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Chinese Chemical Letters 2024年第9期35卷 1-3页

作者： Xinghui Yao Zhouyu Wang da-Gang Yu Department of Chemistry Xihua UniversityChengdu 610039China Key Laboratory of Green Chemistry&Technology of Ministry of Education College of ChemistrySichuan UniversityChengdu 610064China

Chiral compounds play a crucial role in the development of pharmaceuticals,pesticides,fragrances,and materials due to their unique stereochemical *** catalysis,which employs chiral catalysts to favor the production of one enantiomer over its mirror image,has emerged as a pivotal technique in the synthesis of chiral compounds[1].however,traditional asymmetric methods sometimes rely on environmentally harmful reducing or oxidizing agents,presenting a considerable challenge in the pursuit of green chemistry.

关键词： chiral oxidative catalyzed

Atomic hardy-type Spaces between h1 and L1 on Metric Spaces with Non-doubling Measures

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Acta Mathematica Sinica,English Series 2011年第12期27卷 2445-2468页

作者： Li Guang LIU da Chun YANG Dong Yong YANG School of Mathematical Sciences Beijing Normal UniversityLaboratory. of Mathematics and Complex Systems Ministry of EducationBeijing 100875 P. R. China

Let （y, d, dλ） be （Rn, ｜·｜,μ）, where ｜·｜ is the Euclidean distance, μ is a nonnegative Radon measure on Rn satisfying the polynomial growth condition, or the Gauss measure metric space （Rn, ｜·｜,dγ）, or the space （S, d, p）, where S - Rn×R＋ is the （ax ＋ b）-group, d is the left-invariant Riemannian metric and p is the right haar measure on S with exponential growth. In this paper, the authors introduce and establish some properties of the atomic hardy-type spaces {Xs（Y））0〈s≤∞ and the BM0-type spaces {BM0（y, s）}0〈s≤∞. Let hi（Y） be the known atomic hardy space and L01（y） the subspace of f ∈ L1（Y） with integral 0. The authors prove that the dual space of Xs（Y） is SM0（Y,s） when s∈ （0, ∞）, Xs（Y） = h1（Y） when s ∈ （0, 1], and X∞（y） = L01（Y）（or L1（Y））. As applications, the authors show that if T is a linear operator bounded from h1 （Y） to L1 （Y） and from L1（y） to L1,∞（Y）, then for all r ∈ （1, ∞） and s ∈ （r, ∞], T is bounded from Xr（y） to the Lorentz space L1,8（y）, which applies to the Calderon-Zygmund operator on （Rn, ｜·｜,μ）, the imaginary powers of the 0rnstein-Uhlenbeck operator on （Rn, ｜·｜,dγ） and the spectral operator associated with the spectral multiplier on （S, d, p）. All these results generalize the corresponding results of Sweezy, Abu-Shammala and Torchinsky on Euclidean spaces.

关键词： Non-doubling measure polynomial growth Gauss measure (ax + b)-group atomichardy-type space BMO-type space operator

Integrability of auto-B?cklund transformations and solutions of a torqued ABS equation

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Communications in Theoretical Physics 2021年第7期73卷 42-46页

作者： Xueli Wei Peter h van der Kamp da-jun Zhang Department of Mathematics Shanghai UniversityShanghai 200444China Department of Mathematics and Statistics La Trobe UniversityVictoria 3086Australia

An auto-B?cklund transformation for the quad equation Q1_(1) is considered as a discrete equation,called h2^(a),which is a so called torqued version of *** equations h2^(a) and Q1_(1) compose a consistent cube,from which an auto-B?cklund transformation and a Lax pair for h2^(a) are *** generally it is shown that auto-B?cklund transformations admit auto-Backlund *** the auto-Backlund transformation for h2^(a)we derive a seed solution and a one-soliton *** this solution it is seen that h2^(a) is a semi-autonomous lattice equation,as the spacing parameter q depends on m but it disappears from the plane wave factor.

关键词： auto-Bocklund transformation consistency Lax pair soliton solution torqued ABS equation semi-autonomous

磺化碳催化Biginelli反应一锅法合成3,4-二氢-2(1h)-酮和硫酮(英文)

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催化学报 2012年第4期33卷 706-710页

作者： Maryam MOGhADdaS Abolghasem daVOODNIa.majid M.hERAVI Niloofar TAVAKOLI-hOSEINI Department of Chemistry Mashhad BranchIslamic Azad University Department of Chemistry School of SciencesAlzahra University

A sulfonated carbon material was shown to be a highly efficient,eco-friendly,and recyclable solid acid catalyst for the Biginelli reaction of β-ketoester,aldehyde,and urea or thiourea under solvent-free *** gave 3,4-dihydropyrimidin-2(1h)-ones and-thiones in good to excellent *** method has the advantages of a simple procedure with easy work-up,short reaction time,and high *** catalyst can be recycled after a simple work-up and was reused four times without substantial reduction in activity.

