Necklace solitons in Bessel photonic lattice: Stability and internal oscillation

Stability, internal modes and internal oscillation of 12-pearled necklace solitons in photorefractive crystal with imprinted Bessel photonic lattices are investigated. It is shown that the imaginary parts of internal modes are negligible comparing with real parts. The stable solitons perform long-distance and quasi-periodic oscillation of intensity and shape under the perturbation of internal modes.     

套管法Nb_3Al前驱线中Nb/Al界面扩散反应过程

利用套管法制备了Nb-Al七芯前驱体线材,并通过等温热处理的方式分别在700~1500℃对其进行热处理,研究了Nb-Al二元体系在其界面处的反应成相过程.研究发现700℃热处理的样品在其界面处只形成了NbAl3反应层;800~900℃热处理的样品界面处又形成一层Nb:Al≈1:1新反应层;随着热处理温度的增加到1000℃,界面处出现Nb2Al反应层,并随热处理温度的增加Nb2Al反应层的厚度增加;1400℃和1500℃热处理的样品中开始观察到了少量的Nb3Al相,磁性测量表明1400℃和1500℃条件下热处理样品的起始超导转变温度分别为14K和15.8K,说明套管法制备的Nb-Al前驱体线材在1400℃以上热处理可以获得Nb3Al超导相,但由于Nb3Al相中的Al含量偏离理想化学计量比,导致其超导转变温度偏低.     

A note on Poisson stability and controllability

The connection between Poisson stability and controllability is revisited. For the controllability criterion based on weakly positive Poisson stability (WPPS) and Lie algebra rank condition (LARC), it is shown that two natural assumptions about the set of input values are necessary for strictness. By using the relationship between conservative property and WPPS, sufficient conditions for controllability of affine nonlinear systems are further discussed. At last, for systems defined on compact Riemannian manifold, the WPPS is proved to be equivalent to Poisson stability.     

Nafion—玻碳修饰电极阴极溶出伏安法测定痕量铋的研究

研究并提出在HNO_3-NaCl-硫脲(Tu)体系中,Nafion/玻碳(Gc)修饰电极阴极溶出伏安法测定痕量鉍的方法。表明Tu具络合协同作用,使Nation阳离子交换能力提高。本法检出限为5×10~(-9)mol/L Bi~(3+)(td:5min),电极表面易于再生,文中研究了电极过程机理,计算得[Bi(Tu)_6]~(3+)在Nafion膜中的分配系数(K_D),扩散系数(D)和选择性系数(K_H~[Bi(Tu)_6~+]~(3+))分别为7.57×10~5,5.9×10~(-11)cm~2/s及3.39。     

InBr3-catalyzed cyclization of glycosides with arylamines

Glycals have served as excellent substrates in the glycosidation reactions with arylamines to construct both C–C and C–N linkages simultaneously. However, the high reactivity and moisture/alcohol-sensitivity is also responsible for several side reactions. Herein we reported that 2,3-unsaturated glycosides can be used as alternatives of glycals to take part in the corresponding glycosidation as well. Therefore, with 10% of InBr₃ or InI₃ as the catalyst, 2,3-unsaturated glycosides containing various C-1 alkoxy groups reacted with arylamines smoothly and produced the glycosidation products in moderate to good yields as a pair of diastereomers with variant diastereoselectivity.     

State-of-the-art and prospects for orbital dynamics and control near small celestial bodies

小天体探测是未来深空探测的重点领域之一, 而小天体附近轨道动力学与控制问题是小天体探测任务迫切需要解决的关键问题. 该问题涉及形状不规则小天体附近的动力学环境建模与小天体附近轨道动力学机理. 本文从不规则形状小天体引力场的建模、小天体附近的自然轨道动力学、小天体附近的受控轨道动力学3 个方面综述了小天体附近轨道动力学与控制的研究现状与发展趋势, 并分析了小天体附近轨道动力学所面临的挑战与难题, 最后对我国未来小天体探测任务可能涉及的轨道动力学与控制问题的发展方向进行了展望.     

软锰矿吸收SO2废气制取硫酸锰扩大化试验研究

在贵州宏福实业开发有限总公司对软锰矿吸收SO2废气制取硫酸锰进行了扩大化试验研究.实验结果表明,用软锰矿吸收SOz废气是可行的,同时具有吸收率高、工艺流程简单、操作简便、易于实现工业化等特点.该技术的实施不仅环保效益显著,而且有直接的经济效益.     

抗肿瘤多核铂配合物的研究

多核铂配合物作为非经典铂抗肿瘤药物,其抗肿瘤机制与现有铂类抗肿瘤药物不同,因而在克服现有铂类抗肿瘤药物耐药性方面有着巨大的潜力。本文综述了多核铂类抗肿瘤药物的研究进展,以连接铂原子的桥配体结构的不同,可分为六大类:以烷基二胺及其衍生物为桥的多核铂配合物、以含氮杂环为桥的多核铂配合物、以羧酸根为桥的多核铂配合物、以卤素离子为桥的多核铂配合物、以含硫配体为桥的多核铂配合物及以其他配体为桥的多核铂配合物。本文还介绍了这几类多核铂配合物的抗肿瘤机理及在克服顺铂耐药性机理方面的研究进展。     

An improved nonlinear control strategy for deep space formation flying spacecraft

This paper aims to provide further study on the nonlinear modeling and controller design of formation flying spacecraft in deep space missions. First, in the Sun-Earth system, the nonlinear formation dynamics for the circular restricted three-body problem （CRTBP） and elliptic restricted three-body problem （ERTBP） are presented. Then, with the Floquet mode method, an impulsive controller is developed to keep the Chief on the desired Halo orbit. Finally, a nonlinear adaptive control scheme based on Nonzero set- point LQR and neural network is proposed to achieve high precision formation maneuver and keeping. The simulation results indicate that the proposed nonlinear control strategy is reasonable as it considers not only the orbit keeping of the Chief, but also the formation modeling inaccuracy. Moreover, the nonlinear adaptive control scheme is effective to improve the control accuracy of the formation keeping.     

Palladium-catalyzed N-arylation of 2-aminobenzothiazole-4-carboxylates/carboxamides: facile synthesis of PARP14 inhibitors

We have developed a palladium-catalyzed N-arylation of the biologically interesting, but synthetically rather challenging 2-arylaminobenzothiazoles bearing multiple functionalities. This protocol was successfully used to readily synthesize our initial PARP14 inhibitor followed by a limited structural optimization. A more potent PARP14 inhibitor with an IC₅₀ value of 1.69 μM was identified, and the interaction was ascertained by the X-ray co-crystal structure of the catalytic domain of PARP14 in complex with compound 8.