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关键词： 电力电子装置   电力系统   实际应用  

摘要： 随着科学技术的不断发展,电力电子技术也进入了飞速发展的阶段,在电力系统中采用了大量的先进的电力电子装置,它在是电网可靠、安全运行的同时为电力系统的可持续发展提供了有利的保障。本文就是针对我国电力系统的运行现状、电力电力装置的特点以及其在电力系统中的具体应用进行了具体的分析。

关键词： Systematic review   Meta analysis   Guideline   Evidence based medicine   NUCLEAR-MEDICINE PRACTICE   HETEROGENEITY   SENSITIVITY  

摘要： Background Actually, systematic reviews and meta-analyses are the cornerstone of evidence-based practice and the number of these evidence-based articles on diagnostic studies is increasing. Objective The aim of this article is to provide a practical guideline for the researchers who intend to perform a systematic review or meta-analysis of diagnostic studies. Methods A guideline was prepared according to the Preferred Reporting Items for Systematic Reviews and MetaAnalyses (PRISMA) and Cochrane handbook for systematic reviews of diagnostic test accuracy. Results Several steps needed for systematic reviews or meta-analyses of diagnostic studies are briefly discussed (i. e. formulating the question of systematic reviews, search strategy, inclusion and exclusion criteria, quality assessment of the included studies, data extraction, pooling diagnostic indices across studies, reporting heterogeneity and discussion of main findings). Conclusion To publish a high-quality systematic review or meta-analysis of diagnostic test accuracy, certain methodology should be followed. Only methodologically sound systematic reviews or meta-analyses can change or support the clinical use of a diagnostic test. Actually, systematic reviews and meta-analyses are the cornerstone of evidence-based practice and the number of these evidence-based articles on diagnostic studies is increasing.

关键词： Uncertainty assessment   Guidance   Modeling   Ecosystem services   Best practice   SPATIALLY-EXPLICIT SENSITIVITY   LAND-USE   THEORETICAL FRAMEWORK   DECISION-MAKING   MODEL   SUPPORT   SCENARIOS   QUANTITY   SCIENCE   CLIMATE  

摘要： Ecosystem services (ES) analyses are increasingly used to address societal challenges, but too often are not accompanied by uncertainty assessment. This omission limits the validity of their findings and may undermine the `science-based' decisions they inform. We summarize and analyze seven commonly perceived challenges to conducting uncertainty assessment that help explain why it often receives superficial treatment in ES studies. We connect these challenges to solutions in relevant scientific literature and guidance documents. Since ES science is based on a multiplicity of disciplines (e.g. ecology, hydrology, economics, environmental modeling, policy sciences), substantial knowledge already exists to identify, quantify, and communicate uncertainties. The integration of these disciplines for solution-oriented modeling has been the focus of the integrated assessment community for many years, and we argue that many insights and best practices from this field can be directly used to improve ES assessments. We also recognize a number of issues that hinder the adoption of uncertainty assessment as part of standard practice. Our synthesis provides a starting point for ES analysts and other applied modelers looking for further guidance on uncertainty assessment and helps scientists and decision-makers to set reasonable expectations for characterizing the level of confidence associated with an ES assessment.

关键词： 桥梁   隧道   养护   课程改革   探索   实践  

摘要： 结合多年《公路桥梁与隧道养护》教学工作,从教学中遇到的问题、优化授课内容、夯实实习实训环节、集中实训、考核创新等方面阐述了在课程改革中的探索与实践,从而取得了明显的教学效果和实训效果。

关键词： 肝肿瘤   门静脉栓塞术   肝切除术   综述  

摘要： 目前,手术切除部分肝叶仍然是治疗肝脏原发性或转移性恶性肿瘤首选和最有效的方法,然而术后残余肝脏容积不足容易发生肝衰竭,影响预后。选择性门静脉栓塞术通过栓塞荷瘤侧门静脉分支,从而使门静脉血流重分配,增加对侧肝组织的门静脉血流,来增加余留肝脏体积。综述了选择性门静脉栓塞术的理论基础及其在临床中的应用,作为肝切除术前的辅助治疗方法,降低术后肝衰竭发生率,提高肿瘤切除率和手术的安全性,使原来无法行手术治疗的患者得到了手术的机会。

关键词： 期末考试   总结   思考   试卷  

摘要： 本文以《土壤与土壤地理学》课程期末考试为例,对考试试卷从总体质量、试卷内容、试卷题目类型等方面做一个总结,同时对教师的"教"和学生的"学"引发了一些思考。

