并联锂离子电池组建模及不均衡电流分析

近年来电池储能以其响应速度快、能量密度高等优点，在电力系统中发挥重要作用。为满足实际应用的要求，电池储能系统需要将电池或电池组并联从而达到较高的可用容量，但并联电池在实际中受内阻、容量、荷电状态 （SOC）等影响将出现电流不平衡现象，一定程度上制约了电池充放电电流和使用条件，影响了电池性能。针对并联电池组支路电流采集过程繁琐且状态估计复杂的情况，以电池的二阶等效电路为基础，结合回路电流法建立了并联电池组的仿真模型。模型能够根据锂电池的性能参数及状态方程实现并联支路电流的计算，进而估计并联电池组的状态，省去了对并联支路电流的检测环节。同时重点研究了并联电池组的支路不均衡电流现象，以磷酸铁锂电池为例，分析了并联电池组的充电特性。针对并联电池组的支路不均衡电流影响因素较为复杂、难以解耦的特性，采用控制变量法，通过模型详细分析了内阻、容量、初始SOC等因素对支路电流点的影响，为并联电池组的设计、成组优化及性能分析提供了参考

醋酸铬(Ⅱ)水合物实验的改进探索

广西民族学院教改项

Bt抗虫棉的种植对农药施用的影响

虽然Bt抗虫棉在我国得到迅速推广 ,但人们对其发展有不同的看法。本文旨在分　　析Bt抗虫棉在大田上的种植对棉农农药施用的影响。通过对主要棉花生产省份连续三　　年 ( 1 999～ 2 0 0 1年 ) 1 0 55个农户棉花生产情况数据的调查分析后得出结论 ,种植Bt抗虫　　棉比种植非Bt棉每公顷平均减少农药施用 35公斤 ,并由此推算出 1 997～ 2 0 0 1年由于抗　　虫棉推广使全国棉花生产的农药施用量减少了近 1 5万吨以上。在此基础上本文对结论　　的政策含义进行了讨

Effect of bright light therapy combined with five-element music therapy on negative emotions and sleep quality of pregnant women (强光联合五音疗法对孕妇负面情绪及睡眠质量的影响)

Objective To explore the effect of bright light therapy combined with five-element music therapy on negative emotions and sleep quality of pregnant women with depression. Methods Totally 70 cases of depressed pregnant women were selected and randomly divided into control group and study group, with 35 cases each. Patients in the two groups were given routine nursing programs, and the study group was given bright light therapy combined with five-element music therapy. The Self-rating Anxiety Scale(SAS) score, Self-rating Depression Scale (SDS) score, Pittsburgh Sleep Quality Index (PSQI) score and nursing quality indexes were compared between two groups. Results After intervention, except for the SDS score of the control group, the SAS, SDS and PSQI scores of the two groups were lower than before, and the differences were statistically significant (P<0. 01). The SAS, SDS and PSQI of the study group were lower than those of the control group (P<0. 01), and the scores of each item of nursing quality were higher than those of the control group, with significant differences(P<0. 01). Conclusion Bright light therapy combined with five-element music therapy can relieve the negative emotions and improve the sleep quality of pregnant women with depression. (目的 探讨强光联合五音疗法对孕妇负面情绪及睡眠质量的影响。方法 选择2019年1月—12月于苏州高新区人民医院就诊的抑郁孕妇70例, 按随机数字表法分为对照组和研究组, 各35例。2组孕妇均给予常规护理方案, 研究组增加强光联合五音疗法干预。比较2组产妇干预前后焦虑自评量表(SAS)、抑郁自评量表(SDS)、匹兹堡睡眠质量指数(PSQI)和护理质量指标。结果 干预后, 除对照组SDS评分外, 2组SAS、SDS和PSQI评分均较干预前降低, 差异有统计学意义(P<0. 01)。干预后研究组患者SAS、SDS和PSQI均低于对照组, 差异有统计学意义(P<0. 01)。研究组护理质量各项目评分均高于对照组, 差异有统计学意义(P<0. 01)。结论 强光联合五音疗法可改善孕妇的负面情绪和睡眠质量, 提高护理质量。

黄土高原降水计算插值与插值计算结果的对比分析

　收集黄土高原及周边地区74 个气象站1952 —2001 年降水数据, 用ArcGIS913 普通克里金(ordinary kriging) 插 值法采用计算插值(calculate then interpolate , CI) 和插值计算(interpolate then calculate , IC) 的方法生成黄土高原地区 1952 —2001 年50 a 平均年降水量和年降水量线性趋势系数空间分布表面, 并对其进行统计分析和地形分析。结果 表明: 1) 从插值结果统计值看, CI、IC 法生成的黄土高原地区50 a 平均年降水量和线性趋势系数空间分布表面平 均值分别为421165、421156 mm和- 01541 0、- 01423 1 mm/ a , 相似系数分别为99178 %和95199 % , 二者一致性良好; 2) 从插值结果表面光滑度看, IC 法稍优于CI 法,借用地形分析对生成表面进行坡度、坡向运算, 可作为评价表面 光滑度、空间数量变化特征和空间方向变化特征的直观方法; 3) 黄土高原地区50 a 平均年降水量具有东南多西北 少、南多北少、东多西少的分布规律, 其中服从东南西北、南北和东西方向递减的地带性分布规律区域占黄土高原 地区面积的89134 % , 非地带性分布规律区域占10166 %; 4) CI 和IC 法计算的黄土高原地区1952 —2001 年降水线 性趋势系数平均- 01541 0 和- 01423 1 mm/ a ,黄土高原地区年降水量有明显减少趋势

A Survey on the Ways to Chinese Accounting Postgraduate Education ——An Investigation Report of the Cultivation of MA Candidates in Accounting in China

本文以会计学硕士研究生培养为研究对象,通过对中国11所高校的在读会计学硕士研究生的问卷调查,从培养目标、培养方式、导师制、课程设置等多方面分析了会计学硕士培养中要解决的当务之急,最后为缩小会计学硕士生自身期望与现实的差距提出了相应建议。On the basis of the results of a questionnaire survey about accounting postgraduate education in 11 Chinese universities, we make an analysis into some important issues in accounting postgraduate education from such aspects as objectives, teaching methods, tutorial system and courses design. Some suggestions about bridging the gap between the expectation of the postgraduate candidates and the social reality are put forward

An investigation of depression and anxiety of the victims after Yushu earthquake

目的分析研究地震灾害对灾区患者抑郁焦虑的影响。方法采用抑郁自评和焦虑自评量表对住院灾区患者进行调查与评定,与中国成年常模相比较,分析观察指标的相关性。结果 155例灾区患者中抑郁、焦虑情绪的发生率分别为87.09%和53.55%;灾区患者存在一定程度的焦虑、抑郁状况,与文化程度、收入状况、汉语程度、受伤情况及有无陪员相关。结论在临床救治过程中,应考虑到文化程度、收入状况、汉语程度、受伤情况及有无陪员等因素。Objective To study the earthquake-caused depression and anxiety on the disasterstricken victims.Methods Self-rating depression scale and self-rating anxiety scale were used to investigate and evaluate the victims by comparing with Chinese norm and relevant observation factors.Results The incidence of depression and anxiety were 87.09%and 53.55%.Patients have some degree of anxiety and depression.The condition was related to educational level,income, language level,injury degrees and members accompanied.Conclusion In the course of clinical treatment and care,these factors are the essential ones to be considered.甘肃省技术研究与开发专项计划项目(1004TCYA009