浅谈红层地区小型水库的常见地质病害

根据对自贡地区300余座小一型及小二型水库病害的分析、统计,列出红层地区小型水库的普遍性地质病害,为川南、川北以及川东地区的水库病害整治提供一点借鉴作用。     

基于素质教育的中学地理教学改革与方法创新

结合中学地理教学目标、教材特点和当代中学生学习环境的变化,提出了基于素质教育的中学地理教师应具备的素质和技能:教师是复合型研究性人才;具有终身学习理念;具有科学方法论做指导;具有跨学科知识结构体系.根据目前中学地理教学的现状和问题,提出了基于素质教育的中学地理教学改革和方法创新的途径:自觉运用哲学理论和逻辑方法;软化学...     

8周健身运动处方教学对保健班学生身体成分的影响

为了解健身运动处方对保健班学生身体成分的影响,对齐齐哈尔大学23名保健班学生进行8周健身运动处方教学,并对所有学生在8周教学前后的体脂百分比、BMI和身体形态等指标进行测试.结果表明,保健班学生实验后的体脂百分比出现一定程度的下降,符合健康标准的人数逐步增多,胸围和呼吸差发生了一定的变化(P<0.05),腰围在低于风险...     

导引头稳定平台离散时间预设性能控制

针对现有离散时间预设性能控制方法对滑模趋近律依赖度高、抖振缺陷明显的难题,通过创建一种摆脱了滑模控制的设计新框架,为拦截弹导引头稳定平台提出了一种离散时间预设性能控制新方法。首先,设计一种离散时间性能函数对跟踪误差的收敛轨迹进行包络约束;然后,定义一种离散时间转换误差并将其用于构造一种新颖的反馈函数;设计离散时间控制律对新开发的反馈函数而不是转换误差进行镇定,不仅保证了所有跟踪误差均具有期望的预设性能,还摆脱了控制算法对滑模趋近律的依赖性,从根本上解决了控制抖振难题;最后,通过数值对比仿真验证了所提方法的有效性与优势。     

Correcting the January optimism effect

Each month, various professional forecasters give forecasts for next year's real gross domestic product (GDP) growth and unemployment. January is a special month, when the forecast horizon moves to the following calendar year. Instead of deleting the January data when analyzing forecast updates, I propose a periodic version of a test regression for weak-form efficiency. An application of this periodic model for many forecasts across a range of countries shows that in January GDP forecast updates are positive, whereas the forecast updates for unemployment are negative. I document that this January optimism about the new calendar year is detrimental to forecast accuracy. To empirically analyze Okun's law, I also propose a periodic test regression, and its application provides more support for this law.     

黄芪注射液治疗肺心病急性加重期73例疗效观察

目的:探讨黄芪注射液静脉注射治疗肺心病急性加重期的疗效.方法:对照组67例,采用常规的抗感染、平喘、强心及利尿等治疗;治疗组73例,在常规治疗的基础上同时加用黄芪注射液40mL溶于5%葡萄糖250mL中静脉滴注,每日一次,10d为一疗程.结果:治疗组和对照组的有效率分别为91.78%和74.63%(P<0.01);两组治疗后心输出量(CO,L/minm2)、心脏指数(CI)、左室射血分数(LVEF)、左室短轴缩短率(FS)、每搏输出量(SV)、二尖瓣快速充血期和心房收缩期血流速度(E/A)均较治疗前明显改善(P<0.05,P<0.01),但治疗组更优于对照组(P<0.05).两组动脉血气治疗后均有改善,但治疗组改善程度优于对照组(P<0.05).结论:黄芪注射液对肺心病急性加重期具有较好疗效.     

