Microwave spectra and structure of an isoxazole-water complex

The rotational spectrum of a hydrogen-bonded isoxazole-water complex has been measured between 6–18 GHz with a pulsed nozzle Fourier transform microwave spectrometer. In addition to isoxazole-H₂O, the complexes with HDO and D₂O as well as isoxazole-¹⁵ N-H₂O have been investigated in order to determine the structure of the complex. Rotational constants, quartic centrifugal distortion constants and quadrupole coupling constants, where applicable, have been fitted to the measured transition frequencies of the isotopomers. Structural data, which have been deduced from the planar moments of inertia and the quadrupole coupling constants of the isotopomers, have established conclusively that water binds to nitrogen in the ring plane of isoxazole. Ab initio calculations have revealed that complexes with a hydrogen-bond to nitrogen or to oxygen are both stable. The complex with water attached to nitrogen has been found to be more strongly bound than that with water attached to oxygen. Small splittings of the rotational transitions of the two complexes with H₂O have been interpreted as being the result of an internal rotation of water with respect to isoxazole.     

Activation of the pre-supplementary motor area but not inferior prefrontal cortex in association with short stop signal reaction time – an intra-subject analysis

Background  

Our previous work described the neural processes of motor response inhibition during a stop signal task (SST). Employing the race model, we computed the stop signal reaction time (SSRT) to index individuals' ability in inhibitory control. The pre-supplementary motor area (preSMA), which shows greater activity in individuals with short as compared to those with long SSRT, plays a role in mediating response inhibition. In contrast, the right inferior prefrontal cortex (rIFC) showed greater activity during stop success as compared to stop error. Here we further pursued this functional differentiation of preSMA and rIFC on the basis of an intra-subject approach.     

Study of ψ(4415) in the QPC model

Some authors consider the ψ(4415) to be the 4S or 5S excited tate of a cc pair. Starting from this assumption, we study he decays of the ψ(4415) to DD, D^*D^*, D_SD_S, D_S^*D_S^*, and get the corresponding branching ratios in terms of the Quark-Pair-Creation (QPC) model. Compared with the experimental data, we find that the results of 4S state agree much better than those of the 5S state. Therefore, it is more reasonable to assume the ψ(4415) to be a 4S state.     

Nonlinear Local Lyapunov Exponent and Quantification of Local Predictability

Nonlinear local Lyapunov exponent （NLLE） is applied to quantitatively determine the local predictability limit of chaotic systems. As an example, we find that the local predictability limit of Henon attractor varies considerably with time, and some underlying phase-spatial structure does not appear. The local predictability limit of initially adjacent points in phase space may be completely different. This will cause difficulties in making the long-time analogue forecast.     

弹丸高速撞击压力容器损伤实验研究

微流星体及空间碎片的高速撞击威胁着航天器的安全运行。而压力容器是航天器上受微流星体及空间碎片撞击威胁最大的关键部件之一。对压力容器的高速撞击能导致其发生破裂而过早终止航天器的使命。本文的目的是通过实验研究,确定高速撞击条件下压力容器发生具有撕裂的简单穿孔和裂纹失稳破裂的界限。实验样件选择6063铝合金管焊接制成。高速撞击实验采用铝柱状弹丸和球形弹丸在3km/s左右的速度下正撞击铝压力容器,铝压力容器的压力从0～30Bar变化来探索获得不同损伤形式的压力条件。给出了铝压力容器前、后壁从穿孔到裂纹失稳破裂的实验结果。未防护充水铝压力容器的主要损伤是其前壁的裂纹失稳破裂。而防护充水铝压力容器在前璧未穿孔时未发生破裂。未防护充气压力容器在给定的实验条件下前璧未发生破裂而后璧发生破裂。防护充气压力容器在小防护间距时前璧发生破裂。     

顺丁烯二酸β-环糊精酯-N-乙烯基吡咯烷酮水溶性聚合物的合成及其吸附疏水性药物的研究

以γ射线引发顺丁烯二酸β-环糊精酯(CDM)和N-乙烯基吡咯烷酮(NVP)发生自由基链式反应,制备了顺丁烯二酸β-环糊精酯-N-乙烯基吡咯烷酮聚合物(CDM-NVP).优化后的CDM-NVP聚合物的合成条件为: CDM∶NVP为1∶0.7(w/w, CDM 3.6 g 和 NVP 2.52 g),辐照剂量4 kGy,DMF溶液用量为20 mL.在此条件下制备聚合物的产率为84%,重均分子量为20 kDa.结果表明,此聚合物可以同纳他霉素(NM)和多菌灵(MBC)形成稳定复合物.研究了复合物抑菌活性,测定了其表观稳定常数.利用紫外光谱、核磁图谱和相溶解度对药物复合物进行结构表征.303 K下,NM-CDM-NVP和 MBC-CDM-NVP复合物的表观稳定系数分别为12988.54和865.94 L/mol.抑菌实验结果表明,NM-CDM-NVP和 MBC-CDM-NVP复合物可以显著提高NM和MBC的溶解性和抑菌活性.     

用于多组分同时测定的流动注射-CCD阵列探测分光光度装置研究

使用流动注射进样、多色仪分光、ＣＣＤ阵列探测器以及微机处理机等,建立了用于多组分同时测定的流动注射－ＣＣＤ阵列探测器联用分光光度装置。完成以ｍｅｓｏ－四（４－三甲铵苯基）卟啉为显色剂时铅和镉的同时测量,铅的检出限为０．０１４μｍ／ｍＬ,镉为０．０１５μｇ／ｍＬ。     

含N、O和S的Schiff碱配体与铜(Ⅱ)、锌(Ⅱ)配合物的合成及红外光谱研究

本文在40℃条件下制得了5-氯水杨醛,使其与硫脲缩合合成出了一种含N、O、S的新型Schiff碱配体,该配体与铜(Ⅱ)、锌(Ⅱ)能形成稳定的配合物,其组成、结构已由元素分析和红外光谱所表征.     

磁化水技术在电感耦合等离子体-原子发射光谱法中的应用

考察了被测元素谱线强度随磁感应强度的变化情况.在优化磁感应强度0.24T条件下,研究了搅拌条件下样品溶液磁化时间对谱线强度及信背比的影响.经过测量自来水样品中元素Zn、Fe、Mg(I、I)、Si、V谱线强度表明,在对水样品进行搅拌磁化时,所测元素的谱线强度及信背比均有所增大;当水样品被磁化处理3h,上述元素的谱线强度分别比未磁化时增加了42.2%、97.9%、10.4%、10.1%、81.2%和28.8%,而且元素Zn、Fe、Si和V的信背比也分别增加了13.8%、86.9%、64%和28.8%,有利于降低光谱分析检出限.     

点阵全息图衍射效率的测量

提出了测量点阵全息图衍射效率的测试方法和相应的光学系统,其优点在于巧妙让零级与正负二级不能进入聚光系统,只有正负一级可以被记录,并且这种测试方法不受被测点干涉条纹方向变化的影响。并给了几种点阵全息防伪标识的测试结果。