微振动光电检测与数据采集系统的设计

提出了一种新的光学非接触式测量方法测量了物体的微振动振幅。用激光作为光源,以四象限硅光电池[1]作为光电探测器,借助三角测量原理,投射在振动源表面的激光反射光束在光电探测器上产生平面位移,将位移信号放大,通过A/D模块采集电压数值,并通过串口通信机制在PC终端实时显示。实验结果表明,该方法原理正确,灵敏度高,便于实现连续、快速、自动化检测,在工业在线检测方面具有良好的应用前景。     

市场化改革背景下养老机构服务供给博弈研究

考虑政府补贴、市场化程度、养老机构服务成本、老年人偏好等因素,构建了完全国有化、公私并存的半市场化和完全市场化三种情形下公办和民办养老机构之间的两阶段博弈模型,比较分析了市场化程度对养老机构服务价格制定和服务水平选择的影响,实证讨论了各参数变化对养老机构收益及社会福利的影响。研究表明:完全市场化机制会降低养老机构服务质量,完全国有化机制会陷入社会福利陷阱,探索公私并存的最佳市场化水平才能更好地提高社会福利;适度推进市场化改革,提高养老机构服务水平,降低民办养老机构服务成本,适度提高对民办养老机构的补贴,将有效缓解公办和民办养老机构的不公平竞争;提高老年人支付能力,推进养老机构供给侧结构性改革,将保障机构养老服务的有效供给,促进养老服务业的健康有序发展。     

锆基纤维素手性固定相直接拆分萘普生衍生物

萘普生是一种消炎镇痛药 ,其 S对映体的抗炎作用是 R构型的 2 8倍 ,萘普生及其衍生物的拆分具有重要意义 .手性固定相 HPLC直接拆分 [1～ 4 ] 是最简便的分析方法 .氧化锆是近年来备受关注的色谱载体 [5,6 ] .Carr等 [7] 对碱性药物快速拆分表明氧化锆在手性分离Scheme1　 Structuresof chiral naproxen and its derivatives中的独特选择性 .萘普生及其衍生物在锆基手性固定相上的分离未见文献报道 .本组利用自制的球形氧化锆制备了涂敷型纤维素 -三 ( 3,5 -二甲基苯基氨基甲酸酯 ) -Zr O2 手性固定相 ( CDMPC- Zr O2 - CSP) ,在正…     

5－氟尿嘧啶－卟啉化合物的合成及抗癌活性

以37％－45％的产率合成了六个新的5－氟尿嘧啶-卟啉化合物，通过元素分析 、红外光谱、紫外可见光谱、核磁共振谱和质谱确定了其结构。抗癌试验表明，化 合物A3，A4，A5对Hela（宫颈癌细胞）有明显的抑制作用。     

Offline Arbitrated Quantum Blind Dual-Signature Protocol with Better Performance in Resisting Existential Forgery Attack

In this paper, we present an offline arbitrated quantum blind dual-signature protocol by using four-particle entangled Greenberger-Horne-Zeilinger(GHZ) states. By using the special relationship of four-particle GHZ states, we can not only support the security of quantum signature, but also guarantee the anonymity of the message owner. In our protocol, the authority of the arbitrator has been reduced, i.e., he will not help the receiver verify the signature in the verification. Compared with the previous quantum blind signature protocols, the presented arbitrator is offline. Finally, the security analysis and discussion are proposed.     

Redox-Guest-Induced Multimode Photoluminescence Switch for Sequential Logic Gates in a Photoactive Coordination Cage

Molecular or supramolecular level photoluminescence (PL) modulation combining chemical and photonic input/output signals together in an integrated system can provide potential high-density data memorizing and process functions intended for miniaturized devices and machines. Herein, a PL-responsive supramolecular coordination cage has been demonstrated for complex interactions with redox-active guests. PL signals of the cage can be switched and modulated by adding or retracting Fc derivatives or converting TTF into different oxidation states through chemical or photochemical pathways. As a result, reversible or stepwise PL responses are displayed by these host–guest systems because of the occurrence of photoinduced electron-transfer (PET) or fluorescence resonance energy transfer (FREnT) processes, providing unique nanodevice models bearing off/on logic gates or memristor-like sequential memory and Boolean operation functions.     

