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Chinese Chemical Letters 2023年第10期34卷 163-167页

作者： Rui Wang Jie Xu Jin-xiao Li bing-bing Wu Ruo-Xing Jin Yu-xiang bi Xi-Sheng Wang Key Laboratory of Precision and Intelligent Chemistry University of Science and Technology of ChinaHefei 230026China

The synthesis methods ofα-fluoro-arylketones were well-established through electrophilic/nucleophilic fluorination and transition metal catalyzed ***,due to the site selectivity and substrate restriction,only a few cases have been developed to affordα-alkyl-α-***,we report a general and efficient method of preparing diverseα-alkyl-α-fluoro-alkylketones via nickelcatalyzed reductive coupling reaction of monofluoroalkyl triflates with low-cost industrial raw material alkyl carboxylic *** transformations demonstrate high efficiency,mild conditions,and excellent functional group *** strategy provides a general and efficient method for the synthesis ofα-alkyl-α-fluoro-alkylketones。

关键词： Ni-catalyzed Reductive coupling α-Fluoroketones α-Alkyl-α-fluoro-alkylketones Monofluoroalkyl triflates

Interaction of Oblique Waves and A Rectangular Structure with An Opening Near A Vertical Wall

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China Ocean Engineering 2017年第2期31卷 220-229页

作者： ZHANG Hong-sheng ZHENG bi-fang YANG xiao-yan College of Ocean Science and Engineering Shanghai Maritime University School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong University

With the method of separation of variables and the eigenfunction expansion employed, an analytical solution is presented for the radiation and diffraction of a rectangular structure with an opening near a vertical wall in oblique seas, in which the unknown coefficients are determined by the boundary conditions and matching requirement on the interface. The effects of the width of the opening and the angle of incidence on the hydrodynamic characteristics of a rectangular structure with an opening near a vertical wall are mainly studied. The comparisons of the calculation results with wall-present and with wall-absent are also made. The results indicate that the variation trends of the heave added mass and excitation force with wall-present are almost the same as those with wall-absent, and that the peak values in the former case are obviously larger than those in the latter due to the reflection of the vertical wall.

关键词： wave radiation and diffraction rectangular structure opening oblique incidence vertical wall analytical solution hydrodynamic characteristics comparison

A Specification Test of Stochastic Diffusion Models

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Acta Mathematicae Applicatae Sinica 2013年第3期29卷 529-540页

作者： Shu-lin ZHANG Zheng-hong WEI Qiu-xiang bi School of Statistics Southwestern University of Finance and Economics College of Mathematics and Computational Science University of Shenzhen Department of Fixed Income Guangfa SecuritiesCo.Ltd.

In this paper, we propose a hypothesis testing approach to checking model mis-specification in continuous-time stochastic diffusion model. The key idea behind the development of our test statistic is rooted in the generalized information equality in the context of martingale estimating equations. We propose a bootstrap resampling method to implement numerically the proposed diagnostic procedure. Through intensive simulation studies, we show that our approach is well performed in the aspects of type I error control, power improvement as well as computational efficiency.

关键词： Stochastic diffusion model martingale estimating function generalized information equality

Boundedness for a Class of Generalized Commutators on λ-Central Morrey Space

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Acta Mathematica Sinica,English Series 2013年第10期29卷 1917-1926页

作者： xiao YU xiang Xing TAO Department of Mathematics Zhejiang University Department of Mathematics Shangrao Normal University Department of Mathematics Zhejiang University of Science and Technology

Let 0 〈 a 〈 n, Ω be a rough kernel, and let A have derivatives of order m- 1 in CI3MOTM with m ≥ 2. We consider a class of generalized commutators TΩA,α of Cohen-Gosselin type, and obtain the boundedness of TΩA... 详细信息

关键词： Generalized commutator central Morrey 'space central-BMO space

Boundedness of multilinear operators on generalized Morrey spaces

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Applied Mathematics(A Journal of Chinese Universities) 2014年第2期29卷 127-138页

作者： YU xiao TAO xiang-xing Department of Mathematics Shangrao Normal University Department of Mathematics Zhejiang University of Science and Technology

In this paper, the authors prove the boundedness of the multilinear maximal func- tions, multilinear singular integrals and multilinear Riesz potential on the product generalized Rn Rn Morrey spaces Mp1,ωw1 （Rn）... 详细信息

关键词： multilinear singular integral multilinear Riesz potential generalized Morrey space multilinearmaximal function.

