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Using benzene carboxylic acids to prepare zirconium-based catalysts for the conversion of biomass-derived furfural

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International Journal of Coal Science & Technology 2018年第4期5卷 464-472页

作者： Huacong Zhou Yufei sha Zhenhuan Xiao Lu li Jianmin Hao Keli Yang na li Runxia He Quansheng liu College of Chemical Engineering Inner Mongolia University of Tech no logyInner Mongolia Key Laboratory of High-Value Functional Utilization of Low Rank Carbon ResourcesNo.49 Aimin Road Xincheng DistrictHuhhot 010051Inner MongoliaChina

Benzene carboxylic acid (BCAs) are common and useful chemical blocks, which can be derived from the abundant low rank coals (LRCs) via oxidative degradation. In this work, we proposed a novel strategy to utilize BCAs as raw materials to prepare catalysts with transition metal zirconium, and the prepared catalysts were applied into the conversion of the renewable biomass resources. Typical model BCAs in the oxidative products of LRCs, including pyromellitic acid, trimesic acid (TMSA), trimellitic acid, and benzoic acid, were used as the block to construct the Zr- BCAs catalysts. The chemoselective conversion of furfural into furfuryl alcohol (FAL). an important reaction in the biomass conversion chain, is chosen to evaluate the activity of the catalysts. The preparation conditions of the catalysts and experiment factors during the reaction were systematically investigated. The prepared catalysts were characterized by SEM, TEM, XRD and TG-DTG. The results showed that the prepared catalysts were efficient for the conversion of furfural into FAL, among which Zr-TMSA gave the highest activity. Zr-TMSA could be recycled for ten times without obvious deactivation, indicating an excellent stability. The strategy proposed in this work may be beneficial for the value-added utilization of both LRCs and biomass resources.

关键词： Benzene carboxylic acids Low rank coals Zirconium catalyst Biomass Furfural

Universality of an improved photosynthesis prediction model based on PSO-SVM at all growth stages of tomato

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International Journal of Agricultural and Biological Engineering 2017年第2期10卷 63-73页

作者： li Ting Ji Yuhan Zhang Man sha sha li Minzan Key Laboratory of Modern Precision Agriculture System Integration Research Ministry of EducationChina Agricultural UniversityBeijing 100083China Key Laboratory of Agricultural Information Acquisition Technology Ministry of AgricultureChina Agriculture UniversityBeijing 100083China Beijing Research Institute of Uranium Geology Beijing 100029China

CO_(2)concentration is an environmental factor affecting photosynthesis and consequently the yield and quality of *** this study,a photosynthesis prediction model for the entire growth stage of tomatoes was constructed to elevate CO_(2)level on the basis of crop requirements and to evaluate the effect of CO_(2)elevation on leaf *** effect of CO_(2)enrichment on tomato photosynthesis was investigated using two CO_(2)enrichment treatments at the entire growth stage.A wireless sensor network-based environmental monitoring system was used for the real-time monitoring of environmental factors,and the li-6400XT portable photosynthesis system was used to measure the net photosynthetic rate of tomato *** input variables for the model,environmental factors were uniformly preprocessed using independent component ***,the photosynthesis prediction model for the entire growth stage was established on the basis of the support vector machine(SVM)*** particle swarm optimization(PSO)was also used to search for the best parameters c and g of ***,the relationship between CO_(2)concentration and photosynthetic rate under varying light intensities was predicted using the established model,which can determine CO_(2)saturation points at the various growth *** determination coefficients between the simulated and observed data sets for the three growth stages were 0.96,0.96,and 0.94 with the improved PSO-SVM and 0.89,0.87,and 0.86 with the original *** results indicate that the improved PSO-SVM exhibits a high prediction *** study provides a basis for the precise regulation of CO_(2)enrichment in greenhouses.

关键词： photosynthesis greenhouse tomato CO2 enrichment photosynthesis prediction model wireless sensor network environmental monitoring system

Graphite oxide-catalyzed acetylation of alcohols and phenols

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Chinese Chemical Letters 2016年第5期27卷 726-730页

作者： Yuan-Yuan liu Jun-Mei Qi li-sha bai Yue-Long Xu Ning Ma Fei-Fei Sun Department of Chemistry School of ScienceTianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China

Graphite oxide （GO） was used as a catalyst for the reactions of alcohols and phenols with acetic anhydride. The acetates of primary and secondary alcohols were prepared in good to excellent yields in short reaction time under mild conditions. Electron deficient phenols could be converted to the corresponding acetates steadily. As an efficient catalyst, GO is easily available, cheap, moderately toxic and weakly acidic.