关键词：化学催化高压高温

Superconducting fluctuation induced conductance corrections near a pair-breaking quantum phase transition in doubly connected ultrathin cylinders of Al

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Science China(Physics,Mechanics & Astronomy) 2020年第3期63卷 89-97页

作者： Ke Zhang ZongLi Wang da Xu YaZhe Wang h.Wang Ying Liu Department of Physics Zhejiang UniversityHangzhou 310027China Key Laboratory of Artificial Structures and Quantum Control(MOE)and Shanghai Center for Complex Physics School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Materials Research Institute and Department of Physics Pennsylvania State UniversityUniversity ParkPA 16802USA Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

We report measurements on ultrathin,doubly connected superconducting cylinders of Al that exhibit a destructive regime,which refers to the loss of superconductivity in a doubly connected superconductor near applied half flux quanta due to the sample topology and the small size of the sample.A depairing quantum phase transition(QPT)between a superconducting and metallic state tuned by the magnetic flux enclosed in the quasi one-dimensional(1D)cylinder was found at the onset of the destructive *** on magnetic flux and temperature dependent sample resistance as well as current-voltage characteristics revealed the presence of both thermally activated and quantum phase slips near the depairing *** the superconducting side of the QPT,thermally activated phase slips as described by the Langer-Ambegaokar and McCumber-halperin(LAMh)theory were found to describe the sample resistance as the system was pushed towards the QPT by a magnetic field applied along the cylinder ***,deviation from this behavior was found at low temperatures,signaling the presence of the quantum phase *** importantly,we observed a highly unusual negative slope in the resistance versus temperature curves on the metallic side of the QPT as predicted by the diagrammatic calculation of the dc conductivities in a 1D system near a depairing *** work suggests that fluctuations from both the phase and the amplitude of the superconducting order parameter are important for the superconductor-to-metal depairing QPT.

关键词： mesoscopic superconductor quantum phase transition superconducting fluctuation

Low-temperature heat capacities and standard molar enthalpy of formation of N-methylnorephedrine C11h17NO（s）

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Chinese Physics B 2008年第9期17卷 2859-2866页

作者： Di You-Ying Wang da-Qi Shi Quan Tan Zhi-Cheng College of Chemistry and Chemical Engineering Liaocheng University Liaocheng 252059 China Thermochemistry Laboratory Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

This paper reports that low-temperature heat capacities of N-methylnorephedrine C11h17NO（s） have been measured by a precision automated adiabatic calorimeter over the temperature range from T=78K to T=400K. A solid to liquid phase transition of the compound was found in the heat capacity curve in the temperature range of T=342-364 K. The peak temperature, molar enthalpy and entropy of fusion of the substance were determined. The experimental values of the molar heat capacities in the temperature regions of T=78-342 K and T=364-400 K were fitted to two poly- nomial equations of heat capacities with the reduced temperatures by least squares method. The smoothed molar heat capacities and thermodynamic functions of N-methylnorephedrine C11h17NO（s） relative to the standard refer- ence temperature 298.15 K were calculated based on the fitted polynomials and tabulated with an interval of 5 K. The constant-volume energy of combustion of the compound at T=298.15 K was measured by means of an isoperibol precision oxygen-bomb combustion calorimeter. The standard molar enthalpy of combustion of the sample was calculated. The standard molar enthalpy of formation of the compound was determined from the combustion enthalpy and other auxiliary thermodynamic data through a hess thermochemical cycle.

关键词： N-methylnorephedrine C11h17NO(s) heat capacity constant-volume energy of combus-tion standard molar enthalpy of formation

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Bi-capon beamforming for MIMO radar based on rank-reduced correlation matrix

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The Journal of China Universities of Posts and Telecommunications 2013年第1期20卷 85-90页

作者： hE Jie FENG da-zheng Nicolas h. Younan MA Lun School of Information Engineering Chang'an University National Laboratory of Radar Signal Processing Xidian University Department of Electrical and Computer Engineering Mississippi State University

A bi-capon beamforming （BCB） algorithm for multi-input multi-output （MIMO） radar is developed on the basis of correlation domain. By vectorizing the echo matrix and its transpose, the conventional capon cost function is transformed into bi-capon quadratic functions. By calculating two lower dimensional weight vectors with sub-matrices of the correlation matrix, BCB can significantly decrease the computational complexity and the requirement of training samples. In the presence of short data records, BCB can achieve better interference suppression performance than fully adaptive capon algorithm. Simulation results are presented to demonstrate the effectiveness of the proposed method.

