某类高阶偏微分系统离散谱的估计

考虑某类高阶偏微分系统离散谱的估计,利用谱理论、矩阵运算、分部积分、测试函数、Ray—leigh定理和不等式估计等方法,获得了用前n个谱来估计第n＋1个谱的上界的不等式,且其估计系数与区域的几何度量无关,其结论是文献[4—5]的进一步推广．     

协同通信系统中差分调制在Rayleigh衰落信道中的误码性能分析

根据源-中继-目的节点链路的等效信噪比模型,推导了检测传送和选择检测传送两种 协议下目的节点瞬时信噪比的概率密度函数和特征函数,基于此推导了协同DMPSK调制近似 误符号率的闭合表达式。推导结果不含积分表达式,方便计算,为系统设计和功率分配提供 了理论基础。最后通过仿真验证了推导结果的正确性。     

Determinants of Indonesian rural secondary school enrolment: gender,neighbourhood and school characteristics

In recent years the school enrolment rates of children aged 13–15 and 16–18 years have increased sharply in Indonesia, not only in urban but also in rural areas. Using various data sets spanning the years from 1993 to 2007, this paper investigates changes in factors associated with the enrolment of secondary school aged children in rural areas. It sheds light on the roles of gender and of neighbourhood and school characteristics, which have rarely been examined in the Indonesian context. The study finds that the disappearance of a gender gap in secondary enrolments between 1993 and 2007 contributed significantly to the rise in the overall enrolment rate. The findings also show that children living in wealthier communities and communities with a high proportion of enrolled children are more likely to attend school. Finally, various school characteristics are shown not to be strongly or consistently correlated with school enrolment.     

紧邻既有建(构)物等复杂条件高路堑石方爆破技术研究

秘鲁瓦努科至瓦杨柯公路改扩建项目工期紧张,其中一地段为大方量的高路堑石方爆破开挖,但该段路堑紧邻当地民房及既有通行繁忙的道路,施工环境复杂,爆破开挖石方时,确保民众的生命财产安全的压力非常大.本项目周密编制爆破工艺及采取科学合理的安全防护措施,在确保安全的前提下,按既定工期目标完成施工.     

基于不同城市化发展阶段的山西省城镇建设用地适度集约利用研究

研究目的:针对城市化进程中的土地低效利用以及过度集约问题,探讨不同城市化发展阶段的土地集约利用状况及适度集约利用状态。研究方法:采用匹配度模型、曲线估计模型和多目标规划模型,对山西省的土地集约利用进行分区优化。研究结果:(1)1999—2012年山西省土地集约利用与城市化水平之间的匹配趋势逐渐由失调、磨合向协调转变,但不同地区之间的匹配水平差距却在逐渐扩大;(2)2018年山西省城市化水平处于低于30%、30%～70%和高于70%时,以单位城镇建设用地固定资产投资额为表征的土地适度集约利用值分别为249.93万元/km~2、367.57万元/km~2和692.72万元/km~2,两项指标叠加全省可划分为平稳发展区、重点挖潜区和优化拓展区,并提出了不同地区差别化的建设用地管控政策。研究结论:不同城市化发展阶段的土地适度集约利用研究能为制定区域差别化政策提供参考,以促进该地区的土地集约利用水平达到适度状态。     

安徽移动服务差异分析及改进策略探讨

服务质量是决定服务性企业营销效果、经济收益的最重要因素.文章借助于服务质量差异模型对安徽移动服务质量现状进行了深刻分析,从服务过程质量管理与控制角度分析,提出了增强服务意识、提高服务技巧、加大服务有形展示的力度、管理顾客等质量改进策略.     

基于边际税率差模型的税收筹划动力源泉分析

在税收法律制度框架内,现代企业拥有税收筹划与非税收筹划两种节税手段,企业选择非税收筹划必然遭到税收法律的严厉制裁,增加企业的节税成本.通过构建边际税率差模型,我们发现企业存在内在驱动因素使其选择税收筹划来增大企业的税后收益,从而实现企业价值最大化目标,这一内在驱动因素就是边际税率差最小化.     

从句层修辞操作角度看英语写作中的性别差异

在英语写作中,男女生在英语写作中体现出来的句层修辞操作能力存在显著差异。因此,在写作教学中英语教师应充分考虑性别差异,有意识地加强女生的即存优势,重点培养男生的句子修辞操作意识和兴趣。     

Gender,entrepreneurship and food security in Niger

In many African countries, the income generated from the informal sector and the entrepreneurship is particularly important for reducing poverty. Previous studies have not found clear evidence on the relationship between self‐employment by gender and food security. We argue that this may be a result of the gender inequality in resource accessibility. In this paper, we analyze the implication of household entrepreneurship on food security in Niger, where gender disparities in resource accessibility are reduced. We find that owning female‐managed non‐agricultural enterprises is positively related to food accessibility and food availability within female‐headed households. The results draw the attention on reducing gender differences in resource accessibility in entrepreneurship for improving food security.     

欧元区成员国通胀差异成因研究

在欧元区内部,不同国家之间的通胀率存在不容忽视的差别。欧元区各经济体间究竟为什么会存在差别如此之大的通胀率呢?什么因素及在多大程度上影响了通胀率的差异?文章从巴拉萨—萨缪尔森效应、价格的收敛效应、输入性通胀、本国要素市场结构差异、本国财政政策和经济周期等六个方面,使用实证数据和面板数据回归探讨了这些问题。