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排序方式: 共有276条查询结果,搜索用时 31 毫秒
271.
Zhongyi Liu Yue Chen Wenyu Sun Zhihui Wei 《Computational Optimization and Applications》2012,52(2):373-391
Recently an infeasible interior-point algorithm for linear programming (LP) was presented by Liu and Sun. By using similar predictor steps, we give a (feasible) predictor-corrector algorithm for convex quadratic programming (QP). We introduce a (scaled) proximity measure and a dynamical forcing factor (centering parameter). The latter is used to force the duality gap to decrease. The algorithm can decrease the duality gap monotonically. Polynomial complexity can be proved and the result coincides with the best one for LP, namely, $O(\sqrt{n}\log n\mu^{0}/\varepsilon)$ . 相似文献
272.
Tianxin Bai Xiaochen Wang Zhongyi Wang Sujun Ji Xuan Meng Qiujie Wang Ruiling Zhang Peigeng Han Prof. Dr. Ke-li Han Dr. Junsheng Chen Feng Liu Bin Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202213240
Double perovskites (DPs) are one of the most promising candidates for developing white light-emitting diodes (WLEDs) owing to their intrinsic broadband emission from self-trapped excitons (STEs). Translation of three-dimensional (3D) DPs to one-dimensional (1D) analogues, which could break the octahedral tolerance factor limit, is so far remaining unexplored. Herein, by employing a fluorinated organic cation, we report a series of highly luminescent 1D DP-inspired materials, (DFPD)2MIInBr6 (DFPD=4,4-difluoropiperidinium, MI=K+ and Rb+). Highly efficient warm-white photoluminescence quantum yield of 92 % is achieved by doping 0.3 % Sb3+ in (DFPD)2KInBr6. Furthermore, single-component warm-WLEDs fabricated with (DFPD)2KInBr6:Sb yield a luminance of 300 cd/m2, which is one of the best-performing lead-free metal-halides WLEDs reported so far. Our study expands the scope of In-based metal-halides from 3D to 1D, which exhibit superior optical performances and broad application prospects. 相似文献
273.
Zhen Zhang Xiaohui Kang Yang Jiang Zhongyi Cai Shihui Li Prof. Dongmei Cui 《Angewandte Chemie (International ed. in English)》2023,62(4):e202215582
Disentangled ultrahigh molecular weight polyethylene (dis-UHMWPE) has excellent processability but can be achieved under extreme conditions. Herein, we report ethylene polymerization with the binuclear half-sandwich scandium complexes C1-Sc2 and C2-Sc2 to afford UHMWPE . C1-Sc2 bearing a short linker shows higher activity and gives higher molecular weight PEs than C2-Sc2 containing a flexible spacer and the mononuclear Sc1 . Strikingly, all UHMWPEs isolated from C1-Sc2 under broad temperature range (25–120 °C) and wide ethylene pressures (2–13 bar) feature very low degree of entanglement as proved by rheological test, DSC annealing study and SEM. These dis-UHMWPEs are facilely mediated solid-state-process at 130 °C and their tensile strength and modulus reach up to 149.2 MPa and 1.5 GPa, respectively. DFT simulations reveal that the formation of dis-UHMWPE is attributed to the binuclear synergic effect and the agostic interaction between the active center and the growing chain. 相似文献
274.
Yu Chen Prof. Jiafu Shi Dr. Yizhou Wu Zheyuan Guo Shihao Li Wenping Li Zhenhua Wu Dr. Hongjian Wang Dr. Haifei Jiang Prof. Zhongyi Jiang 《Angewandte Chemie (International ed. in English)》2023,62(42):e202310238
Photosynthesis offers a green approach for the recycling of nicotinamide cofactors primarily NADH in bio-redox reactions. Herein, we report an NADH photosynthesis system where the oxidation of biomass derivatives is designed as an electron supply module (ESM) to afford electrons and superoxide dismutase/catalase (SOD/CAT) cascade catalysis is designed as a reactive oxygen species (ROS) elimination module (REM) to inhibit NADH degradation. Glucose as the electron donor guarantees the reaction sustainability accompanied with oxidative products of gluconic acid and formic acid. Meanwhile, enzyme cascades of SOD/CAT greatly eliminate ROS, leading to a ≈2.00-fold elevation of NADH yield (61.1 % vs. 30.7 %). The initial reaction rate and turnover frequency (TOF) increased by 2.50 times and 2.54 times, respectively, compared with those systems without REM. Our study establishes a novel and efficient platform for NADH photosynthesis coupled to biomass-to-chemical conversion. 相似文献
275.
276.
Jonas F. Goebel Julian Löffler Zhongyi Zeng Jens Handelmann Albert Hermann Ilja Rodstein Dr. Tobias Gensch Prof. Dr. Viktoria H. Gessner Prof. Dr. Lukas J. Gooßen 《Angewandte Chemie (International ed. in English)》2023,62(9):e202216160
Palladium-catalyzed couplings of silicon enolates with aryl electrophiles are of great synthetic utility, but often limited to expensive bromide substrates. A comparative experimental study confirmed that none of the established ligand systems allows to couple inexpensive aryl chlorides with α-trimethylsilyl alkylnitriles. In contrast, ylide functionalized phosphines (YPhos) led to encouraging results. A statistical model was developed that correlates the reaction yields with ligand features. It was employed to predict catalyst structures with superior performance. With this cheminformatics approach, YPhos ligands were tailored specifically to the demands of Hiyama couplings. The newly synthesized ligands displayed record-setting activities, enabling the elusive coupling of aryl chlorides with α-trimethylsilyl alkyl nitriles. The preparative utility of the catalyst system was demonstrated by the synthesis of pharmaceutically meaningful α-aryl alkylnitriles, α-arylcarbonyls and biaryls. 相似文献