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Ab initio Study on Structures and Isomerization of Magnesium Fluorosilylenoid H2SiFMgF

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Chinese Journal of Chemical Physics 2008年第6期21卷 541-546页

作者： Yi-jian Zhang Mei-jiang Li Guo-qiao Lai da-cheng feng Sheng-yu feng Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education Hangzhou Normal University Hangzhou 310012 China School of Chemistry and Chemical Engineering Shandong University Ji'nan 250100 China

The structures and isomerization of magnesium fluorosilylenoid H2SiFMgF were investigated by ab initio molecular orbital theory. Four equilibrium structures and three isomeric transition states were located and fully optimized at the B3LYP/6-31G（d,p） and G3MP2B3 levels, respectively. Based on the B3LYP/6- 31G（d,p） optimized geometries, harmonic frequencies of various structures were obtained and 29Si chemical shifts were calculated. The solvent effects were investigated by means of the polarizable continuum model using THF as a solvent at B3LYP/6-31G（d,p） level. Isomerization paths for isomers were confirmed by intrinsic reaction coordinate calculations. The calculated results show that tetrahedral structure has the lowest energy and is the most stable; tetrahedral, three-membered ring, and p-complex structures are suggested to be the experimentally detectable ones; and a-complex structure has the highest energy and will not exist.

关键词： Magnesium fluorosilylenoid Ab initio calculation B3LYP/6-31G(d p) theory Isomerization

An on-line multi-parameter analyzing optical biosensor for real-time and non-invasive monitoring of plant stress responses in vivo

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Chinese Science Bulletin 2009年第21期54卷 4009-4016页

作者： ZHANG LingRui XING da WEN feng MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science South China Normal University Guangzhou 510631China

Photosynthetic dysfunction and reactive oxygen species (ROS) production are the common features of plant stress responses. Based on quantitative measurement of ROS production and delayed fluorescence (DF) emission, which is an excellent marker for evaluating photosynthesis, an on-line multiparameter analyzing optical biosensor for detecting plant stress responses was developed. Performances of the proposed biosensor were tested in the wild type (WT) Arabidopsis and heat shock protein (Hsp) 101 T-DNA knockout mutant (hsp101) plants with different thermotolerance. Results demonstrated that DF intensity correlates with net photosynthesis rate (Pn) in response to elevated temperature in both the WT Arabidopsis and hsp101 mutant plants. The light response characteristics and the recovery dynamics of the DF intensity were also in line with those of Pn in both the WT Arabidopsis and hsp101 mutant plants after heat stress (HS, 40℃ for 30 min), respectively. In all experiments discussed above, the hsp101 plant showed the worse photosynthetic performance than the WT plant. Moreover, after HS, more ROS production in the hsp101 mutant than in WT Arabidopsis, which was found to be mainly localized at chloroplasts, could be directly detected by using the proposed biosensor. In addition, the hsp101 mutant showed severer chloroplasts alterations than the WT plant within the first 1 h of recovery following HS. Nevertheless, pre-infiltration with catalase (CAT) reduced ROS production and prevented the declines of the DF intensity. Therefore, HS-caused declines of photosynthetic performance might be due to oxidative damage to photosynthetic organelle. To sum up, we conclude that Hsp101 plays an important role in preventing oxidative stress, and the proposed optical biosensor might be a powerful tool to determine plant stress responses and identify plant resistant difference.

关键词：光学传感器多参数分析应激反应侵入性监测植物实时体内

ROCK inhibition enhances neurite outgrowth in neural stem cells by upregulating YAP expression in vitro

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Neural Regeneration Research 2016年第6期11卷 983-987页

作者： Xu-feng Jia Fei Ye Yan-bo Wang da-xiong feng Department of Orthopedic Surgery Jianyang People's Hospital of Sichuan Province lianyang Sichuan Province China Department of Spine Surgery the Affiliated Hospital of Southwest Medical University Luzhou Sichuan Province China