Thermal Degradation of HDPE in a Batch Pressure Reactor: Reaction Time and Mechanical Stirring Effect

The effect of reaction time and mechanical stirring on thermal degradation of high density polyethylene(HDPE) was studied at 350°C under nitrogen atomosphere in a batch pressure reactor. Changes in molecular weight(MW), molecular weight distribution (MWD), and crystalline behaviors of the degraded products were investigated by gel chromatography (GPC) and differential scanning calorimetry (DSC). It was found that MWD curves all shifted toward lower molecular weight with increasing reaction time, with both the extent of the movement and its showing a rapid initial drop and then leveling off. In a short period of reaction time, the MW, MWD and crystalline behaviors of the degraded products were affected notably by the mechanical stirring. The of the degraded products without stirring was lower than that of products with stirring in the same time, which should be related to the large difference of temperature distributions in the reactor. When the reaction time reached 4 h, the of the degraded products had dropped to about 5 × 10³g/mol from about 3 × 10⁵g/mol for the original , and the product did not show the melting and crystallization behaviors of high density polyethylene again.     

基于主动式时间反转镜的声呐目标强度测量研究

为提高目标强度测量过程中的抗噪声、混响以及浅海多途干扰性能,从军标文件中的目标强度测量方法以及主动式时间反转镜的基本原理出发,经过研究和推演,发现可将基于单阵元的主动式时间反转镜与相关器结合应用于目标强度测量过程,提出了一种新的目标强度测量方法。该方法利用了主动式时间反转镜的抗多途特性,使得测量具有抗多途的性能;利用噪声与信号的不相关特性,算法结合相关器起到了很好的抗随机噪声效果;混响中的体积混响是随机的,算法具有抗体积混响的性能。论文分别从理论仿真和水池实验验证了算法的有效性和正确性。     

四甲基吡啶卟啉与核酸相互作用的稳态和时间分辨光谱

采用稳态吸收和荧光光谱、圆二色谱和皮秒时间分辨荧光光谱手段, 研究了5,10,15,20-四[4-(N-甲基吡啶)]卟啉(TMPyP4)与腺嘌呤(A)、鸟嘌呤(G)、胸腺嘧啶(T)和胞嘧啶(C)等4种碱基, 以及相应的核苷、核苷酸和单链DNA的结合能力和光谱学性质. 研究结果发现, 嘌呤与TMPyP4的结合能力比嘧啶的强. 对于某一碱基系列, 结合能力强弱顺序依次为: 碱基~核苷<核苷酸<单链DNA. 时间分辨荧光谱研究发现, 除鸟嘌呤外, 核酸和TMPyP4复合物的荧光动力学均含有快(1~2 ns)和慢(约10 ns)两个衰减过程, 它们分别是由激基复合体和环境极性对激发态TMPyP4分子的影响所致. 单链DNA能诱导TMPyP4产生诱导圆二色信号, 而单分子(碱基、核苷、核苷酸)则无此功能.     

季铵盐类相转移催化剂的介绍与其在异相亲核取代反应中的应用——介绍一个国外本科生实验并讨论其相关问题

介绍了一个国外大学化学专业本科生有机化学实验"相转移催化剂的应用"，介绍了实验设计与流程，分析了实验结果，并讨论其相关的问题。该实验涉及到整套的现代有机合成流程，如薄层层析色谱（TLC）技术与硅胶柱色谱分离技术，并通过半微量反应的设计，减少对环境有害物质的使用，体现了"绿色化学"的设计理念，值得国内本科生有机化学实验借鉴与学习。