基于最优规划的汽车租赁调度分析

针对汽车租赁公司不同目标下的效益最大化,运用分步分析、最优规划、直线折旧等方法,建立转运费最低的、短缺损失费和转运费最低的调度规划模型,使用Matlab7和Lingo软件,得到两个不同目标下的汽车调度方案以及各代理点的最低转运费.其次,使用会计学中的直线折旧法构建基于年度获利最大的购买规划模型,得出年度最大利润并给出了新车购置计划.最后,还对年度利润函数做了进一步讨论.     

聚乙二醇支载的磺酸催化合成7-羟基-4-甲基香豆素

在聚乙二醇2000支载磺酸的作用下,以间苯二酚和乙酰乙酸乙酯为原料,合成了7-羟基-4-甲基香豆素.通过实验发现:此方法反应条件温和,操作简单,催化剂可以循环利用,其催化活性通过6次使用后没有明显降低.     

Angiogenic Potential,Circulating Angiogenic Factors and Insulin Resistance in Subjects with Obesity

Altered vascular function and pathological angiogenesis are important factors common to the development of obesity and obesity-associated diseases. Most human studies relating obesity and angiogenesis have compared levels of angiogenic factors in obesity without looking at the serum angiogenic capacity which reflects the balance between the effects of angiogenic and angiostatic factors. Therefore, in this cross-sectional study, the serum angiogenic potential and levels of angiogenic factors in serum of obese (BMI > 25 kg/m²) and lean subjects (BMI < 23 kg/m²), with no history of obesity associated co-morbidities, were assessed. Serum angiogenic potential was significantly higher (p < 0.0001) in both male (n = 67) and female (n = 35) obese subjects and showed a positive correlation (r = 0.4, p < 0.0001) with BMI. Serum levels of the angiogenic factors, vascular endothelial growth factor (VEGF) and angiopoietin were significantly higher in obese subjects. Levels of angiostatic factors such as angiostatin, endostatin were not altered in obese male subjects but were elevated in female obese subjects. Angiogenic potential and levels of VEGF did not vary in obese subjects with high HOMA-IR compared to obese subjects with low HOMA-IR. These results suggest that the angiogenic potential of serum was elevated in obesity and that insulin resistance may not contribute to the increased angiogenic potential in obesity.     

一种基于USB的高速数据采集系统硬件设计

为了提高实际数据采集的速度,保证数据采集的实时性,设计了此高速数据采集系统.本文以Cypress Semiconductor公司的EZ-USB FX2系列的CY7C68013芯片作为核心芯片,主要叙述了整个高速数据采集系统的硬件设计,同时将USB连接技术引入到测试测量中,研制了一套接近实用的便携武高速数据采集系统.通过USB2.0接口,实现了数据的实时高速采集,保证了采集的效率.     

7-氨基-3-甲氧甲基-3-头孢烯-4-羧酸的合成

7-氨基-3-甲氧甲基-3-头孢烯-4-羧酸(7-AMCA)为合成头孢泊肟酯的关键中间体,其合成路线较多,本法对以7-A-CA为起始原料在硫酸单甲酯中合成7-AMCA的工艺进行了探索.     

一种实现MPEG-7标准的基于内容的图像检索系统

图像检索技术中,描述和定义图像资料是关键任务之一,多媒体内容描述接口(MPEG-7)标准,能够以明确的格式结构和语法定义多媒体信息,这些描述与内容本身有关。在此基础上,给出了一种实现MPEG-7标准的图像检索系统的抽象模型,叙述了其中的关键技术。     

Properties of YBa2Cu3O7-∞ granular Josephson junction

YBa₂Cu₃O_7-∞ weak link junctions with width from 0.1 mm to 0.3 mm and length from 0.2 mm to 0.5 mm was made by hand with a razor blade. The current voltage characteristics of the microbridges show, under microwave irradiation, pronounced Shapiro steps up to transition temperature. A careful measurement of the dependence of the critical supercurrent on the external magnetic field and laser light is presented.     

我国公立高等学校法人制度的问题及其改革

高等学校法人制度以高等学校的基本组织属性为价值基础,应当是一项契合高等学校自主性和公共性的法律制度,其内部价值冲突的整合模式包括自主性本位、公共性本位以及自主性和公共性冲突整合三种。我国高等学校法人制度在价值基础方面选择了自主性本位整合模式,并呈现出市场自主性的偏向。其问题表现为:缺乏高等学校自主运转的必要保障机制安排,导致保障高等学校自主性的制度目标未能达成;忽视高等学校的公共机构身份,导致高等学校公共性危机的产生。对其进行改革的应然选择是建立第三部门视野下的高等学校法人制度。     

室内环境监测系统的设计

本文设计了一套基于STC89C51单片机为核心控制的室内环境监测系统。通过温湿度传感器SHT75和气体传感器MQ-7监测室内环境的温度、湿度和一氧化碳的浓度,并使用TLC549芯片进行A/D转换,然后将这些数字信号传给单片机进行处理,最后通过LCD1602显示出来。