Spontaneous axonal regeneration of neurons does not occur after spinal cord injury because of inhibition by myelin and other inhibitory factors. Studies have demonstrated that blocking the Rho/Rho-kinase （ROCK） pathway can promote neurite outgrowth in spinal cord injury models. In the present study, we investigated neurite outgrowth and neuronal differentiation in neural stem cells from the mouse subventricular zone after inhibition of ROCK in vitro. Inhibition of ROCK with Y-27632 increased neurite length, enhanced neuronal differentiation, and upregulated the expression of two major signaling pathway effectors, phospho-Akt and phospho-mitogen-activated protein kinase, and the Hippo pathway effector YAP. These results suggest that inhibition of ROCK mediates neurite outgrowth in neural stem cells by activating the Hippo signaling pathway.

关键词： nerve regeneration spinal cord injury neural stem cells Rho signalingpathway neurite outgrowth myelin YAP neural regeneration

Theoretical Study of the Scattering Resonance State, Reaction Mechanism and Partial Potential Energy Surface of the F+CH4→HF+CH3 Reaction

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Chinese Chemical Letters 2006年第2期17卷 281-284页

作者： Qiang WANG Zheng Ting CAI da Cheng feng Institute of Theoretical Chemistry Shandong University Jinan 250100

The partial potential energy surface was constructed by ab initio method [QCISD（T）/6- 311＋＋G（2df,2pd）]for F＋CH4→HF＋CH3 reaction system. It not only explained the reaction mechanism brought forward by Diego Troya by means of quasiclassical trajectory （QCT） but also successfully validated Kopin Liu＇s experimental phenomena about the existence of the reactive resonance. The lifetime of the scattering resonance state was about 0.07 ps. All these were in agreement with the experiments.

关键词： The partial potential energy surface (PPES) asymmetrical heavy-light-heavy system dynamic Eyring lake the lifetime of the scattering resonance state.

Learning to select pseudo labels: a semi-supervisedmethod for named entity recognition

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Frontiers of Information Technology & Electronic Engineering 2020年第6期21卷 903-916页

作者： Zhen-zhen LI da-wei feng Dong-sheng LI Xi-cheng LU College of Computer National University of Defense TechnologyChangsha 410073China

Deep learning models have achieved state-of-the-art performance in named entity recognition(NER);the good performance,however,relies heavily on substantial amounts of labeled *** some specific areas such as medical,financial,and military domains,labeled data is very scarce,while unlabeled data is readily *** studies have used unlabeled data to enrich word representations,but a large amount of entity information in unlabeled data is neglected,which may be beneficial to the NER *** this study,we propose a semi-supervised method for NER tasks,which learns to create high-quality labeled data by applying a pre-trained module to filter out erroneous pseudo *** labels are automatically generated for unlabeled data and used as if they were true *** semi-supervised framework includes three steps:constructing an optimal single neural model for a specific NER task,learning a module that evaluates pseudo labels,and creating new labeled data and improving the NER model *** results on two English NER tasks and one Chinese clinical NER task demonstrate that our method further improves the performance of the best single neural *** when we use only pre-trained static word embeddings and do not rely on any external knowledge,our method achieves comparable performance to those state-of-the-art models on the CoNLL-2003 and OntoNotes 5.0 English NER tasks.

关键词： Named entity recognition Unlabeled data Deep learning Semi-supervised method

Syntheses and Crystal Structures of Four New Complexes [Mn(4,4′-bip)_2(OH_2)_4](DBA)·4H_2O and [M(OH_2)(HDPA)_2]·3H_2O (M = Mn,Co,Ni)

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Chinese Journal of Structural Chemistry 2006年第8期25卷 895-902页

作者： LIU Ying DOU Jian-Min WANG da-Qi LI da-Cheng XU feng ZHOU Lei SU Huai-Jing College of Chemistry and Chemical Engineering Liaocheng University 252059 China

Four new transition metal complexes, [Mn（4,4′-bip）2（OH2）4]（DBA）-4H2O 1 （4,4′-hip = 4,4′-bipyridine, H2DBA = benzene-1,3-dicarboxylic acid） and [M（OH2）（HDPA）2]-3H2O （M = Mn 2, M = Co 3, M = Ni 4, H2DPA = 2,6-pyridine-dicarboxylic acid）, have been prepared from the reaction of transition metals and carboxylic acids, and characterized by X-ray and elemental analyses. For compound 1, the packing diagram shows that a three-dimensional network is formed via hydrogen bonds and strong π-πinteractions. For compounds 2, 3 and 4, a double-helical chain is formed through hydrogen bonds. Moreover, a three-dimensional network is constructed from chains via complicated hydrogen bonds between crystal water molecules and oxygen atoms of HDPA^-.

