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941.
The nonisothermal decomposition kinetics of Ginkgo biloba leaves polyprenol (GBP) and cleaved situation of its chemical bond during thermal decomposition process were first investigated using thermogravimetric (TG) and TG‐FTIR technology. The results of thermal decomposition kinetics revealed that the nonisothermal decomposition mechanism of GBP corresponds to first‐order chemical reaction with n = 1, integral form g(a) = –ln(1 – a) and differential form f(a) = 1 – a. TG‐FTIR results demonstrated that absorbance of –CH3, unsaturated C–H bond, =CH2, accumulated C=C, –OH, and so on constantly increased with thermal decomposition reaction went on. In addition, storage life of GBP was also evaluated. These data could provide theoretical guidance for purification under high temperature and other thermal application of GBP. 相似文献
942.
Hantzsch Ester as a Photosensitizer for the Visible‐Light‐Induced Debromination of Vicinal Dibromo Compounds
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Wenxin Chen Huachen Tao Wenhao Huang Guoqiang Wang Prof. Dr. Shuhua Li Prof. Dr. Xu Cheng Prof. Dr. Guigen Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(28):9546-9550
The debromination of vicinal dibromo compounds to generate alkenes usually requires harsh reaction conditions and the addition of catalysts. Just recently the visible‐light‐induced debromination of vicinal dibromo compounds emerged as a possible alternative to commonly used methods, but the substrate scope of this reaction is limited and a photocatalyst is necessary for the successful conversion of the starting compounds. A catalyst‐free visible‐light‐induced debromination of vicinal dibromo compounds with a base‐activated Hantzsch ester as photosensitizer is reported. The method has a wide substrate scope and a broad functional‐group compatibility. 相似文献
943.
Back Cover: Sequential Control over Thiol Click Chemistry by a Reversibly Photoactivated Thiol Mechanism of Spirothiopyran (Angew. Chem. Int. Ed. 1/2015)
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944.
L LinHui Ye YanLin Jiang DongXing Hua Hui Zheng Tao Li ZhiHuan Ge YuCheng Li XiangQing Lou JianLing Cao ZhongXin Song YuShou Xiao Jun Li QiTe Qiao Rui You HaiBo Chen RuiJiu Xu HuShan Wang JianSong Guo ZhongYan Zhang XueYing Li Chen Hu ZhengGuo Chen RuoFu Wang Meng Xu ZhiGuo Yue Ke Tang Bin Zang YongDong Zhang XueHeng Yao XiangWu Chen JinDa Bai Zhen 《中国科学:物理学 力学 天文学(英文版)》2011,54(1):136-140
Knockout reaction experiment was carried out by using the 6He beams at 61.2 MeV/u impinging on a CH2 target. The α core fragments at forward angles were detected in coincidence with the recoiled protons at larger angles. From this exclusive measurement the valence nucleon knockout mechanism and the core knockout mechanism can be distinguished by the relation between the polar angles of the core fragments and the recoiled protons, respectively. It is demonstrated that the core knockout mechanism may result in some strong contamination to the real invariant mass spectrum.
相似文献945.
Yikai ZhangZhiliang Lv Hanyu ZhongMingfeng Zhang Tao ZhangWannian Zhang Ke Li 《Tetrahedron》2012,68(47):9777-9787
An efficient and effective microwave-assisted Heck cross-coupling of different terminal olefins with various 3-iodo-benzopyrones including sterically hindered, electron-rich, electron-neutral, and electron-deficient is developed. It proceeded faster and generally gave good to excellent yields under microwave irradiation, phosphine-free, and air condition. The reaction could render this method particularly attractive for the efficient preparation of biologically and medicinally interesting molecules. 相似文献
946.
Nonlinear Dynamics - This work presents a general class of prototype birhythmic dynamical systems, which can be extensively used to study the generation of complex bifurcation of limit cycles.... 相似文献
947.
Xusheng Shao Xinglong Huang Qian Shi Zhong Li Liming Tao Gonghua Song 《Journal of heterocyclic chemistry》2012,49(5):1136-1142
The chlorothiazolyl moiety was an effective bioisoster of chloropyridyl in pesticide molecular design. Replacement of chloropyridyl in cis‐nitromethylene neonicotinoids with chlorothiazolyl generated the chlorothiazolyl counterpart of nitromethylene neonicotinoids with tetrahydropyridine fixed cis‐configuration. Bioassay against cowpea aphis (Aphis craccivora) indicated that the chlorothiazolyl analogs could maintain the high insecticidal activity. 相似文献
948.
Simulation of dielectric resonator for a high-T_c radio frequency superconducting quantum interference device
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Nowadays,the high-critical-temperature radio frequency superconducting quantum interference device (high-T c rf SQUID) is usually coupled to a dielectric resonator that is a standard 10 × 10 × 1 mm 3 SrTiO 3 (STO) substrate with a YBa 2 Cu 3 O 7-δ (YBCO) thin-film flux focuser deposited on it.Recently,we have simulated a dielectric resonator for the high-T c rf SQUID by using the ANSOFT High Frequency Structure Simulator (ANSOFT HFSS).We simulate the resonant frequency and the quality factor of our dielectric resonator when it is unloaded or matches a 50-impedance.The simulation results are quite close to the practical measurements.Our study shows that ANSOFT HFSS is quite suitable for simulating the dielectric resonator used for the high-T c rf SQUID.Therefore,we think the ANSOFT HFSS can be very helpful for investigating the characteristics of dielectric resonators for high-T c rf SQUIDs. 相似文献
949.
In this work, we presented a new method which directly acts on the surface of the Ti sheet by mechanical micro-etching using a grating ruling engine. The effect of the pre-pattern on the morphology and growth speed of TiO2 nanostructure formed on the Ti sheet with the traditional anodization method was investigated. A novel wall structure was observed and the growth speed of TiO2 nanotube (NT) was greatly affected by the pre-pattern. The wall structure increases the surface-to-volume ratio of the nanotube arrays. The new method provided the possibility of further optimization of fast growth of TiO2 nanostructure and improving the efficiency of dye-sensitized solar cell (DSSC) and photocatalysis. 相似文献
950.
YU Tao 《中国科学 数学(英文版)》2011,(9)
In this paper we first prove that a dual Hankel operator R φ on the orthogonal complement of the Dirichlet space is compact for φ∈ W 1,∞(D),and then that a semicommutator of two Toeplitz operators on the Dirichlet space or two dual Toeplitz operators on the orthogonal complement of the Dirichlet space in Sobolev space is compact.We also prove that a dual Hankel operator R φ with φ∈ W 1,∞(D) is of finite rank if and only if B φ is orthogonal to the Dirichlet space for some finite Blaschke product B,and give ... 相似文献