摘要： Objectives: Clinical laboratories frequently receive “extra” tubes of blood, urine, or body fluids. At the time of collection, these specimens have no testing associated with them. The present study seeks to analyze patterns of extra tube collection over an extended time period; we also analyzed utilization of extra tubes for add-on testing after implementation of new laboratory information system (LIS) software (Epic Beaker).Methods: In this retrospective study at an academic medical center, electronic health records were searched to obtain all extra tube orders that were placed during the time period April 1, 2004, to June 15, 2015. Add-on orders placed after implementation of the Epic Beaker software were obtained from August 2, 2014, to June 15, 2015.Results: During the time period of retrospective study, 745,666 extra tubes were collected from 193,596 patients. The emergency department accounted for 37.5% of extra tubes (n = 279,729). Outpatient clinics and services accounted for 32.9% of extra tubes (n = 245,246). Inpatient units accounted for 29.4% of extra tubes (n = 219,493). Operating rooms accounted for 0.2% of extra tubes (n = 1,200). For the period during which we analyzed utilization of extra tubes for add-on testing, 48.6% of add-on orders associated with an extra tube were for chemistry tests, and 43.6% were for hematology and coagulation tests. A single patient had 232 extra tubes collected while receiving care at the institution during the period of study; 572 patients were identified with more than 50 extra tubes collected during the period of study. We observed extra tube totals decrease upon implementation of paperless ordering and implementation of a new LIS. In addition, interventions in two outpatient clinics associated with very high use of extra tubes yielded significant decreases in extra tube collection. In the period since implementation of Epic Beaker, 10.7% of extra tubes were used for add-on test

关键词： PROLONGED EXERCISE   THERMOREGULATORY RESPONSES   CYCLING PERFORMANCE   RUNNING PERFORMANCE   DRINK TEMPERATURE   CORE TEMPERATURE   BODY-TEMPERATURE   THERMAL COMFORT   HEAT   HYPERTHERMIA  

摘要： Background Performing exercise in thermally stressful environments impairs exercise capacity and performance. Cooling during exercise has the potential to attenuate detrimental increases in body temperature and improve exercise capacity and performance. Objective The objective of this review was to assess the effectiveness of practical cooling strategies applied during continuous exercise in hot environments on body temperature, heart rate, whole body sweat production, rating of perceived exertion (RPE), thermal perception and exercise performance. Methods Electronic database searches of MEDLINE, SPORTDiscus, Scopus and Physiotherapy Evidence Database (PEDro) were conducted using medical subject headings, indexing terms and keywords. Studies were eligible if participants were defined as 'healthy', the exercise task was conducted in an environment >= 25 degrees C, it used a cooling strategy that would be practical for athletes to use during competition, cooling was applied during a self-paced or fixed-intensity trial, participants exercised continuously, and the study was a randomised controlled trial with the comparator either a thermoneutral equivalent or no cooling. Data for experimental and comparator groups were meta-analysed and expressed as a standardised mean difference and 95 % confidence interval. Results Fourteen studies including 135 participants met the eligibility criteria. Confidence intervals for meta- analysed data included beneficial and detrimental effects for cooling during exercise on core temperature, mean skin temperature, heart rate and sweat production during fixed-intensity exercise. Cooling benefited RPE and thermal perception during fixed-intensity exercise and improved self-paced exercise performance. Conclusion Cooling during fixed-intensity exercise, particularly before a self-paced exercise trial, improves endurance performance in hot environments by benefiting RPE and thermal perception, but does not appear to attenuate increases in b

关键词： 危废   余热锅炉   事故   成因分析  

摘要： 危废处置中,余热锅炉作为换热设备,目的是将烟气的温度从1 100~1 200℃降至500~600℃以下,同时,产生的低压蒸汽供整个厂区其他工艺单元使用。如果锅炉出口烟气温度不能降至550℃以下将直接影响其下游设备急冷塔的热负荷,甚至会因此造成烟气在急冷塔内再次合成二噁英。因此,余热锅炉能否安全有效运行直接影响其下游烟气处理设备是否能正常运行、烟气排放是否达标、生产是否安全。其运行过程中,也会存在各种问题,甚至发生事故,从而导余热致锅炉运行效率降低甚至停产,严重时甚至能导致人身财产安全受到威胁。笔者希望能通过对运行过程中经常出现的问题及事故进行成因分析,以达到规范生产操作、做到防范于未然、把损失降至最低的目的。