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Actively tunable electromagnetically induced transparency in hybrid Dirac-VO2 metamaterials

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Optoelectronics Letters 2025年第1期21卷 13-20页

作者： DI Ke XIE Meng XIA Huarong CHENG Anyu LIU Yu DU Jiajia Department of Optoelectronic Engineering Chongqing University of Post and Telecommunications chongqing Key Laboratory of Autonomous Navigation and Microsystem Chongqing University of Posts and Telecommunications Department of Automation Chongqing University of Post and Telecommunications

In this paper, we present a metamaterial structure of Dirac and vanadium dioxide（VO2） and investigate its optical properties using the finite-difference time-domain（FDTD） technique. Using the phase transition feature of VO2, the design can realize active tuning of the plasmon induced transparency（PIT） effect at terahertz frequency, thereby converting from a single PIT to a double-PIT. When VO2is in the insulating state, the structure is symmetric to obtain a single-band PIT effect. When VO2is in the metallic state, the structure turns asymmetric to realize a dual-band PIT effect. This design provides a reference direction for the design of actively tunable metamaterials. Additionally, it is discovered that the transparent window's resonant frequency and the Fermi level in this structure have a somewhat linear relationship. In addition, the structure achieves superior refractive index sensitivity in the terahertz band, surpassing 1 THz/RIU. Consequently, the design exhibits encouraging potential for application in refractive index sensors and optical switches.

关键词： Transparency

Preparation of Nitrogen-doped TiO2 Nanoparticle Catalyst and Its Catalytic Activity under Visible Light

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Chinese Journal of Chemical Engineering 2007年第6期15卷 802-807页

作者：於煌郑旭煦殷钟意陶丰房蓓蓓侯苛山 College of Environment and Bioengineering Chongqing Technology and Business University Chongqing 400067China

N-doped TiO2 nanoparticle photocatalysts were prepared through a sol-gel procedure using NH4C1 as the nitrogen source and followed by calcination at certain temperature. Systematic studies for the preparation parameters and their impact on the structure and photocatalytic activity under ultraviolet （UV） and visible light irra-diation were carried out. Multiple techniques （XRD, TEM, DRIF, DSC, and XPS） were commanded to characterize the crystal structures and chemical binding of N-doped TiO2. Its photocatalytic activity was examined by the deg- radation of organic compounds. The catalytic activity of the prepared N-doped TiO2 nanoparticles under visible light （λ〉400nm） irradiation is evidenced by the decomposition of 4-chlorophenol, showing that nitrogen atoms in the N-doped TiO2 nanoparticle catalyst are responsible for the visible light catalytic activity. The N-doped TiO2 nanoparticle catalyst prepared with this modified route exhibits higher catalytic activity under UV irradiation in contrast to TiO2 without N-doping. It is suggested that the doped nitrogen here is located at the interstitial site of TiO2 lattice.

关键词： photocatalysis TiO2 visible light nitrogen-doping preparation

Identification and characterization of a gene encoding a UBX domain-containing protein in the migratory locust, Locusta migratoria manilensis

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Insect science 2013年第4期20卷 497-504页

作者： Zheng-Bo He Yu Xie Feng-Ling Si Bin Chen Institute of Entomology and Molecular Biology Chongqing Key Laboratory of Animal Biology College of Life Sciences Chongqing NormalUniversity Chongqing China

Ubiquitin regulatory X （UBX） domain-containing proteins are believed to func- tion as cofactors for p97/CDC48, an adenosine triphosphatase shown to be involved in mul- tiple cellular processes. In the present study, a full-length complementary DNA （cDNA） of UBX domain-containing gene, termed LmUBX1, was cloned from Locusta migratoria manilensis and characterized, using random amplification of cDNA ends polymerase chain reaction （RACE PCR）, sequence analysis and quantitative real-time PCR. LmUBX1, 1 600 bp in length, is predicted to encode a 446-amino acid protein with a predicted molec- ular weight of 51.18 kDa that contains a central PUB domain and a carboxy-terminal UBX domain. Homology analysis revealed that LmUBX1 has higher similarity to the known UBX domain-containing proteins from insects than from other species. Moreover, based on sequence characteristics and phylogenetic relationships, it is suggested that LmUBX1 can be classified into the UBXD1 subfamily. Expression analysis founded that LmUBX1 exhibited significant expression variations at different developmental stages and in differ- ent tissues, suggesting that the expression of LmUBX1 was highly regulated. Interestingly, its messenger RNA transcript was more abundant in ovary and testis than in other tissues examined, suggesting that it may have more important roles in the reproductive system. In addition, LmUBX1 was differentially expressed in gregarious and solitary locusts and was significantly up-regulated in third and fifth instars of gregarious locusts, implying that LmUBX1 was also likely involved in the phase polyphenisms in L. migratoria manilen- sis. To our knowledge, this is the first report of cloning of a full-length cDNA of UBX domain-containing gene from L. migratoria manilensis.

