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51.
Structures and stabilities of HPS_2 isomers 总被引:1,自引:0,他引:1
The potential energy surface of HPS2 system containing nine isomers and fifteen transition states is obtained at MP2/6-311++G(d, p) and QCISD(t)/6-311++G(3df, 2p)(single-point) levels. On the potential energy surface, the lowest-lying frans-HSPS(EI) is found to be thermodynami-cally the most stable isomer followed by cis-HSPS(E2) and HP(S)S(C2v, E3) at 3.43 and 14.17 kJ/mol higher, respectively. The computed results show that species E1, E2, E3, stereo HP(S)S(Cs, E4) with PSS three-membered ring, isomers trans-HPSS(E5) and cis-HPSS(E6) which coexist with E4 are kinetically stable isomers. The products E6 and E5 in the reaction of HP with S2 can be isomerized into higher kinetic stable isomer E4 with 65.75 and 71.73 kJ/mol reaction barrier height, respectively. The predicated results may correct the possible inaccurate conclusion in that the product was experimentally assigned as isomer cis-HPSS(E6). 相似文献
52.
Potential energy surface of HNOS system is investigated by means of MP2 method with 6-311 G(d,p) basis set.The energy for each minimum and saddle point on the potential energy surface is corrected at the QCISD(T)/6-311 G(3df,2p) level of theory with zero-point vibrational energy included.As a result ,eighteen isomers are theoretically predicted and cis-HNSO is found to be global minimum on the potential energy surface,Wherein,fourteen isomers are considered as kinetically stable species,and should be experimentally observed.Comparisons are made for HNOS system with its analogues,HNO2 and NHS2.The nature of bonding and isomers‘ stability of HNOS system are similar to HNS2.The obvious similarities and discrepancies among HNOS,HNO2 and HNS2 are attributed to the hypervalent capacity of sulfur,oxygen and nitrogen atoms. 相似文献
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GUO Xing-gang DONG Xin-shu CHEN Jie The Affiliated Tumor Hospital of Harbin Medical University Harbin P. R. China 《高等学校化学研究》2009,25(2)
To explore the functional mechanism of tetraarsenic tetrasulfide(As4S4)against the growth and proliferation of colon cancer cells ls174t,MTT method was used to observe the functions of tetraarsenic tetrasulfide for the inhibition of cells ls174t in vitro.Transmission electron microscope was used to observe cell morphologies.FCM assay was performed to measure the change of cell cycle.RT-PCR method was used to detect the expressions of bcl-2 and bax mRNA.Westernblot method was used to detect the expressions of bcl-2 and bax protein.Tetraarsenic tetrasulfide showed an inhibiting effect on the proliferation of cells ls174t in vitro(P<0.01).It induces the apoptosis of cells ls174t,which is related to the decrease in the expression of bcl-2 and the increase in the expression of bax. 相似文献
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本文指出了文献[1]中存在的问题,提出了载荷沿缆长均匀分布时拉力和缆长的计算新方法。采用试算过程假设悬链线参量—α值的方法,对拉力和缆长进行了计算。推导出了二者之间的关系,并阐述了其对光缆工作性能的影响。 相似文献
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通过Langmuir Blodgett技术制备了酞菁铜 氧化铁纳米粒子交替LB膜 ,利用偏振紫外 可见光谱对酞菁铜衍生物在不同制膜条件下所制得的交替膜中的分子取向进行了研究。结果表明 ,在同一氧化铁溶胶亚相中 ,随着表面压的增大 ,或在相同的表面压下 ,随着亚相中氧化铁浓度的减小 ,酞菁铜分子在其复合LB膜中倾斜程度变大。 相似文献
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YANG LuQing SHANG Yan ZHANG Hui SUN Miao LIU Bo & ZHANG GuiLing Key Laboratory of Green Chemical Technology of College of Heilongjiang Province College of Chemical Environmental Engineering Harbin University of Science Technology Harbin China 《中国科学B辑(英文版)》2011,(6)
The charge-doping effect on the geometric and the electronic structures of organosilicon oligomers nSix(C=C)+y has been studied using density functional theory. Charge-doping can significantly lower the excitation energies. Interchain hole hopping mainly occurs between the π-conjugated units. A doped nSix(C=C)+y oligomer can undergo a structural rearrangement. The simulated UV/vis absorption peak of the rearranged structure is located at higher energy than the non-rearranged one. The hole transfer rate is s... 相似文献
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We report high performance InAlN/GaN HEMTs grown on sapphire substrates.The lattice-matched InAlN/GaN HEMT sample showed a high 2DEG mobility of 1210 cm2/(V·s) under a sheet density of 2.6×1013 cm-2.Large signal load-pull measurements for a(2×100μm)×0.25μm device have been conducted with a drain voltage of 24 V at 10 GHz.The presented results confirm the high performances reachable by InAlN-based technology with an output power density of 4.69 W/mm,a linear gain of 11.8 dB and a peak power-added efficiency of 48%.This is the first report of high performance InAlN/GaN HEMTs in mainland China. 相似文献