稠油污水回用锅炉化学除硅技术的研究

以稠油采出污水为主要研究对象,比较分析各种除硅方法的利弊,确定了添加镁剂的化学除硅方法。通过条件实验确定了最佳除硅配方,处理后的污水可达到热采锅炉用水标准。     

石家庄市村镇民房抗震性能调查分析

通过对石家庄市村镇民房的调查 ,将其简化成若干种典型结构模型 ,按照国家相应抗震设防烈度等参数要求进行了抗震验算 ,对村镇民房的抗震能力现状进行了分析研究 ,并在此基础上对新建村镇房屋提出了建议     

基于SNMPv3的RIPng路由协议设计与实现

本文在探讨SNMPv3和RIPng原理及特性的基础上,提出一种利用SNMPv3的SMUX协议管理RIPng系统诸多参数的实现方案,并对向其他IPv6路由协议和其他操作系统的移植做出展望.     

导热胶粘剂研究

导热胶粘剂因良好的导热及力学性能广泛应用于微电子封装以及热界面材料,对于电子元器件散热具有重要意义.介绍了导热胶粘剂导热原理、导热模型,分析了影响导热率的因素,以及提高导热率的途径;综述了导热非绝缘及导热绝缘胶粘剂的研究进展,最后展望了其应用前景.     

Magnetism and Phase Formation in the Candidate Dilute Magnetic Semiconductor System In2 − xCrxO3: Bulk Materials are Dilute Paramagnets

Well‐characterized bulk materials in the candidate dilute magnetic semiconductor system In_{2 − x}Cr_xO₃ are prepared for 0 ≤ x < 0.15, with cation site preferences in the bixbyite structure identified by diffraction methods. Small ferromagnetic moments are observed; their size (<10⁻² µ_B/dopant ion) is not consistent with bulk ferromagnetism. The resulting bulk materials display dilute paramagnetic behaviour, with all of the moment expected per Cr³⁺ cation dopant being involved in this paramagnetic response.     

高效率连续波运转的激光二极管端面抽运914 nm Nd:YVO4激光器

利用激光二极管(LD)抽运Nd∶YVO4晶体产生914 nm谱线振荡,再通过腔内倍频技术获得457 nm激光输出,是获得大功率蓝光激光器的一条重要的技术路线,因而实现高效率运转的914 nm激光输出则是方案的关键。报道了激光二极管端面抽运Nd∶YVO4晶体、连续波运转的大功率914 nm准三能级激光器,方案中采用掺杂原子数分数为0.1%的低掺杂Nd∶YVO4晶体,有效地降低了热效应的影响,并通过准三能级理论模型的模拟计算选择了最佳晶体长度;通过对腔镜介质膜参数的适当控制,有效地抑制了波长为1064 nm和1342 nm的高增益谱线。实验中,914 nm激光器的阈值抽运功率仅为8.5 W,在31 W的抽运功率下914 nm激光输出功率高达7.2 W,激光器的斜率效率为32%,光-光转换效率为23.2%。     

快速成形激光二极管能量源研究

针对现有激光快速成形系统使用气体激光器存在的缺点,研究使用激光二极管(LD)的新型能量源来代替气体激光器.对LD的光束特性和准直扩束技术进行了分析、研究,并对其聚焦后的焦斑功率密度、成形中的扫描速度等参数进行计算与分析.LD新型能量源寿命长、工作可靠,且体积小易于实现装置小型化,有利于提高成形精度和质量,有利于拓宽成形材料范围.     

基于DSP的PMD补偿逻辑控制模块软件设计

文章通过软件编程和调试,完成了基于数字信号处理(DSP)的偏振模色散(PMD)补偿逻辑控制模块的软件设计.详细介绍了系统的工作流程、软件及硬件结构,以及粒子群优化(PSO)算法模块在DSP系统中的应用,最后介绍了将该DSP系统应用到二阶PMD自适应补偿系统中进行验证的情况.结果表明,作者设计的DSP逻辑控制模块对一阶及二阶PMD补偿效果很好.     

固相萃取-高效液相色谱法测定猪肝中的大环内酯类抗生素

建立了猪肝中大环内酯类抗生素螺旋霉素(SPI)、北里霉素(KIT)、替米卡星(TILM)和泰乐菌素(TYL)的高效液相色谱(二极管阵列检测器)检测方法。样品经甲醇提取,Bond Elut SCX固相萃取柱(500 mg,3 mL)净化,液相色谱分析采用Waters Atlantis~(TM)dC_(18)柱(4.6 mm×250 mm,5μm),流动相为0.025 mol/L磷酸缓冲液-乙腈(pH 2.5)梯度洗脱,流速为1.0 mL/min。方法的检出限为0.01～0.037μg/mL,在0.2～20μg/ mL范围内峰面积与质量浓度成良好线性关系,相关系数大于0.998。在2、0.5、0.2μg/mL 3个添加水平下,回收率范围为69.2%～93.2%,精密度<12。方法灵敏,实用性强。     

Comparison of fecal versus rectoanal mucosal swab sampling for detecting Escherichia coli O157:H7 in experimentally inoculated cattle used in assessing bacteriophage as a mitigation strategy

This study was conducted to compare fecal grab (FEC) and rectoanal mucosal swab (RAMS) techniques as sampling methods for surveillance of Escherichia coli O157:H7 in conjunction with administration of a mitigation therapy. The study was nested within a larger experiment that investigated bacteriophage as a preharvest strategy for controlling E. coli O157:H7 in feedlot steers. Samples (FEC and RAMS) were collected from 16 of the 32 feedlot steers (control and oral bacteriophage treatment; n = 8) involved in the mitigation study. All steers had been inoculated on day 0 with 10(10) CFU of nalidixic acid-resistant E. coli O157:H7, and samples were collected on 16 occasions over the next 83 days. FEC samples were assessed by direct plating of serial dilutions in PBS, plus a 6-h enrichment and immunomagnetic separation when E. coli O157:H7 concentrations were below limits detectable by direct plating (i.e., <1 log CFU/g). All RAMS samples were assessed by enrichment and immunomagnetic separation. E. coli O157:H7 was detected more frequently (P < 0.01) by FEC than by RAMS. Overall, 213 of 256 samples were positive either by FEC or RAMS. Discrepancies between sampling techniques were observed in 63 of the 213 positive samples; FEC missed 11 samples that were positive by RAMS, and RAMS missed 52 of those positive by FEC (miss rates of 5.16 and 24.41%, respectively). Kappa values (0.36 to 0.45) indicated only fair to moderate agreement between FEC and RAMS results, but this agreement was higher at lower levels of E. coli O157:H7 shedding (later in the experimental period). Selection of sampling procedure could significantly influence the assessed merit during testing of potential strategies for controlling E. coli O157:H7 on the farm.