建造合同准则中"营业税金及附加"核算探讨

文章以营业税纳税义务发生的时间和<建造合同>准则中施工企业建造合同收入的确认为切入点,对新准则中有关营业税金及附加的计提与现行营业税法发生纳税义务之间差异的核算作一些探讨.     

柴油机燃油喷射试验系统的动态分析与研究

本文建立了柴油机燃油喷射试验系统的动态特性数学模型，对试验系统的动态响应及其影响因素进行了分析，找出了影响系统工作稳定性的原因，并提出和实施了对试验系统改进和调整的措施，获得了较满意的效果．     

农民增收的政策选择

农民问题的核心是农民增收问题。关心农民、支持农业、发展农村,要推进农业结构调整、整合农村土地资源、加快农村富余劳动力转移等以增加农民收入。     

基于协处理器的无线传感器网络MAC设计

提出了一种基于协处理器的媒介访问控制(MAC)体系结构.将不同MAC协议的信道争用机制映射为协处理器内部的软件程序.其特点是兼容IEEE802.15.4协议,利用可编程协处理器增强MAC的可重用性,能支持自适应睡眠媒介访问挖制(S-MAC)、超时媒介访问控制(T-MAC)等无线传感器网络MAC协议.阐述了基于协处理器实现避免冲突的载波侦听多路访问(CSMA-CA)算法、S-MAC和T-MAC协议的方法.并在此基础上分析了CSMA-CA算法的软件时延.在现场可编程门阵列(FPGA)上实现整个MAC,实际测试结果表明:该MAC支持多协议,数据传输速率达20～250 Kbit/s,适应IEEE802.15.4协议要求.面积仅为30 567个等效门.     

宁夏生态功能区划研究

运用GIS技术,采用定性与定量相结合的方法,对宁夏生态环境现状、生态环境敏感性和生态服务功能重要性进行了分析评价,形成了宁夏生态功能区划方案,将宁夏生态环境划分为3个生态区,10个生态亚区,37个生态功能区．根据不同生态功能区特点,确定了区域生态环境特征、生态系统服务功能重要性与生态环境敏感性空间分异规律,提出了保护时策,对维护区域生态安全、促进社会经济可持续发展提供了科学依据．     

用粘度法研究石油中沥青质沉积的起始点

介绍了测定混合物粘度以确定沥青质沉积起始点的方法，考察了将正庚烷或甲苯加入油样过程中体系粘度的变化规律．结果发现，随着正庚烷的加入，体系的粘度呈下降趋势，但在某一浓度时出现明显的偏离，该点即被定义为沥青质沉积的起始点．而用甲苯作溶剂时，体系粘度则始终呈平缓下降趋势，无偏离现象研究还发现，各种原油的沥青质沉积的起始点明显早于其相应的减压渣油，这表明渣油胶体体系比原油的更为稳定，上述结果借助显微照相观察得以证实     

Data association based on target signal classification information

In most of the passive tracking systems, only the target kinematical information is used in the measurement-to-track association, which results in error tracking in a multitarget environment, where the targets are too close to each other. To enhance the tracking accuracy, the target signal classification information （TSCI） should be used to improve the data association. The TSCI is integrated in the data association process using the JPDA （joint probabilistic data association）. The use of the TSCI in the data association can improve discrimination by yielding a purer track and preserving continuity. To verify the validity of the application of TSCI, two simulation experiments are done on an air target-tracing problem, that is, one using the TSCI and the other not using the TSCI. The final comparison shows that the use of the TSCI can effectively improve tracking accuracy.     

Wnt-beta-catenin signaling initiates taste papilla development

Fungiform taste papillae form a regular array on the dorsal tongue. Taste buds arise from papilla epithelium and, unusually for epithelial derivatives, synapse with neurons, release neurotransmitters and generate receptor and action potentials. Despite the importance of taste as one of our five senses, genetic analyses of taste papilla and bud development are lacking. We demonstrate that Wnt-beta-catenin signaling is activated in developing fungiform placodes and taste bud cells. A dominant stabilizing mutation of epithelial beta-catenin causes massive overproduction of enlarged fungiform papillae and taste buds. Likewise, genetic deletion of epithelial beta-catenin or inhibition of Wnt-beta-catenin signaling by ectopic dickkopf1 (Dkk1) blocks initiation of fungiform papilla morphogenesis. Ectopic papillae are innervated in the stabilizing beta-catenin mutant, whereas ectopic Dkk1 causes absence of lingual epithelial innervation. Thus, Wnt-beta-catenin signaling is critical for fungiform papilla and taste bud development. Altered regulation of this pathway may underlie evolutionary changes in taste papilla patterning.     

串联系统精确置信下限计算和奇点消除

本文通过对廖炯生提出的ＩＵＭＶＥ法的变差系数公式进行校正,重新对二部件串联系统的可靠性置信下限进行了计算,不仅消除掉大部分非正常点,而且也使计算结果更加合理,但仍存在着９个非正常点。我们利用系统的等价试验信息来消除非正常点,获得了令人满意的结果。     

适于大斜视角星载SAR系统的改进距离-多普勒算法

分析了当天线斜视角增大时,导致传统距离-多普勒成像算法性能下降的主要误差来源.提出了一种适合大斜视角星载SAR系统的改进距离-多普勒算法,并给出了处理仿真点目标数据得到图像质量的比较.结果表明,在大斜视角情况下,改进算法的性能远大于传统的距离\|多普勒成像算法.