关键词： Graphite oxide Acetates Alcohol Phenol

3D tumor model biofabrication

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Bio-Design and Manufacturing 2021年第3期4卷 526-540页

作者： Ming li Xueer Song sha Jin Kaiming Ye Department of Biomedical Engineering Center of Biomanufacturing for Regenerative MedicineBinghamton UniversityState University of New York(SUNY)PO Box 6000BinghamtonNY 13902USA

Animal models have been extensively used in cancer pathology studies and drug *** models,however,fail to reflect the complex human tumor microenvironment and do not allow for high-throughput drug screening in more human-like physiological ***-dimensional(3D)cancer models present an alternative to automated high-throughput cancer drug discovery and *** this review,we highlight recent technology innovations in building 3D tumor models that simulate the complex human tumor microenvironment and responses of patients to *** discussed various biofabrication technologies,including 3D bioprinting techniques developed for characterizing tumor progression,metastasis,and response to treatment.

关键词： Tumor models Biofabrication Tumor spheroids Microfluidic devices 3D bioprinting

Synthesis of A Novel Fulleroaziridine Carrying 4-Deoxy-4'-demethylepipodophyllotoxin

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Chinese Chemical Letters 2003年第11期14卷 1123-1126页

作者： Qian Rong li sha YANG Structure Research Laboratory University of Science and Technology of ChinaHefei 230026

A novel fulleroaziridine 2 with a closed 6,6-ring junction was synthesized from [60]fullerene and 4-azido-4-deoxy- 4?demethylepipodophyllotoxin 1 in 1, 2-dichlorobenzene at 110℃ for 45 h, in a yield of 39.3 % based o... 详细信息

关键词： Podophyllotoxin derivative azide fullerene fulleroaziridine cycloaddition.

Microstructure and Mechanical Property of Mg‑13Gd‑0.2Ni Alloy Processed by Extrusion and Aging

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1367-1376页

作者： Hang Zhang Jiaying Zhao Rongguang li Boshu liu shanshan li sha sha Yuehong Zhang Man Xu Yan tang School of Mechanical and Power Engineering Shenyang University of Chemical TechnologyShenyang 110142China Instrumental Analysis Center Shenyang University of Chemical TechnologyShenyang 110142China

In this work,a good combination of strength and ductility is achieved in a Mg-13Gd-0.2Ni alloy by conventional extrusion and following aging *** aged Mg-13Gd-0.2Ni alloy exhibits a yield strength(YS)of 363 MPa,an ultimate tensile strength(UTS)of 433 MPa,and an elongation of 11.9%.The aged Mg-13Gd-0.2Ni alloy contains a microstructure with a 95%proportion of dynamically recrystallized(DRXed)grains with a micron size,weak texture,and a high number density of prismaticβ′precipitates within *** bulk compounds enriched with Ni element which are mainly formed during casting and stable in the extruded and aged *** dynamic compounds are formed during extrusion,and a high density of prismaticβ′precipitates are formed during *** high density of prismaticβ′precipitates results in a significant increase in the strength of the Mg-13Gd-0.2Ni alloy,and the YS and UTS are increased by 153 and 136 MPa,*** high proportion of DRXed grains with a weak texture contributes mainly to the high ductility and the fine compounds with a low density at grain boundaries formed during aging have no significant adverse effect on ductility of the aged Mg-13Gd-0.2Ni *** findings for the novel Mg-Gd-Ni alloy can provide guidance for the design of wrought Mg alloys with superior mechanical properties.

关键词： Mg-Gd-Ni alloy Extrusion Aging Strength Ductility

MP-WFRFT and Constellation Scrambling Based Physical Layer Security System

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China Communications 2016年第2期13卷 138-145页

作者： FANG Xiaojie sha Xuejun li Yue Communication Research Center Harbin Institute of Technology

In this paper, a multiple parameters weighted fractional Fourier transform(MPWFRFT) and constellation scrambling(CS) method based physical layer(PHY) security system is proposed. The proposed scheme is executed by two steps. In the first step, MPWFRFT, implemented as the constellation beguiling(CB) method, is applied to change the signal's identity. In the second step the additional pseudo random phase information, regarded as the encryption key, is attached to the original signal to enhance the security. Typically, the pseudo random phase information can be removed effectively by the legitimate receiver. In contrast to the cryptography based encryption algorithms and the conventional PHY secrecy techniques, the main contribution of the proposed scheme is concentrated on the variation in signal's characteristics. Simulation results show that the proposed scheme can prevent the exchanging signal from eavesdroppers' classifi cation or inception. Moreover, the proposed scheme can guarantee the BER performance at a tolerate increasing in computational complexity for the legitimate receivers.

