HPLC法测定人体尿液样品中的4'-羟基黄烷酮和6-甲氧基黄烷酮

报道一种快速测定人体尿液中4'-羟基黄烷酮和6-甲氧基黄烷酮的HPLC方法.采用自制的大蒜新素键合硅胶填充柱(DTSP,4.6 mm i.d.×15 mm,10 μm),以乙腈/1.5%三乙胺-甲酸(65:35,v/v,pH=3.0) 为流动相,流速设定为1.0 mL·minn~(-1),检测波长为 257 nm时,实现了人体尿样品中上述黄烷酮化合物的良好分离.4'-羟基黄烷酮的线性范围为5～100 mg·L~(-1),r=0.992 0;6-甲氧基黄烷酮线性范围为5～100 mg·L~(-1),r=0.999 1,它们的最低检出限分别为1.03 ng和1.56 ng,平均回收率分别为99.02%～99.26%和98.21%~98.62%,相应的RSD分别小于0.354%和0.605%(n=5).该方法快速、简便、可靠,适用于人体尿液样品中上述黄烷酮分离分析.     

Head-flow and npsh performance of an axial piston pump working with organic fluids at different temperatures

A modified version of the standard axial piston pump, normally used with fuels, has been tested with organic fluids R11 and R113. Head-flow characteristics, volumetric and global efficiency, and npsh curves, have been determined at different speeds and fluid temperatures and the results compared with those obtained with kerosene. Pump efficiencies remain satisfactory with high density, very low viscosity and high vapour pressure fluids. In the absence of cavitation, pump performance seems to be a function of kinematic viscosity, while the npsh curves appear to be a complex function of density, viscosity and vapour pressure     

模糊控制器用于改善涡轮增压柴油机的部分负荷性能

模糊控制已在一类缓变的过程控制中得到成功的应用,本文将它引入到柴油机这一高速系统的性能控制,研究了相应的模糊控制器的设计方法,研制了以微计算机为核心的增压空气泄放控制系统,并在B6135-ZG20涡轮增压柴油机上实现了最大爆发压力的闭环控制。这一研究进一步改善了增压系统的性能,也为模糊控制开辟了一个新的应用领域。     

双面碎片的英文文件复原方法研究

对英文材料的双面规则碎片文件复原问题进行了研究.由于碎片边界是规则的几何形状,无法采用几何形状匹配算法进行复原,为此提出了基于碎片边缘像素特征的匹配复原算法,建立了双面二维灰度匹配数学模型.通过加入行约束条件,减少横向匹配中的纵向误差,并通过消除列匹配中的误差,优化了匹配算法.该模型可以实现块状双面英文碎片的完整复原.     

地方公共财政绩效评估指标体系的构建及其应用

在公共财政透明化和高效化的改革要求下,公共财政绩效评估将逐渐日常化和规范化,而科学、有效的公共财政绩效评估核心在于指标体系的构建。基于层次分析法,从公共财政体系的财政收入、财政支出、财政制度、财政管理四个维度构建了一个地方公共财政绩效评估指标体系。结合该指标体系在江西省的实际应用,发现它能客观有效的评价样本政府的公共财政建设情况。     

瓶罐玻璃行业企业绩效评价

笔者依据所能获得的资料———《瓶罐玻璃行业企业经济信息汇编》[6],建立了一套经济实用的瓶罐玻璃行业企业绩效评价指标体系;提供了一种科学评价方法和计算机化的评价技术;能适时地对该行业内各企业绩效进行评价和比较分析;及时获得各企业在全行业内竞争位次;及时发现影响企业绩效的主要因素;为高层管理者制定和调整企业管理决策提供了参考依据。     

利用模拟退火算法进行油井流入动态研究

油井流入动态是油井举升优化设计的基础 ,目前国内外研究油井流入动态的方法有多种 ,但是各有其不足和局限性 .为此利用模拟退火方法进行油井流入动态方法研究 .与以往的近似算法相比 ,该方法不需要将单相流和多相流分开讨论 ,且无任何假设条件 ,适用范围广 ;通过实例 ,把模拟退火的预测的产量结果与利用 Vogel方程所预测的产量结果进行比较和误差分析 ,结果表明 ,该算法的误差是非常小的 .因此 ,利用该算法研究油井流入动态非常可行 .     

Second-Harmonic Generation in Domain-Inverted Grating Induced by Focused Ion Beam

The fabrication of a periodic domain inversion in LiTaO₃ and LiNbO₃ using direct ion-beam writing is presented. The polarization of these materials can be reversed at room temperature by irradiating Si²⁺ ions into +c faces. A first-order periodic domain inversion with a 50% duty cycle, a depth of 300μ, and an interaction length of 1 mm was realized in LiTaO₃. Using this structure, 300μW of blue light was generated for a conversion efficiency of 0.25%/W.     

Robust Output Tracking Control of an Uncertain Linear System via a Modified Optimal Linear-Quadratic Method

This study investigates the robust output tracking problem for a class of uncertain linear systems. The uncertainties are assumed to be time invariant and to satisfy the matching conditions. According to the selected nominal parameters, an optimal solution with a prescribed degree of stability is determined. Then, an auxiliary input via the use of an adapting factor, connected to the nominal optimal control, is introduced to guarantee the robustness and prescribed degree of stability for the output tracking control of the uncertain linear systems. This method is very simple and effective and can reject bounded uncertainties imposed on the states. A maglev vehicle model example is given to show its effectiveness.     

Vessel Arrival Process and Queueing in Marine Ports Handling Bulk Materials

We study the vessel arrival process in bulk ports handling either cargo containers or minerals. Then we introduce the SHIP/G/1 queue to be able to study the queueing behavior at the port. We present approximations for the asymptotic probabilities of delay and the number of vessels at the port. Numerical examples show the accuracy of the approximations. In appendices, we provide details of the analysis of the number of vessels at the port and the correlation properties of the vessel arrival process.