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941.
942.
943.
Guo Hua GAO Jin Bao GAO Wen Juan ZHOU Liang LU Ming Yuan HE 《中国化学快报》2006,17(10):1293-1296
Since much more attention has been paid to the sustainable development, many researchers try to improve conventional chemical process and find new and more, environmentally friendly routes1. Aqueous-phase reactions are of interest as environ- mentally ben… 相似文献
944.
HeSuxiang HanHua 《高校应用数学学报(英文版)》2005,20(2):243-251
The dual algorithm for minimax problems is further studied in this paper. The resulting theoretical analysis shows that the condition number of the corresponding Hessian of the smooth modified Lagrange function with changing parameter in the dual algorithm is proportional to the reciprocal of the parameter,which is very important for the efficiency of the dual algorithm. At last ,the numerical experiments are reported to validate the analysis results. 相似文献
945.
Analysis of cellulose biosynthesis using molecular approaches has been successful in identifying genes in many cellulose-producing
organisms, yet the mechanism of cellulose biosynthesis still remains to be understood. We are interested in developing the
moss Physcomitrella patens as a useful system for the study of cellulose biosynthesis. This moss affords a number of advantages including a haploid
dominated gametophyte and a very high efficiency of homologous recombination in its nuclear DNA for constructing gene knockouts.
In addition, P. patens has only a primary cell wall unlike Arabidopsis thaliana, which has both a primary and a secondary cell wall. We identified two full-length cellulose synthase (CesA) genes of P. patens, PpCesA6 and PpCesA7 from an EST database and have analyzed the genomic sequences. PpCesA6 and PpCesA7 show high similarity to each other, both at the cDNA and genomic DNA levels. Single and double knockouts of PpCesA6 and PpCesA7 were generated and screened for phenotypic changes. While the PpCesA6 and PpCesA7 single knockouts did not show any obvious phenotypic differences from the wild-type, the double knockout had significantly
reduced stem length. These results suggest that PpCesA6 and PpCesA7 probably have a very similar role in cellulose biosynthesis and their functions may be redundant. Additionally, their roles
may overlap with the other P. patens CesAs as observed for CesAs involved in primary cell wall biosynthesis in A. thaliana. 相似文献
946.
Tao Wang Yi Hua Zhang Hui Ji Yan Ping Chen Si Xun Peng 《中国化学快报》2008,19(1):26-28
Novel phthalimide derivatives (4a, 4b and 6a-6e) were designed as hybrids of thalidomide and NO-ASA, and their chemical synthesis and in vitro biological activities were presented. The preliminary results showed that compared to thalidomide 4a and 4b exhibited enhanced activities against ECV304 and HepG2 cells, whereas 6e was more potent against HepG2 cells. 2007 Yi Hua Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. 相似文献
947.
Peng Tao Yanqin Miao Kexiang Wang Hongxin Li Qiang Zhao Hua Wang Jie Li Bingshe Xu Wei Huang 《Tetrahedron letters》2017,58(37):3598-3601
A novel and highly efficient thiophenquinolone-based red iridium(III) complex bearing a bulky fluorophenyl moiety is designed and synthesized. The complex shows intensive red phosphorescence (596 nm with shoulder at 642 nm), high photoluminescence efficiency (0.62) and broad full width at half maximum (81 nm). The bulky fluorophenyl moiety introduced into the complex could improve the efficiency of electroluminescence with the maximum current efficiency, power efficiency and the external quantum efficiency up to 29.0 cd/A, 30.4 lm/W and 17.6% due to the effective steric hindrance in solid states. 相似文献
948.
949.
Jing Hua Zhongguang Wang Jian Zhao Jin Zhang Ruying Li Hengyong Nie Xueliang Sun 《Colloid and polymer science》2011,289(7):783-789
A facile approach to attach high-density and uniform gold nanoparticles on individual multi-walled carbon nanotubes (MWNTs)
is achieved. By simple grinding, water-soluble linear polymers poly(4-vinylpyridine) (PVP)-wrapped around nanotubes and thus
rendered them reversibly soluble in water, ethanol, and DMF. Individual tubes are clearly observed after PVP-wrapped nanotubes
were spin-coated onto a silicon wafer. Subsequently, Au nanoparticles were densely decorated on the individual MWNTs by in
situ reduction of HAuCl4 in the homogeneous aqueous solution of MWNTs–PVP to form stable water-dispersible Au/PVP/MWNTs hybrid. Morphology of Au nanoparticles
was determined by scanning electron microscope and atomic force microscope. The diameter of the Au nanoparticles is controlled
in the range of 3.5 to 13.5 nm. The presence of gold nanoparticles with decreased particle size was also detected by UV–Vis
spectroscopy. 相似文献
950.
Hong Wang Jian Hua Dong Kun Yuan Qiu 《Journal of polymer science. Part A, Polymer chemistry》1998,36(5):695-702
ABA-type block copolymers of poly(trimethylene carbonate) with poly(ethylene glycol) (Mn 6820), PTMC-b-PEG-b-PTMC, were synthesized by the ring-opening polymerization of 1,3-dioxan-2-one (trimethylene carbonate) in the presence of poly-(ethylene glycol) with stannous octoate catalyst, and the copolymers with various compositions were obtained. The PTMC-b-PEG-b-PTMC copolymers were characterized with Fourier transform infrared and nuclear magnetic resonance spectroscopies. The intrinsic viscosities of resulting copolymers increased with the increase of 1,3-dioxan-2-one content in feed while the molar ratio of monomer over catalyst kept constant. It has been observed that the glass transition temperature (Tg) of the PTMC segments in copolymers, recorded from differential scanning calorimetry, was dependent on the composition of copolymers. The melting temperature (Tm) of PEG blocks in copolymer was lower than that of PEG polymer, and then disappeared as the length of PTMC blocks increased. The results of dynamic contact angle measurement clearly revealed that the hydrophilicity of resulting copolymers increased greatly with the increase of PEG content in copolymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 695–702, 1998 相似文献