硫酸沙丁胺醇脉冲缓释片的制备

目的探讨制备硫酸沙丁胺醇脉冲缓释片的方法。方法用粉末直接压片法制备片心,干压包衣技术制备脉冲缓释片。正交试验优选处方,对最优处方进行体外释放度验证。结果脉冲缓释片迟滞时间为2￣3h,迟滞后药物释放符合Higuchi方程。结论硫酸沙丁胺醇脉冲缓释片处方设计和工艺方法可行,质量稳定。     

气相色谱法测定大米中马拉硫磷的残留

本文提出用毛细管气相色谱法来测定大米中马拉硫磷的残留.在选定的气相色谱前提条件下,马拉硫磷的最低检出限为0.004 mg/kg,平均回收率为97.2 %;在浓度0.01 (g/mL～1.00 (g/mL,线形相关系数为0.998.结果显示该方法具有快速、简单、准确、灵敏度高的特点,能够达到国标检测方法的要求.     

一种基于SiGe BiCMOS工艺的单片集成光接收机前端放大电路

基于0.13μm SiGe BiCMOS工艺,设计了一种25 Gbit/s的光接收机前端放大电路单片集成的放大电路。该电路实现了光接收机前端放大电路的单片集成,并采用带反馈系统的跨阻放大器、电感峰化、自动增益控制电路等设计有效提高了增益、带宽和系统稳定性。经仿真与测试,该设计增益达到69.9 dB,带宽为19.1 GHz,并在工业级芯片工作温度(-40℃~+85℃)下带宽误差不超过0.1%。该芯片工作时需要的供电电流为45 mA,功耗为81 mW,信号抖动RMS值为5.8 ps,具有良好的性能和稳定性。本设计提供了一种能够适用于100 Gbit/s(25 Gbit/s×4线)光互连系统的设计方案,具有广泛的应用前景。     

茶多酚制品中有机溶剂多残留检测方法研究进展

现有的茶多酚分离制备工艺大多采用有机溶剂或大孔树脂,给产品带来了有机溶剂残留的安全隐患。本文概述了茶多酚的生产工艺及其残留溶剂的检测方法,主要介绍了直接进样气相色谱法、顶空气相色谱法和固相微萃取气相色谱法这三种方法在残留溶剂测定中的应用进展;提出有必要研究有机溶剂多残留快速检测技术,制定限量标准,提升加工工艺。     

浅析峰峰矿区矿井突水原因及防治

峰峰矿区是华北大水矿区 ,水害严重威胁着下组煤层的开采。本文通过对该矿区典型突水事例的分析 ,探讨了造成突水的原因 ,并提出了防治的措施。     

矿山测量工作管理方法初探

根据多年工作经验及测量工作的特点,探讨了适合煤矿测量工作的管理方法及具体措施。     

城市互联消防安全数字化监控系统的设计与实现

市场上销售的各个厂家生产的火灾自动报警控制系统自成体系,相互之间信息不能共享,不能自动与城市消防接警指挥中心及时通信,造成报警不及时.为此提出了城市互联消防安全数字化监控系统并与互联网相结合的构想,分析其组成原理,设计相应软、硬件,并研制成功.     

A framework of critical resource chain for project schedule analysis

Analysing a schedule is beneficial to help stakeholders understand the scheduled project. Project schedules, which create time plans based on the critical path method (CPM) or on resource‐constrained project scheduling problem (RCPSP) optimization, are targets herein. The Theory of Constraints (TOC) treats a schedule as a system. Schedule elements are suspected constraints and a goal depends on the schedule creation policy. Resource information is further surveyed herein to identify true constraints. A framework is proposed to integrate identified constraints on a schedule, and the critical resource chain concept is introduced. Three scenarios illustrate the proposed framework under different scheduling considerations. Results explain schedule constraints, and several schedule analysis issues are discussed.     

Protein separation mechanisms in surfactant precipitation systems

Separation of globular proteins (cytochrome c and ribonuclease A) from buffer using precipitation by sodium bis-(2-ethylhexyl) sulfosuccinate (AOT), and their recovery with a counterionic surfactant, trioctylmethylammonium chloride (TOMAC) was investigated. The molar ratio between AOT and the protein (R) required for complete removal was 17 for cytochrome c, and 22 for ribonuclease A. Finally, three mixtures of the two proteins and lysozyme (studied earlier by us) were used to determine the factors controlling separation: selectivity was a strong function of surface charge distribution, indicating that charge interactions between the surfactant and surface groups of different proteins was driving precipitation.     

基于Linux的嵌入式便携气相色谱仪温控系统

近年来,随着现场检测工作的迫切需要,便携式、微型化已经成为气相色谱仪发展的一个重要方向。传统的色谱温控系统由于结构复杂、体积较大难以实现便携式。针对这一问题,文中设计了基于Micro2440控制板和Linux系统的嵌入式气相色谱温度控制系统,该控温系统的主要控制过程为主程序通过温度采集模块得到当前温度值,然后根据当前温度值经过PID算法计算出本次加热时间并执行加热。通过实验表明,文中设计的气相色谱温控系统控温精度能达到±0.5℃,并实现了程序升温功能。