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Anisotropic magnetocaloric effect in a dysprosium(Ⅲ) single-molecule magnet——Commemorating the 100th anniversary of the birth of Academician Guangxian Xu

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Journal of Rare Earths 2021年第12期39卷 1554-1559,I0004页

作者： You-Song Ding Yan-zhen zheng Xi'an Jiaotong University Shenzhen Research Academy Shenzhen 518057China Frontier Institute of Science and Technology Xi'an Jiaotong University

Dysprosium compounds with high magnetic anisotropy are widely studied as single molecule magnets(SMMs).Here the anisotropic magnetocaloric effect in a Dy(Ⅲ)SMM,{[Dy(OSiMe_(3))_(2)(4-Mepy)5(BPh_(4))]0.5 Toluene},was studied by single *** dependent magnetization can be observed at 300 K because of its high magnetic *** behavior measured along the easy axis direction is identical to that of the polycrystalline *** magnetization from the easy axis to the hard plane gives a maximum magnetic entropy change(-ΔSR)of 3.05 J/(kg·K)at 19 K atΔB=5 T,which enables the Dy(Ⅲ)SMM to be used as a low-temperature rotating magnetic refrigerant.

关键词： Lanthanide complex Magnetic anisotropy Rotate magnetocaloric effect Single molecule magnets Rare earths

Tourism Route Recommendation Based on A Multi-Objective Evolutionary Algorithm Using Two-Stage Decomposition and Pareto Layering

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IEEE/CAA Journal of Automatica Sinica 2023年第2期10卷 486-500页

作者： Xiaoyao zheng Baoting Han zhen Ni IEEE the School of Computer and Information Anhui Normal UniversityWuhu 241002China the Department of Electrical Engineering and Computer Science Florida Atlantic UniversityBoca Raton FL33431 USA

Tourism route planning is widely applied in the smart tourism *** Pareto-optimal front obtained by the traditional multi-objective evolutionary algorithm exhibits long tails,sharp peaks and disconnected regions problems,which leads to uneven distribution and weak diversity of optimization solutions of tourism *** by these limitations,we propose a multi-objective evolutionary algorithm for tourism route recommendation(MOTRR)with two-stage and Pareto layering based on *** method decomposes the multiobjective problem into several subproblems,and improves the distribution of solutions through a two-stage *** crowding degree mechanism between extreme and intermediate populations is used in the two-stage *** neighborhood is determined according to the weight of the subproblem for crossover ***,Pareto layering is used to improve the updating efficiency and population diversity of the *** two-stage method is combined with the Pareto layering structure,which not only maintains the distribution and diversity of the algorithm,but also avoids the same *** with several classical benchmark algorithms,the experimental results demonstrate competitive advantages on five test functions,hypervolume(HV)and inverted generational distance(IGD)*** the experimental results of real scenic spot datasets from two famous tourism social networking sites with vast amounts of users and large-scale online comments in Beijing,our proposed algorithm shows better *** proves that the tourism routes recommended by our proposed algorithm have better distribution and diversity,so that the recommended routes can better meet the personalized needs of tourists.

关键词： Evolutionary algorithm multi-objective optimization Pareto optimization tourism route recommendation two-stage decomposition

A THEORETICAL MODEL FOR THERMAL-SENSITIVE MICROGEL WITH PNIPAM CORE AND ELASTIC SHELL

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Acta Mechanica Solida Sinica 2012年第5期25卷 520-529页

作者： zhen Wu zheng Zhong School of Aerospace Engineering and Applied Mechanics Tongji Universityshanghai 200092China

Poly （N-isopropylacrylamide）（PNIPAM） microgels are widely used in drug delivery due to their fast response to temperature. In order to get a better biocompatibility, PNIPAM mi- crogels are typically coated with a layer of biocompatible material, resulting in composite microgels with core-shell structure. In a composite microgel prepared recently, for example, a microsphere of PNIPAM gel is enclosed by a phospholipid membrane, and the composite microgel exhibits a substantial volume transition in response to temperature changes. Here we develop a theoretical model to describe the thermal-responsive behavior of this composite microgel. In particular, we treat the phospholipid membrane as an elastic layer behaving like rubber-like elastomers and adopt the form of the free-energy function for nematic gels （which refer to anther species of thermal- sensitive gels whose behavior has been intensively studied） as that for PNIPAM gels. We show that the thermal-responsive behavior of the composite microgel can be markedly influenced by the membrane. By investigating the state of stress on the interface, we further predict that when the coating membrane is stiff and thin, wrinkles are expected to occur on the outer surface of the composite microgel after the volume transition.

