球磨对纳米ZrO2水相悬浮体系性质的影响

实验研究了球磨时间对纳米ZrO₂水悬浮液性质的影响。结果表明,粒径小于15nm ZrO₂在SND6800球磨剂的水相中球磨2h制备的悬浮液,可稳定存在14天。在SND6800球磨剂与ZrO₂的质量比为5:95时,球磨时间对粒子粒度、悬浮液的密度和pH值以及沉降率影响不大;但对悬浮液的吸光度、表面张力和黏度有明显的影响。球磨时间50h是悬浮液的吸光度及表面张力最大,而黏度是球磨40h时最大。     

台达自动化产品在多功能旋压机的应用

本文主要论述台达变频器、PLC、HMI产品在多功能旋压机控制系统的应用原理,在该系统中,变频器驱动主轴电机的旋转;PLC以RS-485通讯方式调节主轴（变频器）的转速,PLC模拟量扩展模块用于控制液压缸的压力和流量,编码器获取左侧液压缸以及右侧液压缸的当前位置信号,HMI监控旋压机的运行状态以及警报信息,展示了台达自动...     

华为6800波分复用系统日常维护

结合张家港广电信息网络有限公司数据运维业务中心波分城域网建设运行实际情况,从日常实际工作中总结了在维护波分设备时的注意事项和一些可行性措施,形成一套日常维护流程,并列举一些维护案例。     

Synthesis of some fluorinated thiazolopyridine from pentafluoropyridine and 4-phenylsulfonyl tetrafluoropyridine

In this study, the reaction of pentafluoropyridine and 4-phenylsulfonyl tetrafluoropyridine with difunctional nitrogen and sulfur nucleophiles such as thiourea, thioamide derivatives, and unsymmetrical bidentate nitrogen nucleophiles such as diamino-triazole and amino-imidazole in the presence of sodium carbonate was investigated.     

Comparison of methods with respect to efficiencies, recoveries, and quantitation of mercury species interconversions in food demonstrated using tuna fish

Eight different analytical extraction procedures commonly used to extract mercury species from biological samples were evaluated by analyzing Tuna Fish Tissue Certified Reference Material (ERM-CE464) certified for the content of total mercury and methylmercury. Speciated isotope dilution mass spectrometry (SIDMS; US Environmental Protection Agency’s method 6800) was utilized to evaluate and effectively compensate for potential errors during measurement and accurately quantify mercury species using all the extraction methods. SIDMS was used to accurately evaluate species transformations during sample pretreatment, preparation and analysis protocols. The extraction methods tested in this paper were based on alkaline extraction with KOH or tetramethylammonium hydroxide; acid leaching with HCl, HNO₃ or CH₃COOH; extraction with l-cysteine hydrochloride; and enzymatic digestion with protease XIV. Detection of total mercury and mercury species from all extraction methods was carried out by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography–ICP-MS, respectively. Microwave-assisted extraction and ultrasound-assisted extraction were found to be the most efficient alkaline digestion protocols that caused the lowest levels of transformation of mercury species (6% or less). Extraction with 5 M HCl or enzymatic digestion with protease resulted in the second-highest extraction efficiency, with relatively lower transformation of methylmercury to inorganic mercury (3 and 1.4%, respectively). Despite frequent use of acid leaching for the extraction of mercury species from tuna fish samples, the lowest extraction efficiencies and the highest mercury species transformation were obtained when microwave-assisted extraction with 4 M HNO₃ or CH₃COOH was used. Transformations as high as 30% were found using some literature protocols; however, all the extractions tested produced accurate quantitation when corrected in accordance with the SIDMS method standardized in the US Environmental Protection Agency’s method 6800. Figure Determinative CRM Tuna Fish Tissue Methylmercury Calibration vs. Determinative Calculation.     

P51XA单片机与图形液晶显示器的接口设计

P51XA是一种与MCS-51兼容的16位单片机,运行速度快,存储器空间大,支持实时多任务操作系统。可以应用在一些复杂的嵌入式系统里,为广大熟悉MCS-51单片机的工程技术人员提供了一种向16位MCU的平滑、快速的过渡。文中介绍P51XA与点阵液晶显示器MGLS240128T接口的软、硬件实现,给出了相应的硬件电路和驱动程序。     

基于IC控制器CM6800的LCD电视机电源设计

以新一代功率因数校正芯片CM6800为核心,提出了一种宽电压输入、固定电压输出的LCD电视机电源的设计方案,重点讲述了CM6800的主要特性及各主要器件参数选择。该方案能在80~265 V宽输入电压范围内得到稳定直流电压输出,具有效率高、总谐波畸变率低、功率因数接近为1等特点。该方案完全能满足LCD电视机电源的要求,并已得到成功应用。     

Boundary trace embedding theorems for variable exponent Sobolev spaces

We study boundary trace embedding theorems for variable exponent Sobolev space W1,p(⋅)(Ω). Let Ω be an open (bounded or unbounded) domain in RN satisfying strong local Lipschitz condition. Under the hypotheses that p∈L^∞(Ω), 1?infp(x)?supp(x)<N, |∇p|∈Lγ(⋅)(Ω), where γ∈L^∞(Ω) and infγ(x)>N, we prove that there is a continuous boundary trace embedding W1,p(⋅)(Ω)→Lq(⋅)(∂Ω) provided q(⋅), a measurable function on ∂Ω, satisfies condition for x∈∂Ω.     

SND6800球磨剂对纳米ZrO2水悬浮液性质的影响

研究了SND6800球磨剂对纳米ZrO₂水悬浮液性质的影响。结果表明。粒径小于15nm ZrO₂在SND6800球磨剂的水相中球磨2h制备的悬浮液,可稳定存在14天。SND6800球磨剂与ZrO₂的质量比为3.5:100,悬浮液的吸光度较小、表面张力较大、黏度较小、沉降率接近最低值。SND6800球磨剂的含量对悬浮液的密度和pH值影响不大。     

基于高速单片机的液晶显示模块控制

为了适应现场自动化的需要并满足现场设备测试系统的终端显示要求,设计了基于高速单片机C8051F120的液晶显示模块(LM6800)控制系统。详细介绍了液晶显示接口硬件设计方案以及软件设计思想,通过实验验证了此液晶模块控制系统的正确性。