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Photo-induced Alignment Behavior of Azobenzene-containing Polymer Films with Different Cross-linking Degree

Chinese Journal of Chemical Physics 2008年第5期21卷 493-499页

作者： Jing Shena Jin-tang Huang Yan-hua Luoa qi-jin Zhang ke-yi Wang CAS key Laboratory of Soft Matter Chemistry Department of Polymer Science and Engineering Key Laboratory of Optoelectronic Science and Technology Anhui Province University of Science and Technology of China Hefei 230025 China Department of Precision Machinery and Precision Instrumentation University of Science and Tech- nology of China Hefei 230025 China

Three series of amorphous copolymers containing azobenzene groups with various substituents and certain amounts of crosslinkable acrylic groups were prepared. The cross-linked polymer films were obtained by thermal polymerization of the acrylic groups in the copolymers, during which, by controlling the time of cross-linking reaction, the films can be made with different cross-linking degree （from 0 to 32%, which was monitored by FT-IR spectra measurement）. Photo-induced alignment process of the films was performed under irradiation with linearly polarized light at 442 nm, and the effect of cross-linking degree on the photo-induced alignment rate was investigated. The dynamics of the photo-induced alignment was analyzed with biexponential curve fitting. The photo-induced alignment rate and the maximum transmittance of the films decreased because of the cross-linking. Furthermore, for the cross-linked samples, it was found that their saturated value of transmittances keep constant after repeated ＂writing＂ and ＂erasing＂ cycles. The findings reveal that the cross-linking of the film can effectively restrain the phototactic mass transport of azopolymer during irradiation by polarized light. The relationship between the cross-linking degree and the photo-induced alignment behavior of azopolymer is discussed in detail.

关键词： Azo polymer Cross-linking Photo-induced alignment Mass transport

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Illuminating Recommendation by Understanding the Explicit Item Relations

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Journal of Computer Science & Technology 2018年第4期33卷 739-755页

作者： qi Liu Hong-ke Zhao Le Wu Zhi Li En-Hong Chen Anhui Province key Laboratory of Big Data Analysis and Application University of Science and Technology of China Hefei 230027 China School of Computer and Information Hefei University of Technology Hefei 230009 China School of Software Engineering University of Science and Technology of China Hefei 230051 China

Recent years have witnessed the prevalence of recommender systems in various fields, which provide a personalized recommendation list for each user based on various kinds of information. For quite a long time, most researchers have been pursing recommendation performances with predefined metrics, e.g., accuracy. However, in real-world applications, users select items from a huge item list by considering their internal personalized demand and external constraints. Thus, we argue that explicitly modeling the complex relations among items under domain-specific applications is an indispensable part for enhancing the recommendations. Actually, in this area, researchers have done some work to understand the item relations gradually from ＂implicit＂ to ＂explicit＂ views when recommending. To this end, in this paper, we conduct a survey of these recent advances on recommender systems from the perspective of the explicit item relation understanding. We organize these relevant studies from three types of item relations, i.e., combination-effect relations, sequence-dependence relations, and external-constraint relations. Specifically, the combination-effect relation and the sequence-dependence relation based work models the intra-group intrinsic relations of items from the user demand perspective, and the external-constraint relation emphasizes the external requirements for items. After that, we also propose our opinions on the open issues along the line of understanding item relations and suggest some future research directions in recommendation area.

关键词： recommender system item relation recommendation interpretability

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Evaluating population exposure to N,N-dimethylformamide in as mall industrial area accounting for population movement

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第10期12卷 794-806页

作者： Yu-mei WEI Wei-li TIAN qing-yu ZHANG Ying-yue zheng Yi-ke YANG Zu-cheng WU qi ZHU Lei ZHOU Si-mai FANG Department of Environmental Engineering Zhejiang University Hangzhou 310027 China Zhejiang Provincial Engineering Research Center of Industrial Boiler ＆ Furnace Flue Gas Pollution Control Hangzhou 311202 China Management Office of the New Rural Cooperative Medical Service Longwan District Health Bureau Wenzhou 325011 China Department of Information Management University of International Business and Economics Beijing 100029 China