腹部消化器官病变部位与两类腹痛部位的关系

目的:探讨腹部消化器官疾病所致内脏痛及腹膜痛的部位与病变部位的关系.方法:收集1226例有腹痛表现的腹部消化器官疾病患者的临床资料,分别统计分析内脏痛部位及腹膜痛部位与内脏病变部位的关系.结果:内脏痛平面与病变内脏起源的原肠的平面呈正相关(rs=0.87,P<0.01).腹膜痛最先出现或最明显的部位与病变内脏的解剖部位一致(=0.96,P<0.01).结论:腹部消化器官疾病所致内脏痛及腹膜痛的部位均与病变部位显著相关.依据腹痛部位定位诊断,需要分清腹痛类型,分别根据内脏痛及腹膜痛部位推测病变内脏的胚胎起源及解剖部位.     

Intermittent demand forecasting in the Enterprise: Empirical verification

Forecasting methods are often valued by means of simulation studies. For intermittent demand items there are often very few non–zero observations, so it is hard to check any assumptions, because statistical information is often too weak to determine, for example, distribution of a variable. Therefore, it seems important to verify the forecasting methods on the basis of real data. The main aim of the article is an empirical verification of several forecasting methods applicable in case of intermittent demand. Some items are sold only in specific subperiods (in given month in each year, for example), but most forecasting methods (such as Croston's method) give non–zero forecasts for all periods. For example, summer work clothes should have non–zero forecasts only for summer months and many methods will usually provide non–zero forecasts for all months under consideration. This was the motivation for proposing and testing a new forecasting technique which can be applicable to seasonal items. In the article six methods were applied to construct separate forecasting systems: Croston's, SBA (Syntetos–Boylan Approximation), TSB (Teunter, Syntetos, Babai), MA (Moving Average), SES (Simple Exponential Smoothing) and SESAP (Simple Exponential Smoothing for Analogous subPeriods). The latter method (SESAP) is an author's proposal dedicated for companies facing the problem of seasonal items. By analogous subperiods the same subperiods in each year are understood, for example, the same months in each year. A data set from the real company was used to apply all the above forecasting procedures. That data set contained monthly time series for about nine thousand products. The forecasts accuracy was tested by means of both parametric and non–parametric measures. The scaled mean and the scaled root mean squared error were used to check biasedness and efficiency. Also, the mean absolute scaled error and the shares of best forecasts were estimated. The general conclusion is that in the analyzed company a forecasting system should be based on two forecasting methods: TSB and SESAP, but the latter method should be applied only to seasonal items (products sold only in specific subperiods). It also turned out that Croston's and SBA methods work worse than much simpler methods, such as SES or MA. The presented analysis might be helpful for enterprises facing the problem of forecasting intermittent items (and seasonal intermittent items as well).     

超支化不饱和聚(酰胺-酯)的改性及热分解动力学

采用不同链长的十四酰氯和十八酰氯对超支化不饱和聚(酰胺-酯)(MHBP)的端羟基进行原位端基改性,制备出2种改性超支化聚合物,用傅立叶红外光谱(FTIR)、热重分析(TGA)、黏度法等对其结构及性能进行表征,并研究了它们的热分解行为及其热分解动力学.结果表明,其热分解反应不是一级反应,改性超支化聚合物的热稳定性与末端烷烃链的长度有关,用Ozawa法求出了热分解表观活化能.     

三种方法测定碱性磷酸酶对肝疾病的诊断价值

目的研究血清碱性磷酸酶检测临床肝疾病时的方法学,提高临床诊断价值。方法收集临床不同肝疾病病人的血清,分别用3种方法测定其碱性磷酸酶的活性,并与健康对照组比较作诊断性能分析。结果各肝疾病组血清碱性磷酸酶的活性与对照组相比有极显著差异（P〈0．001）;3种方法分别测定各组之闻的血清碱性磷酸酶活性无显著性差异（P〉0．05）。2．乙基氨基乙醇、2-氨基-2-甲基-1-丙醇、二乙醇胺3种缓冲液测定试剂盒方法测定的灵敏度分别为55．20％、47．96％、51．13％,特异度分别为100％、100％、93．75％。结论血清碱性磷酸酶可以作为各类肝病的临床诊断指标;对肝疾病血清碱性磷酸酶测定用2,乙基氨基乙醇缓冲液的试剂方法测定效果较好。