关键词： weighted fractional Fourier transform(WFRFT) physical layer (PHY) security secrecycapacity

DDoS Attack Autonomous Detection Model Based on Multi-Strategy Integrate Zebra Optimization Algorithm

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Computers, Materials & Continua 2025年第1期82卷 645-674页

作者： Chunhui li Xiaoying Wang Qingjie Zhang Jiaye liang Aijing Zhang School of Information Engineering Institute of Disaster PreventionLangfang065201China Langfang Key Laboratory of Network Emergency Protection and Network Security Langfang065201China

Previous studies have shown that deep learning is very effective in detecting known ***,when facing unknown attacks,models such as Deep Neural Networks(DNN)combined with Long Short-Term Memory(LSTM),Convolutional Neural Networks(CNN)combined with LSTM,and so on are built by simple stacking,which has the problems of feature loss,low efficiency,and low ***,this paper proposes an autonomous detectionmodel for Distributed Denial of Service attacks,Multi-Scale Convolutional Neural Network-Bidirectional Gated Recurrent Units-Single Headed Attention(MSCNN-BiGRU-sha),which is based on a Multistrategy Integrated Zebra Optimization Algorithm(MI-ZOA).The model undergoes training and testing with the CICDDoS2019 dataset,and its performance is evaluated on a new GINKS2023 *** hyperparameters for Conv_filter and GRU_unit are optimized using the Multi-strategy Integrated Zebra Optimization Algorithm(MIZOA).The experimental results show that the test accuracy of the MSCNN-BiGRU-sha model based on the MIZOA proposed in this paper is as high as 0.9971 in the CICDDoS 2019 *** evaluation accuracy of the new dataset GINKS2023 created in this paper is *** to the MSCNN-BiGRU-sha model based on the Zebra Optimization Algorithm(ZOA),the detection accuracy on the GINKS2023 dataset has improved by 5.81%,precisionhas increasedby 1.35%,the recallhas improvedby 9%,and theF1scorehas increasedby 5.55%.Compared to the MSCNN-BiGRU-sha models developed using Grid Search,Random Search,and Bayesian Optimization,the MSCNN-BiGRU-sha model optimized with the MI-ZOA exhibits better performance in terms of accuracy,precision,recall,and F1 score.

关键词： Distributed denial of service attack intrusion detection deep learning zebra optimization algorithm multi-strategy integrated zebra optimization algorithm

Sparse Estimation of High-Dimensional Inverse Covariance Matrices with Explicit Eigenvalue Constraints

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Journal of the Operations Research Society of China 2021年第3期9卷 543-568页

作者： Yun-Hai Xiao Pei-li li sha Lu Institute of Applied Mathematics College of Mathematics and StatisticsHenan UniversityKaifeng 475000HenanChina School of Statistics Key Laboratory of Advanced Theory and Application in Statistics and Data Science-MOEEast China Normal UniversityShanghai 200062China Department of Mathematics Nanning Normal UniversityNanning 530299GuangxiChina

Firstly,this paper proposes a generalized log-determinant optimization model with the purpose of estimating the high-dimensional sparse inverse covariance *** the normality assumption,the zero components in the inverse covariance matrices represent the conditional independence between pairs of variables given all the other *** generalized model considered in this study,because of the setting of the eigenvalue bounded constraints,covers a large number of existing estimators as special ***,rather than directly tracking the challenging optimization problem,this paper uses a couple of alternating direction methods of multipliers(ADMM)to solve its dual model where 5 separable structures are *** first implemented algorithm is based on a single Gauss–Seidel iteration,but it does not necessarily converge *** contrast,the second algorithm employs the symmetric Gauss–Seidel(sGS)based ADMM which is equivalent to the 2-block iterative scheme from the latest sGS decomposition ***,we do numerical simulations using the synthetic data and the real data set which show that both algorithms are very effective in estimating high-dimensional sparse inverse covariance matrix.

关键词： Non-smooth convex minimization Inverse covariance matrix Maximum likelihood estimation Augmented Lagrangian function Symmetric Gauss–Seidel iteration