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排序方式: 共有652条查询结果,搜索用时 31 毫秒
531.
532.
The Angular Distributions of intermediate Mass Fragments Emittsd in 30 MeV/u 40Ar+58,64Ni and 115In Reactions 下载免费PDF全文
Gou Quanbu Zhu Yongtai Xu Hushan Wei Zhiyong Lu Jun Zhang Yuhu Wang Qi Li Songlin Wu Zhongli 《中国物理C(英文版)》1999,23(4):328-333
The angular distributions of intermediate mass fragments with Z=3-19 emitted in 30 MeV/u 40Ar+58,64Ni and 115In reactions over an angular range of 5°—140°have been measured.Exponential distribution function: dσ/dΩ=N·exp(-θ/a) was used tO fit the measured angular distributions.We have extracted the decay factor a that can be connected with the interaction time τ, and the factor N that is related to the intensity of the emission source.The relationships of a(Z) with Z and N(Z) with Z for different reaction systems and different angular ranges have been discussed. The dependence of angular distributions on isospin and the symmetry of reaction system have also been discussed. 相似文献
533.
Element Distributions of Intermediate Mass Fragments Emitted in 30 MeV/u 40Ar+58,64Ni and 115In Reactions 下载免费PDF全文
Gou Quanbu Zhu Yongtai Xu Hushan Wei Zhiyong Lu Jun Zhang Yuhu Wang Qi Li Songlin Wu Zhongli 《中国物理C(英文版)》1999,23(6):512-517
The element distribuhons of intermediate mass fragments (IMF) emitted over an angular region of 5°—140° have been measured in the reachons of 30MeV/u 40Ar+58,64Ni and 115In. Within 20°—80° range the IMFs with Z=3-24 were observed. The IMF production cross section changes smoothly with its charge number,and the element distribuhon changes continuously when the IMF charge number increases across the charge number of the projectile. There is no strong dependence of the element distribution on the charge number of the projectile in this angular region.The transition nature of the reaction mechanism in the intermediate energy region and the power law of the IMF element distribution,as well as the dependence of element distributions on the threshold of the detectors were discussed. 相似文献
534.
采用蒙特卡罗MMFF94分子力学力场方法搜索一类新发现的生物活性分子Alboatisin A~C的稳定构象,用梯度校正的B3LYP方法,计算其稳定构象的旋光度、振动圆二色谱(VCD)、电子圆二色谱(ECD)等光学活性,并从微观的角度对VCD谱和ECD谱中强或弱的正或负康登效应进行归属.从分子结构、电子结构和分子振动分析了分子手性的微观起源.结果表明,计算与实验的旋光度值相吻合,OH的取代位置与数目可调控旋光度发生在手性骨架上的振动或电子跃迁转移是手性光谱产生的重要原因.Alboatisin的圆二色谱是手性骨架变形振动的光谱响应,是不对称电子跃迁的光谱响应结果. 相似文献
535.
为了探索功能金刚石聚晶的高压合成,使其具有优异的透红外和散热性能,我们采取了提高合成压力、温度和尽量减少结合剂的办法进行试验。首先探索如何使合成的金刚石聚晶具有D-D型结合,然后尽量减少结合剂,以合成出高密度的D-D型金刚石聚晶。为了尽量减少结合剂含量,不用粉末混合法,而是分别采用7~14 μm和63~80 μm粒度的金刚石为原料,与纯Ni或Ni70Mn25Co5合金为基底积层组装,通过高温高压下触媒金属向金刚石晶粒间渗透进行烧结生长。在6.3 GPa的压力和1 440~1 650 ℃的不同温度下分别保持3~40 min。所得到的金刚石聚晶在触媒金属渗透得充分的区域形成了D-D结合型结构,而没有发现碳化物生成及金刚石表面石墨化等现象。 相似文献
536.
