增塑剂对可吸收缝合线后处理工艺条件和降解性能的影响

分别在对二氧环己酮均聚物和对二氧环己酮-乙交酯共聚物中加入增塑剂进行纺丝,制得聚对二氧环己酮单丝缝合线(PDS)和对二氧环己酮-乙交酯共聚物单丝缝合线(PDG).用DSC方法研究了增塑剂含量对PDS缝合线热性能的影响和不同热定型条件的PDG缝合线的热性能,测试了热定型温度对PDG缝合线初始强度、模量及柔量的影响,考察了增塑剂含量对两种缝合线的生物降解性能和力学降解性能影响.研究结果表明,PDS缝合线的玻璃化转变温度Tg、结晶温度Tc以及熔融温度Tm均随着增塑剂含量的增加而降低,但其结晶能力增加.随着热定型温度的增加,PDG缝合线的初始打结强度、熔融热均提高,熔融温度Tm基本保持不变.两种缝合线的强度保留率随着增塑剂含量的增加均先增加后减小,而重量保留率随着增塑剂含量增加始终减小.     

乙二胺溶剂热还原法制备碳纳米管

以乙二胺作为溶剂和碳源,用KBH4还原NiCl2得到的镍作为催化剂,于300℃制备碳纳米管。X-射线衍射(XRD)、透射电子显微镜(TEM)、选区电子衍射(SAED)和Raman光谱分析证明,产品为多壁碳纳米管,直径约为100nm,长度达几微米。该方法具有反应温度低、反应时间短、操作简便等特点。     

pH指示剂吸光度比法测定喷昔洛韦钠原料药含量

本文采用pH指示剂吸光度比法测定喷昔洛韦钠原料药的含量,并与紫外分光光度法和高效液相色谱法两种方法进行了比较。该法简单、准确、快速、灵敏且重现性好,有应用前景。     

Cr-AlPO4-5的合成及其对苯直接氧化制苯酚反应的催化性能

 以Cr(NO3)3为Cr源用水热法合成了Cr-AlPO4-5分子筛,并用XRD,FT-IR和XPS对分子筛进行了表征. 结果表明,Cr已进入到Cr-AlPO4-5分子筛骨架结构中; 焙烧后分子筛样品的L酸中心和B酸中心数量均大幅度增加,Cr主要以Cr(Ⅴ)形式存在. 将分子筛样品用于催化H2O2氧化苯制苯酚反应,苯酚收率最高可达4.7%,选择性可达99.5%以上. 非骨架Cr物种是导致H2O2无效分解和选择性下降的主要因素,而骨架Cr物种是反应的活性中心. 提出了以骨架Cr过氧化物为中间物种的可能的反应机理,并用原位红外光谱初步验证了中间物种的存在.     

2级VMI集成的Shapley指数收益分配方案

本文在回顾了VMI集成相关文献基础之上,将解决多人合作博弈问题的Shapley值方法用于解决两级VMI联盟的收益分配问题,从而提出了一种各方均可接受且稳定的收益分配方案.在此收益分配方案下,供应链各方均会从VMI集成中得到利润水平上的提升,而且兼顾到了各方公平.     

Identification of alkyl carbazoles and alkyl benzocarbazoles in Brazilian petroleum derivatives

The present work describes (a) the identification and characterization of an impurity, 2,4,5,7-tetrabromo-6-hydroxy-9-(2,3,4,5-tetrachlorophenyl)-3H-xanthen-3-one (BCPX), in the color additives D&C Red Nos. 27 and 28 (phloxine B) and (b) the determination of the extent and level of BCPX contamination in certified lots of these colors. For these purposes, BCPX (a compound not previously reported in the literature) was synthetically prepared. Test portions from 42 certified lots of D&C Red Nos. 27, 28 and 27 lakes were analyzed for BCPX using an HPLC method that included gradient elution and UV-vis photodiode array detection. Those lots were submitted for certification by both domestic (six) and foreign (six) manufacturers during the past 4 years. Of the test portions analyzed, 32 (76.2%) contained BCPX in amounts ranging from 0.01 to 3.21%. The remaining 10 test portions (23.8%) contained no detectable BCPX or less than 0.008%, which is the limit of quantification for the present method. The analyses revealed substantial differences in the level of BCPX across different manufacturers. The wide range of BCPX levels found in the analyzed lots suggests that the presence of BCPX in D&C Red Nos. 27 and 28 may be avoided or significantly reduced during the manufacturing process.     

Entanglement Dynamics of Three Superconducting Charge Qubits Coupled to a Cavity

We investigate the entanglement dynamics of a quantum system consisting of three superconducting charge qubits (SCQs) interacting with a microwave field. For separable and entangled states of the SCQs, the evolutions are studied under various photon numbers of cavity field. The results show that the amplitude and period of the bipartite entanglement square concurrences can be controlled by the choice of initial states of SCQs and photon numberof cavity field, respectively. This simple model of a quantum register allows us to understand the dynamic process of the quantum storage of information carried by charge qubit.     

几种应变检测的光力学测试方法及其比较

应变测量技术在工程应用中有重要意义.一是它可以直接用来获得应力场,可以用来评价材料的安全性和可靠性;二是应变梯度很大的部位往往又是材料破坏的起始点,所以应变测量又可以用于进行材料的无损检测.当前几种光力学方法受到了重视,即云纹干涉法、电子剪切散斑干涉法和数字相关散斑法,对上述方法的原理、光路设计、特点作了介绍,以便这些传统方法的进一步推广,文中还特别介绍了一种作者近来在国内率先开展的微压痕应变花法.这一方法可以方便用于金属等材料上,可以较精确定量研究测试物体的应变而且对刚体位移不敏感,应用起来更加直接和方便,更有推广和应用前景.本文有利于针对研究对象的特点,选用更加合适的应变测量方法.     

Disk-shaped Symmetric Hexa-substituted Triphenylene Derivatives: Synthesis,Physical Properties and Self-assembly

A series of triphenylene derivatives with six symmetric substituents was synthesized from hexabromotriphenylene. The synthesis was conducted by six-fold palladium-catalyzed Hagihara-Sonogashira cross- coupling reactions to yield the hexa-alkynyl substituted triphenylene derivatives of HTP1, HTP2, HTP3 and HTP4. The six symmetric substituents can not only endow the triphenylene the longer π-conjugated range, but also increase the solubility of the compounds. Their photophysical, electrochemical, thermal properties were investigated respectively. With the comparison of their properties, the structure-property relationships were established which demonstrated the influences of different substituents on the electronic nature and the mesomorphic phase of these disk-shaped molecules. In addition, with the scanning electron microscopy(SEM) and polarized optical microscopy(POM) characterization, the self-assembly behaviors of the compounds were also investigated.     

知识共享与间接互惠:基于计算实验方法的研究

团队中,个体知识共享行为的回报往往来自第三方而非受助者,而以直接互惠为视角的知识共享研究却不足以解释此类现象。采用基于计算机仿真实验方法,通过赋予Agent记忆、推理、决策和沟通等能力,研究受表型背叛、组织信任氛围及声誉传播机制影响下,间接互惠机制对团队大范围知识共享行为的维系机理。研究发现,由于辨别者的存在,即使无条件共享者会成为绝对多数,隐藏者并不会大量侵入群体。这意味着间接互惠机制维系了团队大范围知识共享行为。在低的组织信任氛围水平下,辨别者和隐藏者虽然能够共存,团队内的知识共享行为却没有出现。即使只有少数成员能观察到周围同事的知识共享行为,只要声誉信息能够有效传播,间接互惠对广泛知识共享行为的维系作用就能够发挥。