Numerical simulation of aircraft arresting process with an efficient full-scale rigid-flexible coupling dynamic model

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Chinese Journal of Aeronautics 2024年第5期37卷 586-602页

作者： Haoyuan SHAO Daochun LI Zi KAN Lanxi bi Zhuoer YAO Jinwu xiang School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Tianmushan Laboratory Hangzhou 310023China

The arresting process of carrier-based aircraft is widely recognized as a challenging task,characterized by the highest accident rate among all carrier-based aircraft *** simulation plays a crucial role in assessing the intricate responses of the arresting process,favoring the design of carrier-based *** efficient and accurate rigid-flexible coupling model for analyzing the dynamic response of the arresting process is *** combining the dynamic characteristics of airframe,landing gear,arresting hook and arresting gear system,the rigid-flexible coupling dynamic model is established to reflect the relative motion of the coupling parts and arresting *** dynamic model is verified through simulations of landing gear landing drops and by comparing the arresting simulation results with corresponding data in the US military ***,simulations of the arresting process under different off-center distance and aircraft yaw angle are conducted to obtain the dynamic response of the aircraft during the arresting *** result indicates that the rigid-flexible coupling dynamic model proposed is effective for analyzing the arresting dynamics response of carrier-based *** axial force of the arresting cable on both sides of the hook engagement point,pitch and yaw angle of aircraft are inconsistent under yaw and off-center *** analysis method and obtained results provide valuable references for assessing the dynamic responses of carrier-based aircraft during arresting process and offer valuable in-sights in the design of carrier-based aircraft.

关键词： Carrier-based aircraft Deck landing Rigid-flexible coupling dynamic model Finite element method Dynamic analysis

DIRECT MEASUREMENT OF WEAK DEPLETION FORCE BETWEEN TWO SURFACES

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Chinese Journal of Polymer Science 2011年第1期29卷 1-11页

作者： xiang-jun Gong xiao-chen Xing xiao-ling Wei To Ngai Department of Chemistry the Chinese University ofHong Kong Shatin N.T. Hong Kong China Department of Physics the Chinese University ofHong Kong Shatin N.T. Hong Kong China

In a mixture of colloidal particles and polymer molecules, the particles may experience an attractive ＂depletion force＂ if the size of the polymer molecule is larger than the interparticle separation. This is because individual polymer molecules experience less conformational entropy if they stay between the particles than they escape the inter-particle space, which results in an osmotic pressure imbalance inside and outside the gap and leads to interparticle attraction. This depletion force has been the subject of several studies since the 1980s, but the direct measurement of this force is still experimentally challenging as it requires the detection of energy variations of the order of kBT and beyond. We present here our results for applying total internal reflection microscopy （TIRM） to directly measure the interaction between a free-moving particle and a flat surface in solutions consisting of small water-soluble organic molecules or polymeric surfactants. Our results indicate that stable nanobubbles （ca. 150 nm） exist free in the above aqueous solutions. More importantly, the existence of such nanobubbles induces an attraction between the spherical particle and flat surface. Using TIRM, we are able to directly measure such weak interaction with a range up to 100 nm. Furthermore, we demonstrate that by employing thermo^sensitive microgel particles as a depleting agent, we are able to quantitatively measure and reversibly control kBT-scale depletion attraction as function of solution pH.