Using magnetic layered double hydroxide (MLDH) as carrier of fluorescein (FLU), a fluorescent composite of MLDH-FLU was prepared via intercalation reaction of ion change. The crystal properties of MLDH-FLU were investigated through XRD, IR, TEM and TG-DSC characterization. It is shown that the crystal type of MLDH-FLU composite matched well with R-hexagonal crystal system of MLDH, with crystal cell parameters of a, c and channel height h equal to 0.3199, 2.411 and 0.3267 nm respectively. The superabundant pigment adsorbed outside the composite should be cleared before interference with cells, but excessive wash would decrease stability and cause crystal phase transformation of MLDH. 相似文献
537.
A novel shape–memory nanocomposite that exhibits electrical actuation capabilities was fabricated by incorporating a conductive multiwalled carbon nanotube (MWCNT) nanopaper into shape–memory polymer matrix. The self‐assembled MWCNT nanopaper was made on hydrophilic polycarbonate membrane. This process was based on well‐defined dispersion of the nanosized individual MWCNT and controlled traditional pressure vacuum deposition procedure. The self‐assembled MWCNTs in the nanopaper provided a percolating conductive network with a large interfacial area. It not only offered a high electrical conductivity but also simultaneously enhanced recovery speed by electrically resistive heating, with increasing the content of MWCNT nanopaper in nanocomposite. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
538.
Internal Dynamics in Halogen‐Bonded Adducts: A Rotational Study of Chlorotrifluoromethane–Formaldehyde 下载免费PDF全文
Dr. Qian Gou Dr. Gang Feng Dr. Luca Evangelisti Dr. Montserrat Vallejo‐López Lorenzo Spada Prof. Dr. Alberto Lesarri Dr. Emilio J. Cocinero Prof. Dr. Walther Caminati 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(10):4148-4152
The rotational spectra of two isotopologues of the 1:1 complex between chlorotrifluoromethane and formaldehyde have been recorded and analyzed by using Fourier‐transform microwave spectroscopy. Only one rotamer was detected, with the two constituent molecules held together through a Cl???O halogen bond (RCl???O=3.048 Å). The dimer displays two simultaneous large‐amplitude intramolecular motions. The internal rotation of formaldehyde around its symmetry axis (V2=28(5) cm?1) splits all the rotational transitions into two component lines with a relative intensity ratio of 1:3. On the other hand, the almost free internal rotation (V3≈2.5 cm?1) of the CF3 symmetric top increases the “rigid” value of the rotational constant A by almost one order of magnitude. In addition, all the transitions display a hyperfine structure due to the 35Cl (or 37Cl) nucleus quadrupole effects. 相似文献
539.
Jun-Ichi Hamagami Gou Yamaguchi Kiyoshi Kanamura Takao Umegaki 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8-9):1921-1922
An in situ atomic force microscope (AFM) combined with surface potential measurement was used to observe the apatite formation on the 45S5 Bioglass-type glass in simulated body fluid (SBF). From the observation, it can be seen that small islands with 5-10 nm size are formed on the glass surface in the initial soaking period within 1 h. 相似文献
540.
Novel antitumor dinuclear platinum (II) complexes with a new chiral tetradentate ligand as the carrier group 下载免费PDF全文
Chuanzhu Gao Yan Zhang Tianshuai Wang Ji Chen Yunxu Qian Bo Yang Shaohua Gou Peng Dong Yingjie Zhang 《应用有机金属化学》2015,29(7):481-486
Seven dinuclear platinum(II) complexes with a novel chiral tetradentate ligand, (1R,1′R,2R,2′R)‐N1,N1′‐(1,4‐phenylenebis(methylene))dicyclohexane‐1,2‐diamine, were designed, synthesized and spectrally characterized. All the complexes were evaluated for their in vitro cytotoxicity against human HepG‐2, A549, HCT‐116 and MCF‐7 cancer cell lines. The results indicated that all compounds showed positive biological activity against HepG‐2, A549 and HCT‐116 cancer cell lines. In particular, compounds D7 and D2 showed better activity than carboplatin against HepG‐2 and A549 and compound D7 also showed an activity close to that of oxaliplatin. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献