL settings.

Relationship Between English Learning Strategies and Learning Style Preferences： An Empirical Study

In recent years, research emphasis in the field of SLA （second language acquisition） has shifted to the study of the learning process and behaviors of learners than that of teachers. Researches concerning the learners＇ language learning strategies and learning styles have been conducted in different cultural backgrounds. However, comparatively speaking, there are few studies focusing on the relationship between language learning strategies and learning style preferences in English learning among Chinese students. This paper elaborates on the research questions and hypotheses according to the English Learning Questionnaire, which consists primarily of SILL （Strategy Inventory for Language Learning） （Oxford, 1990） and PLSP （Perceptual Learning Style Preference） Survey （Reid, 1987） to identify their English learning strategy uses and learning style preferences. Then, with statistical analysis （by SPSS （Statistical Product and Service Solutions）） of the results of the questionnaire, discussions are made on the correlation between learning strategies, learning style preferences, and their gender differences, followed by pedagogical implications for English teaching and learning in the university settings in China.

Expression and significance of cyclooxygenase-2 in human lung cancer

Objective: We aimed to examine the expression of cyclooxygenase-2 and the relationship with the pathological types, TNM stage, lymph node metastasis, the degree of differentiation, smoking and the survival. Methods: Immunohistochemical staining method was used to examine the expression of cyclooxygenase-2 of 121 cases of lung cancer and three control groups. The data were statistically analyzed. Results: Compared with the health group, cyclooxygenase-2 was over expressed in the inflammatory tissue(P = 0.036), lung adenocarcinoma(P = 0.005) and squamous carcinoma(P = 0.047). Compared with patients without lymph node metastasis, cyclooxygenase-2 was over expressed(P = 0.033) in patients with lymph node metastasis. Compared with high differentiation group, cyclooxygenase-2 was over expressed(P = 0.004) in low differentiation group. Compared with non-smokers, the expression of cyclooxygenase-2 increased in smokers(P = 0.000). The median survival time of patients that the expression of cyclooxygenase-2 were negative was 9 months(95% CI, 5.6–12.4 months). The median survival time of patients that the expression of cyclooxygenase-2 were positive was 5 months(95% CI, 3–7 months). They was statistical difference(P = 0.001). Conclusion: Overexpression of cyclooxygenase-2 is associated with pathological types, TNM stage, lymph node metastasis, degrees of differentiation, smoking and prognosis in lung cancer.

Research on Remote Aerobics Network Learning System based on B/S

through the design of teaching aerobics web-based course and application practice, the instructional design process based on B/ S learning are analyzed, and discusses several key problems in the design and teaching. This paper presents the resource based learning aerobics teaching design network course should adapt to the application mode of network teaching and traditional classroom combination; that will provide teaching demonstration, teaching contents for students as well as the function of self testing evaluation and provide the job management, teacher online Q ＆ A, database and knowledge base construction, greatly improving the ＂aerobics＂ teaching efficiency.

Wear analysis of revolute joints with clearance in multibody systems

In this work, the prediction of wear for revolute joint with clearance in multibody systems is investigated using a computational methodology. The contact model in clearance joint is established using a new hybrid nonlinear contact force model and the friction effect is considered by using a modified Coulomb friction model. The dynamics model of multibody system with clearance is established using dynamic segmentation modeling method and the computational process for wear analysis of clearance joint in multibody systems is presented. The main computational process for wear analysis of clearance joint includes two steps, which are dynamics analysis and wear analysis. The dynamics simulation of multibody system with revolute clearance joint is carried out and the contact forces are drawn and used to calculate the wear amount of revolute clearance joint based on the Archard's wear model. Finally, a four-bar multibody mechanical system with revolute clearance joint is used as numerical example application to perform the simulation and show the dynamics responses and wear characteristics of multibody systems with revolute clearance joint. The main results of this work indicate that the contact between the joint elements is wider and more frequent in some specific regions and the wear phenomenon is not regular around the joint surface, which causes the clearance size increase non-regularly after clearance joint wear. This work presents an effective method to predict wear of revolute joint with clearance in multibody systems.

Advances in numerical algorithms and methods in computational geosciences with modeling characteristics of multiple physical and chemical processes

This paper aims to provide a brief introduction to recent advances in numerical algorithms and methods in the emerging computational geoscience filed with general simulation characteristics of modeling multiple chemical and physical processes that take place in ore-generating systems within the Earth's crust. Due to significant differences between Earth systems and engineering systems, the existing numerical algorithms and methods, which are designed for simulating realistic problems in the engineering fields, may not be straightforwardly used to simulate ore-generating problems without significant improvements. Thus, extensive and systematic studies have been conducted, in recent years, to develop new numerical algorithms and methods for simulating different aspects of ore-generating problems. Not only can the outcomes of these studies provide new simulation tools for better understanding the controlled dynamic mechanisms that take place in ore-generating systems, but also they have enriched the research contents of computational mechanics in the broad sense.