关键词： Depletion interaction Total internal reflection microscopy (TIRM) Nanobubbles Microgel particles

Response of arbuscular mycorrhizal fungi and phosphorus solubilizing bacteria to remediation abandoned solid waste of coal mine

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International Journal of Coal Science & Technology 2019年第4期6卷 603-610页

作者： Yinli bi Li xiao Rongrong Liu State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology(Beijing)Beijing 100083China

Coal is the vital resource of energy in China,but abandoned coal ash and gangue lead to the degradation of vegetation cover and reduce soil *** arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing bacteria (PSB) play a key role in biogeochemical cycle such as soil organic matter decomposition,nutrition release,and energy *** improve and reclamation the soil quality and ecological efficiency of the coal mining waste,we investigated the effects of an AMF strain (Glomus mosseae) and a PSB strain (Pantoesstewarti) on phytate mineralization and subsequent transfer to the host plant (Medicago sativa L.) using a two-compartment microcosm with a central 30 mm nylon mesh *** results showed that significantly higher available P (AP),above ground biomass (AGB) and underground biomass (UGB) were in combined inoculation of AMF-PSB than other treatments in root and hyphae *** microbial inoculum of the AMF or PSB had a significant influence on soil acid phosphatase activities (ACP).AMF-PSB enhanced phytate mineralization,improved plant *** and ACP positively influenced the AGB and ***-PSB could be used as bioinoculant to enhance sustainable production of the plant in abandoned solid waste of coal mine.

关键词： Arbuscular mycorrhizal fungi Phosphorus solubilizing bacteria Abandoned solid waste Ecological reclamation Coal mine

Multiple Measurement Models of Articulated Arm Coordinate Measuring Machines

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Chinese Journal of Mechanical Engineering 2015年第5期28卷 994-998页

作者： ZHENG Dateng xiao Zhongyue XIA xiang College of Mechanical & Electrical Engineering Jinggangshan University

The existing articulated arm coordinate measuring machines（AACMM） with one measurement model are easy to cause low measurement accuracy because the whole sampling space is much bigger than the result in the unstable calibration parameters. To compensate for the deficiency of one measurement model, the multiple measurement models are built by the Denavit-Hartenberg＇s notation, the homemade standard rod components are used as a calibration tool and the Levenberg-Marquardt calibration algorithm is applied to solve the structural parameters in the measurement models. During the tests of multiple measurement models, the sample areas are selected in two situations. It is found that the measurement errors＇ sigma value（0.083 4 ram） dealt with one measurement model is nearly two times larger than that of the multiple measurement models（0.043 1 ram） in the same sample area. While in the different sample area, the measurement errors＇ sigma value（0.054 0 ram） dealt with the multiple measurement models is about 40% of one measurement model（0.137 3 mm）. The preliminary results suggest that the measurement accuracy of AACMM dealt with multiple measurement models is superior to the accuracy of the existing machine with one measurement model. This paper proposes the multiple measurement models to improve the measurement accuracy of AACMM without increasing any hardware cost.

关键词： articulated arm coordinate measuring machine multiple measurement models sample area measurement accuracy

Interaction effect of micro-and macro-organic on the biogeochemical function of the sediment and aquatic interface

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Journal of Environmental Sciences 2006年第3期18卷 468-474页

作者： xiao xiang LIAO Ling ZHANG Xin-hua Guangzhou Environment Protection Bureau Guangzhou 510032 China Guangzhou Research Institute of Environmental Protection Guangzhou 510620 China South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China

Constructed stormwater infiltration basins have been broad applied in urban areas in terms of stormwater disposal and compensation of reduced groundwater recharge. However, stormwater derived from sediments accumulating in infiltration beds may act as a source of dissolved contaminants for groundwater. Concentrations of DO, NO3-N, NO2^--N, NH4^＋-N and PO4^3--P were monitored at multiple depth with time. The results showed that the occurrence of denitrificarion was restrained by sediments in term of no invertebrates. Under the conditions of invertebrates inoculated, the concentrations of DO, NO^3--N, NO2^＋-N, NH4^＋-N and PO4^3＋-P varied respectively with time and the occurrence of nitrification and mobilizing nitrate in the sediment. It is concluded that there exist the invertebrate activities such as building tubes and galleries and excreting faecal pellet which may increase water dispersion and enhance accessibility of nutrient, and stimulate microbial process effected in the sediment. Besides, the natural death and rot of worms were also found to be important factors of the invertebrate activities.

关键词： infiltration basins urban stormwater polluted sediments invertebrates effects