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Efficient and simple synthesis of B_(2)O_(3)-Al_(2)O_(3)nanocomposites assisted by deep eutectic solvent for production of 5-hydroxymethylfurfural from glucose

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Nano Research 2025年第1期18卷 236-248页

作者： Yuchen Wang Kai Rong Shanlei Chang Youxing Fang Shaojun Dong State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China college of Chemistry Jilin UniversityChangchun 130012China

The catalytic conversion of glucose to high valueadded platform chemical 5-hydroxymethylfurfural(HMF)is a promising biorefinery process,and alumina-boria catalysts are considered to be green and mild solid acid catalysts for this catalytic ***,compared to the common synthesis methods with complicated steps,we reported a simple and efficient strategy to prepare B_(2)O_(3)-Al_(2)O_(3)nanocomposites by calcining cost-effective glucose-urea deep eutectic solvent(DES)solution containing the *** prepared B_(2)O_(3)-Al_(2)O_(3)nanocomposites exhibited an open three-dimensional skeleton and two-dimensional porous lamellar substructure,endowing them with a high specific surface area(228.27 m2/g).The introduction of boron changed the ratios of different aluminum species(AlⅣ,AlⅤ,and AlⅥ)and borate species(BO3 and BO4),thus further affecting the acidity and the types of acid sites of the *** prepared B_(2)O_(3)-Al_(2)O_(3)bifunctional acid catalysts possessing abundant Lewis acid sites and adjustable Brønsted acid sites showed complete glucose conversion and 55.38%of HMF yield under the optimum *** study proposed a concise method to synthesize alumina-boria solid acid catalysts assisted by glucose-urea *** hope to extend the application and prospect of this efficient and simple synthesis strategy.

关键词： 5-hydroxymethylfurfural(HMF) deep eutectic solvent glucose alumina-boria acid catalyst

Prediction Model for Coronavirus Pandemic Using Deep Learning

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computer Systems Science & Engineering 2022年第3期40卷 947-961页

作者： Mamoona Humayun Ahmed Alsayat Department of Information Systems College of Computer and Information SciencesJouf UniversityKSA Department of computer Science College of Computer and Information SciencesJouf UniversityKSA

The recent global outbreak of COVID-19 damaged the world health systems,human health,economy,and daily life *** of the countries was ready to face this emerging health *** professionals were not able to predict its rise and next move,as well as the future curve and impact on lives in case of a similar pandemic situation *** created huge chaos globally,for longer and the world is still struggling to come up with any suitable *** the better use of advanced technologies,such as artificial intelligence and deep learning,may aid healthcare practitioners in making reliable COVID-19 *** proposed research would provide a prediction model that would use Artificial Intelligence and Deep Learning to improve the diagnostic process by reducing unreliable diagnostic interpretation of chest CT scans and allowing clinicians to accurately discriminate between patients who are sick with COVID-19 or pneumonia,and also empowering health professionals to distinguish chest CT scans of healthy *** efforts done by the Saudi government for the management and control of COVID-19 are remarkable,however;there is a need to improve the diagnostics process for better *** used a data set from Saudi regions to build a prediction model that can help distinguish between COVID-19 cases and regular cases from CT *** proposed methodology was compared to current models and found to be more accurate(93 percent)than the existing methods.

关键词： Artificial Intelligence(AI) deep learning(DL) COVID-19 pandemic

Consistent Nonnegative Estimates of Variance Components

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Acta Mathematicae Applicatae Sinica 2010年第2期26卷 177-186页

作者： Li-wen Xu Song-gui Wang Jian-hong Shi college of sciences North China University of Technology Beijing 100144 China college of applied sciences Beijing University of Technology Beijing 100022 China School of Mathematics and computer sciences Shanxi Normal University Linfen 041004 China

In this paper, the estimation of variance components in the linear mixed model with two random effects is investigated. The class of combination estimates based on the quadratic invariant statistics and consistent nonnegative estimates are obtained. Furthermore, it is shown that the consistent nonnegative estimate dominates ANOVA estimate under some conditions.

关键词： Linear mixed models invariant statistics consistency nonnegative estimate

Rational time-frequency multi-window subspace Gabor frames and their Gabor duals

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Science China Mathematics 2014年第1期57卷 145-160页

作者： ZHANG Yan LI YunZhang college of applied sciences Beijing University of Technology

This paper addresses the theory of multi-window subspace Gabor frame with rational time-frequency parameter *** the help of a suitable Zak transform matrix,we characterize multi-window subspace Gabor frames,Riesz bases,orthonormal bases and the uniqueness of Gabor duals of type I and type *** these characterizations we obtain a class of multi-window subspace Gabor frames,Riesz bases,orthonormal bases,and at the same time we derive an explicit expression of their Gabor duals of type I and type *** an application of the above results,we obtain characterizations of multi-window Gabor frames,Riesz bases and orthonormal bases for L2(R),and derive a parametric expression of Gabor duals for multi-window Gabor frames in L2(R).