关键词： gel poly (N-isopropylacrylamide) volume transition core-shell structure

Near minimum-time feedback attitude control with multiple saturation constraints for agile satellites

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Chinese Journal of Aeronautics 2016年第3期29卷 722-737页

作者： Liu Xiangdong Xin Xing Li zhen Chen zhen sheng Yongzhi School of Automation Beijing Institute of Technology National Key Laboratory of Complex System Intelligent Control and Decision Beijing Institute of Technology

Agile satellites are of importance in modern aerospace applications, but high mobility of the satellites may cause them vulnerable to saturation during attitude maneuvers due to limited rating of actuators, This paper proposes a near minimum-time feedback control law for the agile satellite attitude control system. The feedback controller is formed by specially designed cascaded sub-units. The rapid dynamic response of the modified Bang Bang control logic achieves the near optimal property and ensures the non-saturation properties on three-axis. To improve the dynamic performance, a model reference control strategy is proposed, in which the oniline near optimal attitude maneuver path is generated by the cascade controller and is then tracked by a nonlinear back-stepping controller. Furthermore, the accuracy and the robustness of the control system are achieved by momentum-based on-line inertial identification. The rapid attitude maneuvering can be applied for tasks including the move to move case. Numerical simulations are conducted to verify the effectiveness of the proposed control strategy in terms of the saturation-free property and rapidness.

关键词： Actuator saturation Attitude control Identification Momentum transfer Satellites

Decoding brain responses to pixelized images in the primary visual cortex: implications for visual cortical prostheses

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Neural Regeneration Research 2015年第10期10卷 1622-1627页

作者： Bing-bing Guo Xiao-lin zheng zhen-gang Lu Xing Wang zheng-qin Yin Wen-sheng Hou Ming Meng Department of Biomedical Engineering Chongqing University Department of Psychological and Brain Sciences Dartmouth College Key Lab of Visual Damage and Regeneration & Restoration Third Military Medical University

Visual cortical prostheses have the potential to restore partial vision. Still limited by the low-resolution visual percepts provided by visual cortical prostheses, implant wearers can currently only ＂see＂ pixelized images, and how to obtain the specific brain responses to different pixelized images in the primary visual cortex（the implant area） is still unknown. We conducted a functional magnetic resonance imaging experiment on normal human participants to investigate the brain activation patterns in response to 18 different pixelized images. There were 100 voxels in the brain activation pattern that were selected from the primary visual cortex, and voxel size was 4 mm × 4 mm × 4 mm. Multi-voxel pattern analysis was used to test if these 18 different brain activation patterns were specific. We chose a Linear Support Vector Machine（LSVM） as the classifier in this study. The results showed that the classification accuracies of different brain activation patterns were significantly above chance level, which suggests that the classifier can successfully distinguish the brain activation patterns. Our results suggest that the specific brain activation patterns to different pixelized images can be obtained in the primary visual cortex using a 4 mm × 4 mm × 4 mm voxel size and a 100-voxel pattern.

关键词： nerve regeneration primary visual cortex electrical stimulation visual cortical prosthesis low resolution vision pixelized image functional magnetic resonance imaging voxel size neural regeneration brain activation pattern

Evidence-based appraisal in laparoscopic Nissen and Toupet fundoplications for gastroesophageal reflux disease

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World Journal of Gastroenterology 2010年第24期16卷 3063-3071页

作者： Shan, Cheng-Xiang Zhang, Wei zheng, Xiang-Min Jiang, Dao-zhen Liu, sheng Qiu, Ming Second Mil Med Univ Changzheng Hosp Dept Minimally Invas Surg Shanghai 200003 Peoples R China

AIM: To demonstrate the optimal surgical procedure for gastroesophageal reflux disease. METHODS: The electronic databases of Medline, Elsevier, Springerlink and Embase over the last 16 years were searched. All clinical trials involved in the outcomes of laparoscopic Nissen fundoplication (LNF) and laparoscopic Toupet fundoplication (LTF) were identified. The data of assessment in benefits and adverse results of LNF and LTF were extracted and compared using metaanalysis. RESULTS: We ultimately identified a total of 32 references reporting nine randomized controlled trials, eight prospective cohort trials and 15 retrospective trials. These studies reported a total of 6236 patients, of whom 4252 (68.18%) underwent LNF and 1984 (31.82%) underwent LTF. There were no differences between LNF and LTF in patients' satisfaction, perioperative complications, postoperative heartburn, refluxrecurrence and reoperation. Both LNF and LTF enhanced the function of lower esophageal sphincter and improved esophagitis. The postoperative dysphagia, gasbloating syndrome, inability to belch and the need for dilatation after LNF were more common than after LTF. Subgroup analyses showed that dysphagia after LNF and LTF was similar in patients with normal esophageal peristalsis (EP), but occurred more frequently in patients with weak EP after LNF than after LTF. Furthermore, patients with normal EP after LNF still had a higher risk of developing dysphagia than did patients with abnormal EP after ***: Compared with LNF, LTF offers equivalent symptom relief and reduces adverse results.