Population exposure to pollutants is important for studies on the exposure-response relationship. However, it is difficult to evaluate population exposure to non-conventional pollutants due to limited data on concentration levels and the movement patterns of inhabitants. In this study, an air dispersion model was used to simulate N, N-dimethylformarnide （DMF） concentrations, as a proxy to monitoring concentrations. A total of 1289 randomly selected household representatives were surveyed to obtain information on movement characteristics. Subsequently, population movement patterns were combined with DMF concentration levels on maps of 100 m× 100 m resolution to calculate population exposure. During 2008, the estimated population exposure to DMF ranged from 0.002 to 0.64 mg/m^3. The highest level of population exposure to DMF was found in the north and northwest sub-districts of the study area, ranging from 0.42 to 0.64 mg/m^3. The population exposure to DMF for different occupational groups indicated that retired people and farmers were vulnerable subpopulations among people highly exposed to DME This was mainly because they spent most time at home where the DMF concentration was high. As pollutant concentrations were divided into small grids, we found that exposure levels were substantially impacted by population movement characteristics.

关键词： Volatile organic compound Dispersion model Concentration distribution Movement characteristics Longwan

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大学生“蹲考族”现象研究:理性人假设的视角

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广西师范大学学报（哲学社会科学版） 2025年第1期61卷 72-84页

作者：吴克明欧阳奥琪冯帮湖南师范大学教育科学学院湖南长沙410081 广东技术师范大学教育科学学院广东广州510665

近年来,大学生就业形势日益严峻,越来越多的失业大学生选择了“蹲考”。访谈和问卷调查发现,蹲考族表现为以自愿性蹲考为主、获得家庭支持、期望到体制内单位和大城市或家乡城市就业等特征。从理性人假设的角度来看,蹲考族现象的原因在... 详细信息

近年来,大学生就业形势日益严峻,越来越多的失业大学生选择了“蹲考”。访谈和问卷调查发现,蹲考族表现为以自愿性蹲考为主、获得家庭支持、期望到体制内单位和大城市或家乡城市就业等特征。从理性人假设的角度来看,蹲考族现象的原因在于蹲考的预期收益大于预期成本。严峻的就业形势降低了蹲考的机会成本,家庭的支持增强了蹲考族对经济成本和心理成本的承受能力;蹲考的预期收益包括更多的就业机会和更高的就业质量。蹲考是失业大学生为了实现预期收益最大化的理性选择,是一种人力资本投资行为,体现了一种自立自强的奋斗精神和人生态度,无法也无必要完全消除。应对蹲考族现象的解决思路在于:提高其考试成功概率,提高大学生就业率和就业质量。

关键词：蹲考族理性人假设预期收益预期成本人力资本投资大学生就业代际流动

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UV-triggered Polymerization of Polyelectrolyte Composite Coating with Pore Formation and Lubricant Infusion

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Chinese Journal of Polymer Science 2023年第3期41卷 365-372,I0004,I0006页

作者： Jia-qi Hu Wei-Pin Huang Jing Wang ke-Feng Ren Jian Ji MOE key Laboratory of Macromolecular Synthesis and Functionalization International Research Center for X PolymersDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

Porous coatings with the features of muti-interfaces and high specific surface area have emerged as an excellent material platform for the manipulation of porous ***-by-layer(Lb L)assembly technique has been widely used in preparing porous polyelectrolyte ***,the efficient construction of stable film from the Lb L technique is still a ***,we reported a new solution to construct a stabilized polyelectrolyte coating with porous *** by the mechanical reinforcement of double-network hydrogel,we constructed the poly(ethylenimine)(PEI)/poly(acrylic acid)(PAA)coating by in situ photopolymerization of acrylic acid in the PEI network instead of assembling PEI and *** with the Lb L films,the in situ polymerized coating kept higher stability after 30 iterations of *** structures could also be constructed after acid treatment,which was utilized to load lubricant to enhance the lubricating property of the *** work provides a new method for the construction of dynamic and stable polyelectrolyte coatings,expediting more development of practical applications.

