全自动数字压力控制器(静态)测量结果不确定分析

本文介绍了以气体活塞压力计校准数字压力控制器时,其测试结果的不确定度分析,给出了相对扩展不确定度。由于只是对控制器内置的压力传感器进行静态校准,没有牵扯到其控制准确度对不确定度的贡献。     

The Plasma Channel Evolution Characteristics of Pulsed Flashlamps Working in an Array

This work is devoted to the study of plasma channel evolution characteristics in pulsed xenon flashlamps working in an array. Influencing factors on the plasma channel evolution process are studied, including pre-ionization pulse and neighbor flashlamps. It has been found that neighbor flashlamps affect the plasma channel by shaping the electric potential distribution, rather than by Lorentz force. Branching is observed in the plasma channels of the flashlamps in the middle of the array. Inconsistency also exists in the plasma channels of these flashlamps in different tests. The branching and inconsistency are both caused by the unique electric field distribution in these flashlamps. Besides, the pre-ionization pulse can help the main pulse plasma channel to develop more smoothly and faster, which will weaken the shock wave and benefit the mechanical strength of the flashlamp.     

浮子法测量管外油水界面试验研究

江苏金坛盐穴地下储气库井腔体试压密封监测需要精确监测套管和测试管柱之间的环形空间中油水界面位置变化情况,为此研制了一种新型的油水界面监测装置（浮子）。文章简单介绍浮子的结构、测量原理,详细阐述监测过程及应用前景。浮子法对油水界面监测有良好应用效果。     

靠思想政治工作推动农村小康建设

靠思想政治工作推动农村小康建设井陉县水利局史墨文，刘会忠，李海兵井陉县水利局驻东梁洼村小康工作队进村以后，同村支部、村委“一班人”团结协作、密切配合，面对在小康建设中出现的新情况、新问题，共同学习文件，开动脑筋，审时度势，不失时机地做好思想政治工作，...     

基于MySQL的负载均衡的搭建与研究

MySQL是一种关系型数据库系统。由于它的开源性使得它的应用非常广泛。适用于很多平台,扩展能力强。为了提高数据库系统的高效性和稳定性,我们可以搭建多台负载均衡的MySQL服务器集群。我们首先介绍了搭建服务器集群的好处,其次举例在RedHat9.0系统上如何部署实现MySQL服务器集群,最后概述应对主从服务器崩溃的解决方法。     

混凝土含气量测定仪校准方法的讨论

混凝土含气量测定仪在建筑材料检测中有着重要的作用,针对目前在没有相应的国家计量检定规程和国家标准的情况下,介绍了含气量测定仪的工作原理和结构,并对三台含气量测定仪的参数进行了测量,包括量钵的体积、气室的体积和含气量与压力值之间的关系。最后提出了存在的一些问题和建议。     

Construction of type-II QC-LDPC codes with fast encoding based on perfect cyclic difference sets

In view of the problems that the encoding complexity of quasi-cyclic low-density parity-check (QC-LDPC) codes is high and the minimum distance is not large enough which leads to the degradation of the error-correction performance, the new irregular type-II QC-LDPC codes based on perfect cyclic difference sets (CDSs) are constructed. The parity check matricesof these type-II QC-LDPC codes consist of the zero matrices with weight of 0, the circulant permutation matrices (CPMs) with weight of 1 and the circulant matrices with weight of 2 (W2CMs). The introduction of W2CMs in parity check matrices makes it possible to achieve the larger minimum distance which can improve the error-correction performance of the codes. The Tanner graphs of these codes have no girth-4, thus they have the excellent decoding convergence characteristics. In addition, because the parity check matrices have the quasi-dual diagonal structure, the fast encoding algorithm can reduce the encoding complexity effectively. Simulation results show that the new type-II QC-LDPC codes can achieve a more excellent error-correction performance and have no error floor phenomenon over the additive white Gaussian noise (AWGN) channel with sum-product algorithm (SPA) iterative decoding.     

基于高斯消元的BATS码的改进译码算法

BATS码是一种包括外码和内码的纠删码,外码是喷泉码的矩阵形式。内码是网络编码结构,采用随机线性网络编码算法。BATS码的常用译码算法为BP译码算法,但对有限长BATS码,BP译码算法的性能有大幅度的衰减。因此,在计算资源充足的情况下,可以在BP译码器后采用高斯消元算法对BATS码进行译码。采用高斯消元算法时,矩阵满秩则输入数据包可译,反之则不可译。因此,利用当矩阵不满秩时也有部分包可译的特点,识别并将这部分可译包译出,从而提高高斯消元译码器的译码性能。     

太阳能高反射薄膜制备技术对薄膜性能的影响

采用磁过滤阴极真空弧沉积(FCVAD)与磁控溅射(MS)两种技术在玻璃上制备厚度分别为75 nm和165 nm的Glass/Al高反射薄膜,利用Lambda 950分光光度计、扫描电子显微镜、原子力显微镜、附着力测试仪、摩擦试验机和加速老化试验箱分别表征薄膜的反射率、表面形貌、粗糙度、附着力、耐摩擦和耐老化性能,通过薄膜性能评估分析两种技术制备高反射膜性能的差异。结果表明:在双方优化工艺下,FCVAD制备的薄膜表面形貌和附着力优于MS薄膜;FCVAD制备的75 nm和165 nm薄膜反射率比同厚度MS薄膜高出3.3%~4.2%;75 nm厚的薄膜方均根粗糙度明显小于同厚度的MS薄膜;FCVAD制备的75 nm薄膜老化后反射率仅下降1.2%,而MS同厚度薄膜反射率下降了3.3%~4%。说明FCVAD在制备高反射膜方面比磁控溅射更有优势。     

工艺矿物学在云南某胶磷矿浮选中的应用研究

针对云南某选厂生产中存在的磷精矿w(MgO)难以降低到0.8%以下以及药剂消耗量偏高问题,对其生产流程样进行工艺矿物学研究,包括矿样化学组成、矿物组成以及单体解离度。结合选矿实验,查明该类矿石原矿中有部分难以解离的杂质,增加磨矿细度、捕收剂用量及精选流程都难以获得满意的精矿指标。