关键词： Laparoscopic fundoplication Nissen, Toupet Gastroesophageal reflux disease Antireflux surgery Esophageal peristalsis Metaanalysis

Transplantation of fetal liver epithelial progenitor cells ameliorates experimental liver fibrosis in mice

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World Journal of Gastroenterology 2006年第45期12卷 7292-7298页

作者： Jin-Fang zheng Li-Jian Liang Chang-Xiong Wu Jin-Song Chen zhen-sheng Zhang Department of Hepatobiliary Surgery the First Affiliated Hospital Sun Yat-Sen University Guangzhou 510080 Guangdong Province China Department of Hepatobiliary Surgery the People's Hospital of Hainan Province Haikou 570311 Hainan Province China

AIM： To investigate the effect of transplanted fetal liver epithelial progenitor （FLEP） cells on liver fibrosis in mice. METHODS： FLEP cells were isolated from embryonal day （ED） 14 BALB/c mice and transplanted into female syngenic BALB/c mice （n = 60）. After partial hepatectomy （PH）, diethylnitrosamine （DEN） was administered to induce liver fibrosis. Controls received FLEP cells and non-supplemented drinking water, the model group received DEN-spiked water, and the experimental group received FLEP cells and DEN. Mice were killed after 1, 2, and 3 mo, and alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, hyaluronic acid （HA）, and laminin （LN） in serum, and hydroxyproline （Hyp） content in liver were assessed. Alpha-smooth muscle actin （α-SMA） of liver was tested by immunohistochemistry. Transplanted male mice FLEP cells were identified by immunocytochemistry for sty （sex determination region for Y chromosome） protein. RESULTS： Serum ALT, AST, HA, and LN were markedly reduced by transplanted FLEP cells. Liver Hyp content and （α-SMA staining in mice receiving FLEP cells were lower than that of the model group, which was consistent with altered liver pathology. Transplanted cells proliferated and differentiated into hepatocytes and bile duct epithelial cells with 30%-50% repopulation in the liver fibrosis induced by DEN after 3 mo. CONCLUSION： Transplanted FLEP cells proliferate and differentiate into hepatocytes and bile duct epithelial cells with high repopulation capacity in the fiberized liver induced by DEN, which restores liver function and reduces liver fibrosis.

关键词： Fetal liver Epithelial progenitor cells Ce therapy Proliferation Liver fibrosis

Studies on the Quantitative Structure-activity Relationship of Toxicity of Chlorophenol Serial Compounds in the ab initio Methods and Substitutive Position of Chlorine Atom (N_(PCS))

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Chinese Journal of Structural Chemistry 2007年第8期26卷 933-938页

作者： zheng Qing WANG Lian-sheng Chemistry ＆ Bioengineering College Yancheng Institute of Technology Yancheng Jiangsu 224003 China School of the Environment Nanjing University Nanjing Jiangsu 210093 China

20 Quantum chemical parameters of chlorophenol compounds were fully optimized by using B3LYP method on both 6-31G^＊ and 6-311G^＊ basis sets. These structural parameters are taken as theoretical descriptors, and the experimental data of 20 compounds＇ aquatic photogen toxicity（-lgEC50） are used to perform stepwise regression in order to obtain two predicted -lgEC50 correlation models whose correlation coefficients R^2 are respectively 0.9186 and 0.9567. In addition, parameters of chlorine atom＇s substitutive positions and their correlations （NPCs） are taken as descriptors to obtain another predicted -lgEC50 model with the correlation coefficient R2 of 0.9444. Correlation degree of each independent variable in the three models is verified by using variance inflation factors （VIF） and t value. In the cross-validation method, cross-validation coefficients q^2 of 3 models are respectively 0.8748, 0.9119 and 0.8993, which indicates that the relativity and prediction ability of this model are superior to those of the model obtained by topological and BLYP methods.

关键词： chlorophenol toxicity (-lgEC50) linear dissolving energy theory density functional theory (DFT) substitutive position of chlorine atom (NPCS) QSAR

Biological effect and molecular mechanism study of biomaterials based on proteomic research

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Journal of Materials Science & Technology 2017年第7期33卷 607-615页

作者： zhen zhen Yufeng zheng Zigang Ge Chen Lai Tingfei Xi Academy for Advanced lnterdisdplinary Studies Peking University Beijing 100871 China

Along with the role transformation of biomaterials from bioinert substitute to regenerative inducer, the biological effect and mechanism of material-organism interaction become more important. Since most of animal tests and cellular experiments stay on the phenomenon description instead of mechanism interpretation, the development of proteomics technologies provides a golden opportunity to uncover the molecular interaction mechanism between biomaterial-organism on whole scale. This review summarizes current application of proteomics in biological effect and mechanism study of biomaterials, and discusses the development and challenges for future studies.

关键词： Proteomics Biomaterials Biological effect Molecular mechanism