关键词： frame Gabor frame dual

The ANOVA-Type Inference in Linear Mixed Model with Skew-Normal Error

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Journal of Systems Science & Complexity 2017年第3期30卷 710-720页

作者： WU Mixia ZHAO Jing WANG Tonghui ZHAO Yan college of applied sciences Beijing University of Technology Department of Mathematical sciences New Mexico State University

Linear mixed effect models with skew-normal errors and distribution-free random effects are considered. The ANOVA-type F-tests are proposed to test the significance of random effects and the hypothesis on fixed effects of interest, respectively. Both tests are proved to be exact F-tests under this model, and the exact confidence interval for fixed effects of interest is derived. Simulation results are given to study the powers of ANOVA-type tests.

关键词： ANOVA-type estimator ANOVA-type F-test skew-normal error.

Compact, temperature-stable multi-gigahertz passively modelocked semiconductor disk laser

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Chinese Physics B 2015年第8期24卷 356-361页

作者：宋晏蓉郭于鹤洋张鹏田金荣 college of applied sciences Beijing University of Technology college of Physics and Electronic Engineering Chongqing Normal University

We present a compact passively mode-locked semiconductor disk laser at 1045 nm. The gain chip without any post processing consists of 16 compressively strained In Ga As symmetrical step quantum wells in the active region. 3-GHz repetition rate, 4.9-ps pulse duration, and 30-mW average output power are obtained with 1.4 W of 808-nm incident pump power. The temperature stability of the laser is demonstrated to have an ideal shift rate of 0.035 nm/K of the lasing wavelength.

关键词： mode-locked lasers thermal effects diode-pumped

Tritium concentration in soybean plants exposed to atmospheric HTO during nighttime and daytime

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Nuclear Science and Techniques 2016年第2期27卷 44-51页

作者： Hui-Fang Shen Wei Liu college of Arts and sciences Shanxi Agricultural University Shanghai Institute of applied Physics Chinese Academy of Sciences

Potted soybean plants were exposed to evaporate HTO for 1 h inside an exposure box at two different growth stage(flowering and podding stage, filling stage)during nighttime and daytime. The concentration of tissuefree water tritium(TFWT) and organically bound tritium(OBT) in leaves and beans was measured at the end of the exposure. The results indicated that the quasi-equilibrium between the TFWT concentrations in the soybean leaves and the HTO concentration of the ambient air moisture required more than 1 h to be reached. The relative TFWT concentrations in the nighttime represent about 1/2 to 2/3of the concentrations obtained in the day in the leaves compared to about 1/2 to 4/3 in the beans. The relative OBT concentrations under night conditions were about 2/5 to 1/2 of those under day conditions in the leaves, contrary to 1/2–7/10 for the beans. By developing tritium concentration assessment model with a short-term release of atmospheric HTO, we comprehensively considered the plant growth stage and the environmental conditions.

关键词：大豆叶片氚浓度植物大气白天高浓度条件游离水评价模型

Laser cooling of internal degrees of freedom of molecules

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Frontiers of physics 2016年第4期11卷 109-126页

作者： R. Horchani college of Arts and applied sciences Dhofar University Salalah Oman

Optical pumping techniques using laser fields combined with photo-association of ultracold atoms leads to control of tile vibrational and/or rotational population of molecules. In this study, we review tile basic concepts and main steps that should be followed, including the excitation schemes and detection techniques used to achieve to-vibrational cooling of Cs2 molecules. We also discuss the extension of this technique to other molecules. In addition, we present a theoretical model used to support the experiment. These simulations can be widely used for the preparation of various experiments because they allow the optimization of several important experimental parmneters.

关键词： cold molecule photo-association optical pumping vibrational and rotational cooling

Wavelength tunable ultra-short pulses based on a flat broadband spectrum generated in a nonlinear ytterbium-doped fiber amplifier

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Chinese Physics B 2017年第1期26卷 220-223页

作者： Run-Qin Xu Zi-Kai Dong Jin-Rong Tian Ke-Xuan Li Yan-Rong Song college of applied sciences Beijing University of Technology Beijing 100124 China

We present a nonlinear ytterbium-doped fiber amplifier based on enhanced nonlinear effects that can produce a flat broadband spectrum ranging from 1050–1225 nm with a maximum average output power of 7.8 W at 14 W pump *** repetition rate is 89 MHz. Using a pair of gratings and two knife edges as a filter, wavelength tunable picosecond pulses of tens to hundreds of milliwatts can be obtained in the broadband spectrum range. The output power, pulse width, and spectrum（center wavelength and linewidth） are adjusted by tuning the distance of the grating pair and/or the knife *** the distance between the two gratings at 15 mm and keeping the output spectrum linewidth at approximately 20 nm,the shortest pulse width obtained is less than 1 ps centered at 1080 nm. The longest wavelength of the short pulses is around1200 nm, and its output power and pulse width are 40 m W and 5.79 ps, respectively. The generation of a flat broadband spectrum is also discussed in this paper.

关键词： tunable ultra-short pulse broadband spectrum nonlinear amplifier