定位定向接收机校准技术研究

介绍了全球导航卫星系统的组成与应用,利用本实验室的短基线场,对定位定向接收机进行实际大地坐标的定位与定向校准实验。给出了实验原理、实验过程及实验结果;并通过仿真机产生标准信号对接收机进行校准实验,对两种校准实验结果进行比较,分析了影响因素。     

Community assessment of availability, consumption, and cultural acceptability of food sources of (pro)vitamin A: toward the development of a dietary intervention among preschool children in rural Burkina Faso

BACKGROUND: Vitamin A deficiency remains a public health problem in Burkina Faso and elsewhere in the developing world. Dietary diversification is a promising strategy that needs to be explored to strengthen the country's ongoing supplementation program. OBJECTIVE: The purpose of this study was to identify locally available and acceptable (pro)vitamin A-rich foods to be included in a dietary intervention addressing vitamin A deficiency in children aged six months to three years. METHODS: A food ethnographic study combining recall methods, observation, and focused group discussion was conducted in the dry and rainy seasons. Thirty-five mother-child pairs were randomly selected and included in the study. RESULTS: The dietary pattern of children was characterized by low diversity with extremely low energy and vitamin A intake in both seasons. The study identified the availability of numerous (pro)vitamin A-rich foods, but these foods are either not consumed or consumed by few in low amounts and/or in low frequencies. The main constraining factors identified are related to financial accessibility (for liver), seasonal availability (for egg, milk, mango, papaya, and green leafy vegetables), and beliefs related to consumption and preparation (for green leafy vegetables). However, the study also revealed that the study population associated all identified (pro)vitamin A-rich foods with positive attributes such as health, strength, and vitamin richness, which might offer an entry point for designing and implementing dietary interventions. CONCLUSIONS: Based on the findings of this formative research, intervention strategies with mango and liver are proposed to improve the vitamin A intake and status of children in the rural areas of Burkina Faso.     

水相介质中纳米TiO2粒子软团聚体的解团聚

纳米TiO₂等无机粒子在水相介质中极易发生团聚,进而会严重影响其功效的充分发挥。本文考察了TiO₂水分散液体系中TiO₂粒子的团聚形式,比较了几种常规分散技术以及表面锚固改性技术对这些团聚体的解团聚效果。结果发现：大部分TiO₂粒子在水相介质中以软团聚体形式存在,高速剪切和添加分散剂对这些软团聚体的解团聚作用有限,超声分散可产生暂时性的解团聚效应,但随着超声场的去除,被分散的TiO₂粒子又会再次逐渐聚集。TiO₂粒子表面的聚合物原位锚固改性可改变其表面性质,因而对软团聚体具有更为高效稳定的解团聚作用,从而可明显提高复合粒子中的TiO₂粒子在水相介质和目标织物表面的分散性和分散稳定性。     

用I2C总线扩展I/O

在系统应用中,需监控不同的输入信号或控制几个输出信号,有时把这些信号线直接连接到微处理器引脚.这些监控和控制用软件来做.然而,这种技术需要很多微处理器引脚.     

一氧化氮合酶途径在精氨酸诱导番茄果实采后抗病性中的作用

以绿熟期‘中蔬4号’番茄果实为实验材料,研究了精氨酸（arginine,Arg）对番茄果实灰霉病发生的影 响及一氧化氮合酶（nitric oxide synthase,NOS）途径在其中的作用及机制。结果表明：0.0～10.0 mmol/L范围内, 5.0 mmol/L的Arg对番茄果实灰霉病的发生率及病斑面积的扩展控制效果最佳。同时5.0 mmol/L Arg处理明显提高 了番茄果实NOS活力及NO含量,促进了酚类物质的积累,提高了番茄果实体内苯丙氨酸解氨酶、多酚氧化酶、 β-1,3-葡聚糖酶和几丁质酶等抗病相关酶的活力,诱导了病程相关蛋白（pathogenesis-related proteins,PRs）PR2a、 PR2b、PR3a和PR3b的表达。而NOS抑制剂N-硝基-L-精氨酸通过抑制NOS的活力和NO的水平,明显削弱了Arg对番 茄果实的这种诱导作用,因此Arg可能是通过调控NOS途径诱导了番茄果实抵抗灰霉病的抗性。     

基于FLAC~(3D)的非充分采动地表移动求参方法

依据少数零散观测点很难求取地表移动参数.利用FLAC3D模拟了某矿12111工作面开采后的地表移动变形值,根据模拟结果和非充分开采沉陷规律,求取了该矿的地表移动参数,提供了一种基于数值模拟的非充分采动地表移动求参方法.用所求参数对12111工作面进行了概率积分法计算,并与零散观测点的下沉量进行了对比分析,结果表明,在非充分条件下可以利用数值模拟方法求取地表移动参数.     

菜籽蛋白和酚的固-液相平衡

为探索消除菜籽蛋白中酚污染的技术途径,采用菜籽蛋白沉淀率和菜籽蛋白-酚分配系数为指标,考察了菜籽蛋白与酚共存体系的固-液相平衡关系,并基于相行为特征提出了菜籽蛋白提取工艺的改进措施。结果表明:在碱性环境下,酚酸和单宁均可与菜籽蛋白发生共沉淀作用,且浓度越高该作用越显著;在p H 4环境下,菜籽蛋白不仅溶解度最低,而且与单宁或菜籽多酚的结合作用最弱;而在溶液中添加1%的Na Cl有利于进一步提升菜籽蛋白和酚的分离效果。在菜籽蛋白的富集或提取工艺中,溶剂用量(液固比)、p H以及盐添加量都可对菜籽蛋白和酚的相互作用产生影响,对这些参数的优化将有利于提高菜籽蛋白提取的选择性并降低酚的混杂。