关键词： MIMO radar capon beamforming correlation complexity performance

Preparation of MCM-41 in Industrial Scale and Its Application in heavy Oil Processing

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Chemical Research in Chinese Universities 2002年第2期18卷 169-174页

作者： Jianwen da Tiancun Xiao Jianming Su Xingzhong Xu Malcolm L.h.Green Research Institute of Qilu Petrochem.Corp. Zibo 255400China The Wolfson Catalysis Centre Inorganic Chemistry LaboratoryUniversity of OxfordSouth Parks RoadOxfordOX13QRUK

A series of MCM 41 molecular sieves have been prepared on an industrial scale, and the effect of preparation factors such as aging temperature, ph values on the structure and pore distribution of the MCM 41 product have been studied by using X ray diffraction(XRD), thermogravimetric(TG) and electron microscopy(TEM). It is shown that the ph values have a significant effect on the crystallinity of the synthesized product. Under proper conditions, the MCM 41 prepared on an industrial scale has the same performance as the samples prepared on an Lab scale. The prepared MCM 41 was used as a modifier of zeolite Y for fluid catalytic cracking(FCC) of residual oil. It is shown that the addition of the MCM 41 in the zeolite Y catalyst increases the pore size, and surface area of the catalysts, which helps to increase the yield of gasoline and diesel and decrease the production of gaseous product and carbon deposition in the catalyst. The better performance of the MCM 41 modified zeolite Y catalyst is believed to be due to its adjustment on the acidity and increase of the pore size.

关键词： MCM-41 Industrial scale synthesis FCC catalyst

COVID19 Classification Using CT Images via Ensembles of Deep Learning Models

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Computers, Materials & Continua 2021年第10期69卷 319-337页

作者： Abdul majid Muhammad Attique Khan Yunyoung Nam Usman Tariq Sudipta Roy Reham R.Mostafa Rasha h.Sakr Department of Computer Science HITEC University TaxilaTaxila47080Pakistan Department of Computer Science and Engineering Soonchunhyang UniversityAsanKorea College of Computer Engineering and Sciences Prince Sattam Bin Abdulaziz UniversityAl-KhrajSaudi Arabia PRTTL Washington University in Saint LouisSaint LouisMO 63110USA Department of Information Systems Faculty of Computers and Information SciencesMansoura UniversityMansoura35516Egypt Department of Computer Science Faculty of Computers and Information SciencesMansoura UniversityMansoura35516Egypt

The recent COVID-19 pandemic caused by the novel coronavirus,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has had a significant impact on human life and the economy around the world.A reverse transcription polymerase chain reaction(RT-PCR)test is used to screen for this disease,but its low sensitivity means that it is not sufficient for early detection and *** RT-PCR is a time-consuming procedure,there is interest in the introduction of automated techniques for *** learning has a key role to play in the field of medical *** most important issue in this area is the choice of key ***,we propose a set of deep learning features based on a system for automated classification of computed tomography(CT)images to identify ***,this method was used to prepare a database of three classes:Pneumonia,COVID19,and *** dataset consisted of 6000 CT images refined by a hybrid contrast stretching *** the next step,two advanced deep learning models(ResNet50 and darkNet53)were fine-tuned and trained through transfer *** features were extracted from the second last feature layer of both models and further optimized using a hybrid optimization *** each deep model,the Rao-1 algorithm and the PSO algorithm were combined in the hybrid ***,the selected features were merged using the new minimum parallel distance non-redundant(PMDNR)*** final fused vector was finally classified using the extreme machine *** experimental process was carried out on a set of prepared data with an overall accuracy of 95.6%.Comparing the different classification algorithms at the different levels of the features demonstrated the reliability of the proposed framework.

关键词： COVID19 preprocessing deep learning information fusion firefly algorithm extreme learning machine

Molecular Characterization and Functional Analysis of Krüppel-homolog 1(Kr-h1) in the Brown Planthopper, Nilaparvata lugens(Stl)

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Journal of Integrative Agriculture 2014年第9期13卷 1972-1981页

作者： JIN Min-na XUE Jian YAO Yun LIN Xin-da College of Life Sciences China Jiliang University Institute of Insect Science Zhejiang University

The brown planthopper, Nilaparvata lugens（Stl）, is the most serious insect pest of rice. It has developed high resistance to traditional insecticides because of their intensive use. Juvenile hormone（Jh） analogs have been used successfully to control this species and other pest insects. however, the molecular mechanism of Jh signaling is not well understood. Krüppel-homolog 1（Kr-h1） is a transcription factor involved in the Jh pathway. In this study, the Kr-h1 cDNA was cloned and characterized from N. lugens by rapid amplification of cDNA ends（RACE） and reverse transcription PCR（RT-PCR）. Its spatial and temporal expression profiles were examined by real-time quantitative PCR, and its function was also studied by RNA interference（RNAi）. The open reading frame of NlKr-h1 is 1 833 bp encoding for 611 amino acids. The protein contains eight conserved zinc-finger motifs. NlKr-h1 was expressed at all life stages, with the highest mRNA level in the 4-day embryo. NlKr-h1 mRNA levels rose during each nymphal molt after the 2nd instar. In the adults, the mRNA level in males was significantly higher than that in females of either the macropterous or brachypterous type. The highest expression was observed in the female midgut. NlKr-h1 was activated by juvenile hormone III（Jh III） in the 3rd-5th instar nymphs. Disruption of Nlkr-h1 expression by RNAi caused stunted wing development and malformations of both male and female external genitalia. Our findings suggest that Kr-h1 may be a useful target for pest insect management.

关键词： brown planthopper Krüppel-homolog 1 RNA interference juvenile hormone signaling pathway