关键词： cloning expression Locusta migratoria manilensis UBX domain-containing protein

Effect of Host Plants on Development,Fecundity and Enzyme Activity of Spodoptera exigua (Hübner)(Lepidoptera:Noctuidae)

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Agricultural sciences in China 2011年第8期10卷 1232-1240页

作者： ZHANG Bin LIU Huai Helen Hull-Sanders WANG Jin-jun chongqing Key Laboratory of Entomology and Pest Control Engineering Southwest UniversityChongqing 400716P.R.China chongqing Tobacco Company China National Tobacco CorporationChongqing 400023P.R.China

The beet armyworm,Spodoptera exigua （Lepidoptera：Noctuidae）,is an economically important pest of crops worldwide,attacking plants from over 20 families including trans-continental agricultural cotton,corn and citrus *** this study,performance and subsequent enzyme activity of beet armyworm reared on host plants from five families were *** differences were found in development,fecundity and enzyme activity on different host *** rate was the highest （42.8%） on asparagus lettuce （Lactuca sativar ***） and the lowest （17.0%） on sweet pepper （Capsicum annuum）.Larval duration was the shortest on asparagus lettuce （12.0 d）,and was 43.4% longer on sweet peppers （21.2 d）.The activity of acetylcholine esterase （AChE） and carboxylesterase （CarE） in 3rd instar larvae,and soluble carbohydrate and crude protein contents in different host plants were *** activity was the highest in the larvae feeding on Chinese cabbage （Brassica rapa）,but declined by nearly 60% on maize （Zea mays） *** ratio of soluble carbohydrate content to crude protein content in host plants was found to have a positive effect on oviposition and a negative correlation with larval duration and life time （from larval to adult stages） of the insect.

关键词： beet armyworm Spodoptera exigua host plants nutrition enzyme activity

Thermodynamic database of the phase diagrams in the Mg-Al-Zn-Y-Ce system

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Rare Metals 2006年第5期25卷 441-447页

作者： LIU Xingjun WANG Cuiping WEN Mingzhong CHEN Xing PAN Fusheng Department of Materials science and Engineering Xiamen University Xiamen 361005 China College of Materials science and Engineering Chongqing University Chongqing 400045 China

The Mg-Al-Zn-Y-Ce system is one of the key systems for designing high-strength Mg alloys. The purpose of the present article is to develop a thermodynamic database for the Mg-Al-Zn-Y-Ce multicomponent system to design Mg alloys using the calculation of phase diagrams （CALPHAD） method, where the Gibbs energies of solution phases such as liquid, fcc, bcc, and hcp phases were described by the subregular solution model, whereas those of all the compounds were described by the sublattice model. The thermodynamic parameters describing Gibbs energies of the different phases in this database were evaluated by fitting the experimental data for phase equilibria and thermodynamic properties. On the basis of this database, a lot of information concerning stable and metastable phase equilibria of isothermal and vertical sections, molar fractions of constituent phases, the liquidus projection, etc., can be predicted. This database is expected to play an important role in the design of Mg alloys.

关键词： thermodynamic database CALPHAD method phase diagram Mg-Al-Zn-Y-Ce system magnesium alloys

Preparation of high acidity coefficient slag wool fiber with blast furnace slag and modifying agents

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Journal of Iron and Steel Research International 2023年第7期30卷 1440-1450页

作者： Wen-chao He Ming-shuai Luo Yin Deng Yue-lin Qin Shuo Zhang Xue-wei Lv Yong Zhao Cheng-zhe Jiang Zheng-de Pang School of Metallurgy and Materials Engineering Chongqing University of Science and TechnologyChongqing 400044China College of Materials science and Engineering Chongqing UniversityChongqing 400044China Environmental Resources technology Co. Ltd.Baowu GroupShanghai 201999China

Preparation of high acidity coefficient slag wool fiber with molten slag and modifying agents is considered to be a positive approach for value-added utilization of blast furnace slag. In order to achieve the multi-purposes of fiber-forming, energy saving, and waste heat recovery, the modifying agents that can improve the acidity coefficient of slag effectively, economically, and environmentally were investigated. Three agents with different acidity coefficients were adopted to modify slag and manufacture wool fibers. The effect of agent and slag proportion on the melting temperature and viscosity of molten slag was studied at a fixed acidity coefficient of 1.8 and 2.0. The results indicate that the sample modified with high acidity coefficient agent and high slag proportion has lower melting temperature and viscosity. The effect of agent and slag temperature on the fiber diameter was also investigated when the acidity coefficient of slag is 2.0. At a fixed slag proportion of 50 wt.%, the mean diameter decreases with increasing temperature and decreasing viscosity coefficient. Besides, the temperature drops caused by the addition of agents and energy consumption of samples for heating the slag were also analyzed.

