一个用于VHSIC连接线瞬态分析的电路模拟器

本文介绍了一个可对含连接线的电路进行瞬态分析的电路模拟器,该模拟器是在SPICE基础上经修改扩充而成的,连接线的处理采用了文献[1]的方法.文中介绍了方法的基本原理,讨论了数值Laplace反变换时参数的选择与误差的控制.实际VHSIC电路的试算结果表明,该模拟器是相当有效的.     

一种神经元控制模型参考自适应伺服系统

针对存在于摩擦非线性和负载转动惯量时变的伺服系统,提出一种神经元模型参考自适应控制设计方法。导出了控制对象离散数学模型,介绍了伺服系统结构和控制器设计,并用波波夫超稳定性理论证明该系统是渐近超稳定的。仿真结果表明系统具有良好的动态性能、稳态精度和鲁棒性。     

液相安培法检测鳗鱼中的磺胺类药物

本文建立了液相色谱安培检测鳗鱼中常用8种磺胺检测方法,采用甲醇:磷酸盐缓冲液(pH=3)梯度淋洗,反相C18分离.样品采用乙腈提取后,正己烷脱脂,用Oasis MCX、MAX小柱净化后,采用玻碳电极直流安培1.3V检测.线性范围为0.05-100μg/mL,分别做3个浓度的添加回收,方法回收率在52.8～102.0%之间,方法精密度在0.8～4.6%之间,方法定量限为0.5-4μg/kg.     

三轴试验中非饱和土试样吸力的量测

本文作者改装了常规三轴仪使之能量测非饱和土试样的孔隙水压力和控制孔隙气压力，并与轴移技术所测得的吸力进行了对比验证。利用这种改装的仪器和轴移技术，进行了一组非饱和土试样的排气常含水量三轴剪切试验，量测出剪切过程中的吸力变化值，试验中发现围压和剪切应变对试样的吸力均有较大影响。     

一种模型参考自适应转台伺服系统

本文提出一种基于稳定性理论的模型参考自适应复合控制转台伺服系统的设计方法,介绍一例及其数字仿真及参数优化的结果。     

Matrix interference-free method for the analysis of small molecules by using negative ion laser desorption/ionization on graphene flakes

This work presents a new approach for the analysis of small molecules with direct negative ion laser desorption/ionization (LDI) on graphene flakes. A series of matrix interference-free mass spectra were obtained for the analysis of a wide range of small molecules including peptides, amino acids, fatty acids, as well as nucleosides and nucleotides. The mixture of analytes and graphene flakes suspension were directly pipetted onto a sample plate for LDI-time-of-flight mass spectrometry (TOFMS) analysis. Deprotonated monomeric species [M-H](-) ions were homogeneously obtained on uniform graphene flakes film when negative ion mode was applied. In positive ion mode, the analytes were detected in form of multiple adduct ions such as sodium adduct [M+Na](+), potassium adduct [M+K](+), double sodium adduct [M+2Na-H](+), double potassium adduct [M+2K-H](+), as well as sodium and potassium mixed adduct [M+Na+K-H](+). Better sensitivity and reproducibility were achieved in negative ion mode compared to positive ion mode. It is believed that the new method of matrix interference-free negative ion LDI on graphene flakes may be expanded for LDI-MS analysis of various small molecules.     

On-column coaxial flow chemiluminescence detection for underivatized amino acids by pressurized capillary electrochromatography using a monolithic column

A new method for pressurized capillary electrochromatography (pCEC) coupling with chemiluminescence (CL) detection using a modified on-column coaxial flow detection interface was developed. To evaluate the feasibility and reliability of the experimental setup, the typical CL compounds luminol and isoluminol were separated and detected by using this pCEC-CL system. A detailed investigation of CL detection interface and postcolumn CL reagent flow rate parameters was described. The excellent resolution and detection sensitivity was achieved by using 3-microm ODS-C18 packed column with 30% ACN (v/v), 5 mmol/L phosphate buffer (pH 8.0). Moreover, with the presence of Co(II) (1.0 x 10(-4) mol/L) in the mobile phase, the linear range of the concentration for luminol was 2.0 x 10(-9)-2.0 x 10(-6) mol/L with a detection limit (S/N = 3) of 2.0 x 10(-10) mol/L, and 2.5 x 10(4) theoretical plates was achieved. In addition, separation and detection of the underivatized amino acids (l-threonine and l-tyrosine) were accomplished by using a polymerized monolithic column based on the principle of the luminol-H2O2-Cu(II)-amino acid CL system. Under the optimum conditions, the mixture of amino acids was efficiently separated with satisfactory results.     

Ultrasensitive aptamer-based multiplexed electrochemical detection by coupling distinguishable signal tags with catalytic recycling of DNase I

This work reports an aptamer-based, disposable, and multiplexed sensing platform for simultaneous electrochemical determination of small molecules, employing adenosine triphosphate (ATP) and cocaine as the model target analytes. The multiplexed sensing strategy is based on target-induced release of distinguishable redox tag-conjugated aptamers from a magnetic graphene platform. The electronic signal of the aptasensors could be further amplified by coupling DNase I with catalytic recycling of self-produced reactants. The assay was based on the change in the current at the various peak potentials in the presence of the corresponding signal tags. Experimental results revealed that the multiplexed electrochemical aptasensor enabled the simultaneous monitoring of ATP and cocaine in a single run with wide working ranges and low detection limits (LODs: 0.1 pM for ATP and 1.5 pM for cocaine). This concept offers promise for rapid, simple, and cost-effective analysis of biological samples.     

光电薄膜SnS的制备及其性能

在溶液的pH=2.7,离子浓度比Sn2+/S2O2－3=1/5和电流密度J=3.0mA／cm2的条件下,用阴极恒电流沉积法在ITO导电玻璃基片上制备出了Sn0.995S1.005膜层,并用扫描电镜观察了该薄膜的表面形貌，发现其颗粒较均匀，粒径大小在200～800nm之间．用X射线衍射分析了其物相结构，表明它是具有正交结构的SnS多晶薄膜．通过测量薄膜样品的透射光谱和反射光谱，计算得到其直接禁带宽度Eg=1.23eV．用四探针法测得其导电类型为p型，电阻率为7.5Ω·cm.     

人促红细胞生成素检测方法研究进展

人促红细胞生成素具有重要的临床价值,同时还被认为是最具"欺骗性"的兴奋剂之一.本文在对人促红细胞生成素的结构、生理功能以及类型进行介绍的基础上,总结了人促红细胞生成素的血液学参数间接检测法,同时对等电聚焦、毛细管电泳、免疫等直接检测方法进行了阐述.