关键词： Porous coating Polyelectrolyte coating Dip-coating UV-triggered polymerization Stability

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Magnetic properties and anomalous Hall effect of Mn3Sn thin films controlled by defects and ferroelectric 0.7Pb(Mg_(1/3)Nb_(2/3))O_(3)–0.3PbTiO_(3) substrate

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Rare Metals 2021年第10期40卷 2862-2867页

作者： Zhong-Ping Zhao qi Guo Feng-Hua Chen ke-Wei Zhang Yong Jiang School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China

Noncollinear antiferromagnetic Mn_(3)Sn films have received much attention due to their potential applications in antiferromagnetic spintronic devices. In this work, single-phase polycrystalline antiferromagnetic Mn_(3)Sn thin films were successfully prepared by magnetron sputtering. The defects in the thin films were regulated by adjusting the sputtering power. The relationship among the films structure, the anomalous Hall effect(AHE) and the defects was investigated. High defect concentration in the Mn_(3)Sn films led to large room temperature ferromagnetic moments. The maximum saturation magnetization reached up to ~16 k A·m^(-1)(36 mlB/Mn), which was much larger than the values reported in literatures. The coercive field of38 mT was obtained in a high-quality Mn_(3)Sn film, which effectively reduced the flipping magnetic field. Moreover,the anomalous Hall resistance and coercive field of the Mn_(3)Sn films prepared on the ferroelectric substrates were manipulated through an applied electric field, indicating that the piezoelectric stress has a great influence on the nonzero Berry curvature of the triangular spin structure in the antiferromagnetic materials. These results will promote the potential application of Mn_(3)Sn in high-density and lowpower antiferromagnetic spintronic devices.

关键词： Noncollinear antiferromagnet Mn_(3)Sn Anomalous Hall effect Ferromagnetic moment Electric field manipulation

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Sequential Experiment Design Method Based on Uniformity and Distortion of Responses

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Acta Mathematicae Applicatae Sinica 2023年第3期39卷 778-790页

作者： qian-yi HUANG Liang-wei qi Jing-ke ZHANG Yu TANG State key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System(CEMEE) Luoyang 471003China School of Mathematical Sciences Soochow UniversitySuzhou 215006China

With the development of modern electronic countermeasure technology,the fight between radar jamming and anti-jamming in aviation military has become increasingly *** are some special requirements for radar countermeasure *** example,such experiments are often divided into several stages,and responses of the previous stages will become factors of the next ***,the experiment design can only consider some typical level values of the ***,the experiment factors are mostly continuous *** when there are some jumps in the response,and the value granularity of the factor level is large,the responses fail to reflect the distortion process,which makes it difficult to explore the radar performance ***,it is necessary to study the sequential experiment design method with the optimization goals of response uniformization and response distortion process *** this paper,a sequential experiment design strategy based on Kriging model is ***,Kriging model is used to fit the initial experimental data to obtain the response *** order to enhance the uniformity of response distribution,Shannon entropy is applied to the objective function as the measure of *** for the situation of response distortion,we consider replacing the existing experiment points with those whose corresponding responses have a larger gradient *** means that the response value near these points will change rapidly,so they are more valuable for *** we use the peak surface in the three-dimensional space to intuitively verify the effect of the above algorithms on response uniformization and response distortion process characterization,and use the simulated annealing algorithm to solve *** simulation results show that our sequential experiment strategy has a good ***,we apply the strategy to the practical problem of radar countermeasure experiment,and the obtained results

关键词： radar countermeasure experiments response distortion sequential experiment uniform distribution

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Obtaining tetragonal FeAs layer and superconducting K_(x)Fe_(2)As_(2)by molecular beam epitaxy

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Nano Research 2023年第2期16卷 3040-3045页

作者： Cui Ding Yuanzhao Li Shuaihua Ji ke He Lili Wang qi-Kun Xue State key Laboratory of Low-Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China Beijing Academy of Quantum Information Sciences Beijing 100193China Collaborative Innovation Center of Quantum Matter Beijing 100084China Department of Physics Southern University of Science and TechnologyShenzhen 518055China

Atomic characterization on tetragonal FeAs layer and engineering FeAs superlattices is highly desirable to get deep insight into the multi-band superconductivity in *** fabricate the tetragonal FeAs layer by topotactic reaction of FeTe films with arsenic and then obtain KxFe_(2)As_(2)upon potassium intercalation using molecular beam *** in-situ low-temperature√2×√2scanning tunneling microscopy/spectroscopy investigations demonstrate characteristic reconstruction of the FeAs layer and stripe pattern of KxFe_(2)As_(2),accompanied by the development of a superconducting-like *** ex-situ transport measurement with FeTe capping layers shows a superconducting transition with an onset temperature of 10 *** work provides a promising way to characterize the FeAs layer directly and explore rich emergent physics with epitaxial superlattice design.

