植物生长调节物质对矮生一品红不定芽增殖的影响

以几种矮生一品红为材料,研究了植物生长调节剂BA,KT,IAA对不定芽增殖的影响.结果表明,影响一品红芽增殖的主要因素是细胞分裂素,以BA的增殖效果较好.不同品种(自由红、彼德之星、金钱豹、塔巴璐卡)芽增殖所需植物生长调节剂的浓度有所不同,矮生一品红试管苗芽增殖的适宜培养基为MS+BA0.5—2.0mg/L+IAA0.25—0.50mg/L.     

Scheduling Updates of Probabilistic Risk Assessments: The Arkansas Nuclear One-Unit 1 Experience

This paper presents the results of a study that identified how often a probabilistic risk assessment (PRA)should be updated to accommodate the changes that take place at nuclear power plants. Based on a 7-year analysis of design and procedural changes at one plant, we consider 5 years to be the maximum interval for updating PRAs. This conclusion is preliminary because it is based on the review of changes that occurred at a single plant, and it addresses only PRAs that involve a Level 1 analysis (i.e., a PRA including calculation of core damage frequency only). Nevertheless, this conclusion indicates that maintaining a useful PRA requires periodic updating efforts. However, the need for this periodic update stems only partly from the number of changes that can be expected to take place at nuclear power plants–changes that individually have only a moderate to minor impact on the PRA, but whose combined impact is substantial and necessitates a PRA update. Additionally, a comparison of two generations of PRAs performed about 5 years apart indicates that PRAs must be periodically updated to reflect the evolution of PRA methods. The most desirable updating interval depends on these two technical considerations as well as the cost of updating the PRA. (Cost considerations, however, were beyond the scope of this study.)     

N-硝基-N-氨基(取代)甲酰-2,4,6-三氯苯氨类化合物的合成

合成了两种新型兼有植物生长调节剂和除草剂功效的N硝基 -N -氨基 (取代 )甲酰 - 2 ,4 ,6 -三氯苯氨类化合物 ,并经元素分析、红外光谱等证实了它们的结构 .     

二元结构下城市化滞后效应及其成因分析

城市化滞后带来一系列的负面效应,分析其原因在于计划经济时期产生并延续下来的制度性二元结构。解决我国城市化滞后的根本途径是改革当前具有浓厚二元结构特征的各种政策制度,重构城乡联动发展的制度体系,走城乡一体化道路。     

中国乡镇企业崛起的多维分析

乡镇企业随着中国社会变革和现代化进程的深入应运而生,其产业特征并不符合标准的转轨型经济模式,它诞生之初面对的是市场交易和私产受到严格限制的计划经济体制,贫困且对现代工业技术一无所知的农民是如何创办工业企业的,需要从多重角度分析。     

住宅户型设计探讨

近年来我国住宅建设日趋兴盛，住宅成为居民新的消费热点，住宅设计进入新的发展阶段，本文比较与研究已建住宅的优点与不足，探讨住宅户型设计在现阶段的重要性，设计原则及应关注的问题。     

植物动力2003叶肥对黄瓜的喷施效果

通过田闻小区试验研完了植物动力2003叶肥对保护地黄瓜的喷施效果，结果表明：于开花期喷施植物动力2003叶肥对瓜长、瓜形、瓜重都产生显著影响而且明显提高了瓜数，从而具有显著的增产效果。     

国际植物新品种保护的发展趋势

目前,国际上对于植物新品种的保护主要采取专利保护和植物新品种保护的两种模式,美国率先给予植物新品种以专利保护,其对于国际植物新品种保护双重格局的形成具有举足轻重的作用。文章通过分析美国植物新品种保护制度对国际植物新品种保护制度的影响,论述了国际植物新品种保护的发展趋势以及我国作为发展中国家所面临的选择。     

制造业设备维护与管理的相对有效性评估

在设备维护与管理的评估中引入数据包络分析,以此为核心构建了设备维护与管理相对有效性的评估方法。该方法在系统功能建模的基础上,全面分析了设备维护与管理作为服务系统的投入与产出构成,以数据包络分析为计算模型完成了设备维护与管理有效性的评估。该方法满足了设备维护与管理评估全面性和客观性的要求,其有效性和可信度通过在某石化企业的应用得到了验证。     

Does Part-Time Mothering Help Get a Job? The Role of Shared Custody in Women’s Employment

Though child shared physical custody arrangements after divorce are much more frequent and parents who use it more diverse in many European countries, little is known about their economic consequences for parents. By relaxing family time constraints, does shared custody help divorced mothers return to or stay on work more easily? Since lone mothers are one of the least-employed groups, and they face high unemployment rates, the type of child custody arrangement adopted after divorce is of particular interest for their employability. This article analyses to what extent the type of child custody arrangement affects mothers’ labour market patterns after divorce.Using a large sample of divorcees from an exhaustive French administrative income tax database, and taking advantage of the huge territorial discrepancies observed in the proportion of shared custody, we correct for the possible endogeneity of shared custody. Results show that not repartnered mothers with shared custody arrangements are 24 percentage points more likely to work one year after divorce compared to those having sole custody, while no significant effect is found for repartnered mothers. Among lone mothers, we also highlight huge heterogeneous effects: larger positive effects are observed for previously inactive women, for those belonging to the lowest income quintiles before divorce, for those with a young child, and for those who have three or more children. Thus, shared physical custody arrangements may reduce work–family conflict by diminishing childcare expenses and enlarge the possibilities to find a suitable job because of more relaxed time constraints for lone mothers.