高精度转台控制系统研究

—本文针对精密转台控制系统在大偏差下的不稳定问题，对其控制系统进行了分析和设计，同时对其高分辨率的指令系统进行了设计，为提高转台的精度及其动态性能提供了新的途径。     

One pot iridium-catalyzed asymmetrical double allylations of sodium sulfide: a fast and economic way to construct chiral C2-symmetric bis(1-substituted-allyl)sulfane

One pot asymmetrical double allylations of sodium sulfide catalyzed by an iridium complex along with a combination of caesium fluoride and water in dichloromethane have been realized and the double allylation products with two C-S bond chiral centers were obtained in 67-99% yields with b/l 81/19-99/1, dr 85/15-99/1, and 96-99% ee.     

油酸钠改性无水硫酸钙晶须及其机理研究

采用油酸钠改性无水硫酸钙晶须(AW),既可以增强无水硫酸钙晶须的疏水性,又可以在晶须表面引入-C=C-增加其功能性.利用晶须在甲基丙烯酸甲酯(MMA)的分散性能探究油酸钠加量、时间、改性温度等因素对改性效果的影响;采用XRD、XPS和DRIFTS探索晶须的吸附及改性机理、Washburn法测定晶须的疏水性能.结果表明随油酸钠用量的增加,分散性能先变好后变差,油酸钠与晶须质量比为1:100时,沉降高度和沉降速度由油酸钠与晶须质量比为1:200时的3.1 cm和0.31 cm/min大幅增加到10.6 cm和1.06 cm/min;分散性能开始出现突变时的油酸钠用量随温度升高而增加;DRIFTS表明油酸钠中的油酸根离子主要以物理吸附和化学吸附的方式与钙离子结合存在于晶须表面,其特征吸收峰分别是1577 cm-1和1540 cm-1的双峰和1547 cm-1的单峰;改性后的晶须疏水性较改性前大幅增加,与水的接触角从改性前的0.04°增加到改性后的77.35°.     

响应面试验优化超声波辅助提取龙眼愈伤组织中单宁的工艺

为提高龙眼愈伤组织中单宁的提取率,采用超声波辅助浸提法,基于乙醇浓度（A）、超声波功率（B）与提取时间（C） 3个单因素试验,通过响应面试验优化设计,建立了龙眼愈伤组织单宁提取工艺。 研究结果表明,龙眼愈伤组织中单宁的最佳提取条件为乙醇浓度61%、超声波功率140 W,提取时间54 min,提取温度60 ℃,在此工艺条件下,提取量为7.53 mg·g^-1。     

Synthesis and spectral studies of diorganotin heterocyclic dithiocarbamate complexes and crystal structures of (2‐F‐Bz)2Sn(Cl) S2CN(CH2CH2)2NEt and (3‐Cl‐Bz)2Sn [S2CN(CH2CH2)2NEt]2 ⋅ 0.5HN(CH2CH2)2NH

Some new diorganotin(IV) complexes of heterocyclic dithiocarbamate having general formula R₂Sn(Cl)S₂CNR'₂ and R₂Sn(S₂CNR'₂)₂ [R = 2‐F‐Bz, 3‐Cl‐Bz; NR'₂ = N(CH₂CH₂)₂NMe, N(CH₂CH₂)₂NEt, and N(CH₂CH₂)₂NBz] have been prepared, respectively. Elemental analyses, IR, and NMR spectral data characterized all compounds. The crystal structures of (2‐F‐Bz)₂Sn(Cl)S₂CN(CH₂CH₂)₂NEt 2 and (3‐Cl‐Bz)₂Sn[S₂CN(CH₂CH₂)₂NEt]₂ ⋅ 0.5 HN(CH₂CH₂)₂NH 5 were determined by single crystal X‐ray diffractometer. In the crystal of complex 2 , the tin atom is rendered five‐coordination in a trigonal bipyramidal configuration by coordinating with S atoms of dithiocarbamate groups. For complex 5 , the central Sn atom exists in a skew‐trapezoidal planar geometry defined by two asymmetrically coordinated dithiocarbamate ligands and two 3‐chlorobenzyl groups. © 2005 Wiley Periodicals, Inc. 16:271–277, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20096     

伺服台台面与恒温箱间的隔热方法

本文提出了伺服转台台面恒温箱与台面之间的隔热方法，通过理论计算和实验结果证实，隔热效果显著，能够达到理想的技术指标。     

Characterization of the IF Noise of a Submillimeter SIS Receiver

A fitting method is presented here for the accurate characterization of the IF noise contribution of a sub-millimeter SIS receiver. By fitting the mixer's IF output power response and junction's IV curve of an SIS mixer without LO pumping, we can obtain the IF noise contribution, the physical temperature of the isolator connected just behind the SIS mixer, the output mismatching of the mixer, and the total gain of the IF chain. Differing from a conventional method, which only uses the normal-state (linear) branch of the junction's IV curve, the method proposed here also includes the nonlinear portion around the gap voltage. The dynamic resistance in this portion is varied dramatically, providing us a good probe to characterize the output mismatching of the mixer, as well as other parameters.     

Glucose and pH Dual‐Responsive Nanogels for Efficient Protein Delivery

Direct delivery of protein suffers from their in vitro and in vivo instability, immunogenicity, and a relatively short half‐life within the body. To overcome these challenges, pH and glucose dual‐responsive biodegradable nanogels comprised of dextran and poly(L‐glutamic acid)‐g‐methoxy poly‐(ethylene glycol)/phenyl boronic acid (PLG‐g‐mPEG/PBA) are designed. The cross‐linked network imparted drug‐loading efficacy of α‐amylase up to 55.6% and hyaluronidase up to 29.1%. In vitro protein release profiles reveal that the release of protein is highly dependent on the pH or glucose concentrations, that is, less amount of protein is released at pH 7.4 or healthy blood glucose level (1 mg mL^?1 glucose), while quicker release of protein occurs at pH 5.5 or diabetic blood glucose level (above 3 mg mL^?1 glucose). Circular dichroism spectra show that the secondary structure of released protein is maintained compared to naive protein. Overall, the nanogels have provided a simple and effective strategy to deliver protein.     

精密测角系统的幅相变换与误差补偿

本文重点介绍ＳＪ－１型测角系统幅相变换部分的工作原理、误差分析及误差补偿。该系统的主要特点是：采用单相激磁的双通道工作方式，在幅相变换和误差补偿方面，突破了一次谐波和二次谐波误差补偿的技术关键，具有较高的抗干扰能力及长期工作的稳定、可靠。     

高精度转台测角系统温漂补偿的研究

本文从感应同步器原理出发，推导了由于激磁电源的非正交性引起的测量误差模型，并从实验出发检测了测角误差与温度的关系，提出了一种温漂补偿方法，提高了测角系统的温度稳定性和测量精度。