关键词： Blast furnace slag Slag wool fiber High acidity coefficient Modifying agent Slag proportion

Emphasizing Essential Words for Sentiment Classification Based onRecurrent Neural Networks

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Journal of Computer science & technology 2017年第4期32卷 785-795页

作者： Fei Hu Li Li Zi-Li Zhang Jing-Yuan Wang Xiao-Fei Xu College of Computer and Information science Southwest University Chongqing 400715 China Network Centre Chongqing University of Education Chongqing 400065 China

With the explosion of online communication and publication, texts become obtainable via forums, chat messages, blogs, book reviews and movie reviews. Usually, these texts are much short and noisy without sufficient statistical signals and enough information for a good semantic analysis. Traditional natural language processing methods such as Bow-of-Word (BOW) based probabilistic latent semantic models fail to achieve high performance due to the short text environment. Recent researches have focused on the correlations between words, i.e., term dependencies, which could be helpful for mining latent semantics hidden in short texts and help people to understand them. Long short-term memory (LSTM) network can capture term dependencies and is able to remember the information for long periods of time. LSTM has been widely used and has obtained promising results in variants of problems of understanding latent semantics of texts. At the same time, by analyzing the texts, we find that a number of keywords contribute greatly to the semantics of the texts. In this paper, we establish a keyword vocabulary and propose an LSTM-based model that is sensitive to the words in the vocabulary; hence, the keywords leverage the semantics of the full document. The proposed model is evaluated in a short-text sentiment analysis task on two datasets: IMDB and SemEval-2016, respectively. Experimental results demonstrate that our model outperforms the baseline LSTM by 1%similar to 2% in terms of accuracy and is effective with significant performance enhancement over several non-recurrent neural network latent semantic models (especially in dealing with short texts). We also incorporate the idea into a variant of LSTM named the gated recurrent unit (GRU) model and achieve good performance, which proves that our method is general enough to improve different deep learning models.

关键词： short text understanding long short-term memory (LSTM) gated recurrent unit (GRU) sentiment classification deep learning

Influence of impurities on damping properties of ZK60 magnesium alloy

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Transactions of Nonferrous Metals Society of China 2010年第7期20卷 1305-1310页

作者：陈先华毛建军潘复生彭建王敬丰 College of Materials science and Engineering Chongqing University National Engineering Research Center for Magnesium Alloys Chongqing University

The influence of impurities on damping capacities of ZK60 magnesium alloys in the as-cast,as-extruded and T4-treated states was investigated by dynamically mechanical analyzer at room *** and Lucke dislocation pinning model was employed to explain damping properties of the *** is found that reducing impurity content can decrease the amount of second-phase particles,increase grain size and improve damping capacity of the as-cast alloy *** as-extruded alloy with lower impurity content is found to possess obviously higher damping capacity in the relatively high strain region than that with higher impurity concentration,which appears to originate mainly from different dislocation *** variation tendency of damping property with change of impurity content after solution-treatment is also similar to that in the as-extruded and as-cast states. Meanwhile,the purification of the alloy results in an evident improvement in tensile yield strength in the as-extruded state.

关键词： ZK60 magnesium alloy impurities damping dislocation

Preemptive and non-preemptive scheduling of optical switches with configuration delay

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science in China(Series F) 2006年第5期49卷 653-664页

作者： ZHANG Zhizhong CHENG Fang LUO Jiangtao MAO Qijian WANG Jun QIU Shaofeng Department of Communication Engineering Chongqing University of Posts and Telecommunications Chongqing 400065 China

Utilizing optical technologies for the design of packet switches and routers offers several advantages in terms of scalability, high bandwidth, power consumption, and cost. However, the configuration delays of optical crossbars are much longer than that of the electronic counterpart, which makes the conventional slot-by-slot scheduling methods no longer the feasible solution. Therefore, some tradeoff must be found between the empty time slots and configuration overhead. This paper classifies such scheduling problems into preemptive and non-preemptive scenarios, each has its own advantages and disadvantages. Although non-preemptive scheduling is inherently not good at achieving the above-mentioned tradeoff, it is shown, however, that the proposed maximum weight matching （MWM） based greedy algorithm is guaranteed to achieve an approximation 2 for arbitrary configuration delay, and with a relatively low time complexity O（N^2）. For preemptive scheduling, a novel 2-approximation heuristic is presented. Each time in finding a switch configuration, the 2-approximation heuristic guarantees the covering cost of the remaining traffic matrix to have 2-approximation. Simulation results demonstrate that 2-approximation heuristic （1） performs close to the optimal scheduling, and （2） outperforms ADJUST and DOUBLE in terms of traffic transmission delay and time complexity.

关键词： optical switches scheduling configuration delay.