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The title complex [La(betaine)2(H2O)6Fe(CN)6](2H2O (betaine = (CH3)3NCH2CO2) has been synthesized and characterized by X-ray single-crystal structure analysis. The crystal crystallizes in monoclinic, space group P21/n with a = 15.793(5), b = 8.927(3), c = 22.257(7) (A), β = 110.147(5)°, C16H38FeLaN8O12, Mr = 729.31, Z = 4, V = 2946.0(15) (A)3, Dc = 1.640 g/m3, μ(MoKα) = 1.988 mm-1, F(000) =1476, R = 0.0388 and wR = 0.0827 for 4237 observed reflections (I > 2σ(I)). The La3+ ion is nine-coordinated by one cyano nitrogen atom and eight oxygen atoms of two betaine and six water molecules. Each complex molecule is connected to form a 3D network structure by some O-H…O and O-H…N hydrogen bonds. 相似文献
444.
基于星历匹配法的载人小行星探测轨迹优化问题求解 总被引:1,自引:0,他引:1
对基于星历匹配法的载人小行星探测轨迹优化问题解法进行了研究. 提出星历匹配法的概念,利用其求出最优发射窗口初值与候选最优探测序列,然后利用遗传算法对特定探测序列的时间节点等参数进行优化,最后利用基于庞德里亚金极大值原理的同伦法进行小推力转化以求得最终探测轨道及其推力控制律. 结果显示星历匹配法可以快速准确地求出最优发射窗口初值与候选探测序列,这大大提高了载人小行星探测等多目标交会探测问题的求解效率. 相似文献
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The title coordination polymer, [Co(1,4-ndc)(L)(H2O)]n 1 (1,4-H2ndc = 1,4-na- phthalenedicarboxylic acid and L =1-(5-(1H-imidazol- 1-yl)pentyl)- 1H-imidazole) has been hydrothermally synthesized and characterized by IR and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/n with a = 12.4333(12), b = 13.2963(13), c = 13.4678(13)A, α =β = 90°, y =107.302(2)°, V= 2125.7(4)A^3, Z = 4, CoC22H22N4O5, Mr = 481.37, De = 1.504 g/cm^3, F(000) = 996, μ(MoKa) = 0.850 mm^-1, R = 0.0472 and wR = 0.0984. Compound 1 exhibits a two-dimensional layer structure. The O-H...O and C-H...O hydrogen bonds stabilize the structure of 1. 相似文献
447.
针对侧斜螺旋桨船舶建立了一种螺旋桨空化噪声调制谱理论模型。将螺旋桨旋转过程中崩溃的空泡体积的周期性变化近似为空化噪声能量的变化,根据船尾伴流速度与空泡噪声体积成比例以及螺旋桨转速与空泡数量成比例的关系,推导出了空化噪声调制谱数学表达式。理论分析和仿真验证了桨叶之间的差异性是调制谱轴频线谱存在的主要原因,而影响调制谱叶频强度的主要因素为螺旋桨侧斜角度以及转速。研究结论为辐射噪声调制谱特征分析与提取提供了理论依据,同时对螺旋桨结构设计和船舶降噪也具有一定的参考价值。 相似文献
448.
Xueke Zhao Xiang Li Xiaoping Huang Shuyu Liang Penggen Cai Yuhui Wang Yongming Cui Wu Chen Xiongwei Dong 《Arabian Journal of Chemistry》2021,14(7):103241
Hepatic copper deposition leads to metabolic disorders, rapid increase in reactive oxygen species (ROS) levels, and even the occurrence and metastasis of hepatocellular carcinoma. Copper chelation or copper transporter inhibition have already been developed into an effective method to control the canceration of hepatocytes and kill the hepatocarcinoma cells. Here, we designed three novel lactobionic acid conjugated copper chelators (GT1, 9 and 10), which have the potential to be recognized by asialoglycoprotein receptor (ASGPR), a high-capacity C-type lectin receptor selectively expressed in liver. Both GT1, 9 and 10 can selectively and efficiently coordinate with copper in solution and in the high-copper treated hepatocellular carcinomas model (HC HepG2 cells). The thiosemicarbazone-based chelator GT1 should more effectively eliminate copper and promote apoptosis of HC HepG2 cells, which might have application prospects in preventing cancerization and other pathological lesions caused by copper deposition of liver. Moreover, our results also revealed the potential of GT1 to be harnessed as preventive leading structures of the hepatocellular carcinomas. 相似文献
449.
采用轨道受限运动方法研究了极区夏季中层顶区域的尘埃粒子电荷数与尘埃粒子半径。利用尘埃等离子体充电理论,建立了尘埃粒子充电方程模型,得到尘埃粒子充电时尘埃电荷数和半径的比值。然后结合ECT02实验数据,分析了发生极区中层夏季回波现象时极区中层顶区域尘埃粒子电荷数和半径的比值,并得到尘埃粒子的半径以及尘埃粒子所带电荷量。结果表明,极区中层顶区域的尘埃粒子平均所带电荷不到一个,它的半径约为20nm。 相似文献
450.
The dynamic performance of heat assisted magnetic recording (HAMR) on different media is investigated. Signal and signal-to-noise ratio enhancement are achieved in high coereivity perpendicular media with the aid of laser heating. Linear recording density is increased while saturation write current is lowered. Trailing field partial erasure is observed in lower coercivity media with a ring head, which causes signal reduction with increasing write current or application of a laser. Precautions should be taken against partial erasure in overall recording system optimization of HAMR in order to achieve ultrahigh recording density. 相似文献