关键词： manganese cobalt nickel 4,4′-bipyridine benzene-1,3-dicarboxylic acid 2,6-pyridine-dicarboxylic acid X-ray analysis

Synthesis, Structure, and Magnetic Properties of One Polyoxometalate (W/Mo) Compound: H_8K{[Ni(H_2O)_5]_2(H_2Mo_(1.80)W_(10.20)O_(42))}Cl_3·16H_2O

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Chinese Journal of Structural Chemistry 2007年第5期26卷 599-605页

作者： LIU Ying DOU Jian-Min WANG da-Qi ZHANG Xian-Xi LI da-Cheng XU feng ZHOU Lei College of Chemistry and Chemical Engineering Liaocheng University Liaocheng 252059 China

One new polyoxometalate compound connected via nickel/potassium cations, H8K{[Ni（H2O）5]2（H2Mo1.80W10.20O42）}Cl3·16H2O 1, was prepared and characterized by elemental analysis and IR spectroscopy. Single-crystal X-ray diffraction analysis results reveal that clusters of [Ni（H2O）5]2（H2Mo1.80W10.20O42）}^6-in compound 1 are linked by potassium cations to form one- dimiensional chains, based on which a three-dimensional network is further constructed via the hydrogen bonds of O…O and O…Cl. Magnetic measurements show that compound 1 has paramagnetic properties. Crystal data： H62Cl3KMo1.80Ni2O68W10.20, Mr = 3461.33, monoclinic, space group C2/c, a = 18.9291（19）, b = 16.6758（17）, c = 19.1064（19）A, β = 106.6880（10）°, V = 5777.1（10）A^3, Z = 4, Dc = 3.980 g/cm^3, F（000） = 6250, μ = 21.574 mm^-1, R = 0.0579 and wR = 0.1623 （Ⅰ 〉 2σ（Ⅰ））.

关键词： polyoxomolybdate molybdate nickel sodium X-ray analysis magnetic

The Efficiency Improvement of Blue InGaN Multiple Quantum-Well Light-Emitting Diodes with AlGaN/InGaN Superlattice Barriers

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Chinese Physics Letters 2013年第3期30卷 198-200页

作者： LUO da-feng CHEN Cui-Ping PENG Ju School of Science Nantong UniversityNantong 226019

The characteristics of blue InGaN light emitting diodes with AlGaN/InGaN superlattice barriers are *** efficiency droop can be improved when AlGaN/InGaN superlattice barriers are *** improvement can be attributed to t... 详细信息

关键词： AlGaN polarization Efficiency

Deep reinforcement learning:a survey

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Frontiers of Information Technology & Electronic Engineering 2020年第12期21卷 1726-1744页

作者： Hao-nan WANG Ning LIU Yi-yun ZHANG da-wei feng feng HUANG Dong-sheng LI Yi-ming ZHANG Science and Technology on Parallel and Distributed Processing Laboratory National University of Defense TechnologyChangsha 41OOOOChina

Deep reinforcement learning(RL)has become one of the most popular topics in artificial intelligence *** has been widely used in various fields,such as end-to-end control,robotic control,recommendation systems,and natural language dialogue *** this survey,we systematically categorize the deep RL algorithms and applications,and provide a detailed review over existing deep RL algorithms by dividing them into modelbased methods,model-free methods,and advanced RL *** thoroughly analyze the advances including exploration,inverse RL,and transfer ***,we outline the current representative applications,and analyze four open problems for future research.

关键词： Reinforcement learning Deep reinforcement learning Reinforcement learning applications