时变时滞及中立型时滞大系统的稳定条件

应用大系统的分解方法和一个不等式对具有时变时滞与连接时滞的两类系统进行了研究,给出了其渐近稳定的充分条件,并对一类中立型时滞大系统进行了讨论,利用常数变易法及对系统微分方程解的直接估计,获得了一个关于此系统解的指数稳定的判别方法,对这两类系统的讨论都是在具有连接时滞与变时滞的复杂情况下进行,得到了与以前的文献不同的结果.     

大型重载轴承CAD系统的研究与开发

介绍了一种基于轴承“极限负荷设计法”的智能化、专业化CAD系统 ,改变了传统轴承设计的设计周期长、分析计算繁杂且计算结果不准确、不易实现最优化参数设计的缺陷。该系统已经在成都科华重型轴承有限公司推广使用     

A GIS-Based Framework for Hazardous Materials Transport Risk Assessment

This article presents a methodology for assessment of the hazardous materials transport risk in a multicommodity, multiple origin-destination setting. The proposed risk assessment methodology was integrated with a Geographical Information System (GIS), which made large-scale implementation possible. A GIS-based model of the truck shipments of dangerous goods via the highway network of Quebec and Ontario was developed. Based on the origin and destination of each shipment, the risk associated with the routes that minimize (1) the transport distance, (2) the population exposure, (3) the expected number of people to be evacuated in case of an incident, and (4) the probability of an incident during transportation was evaluated. Using these assessments, a government agency can estimate the impact of alternative policies that could alter the carriers' route choices. A related issue is the spatial distribution of transport risk, because an unfair distribution is likely to cause public concern. Thus, an analysis of transport risk equity in the provinces of Quebec and Ontario is also provided.     

Probiotics and human lactational mastitis: A scoping review

ProblemLactational mastitis is a common condition amongst breastfeeding women. It is associated with decreased breastfeeding rates and often treated with antibiotics.BackgroundThe anti-inflammatory effects of probiotics have been identified as a potential treatment or prevention strategy for lactational mastitis leading to increased commercial and public interest. Despite the marketing of probiotics to women, evidence is still emerging as to its efficacy.Aim/MethodsThis scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) to identify and examine the evidence around probiotic consumption and lactational mastitis. The review addressed the question; what is the evidence regarding probiotic consumption and human lactational mastitis? Studies were critically appraised using the Joanna Briggs Institute checklist for randomised control trials (RCTs).FindingsFive RCTs met the inclusion criteria; three concerned probiotic consumption for the treatment of mastitis, two for the prevention of mastitis. All reported a lower incidence of mastitis in the probiotic groups.DiscussionAlthough potentially promising results were reported across all studies there were significant methodological limitations concerning; appropriately described baseline characteristics, study hypotheses, lack of power calculations, definitional issues, and potential conflicts of interest.ConclusionProbiotics may have utility for the treatment or prevention of lactational mastitis. However only a few studies with significant limitations have been published to date. Well designed and conducted studies are needed before evidence-based recommendations can be made for use of probiotics in the treatment or prevention of lactational mastitis.     

上海市宝山区依托大工程发展区域经济的基本经验及其借鉴

十几年来,国家投入大量人力、物力、财力,在北仑区域兴办了一批大型企业。大工程项目成为北仑区域的一大特点和优势。因而,如何做好“我为大工程服务”及“大工程为我所用”这篇文章,已是北仑面临的重要课题。通过对上海市宝山区依托大工程发展区域经济做法的介绍,分析,总结出值得北仑借鉴和学习的经验。     

生长獭兔和肉兔的饲喂方式、采食量及其效果比较试验

对生长獭兔和两个品种肉兔的饲喂采用以青饲料为主，适当补充精料，相间定时饲喂，自由饮水的方式，结果加州肉兔的幼兔和青年免比同期獭兔多采食青料25％～33．3％，生长速度分别比獭兔提高18．5％和20．4％；齐卡肉兔的初生重明显高于獭兔，产仔数明显低于獭兔，35日龄断奶成活率稍高于獭兔，幼兔日增重比獭兔提高17．6％。     

实施大公司大集团发展战略的意义及其途径探索

当今世界经济发展呈现出一些新趋势和新特点，实施大公司大集团发展战略，是适应新形势的需要。文章阐述了宁波市实施大公司大集团发展战略和营造实力工程的意义，探讨了企业规模扩张的七种途径。同时指出，营造实力工程企业必须全面深入学习镇海炼化经验     

种粮大户融资需求意愿及需求量的差异分析

以黑龙江省510户种粮大户实地调研数据为例,对不同规模种粮大户的融资需求意愿及融资需求量进行实证分析。结果表明,种粮大户的融资需求随着种植面积的增加呈递增趋势,但不同规模种粮大户之间差异明显;不同规模种粮大户在借贷金额、借贷期限、借贷利率上存在一定差异,但在借贷用途和融资渠道选择上并没有表现出明显差异。进一步分析总样本和不同规模组种粮大户融资需求意愿及融资需求量的影响发现,总体上,户主技能、家庭收入、土地规模、信贷政策了解程度及地区变量对种粮大户融资需求意愿有显著影响,年龄、户主技能、家庭收入、土地规模及信贷政策了解程度是影响种粮大户融资需求量的主要因素;但从不同分组角度看,种粮大户的融资需求意愿及融资需求量的影响存在一定差异。     

规模农户病虫害防治机械投资及其效应

利用江苏省水稻产业体系对规模种植户的调研数据,使用Heckman样本选择模型,从作业质量风险认知和作业及时性风险认知角度出发分析病虫害防治环节影响规模种植户机械投资和投资水平的原因,并进行稳健性检验,在此基础上分析投资机械自给服务对农户农业产出的影响。研究发现：规模种植户是否进行机械投资以及投资水平不仅受外包服务作业质量风险认知的影响,农户对于外包服务作业的及时性风险认知也是影响其机械投资的关键,并且农户的风险规避程度在风险认知影响病虫害防治机械投资决策之间具有显著的调节作用。进一步分析发现,规模农户投资病虫害机械自我防治可以显著提升农业产出水平。     

Book Review

Book reviewed:
J. Scott Armstrong, Principles of Forecasting: A Handbook for Researchers and Practitioners