二氧化氮消除柴油机排气中炭烟过程基础研究

用热重法对柴油机排气中的炭烟与NO2的反应性能进行了研究，考察了反应温度和NO2浓度对消炭速率的影响，并根据实验数据在NO2气氛下对炭烟的消炭速率进行了反应动力学处理，得到了可用以计算炭烟消炭速率的动力议程与有关的参数。与在氧气气氛下炭烟消炭速率的比较可见，NO2的消炭速率远大于O2。     

JK-泡沫玻璃在既有建筑外墙节能改造中的应用

通过工程实例,介绍JK-泡沫玻璃保温隔热材料的性能及其改造成本,以此说明采用泡沫玻璃保温隔热体系改造既有建筑的围护结构,经济合理,节能效果好.     

Level and source of 129I of environmental samples in Xi'an region, China

Iodine-129 is widely used as a tracer in various environmental practices such as monitoring of nuclear environmental safety, seawater exchange and transport, geochemical cycle of stable iodine and dating of geological events. The spatial distribution of ¹²⁹I concentration varies significantly on global scale because of anthropogenic input from nuclear activities coupled with scarcity of data on environmental ¹²⁹I variability in many parts of the world including Asia. Here we report new data on ¹²⁹I and ¹²⁷I concentrations in soil, vegetation, river water and precipitation collected from Xi'an area, China. The results indicate values for environmental ¹²⁹I/¹²⁷I ratios in the investigated area range from 1.1 × 10^− 10 to 43.5 × 10^− 10 with a mean of 20.6 × 10^− 10, which is 1-3 orders of magnitude lower than the ratios observed in Europe, but comparable with those observed in the locations far from direct effect of point release sources and at similar latitude. The main source of ¹²⁹I in the investigated area is attributed to the global fallout of both atmospheric nuclear weapons testing and long distance dispersion of fuel reprocessing releases.     

平整机除尘设备的改进与创新

通过对平整机传统除尘设备的分析,指出被动除尘的不足之处,介绍一种新型刷辊旋转主动除尘方法,并对相关设备改进和创新进行探讨。     

面向关键链识别的矿山项目进度优化与仿真

针对矿山工程项目的工序复杂性与资源约束问题,以项目中所需的多种资源与工序逻辑关系为约束条件,以实现成本最低与工期最短为目标,引入关键链技术并建立项目进度管理模型。模型中首先设置对照组,并改变资源供应限制量,通过比较成本与工期来确定最佳的资源限制量和初始计划;其次在关键链的识别方法上采用灰色关联分析,通过综合考虑工序持续时间、资源影响度与紧后工序持续时间来确定灰色关联度,以此调整工序的优先级;最后结合缓冲区得出完整的进度计划。以山东某矿山智能选厂项目为例,运用基于关键链技术的进度优化模型对项目进行计划编制,得出该模型既能保证项目按期完成又可节约成本,对于有多种资源约束且项目工序结构复杂的项目具有适用性。     

矿用无底架铰接洒水车罐体的有限元分析

利用有限元分析方法,对矿用无底架铰接洒水车车体的主要结构——罐体进行静态分析和模态分析,得出了罐体的位移分布、应力分布和前5阶自振频率和振型。通过对计算结果的分析,找出了结构不合理的地方,并且提出若干设计准则和建议。     

基于混合编码的FPGA系统配置文件压缩算法

随着集成电路制作工艺的提升,FPGA可重构资源数量不断增加,导致配置文件体量过大从而引起配置过程耗时较长.针对这个问题,提出了一种基于混合编码的配置文件压缩算法MH-RLE.该算法根据二进制配置文件中“0”和“1”的分布特点,首先,采用RLE定长压缩方法对其进行压缩;然后,采用Huffman编码解决RLE定长压缩计数位“空零”问题;最后,使用提出的掩码方式进行二次压缩以进一步提升压缩率.实验结果表明:MH-RLE的平均压缩率为49.82%,相较于其他6种压缩算法其压缩率均有不同程度的提升,最多可提升12.4%.     

滚珠丝杠螺距误差前馈补偿法提高X-Y工作台定位精度的研究

在详细论述了激光多普勒测量仪的原理及测量方法后 ,对滚珠丝杠螺距误差的情况进行了分析 ,通过软硬结合的方法对重复定位误差和螺距误差的补偿进行了研究 ,并且通过实验验证了方法的有效性     

ICP-MS测定新类型沉积稀土矿中关键稀土元素方法研究

这是一篇矿物分析领域的论文。近年来我国地质科研人员在滇、黔地区发现了一种新型沉积型稀土矿,它既不同于氟碳铈矿和独居石矿,也不同南方离子型稀土矿,而是赋存于黏土岩中一种独特的稀土矿。本文通过对滇黔相邻区的不同矿点,不同品位的两个稀土样品的溶矿方法进行对比研究,并详细研究了关键稀土元素（Pr、Nd、Tb、Dy）配分、仪器参数的优化及关键稀土元素测定方法的准确度和精密度。结果表明采用密闭消解四酸溶矿体系为该新型沉积稀土矿的较佳溶矿方式,而ICP-MS为准确、高效的测定方法,并具有良好的精密度和准确度。     

AAV13 Enables Precise Targeting of Local Neural Populations

As powerful tools for local gene delivery, adeno-associated viruses (AAVs) are widely used for neural circuit studies and therapeutical purposes. However, most of them have the characteristics of large diffusion range and retrograde labeling, which may result in off-target transduction during in vivo application. Here, in order to achieve precise gene delivery, we screened AAV serotypes that have not been commonly used as gene vectors and found that AAV13 can precisely transduce local neurons in the brain, with a smaller diffusion range than AAV2 and rigorous anterograde labeling. Then, AAV13-based single-viral and dual-viral strategies for sparse labeling of local neurons in the brains of C57BL/6 or Cre transgenic mice were developed. Additionally, through the neurobehavioral test in the ventral tegmental area, we demonstrated that AAV13 was validated for functional monitoring by means of carrying Cre recombinase to drive the expression of Cre-dependent calcium-sensitive indicator. In summary, our study provides AAV13-based toolkits for precise local gene delivery, which can be used for in situ small nuclei targeting, sparse labeling and functional monitoring.