A new strategy for synthesis of branched cyclic peptide by Asn side-chain hydrazide ligation

Here, we report a new strategy for rapid synthesis of branched peptide by side-chain hydrazide ligation at Asn. The hydrazide was converted to thioester at Asn side chain by NaNO₂ and thiol reagent, and sequential ligation with an N-terminus Cys-peptide efficiently afforded the branched peptide. A branched cyclic peptide was successfully synthesized by side-chain ligation with a two-Cys-peptide and formation of a disulfide bond. This approach provides a new way for expeditious synthesis of branched peptides and facilitates the design of neopeptides as functional bio-mimics.     

Eye-safe compact scanning LIDAR technology

A 1.5-μm eye-safe, 3-D scanning, and compact Mie LIght Detection and Ranging (LIDAR) is presented. The transmitter of the LIDAR is based on a KTA optical parameter oscillator (OPO) resonator. For detecting return signals, an InGaAs APD is used. The all solid-state OPO laser transmitter has the feature of small volume and lightweight, which allows a 165-lb compact eye-safe scanning LIDAR to be constructed. A system simulation using our own model was conducted to direct the system development. A method to solve the problem with small active area APD detectors was developed and described. The preliminary field-test measurement results indicated that the LIDAR has the capability to detect aerosols and clouds in lower atmospheres up to three dimensions.     

智能高速罐身电阻焊机数字化控制系统

提出了以国产MCT80 0 0F8运动控制器为核心的智能高速罐身电阻焊机数字化控制系统 ,并介绍了系统的组成、工作原理、硬件接口、电机控制方法以及伺服电机的运动关系数学模型 .新的系统有利于提高罐身电阻焊机的制罐生产速度 ,并具有功能全面、可靠性高、控制精确、开放性好以及成本较低等优点     

Sensitive chemically amplified electrochemical detection of ruthenium tris-(2,2′-bipyridine) on tin-doped indium oxide electrode

Optimized combination of chemical agents was selected for sensitive electrochemical detection of dissolved ruthenium tris-(2,2′-bipyridine) (Ru-bipy). The detection was based on the chemical amplification mechanism, in which the anodic current of a redox-active analyte was amplified by a sacrificial electron donor in solution. On indium-doped tin oxide (ITO) electrodes, electrochemical reaction of the analyte was reversible, but that of the electron donor was greatly suppressed. Several transition metal complexes, such as ferrocene and tris-(2,2′-bipyridine) complexes of osmium, iron and ruthenium, were evaluated as model analyte. A correlation between the amplified current and the standard potential of the complex was observed, and Ru-bipy generated the largest current. A variety of organic bases, acids and zwitterions were assessed as potential electron donor. Sodium oxalate was found to produce the largest amplification factor. With Ru-bipy as the model analyte and oxalate as the electron donor, the analyte concentration curve was linear up to 50 μM, with a lower detection limit of approximately 50 nM. Preliminary work was presented in which a Ru-bipy derivative was attached to bovine serum albumin and detected electrochemically. Although the combination of Ru-bipy, oxalate and ITO electrode has been used before for electrochemiluminescent detection of Ru-bipy and oxalate, as well as electrochemical detection of oxalate, its utility in amplified voltammetric detection of Ru-bipy as a potential electrochemical label has not been reported previously.     

提高实验人员素质,加强实验队伍建设

本文阐述了实验队伍建设的重要性,分析了目前高校实验技术队伍中存在的问题,并提出了解决问题的若干措施和对策.     

如何做好桩基工程旁站监理

文章介绍了桩基工程旁站监理的过程和实效及保证监理目标实现的具体措施。     

基于BP网络的反馈控制器设计

针对常规反馈控制器参数在对象时变情况下难以获得最优的问题，利用BP神经网络构成系统反馈控制器，通过自适应学习速率在线调整网络权值以逼近对象的逆动态模型，并利用Lyapunov方法给出了该算法的收敛的条件。将算法应用于循环水温度控制系统表明：该控制器对模型参数不依赖，能有效地适应控制对象参数的变化，系统具有较强的鲁棒性。     

自主机器人人工进化方法研究

在介绍人工进化研究状况的基础上 ,着重阐述了进化机器人学的关键问题 :基本概念、进化技术、进化计算和实验研究方法等 ,探索了进化机器人学未来的研究趋势及所面临的挑战 .     

尾水管水力振动的监测与故障判断

从模型及真机试验结果出发，叙述混流式水轮机一般的水力故障形式，研究了尾水管的水力振动特点及振动随运行工况而变化的情况，介绍了以压力脉动频率及幅值作为特征参量对尾水管进行振动监测及故障判断的方法。