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Designs, Codes and Cryptography - According to a magnific method due to I. Tamo and A. Barg, a class of polynomials over finite fields, called good polynomials, was introduced and used to construct... 相似文献
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Yuzhi Xu Yanfei Zhang Huihui Yang Wen Yin Leli Zeng Shuo Fang Si-Yang Liu Zong Dai Xiaoyong Zou Yihang Pan 《中国化学快报》2022,33(2):968-972
A reliable and sensitive strategy which can assess nucleic acid levels in living cells would be essential for fundamental research of biomedical applications. Some nanomaterial-based fluorescence biosensors recently developed for detecting nucleic acids, however, are often with expensive, complicated and timeconsuming preparation process. Here, by using a facile bottom-up synthesis method, a two-dimensional(2 D) coordination polymer(CP) nanosheet, [Cu(tz)](Htz = 1,2,4-triazole), was successfully... 相似文献
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Second harmonic generation (SHG) using intense Hermite-Gaussian laser beam (HGLB) propagating through the plasma for mode-indices m = 0 and m = 1 is reported in the present work. Ponderomotive force induced density perturbation beats with the oscillatory velocity of electrons at incident laser frequency, generate the second harmonic nonlinear current that give rise to SHG. Using paraxial approximations, we have derived the coupled equations for the beam width parameter of HGLB and second harmonic's normalized amplitude. Resonance condition is obtained by considering wiggler magnetic field which providing an extra momentum to the second harmonic photon and this result a significant increase in the amplitude of SHG. Our analysis shows the prominent rise in normalized amplitude of second harmonic on increasing the value of the intensity of fundamental laser pulse, normalized wiggler magnetic field and normalized density of plasma. It is notified that the gain of SHG is more prominent for m = 1. Dependency of laser and plasma parameters on SHG is also reported in the current work. 相似文献
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Sourcing components in a complex global supplier network may lead to a high degree of supply uncertainty. Events, such as unexpected production defects or insufficient supplier capacity, can cause unexpected shortages of required components and halt the assembly of final products. Accordingly, the assembly enterprises must effectively manage various supply uncertainties in their component ordering decisions to avoid such component shortfalls. These issues have guided this research to investigate the optimal ordering strategies of an assembler facing the following two types of supply uncertainty: the uncertain production capacity of a standard component (component 1) and the random production yield of a core component (component 2). The assembler makes the component ordering decisions before these supply uncertainties are realized. We characterize the optimal ordering decision and find that the assembler should order components 1 and 2 according to a fixed ratio, which only depends on the random yield of component 2 and the production cost of component 1, but not on the uncertain capacity of component 1. A case study is presented to further explore the intertwined effects of these two uncertainties in an assembly system. Finally, the model is extended to consider a secondary option of buying additional component 1 s after observing some or all of the supply uncertainties, and this secondary option endows the firm with different capabilities in counteracting the supply uncertainties. 相似文献
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Jiahao Liu Weikang Li Dr. Yinwu Li Prof. Dr. Yan Liu Prof. Dr. Zhuofeng Ke 《化学:亚洲杂志》2021,16(20):3124-3128
The first implementation of a molybdenum complex with an easily accessible bis-N-heterocyclic carbene ligand to catalyze β-alkylation of secondary alcohols via borrowing-hydrogen (BH) strategy using alcohols as alkylating agents is reported. Remarkably high activity, excellent selectivity, and broad substrate scope compatibility with advantages of catalyst usage low to 0.5 mol%, a catalytic amount of NaOH as the base, and H2O as the by-product are demonstrated in this green and step-economical protocol. Mechanistic studies indicate a plausible outer-sphere mechanism in which the alcohol dehydrogenation is the rate-determining step. 相似文献
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Haifeng Zhang Hongqing Zhao Kuo Zheng Xiangyu Li Guangli Liu Yujue Wang 《Journal of Thermal Analysis and Calorimetry》2014,116(1):373-381
The formation of hazardous air pollutants (HAPs) in thermal decomposition of furan no-bake foundry binders was investigated using analytical pyrolysis techniques. Two furan binders cured with p-xylenesulfonic acid (conventional acid catalyst used in foundries) and methanesulfonic acid (alternative catalyst proposed for diminishing HAPs) were flash pyrolyzed in a Curie-point pyrolyzer at 920 °C and slowly pyrolyzed in a thermogravimetric analyzer from 50 to 800 °C with a heating rate of 20 °C min?1. Similar HAPs (mainly benzene, toluene, and xylenes) were identified in the emissions of the two binders. However, the HAP yields were much higher for the binder cured with p-xylenesulfonic acid than for the binder cured with methanesulfonic acid (3.74 and 1.24 mg HAPs/g binder pyrolyzed, respectively). By analyzing the HAP formation pathways, it was concluded that for the binder cured with p-xylenesulfonic acid, the aromatic HAPs were originated mainly from the acid catalyst. In addition, some HAPs (predominantly benzene) could be formed from the recombination of furan-derived fragments (e.g., C2–C4 radicals generated from ring-opening of furans). The results suggest that by replacing the conventionally used catalysts (arylsulfonic acids) with methanesulfonic acid, the HAP emissions from furan no-bake molds can be decreased significantly in metal casting processes. 相似文献
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复杂网络广泛存在于日常生活,首先,给出几类标准的网络模型;然后,利用稳定性控制方法设计并实现了具有时滞与非时滞耦合的复杂网络模型快速控制;最后,通过构造优化Lyapunov函数,讨论其模型的射影同步问题,得到了系统全局稳定的条件和有效的控制器,以实例数值验证其方法的可行性。 相似文献
10.
《中国化学快报》2023,34(3):107664
Assembling MnO2 nanowires into macroscopic membrane is a promising engineered technology for catalyst separation and enhancement of Fenton-like reaction activity, yet its development is limited by the deficiencies in preparation and property modulation of the MnO2 nanowires. In this work, we developed a facile method using C2H5OH and CH3COOK as reductive and vital control reagents to react with KMnO4 by hydrothermal reaction at 140 °C for 12 h, to prepare the ultralong α-MnO2 nanowires up to tens of micrometers with high purity and aspect ratio. Such strategy not only had the advantages of being mild, easily controlled and environmental pollution-free, but also endowed α-MnO2 nanowires with excellent ability as a Fenton catalyst when assembled into free-standing membrane for degrading phenolic compounds (kobs = 0.0738 ~ 0.1695 min?1) in a continuous flow reaction. The reactive oxygen species (i.e., ?OH) from Fenton-like reaction were enriched within this α-MnO2 nanowire membrane via nanoconfinement effect, which further enhanced the mass transportation of ?OH available for phenolic contaminants. MnO2 nanowire membrane using our method possessed the high practical potential for water purify due to its easy-preparation and enhanced catalytic performances. 相似文献