关键词： tetragonal FeAs KxFe_(2)As_(2) interface enhanced superconductivity topotactic reaction molecular beam epitaxy

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基于自研光谱仪的痕量气体光解速率测量研究

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光谱学与光谱分析 2025年第1期45卷 15-23页

作者：李浩然曾议朱磊窦科刘志宏常振江宇司福祺中国科学院合肥物质科学研究院安徽光学精密机械研究所环境科学与技术重点实验室安徽合肥230031 中国科学技术大学科学岛分院安徽合肥230026 合肥大学生物食品与环境学院安徽合肥230601

光解速率及其测量技术最早由德国科学家提出,21世纪初Metcon公司开发了光解速率测量仪,该技术在国内得到关注,部分高校和公司对光解速率测量系统开展了研究和开发。国外产品一般体积较大,价格昂贵。国内产品中光谱仪、接收器等核心器件... 详细信息

光解速率及其测量技术最早由德国科学家提出,21世纪初Metcon公司开发了光解速率测量仪,该技术在国内得到关注,部分高校和公司对光解速率测量系统开展了研究和开发。国外产品一般体积较大,价格昂贵。国内产品中光谱仪、接收器等核心器件仍依赖于国外进口,易受国外技术封锁影响。在我国“十四五”国家重点研发计划中“大气与土壤、地下水污染综合治理”重点专项对化学气候综合站检测技术与装备需求引导下,研制了测量大气物质光解速率的光谱仪系统,并满足其核心部件国产化的要求。系统采用自主设计的小型光谱仪作为核心部件,配合各向均匀响应的光学接收器,经实验室光学定标后测得各种物质的光解速率。该系统工作波段为285~430 nm,时间分辨率可达0.1 s,可测物质包括NO_(2)、HONO、HCHO、H_(2)O_(2)等,与国外进口测量仪器对比,各气体物质光解速率的测量误差小于5%,相关性均超过0.93。采用该系统在合肥市董铺岛对大气中气体光解速率开展了长时间的连续监测。对NO_(2)光解速率变化趋势以及NO_(2)光解速率与浓度间的相关性进行分析,发现光解反应与驱动光化反应的能量密切相关,晴天的光解速率数值明显高于阴天与雨天。发现NO_(2)光解速率与浓度的积分曲线间存在一种经验公式,相关性大于0.9,可通过测量NO_(2)光解速率对NO_(2)浓度的累积量进行估计。该系统实现了核心部件的国产化,整体结构简单、便携,方便外场试验安装的同时,降低成本,提高经济性。研究为大气污染综合监测治理提供数据支撑,对各地区的环境监测及污染预防具有参考意义。

关键词：光解速率光谱仪辐亮度光学接收器

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Effects of torsion charge on optical appearance and additional photon rings of an asymmetric thin-shell wormhole

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Chinese Physics C 2024年第11期48卷 138-148页

作者： qi-qin Jing ke-Jian He Zhi Luo Sichuan Province Beichuan High School Beichuan 622750China Department of Mechanics Chongqing Jiaotong UniversityChongqing 400074China Department of Physics Chongqing UniversityChongqing 401331China

In this paper,we study the optical properties of asymmetric thin-shell wormholes(ATWs)under torsion *** the cut-and-paste method developed by Visser,we construct these wormholes and determine their key physical properties,such as the radius of the photon sphere and critical impact parameters,under different torsion ***,we investigate the effective potential and behavior of photon motion within the wormhole spacetime,identifying a relationship between photon trajectories and impact *** study focuses on scenarios where thin accretion disks act as the primary light *** reveals that the optical features of ATWs under torsion charge significantly differ from those of black holes(BHs).Notably,an increase in torsion charge leads to a reduction in the sizes of both extra photon rings and lensing bands,which serve as important markers for distinguishing and characterizing ATW spacetimes from those of BHs.

关键词： asymmetric thin-shell wormhole torsion charge additional photon ring

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