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Superior Ductile and High-barrier Poly(lactic acid)Films by Constructing Oriented Nanocrystals as Efficient Reinforcement of Chain Entanglement Network and Promising Barrier Wall

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Chinese Journal of Polymer Science 2022年第10期40卷 1201-1212,I0009页

作者： Lin Zhou Ping-Ping xu Shi-Hao Ni Ling xu Hao Lin Gan-Ji zhong Hua-Dong Huang zhong-Ming Li Collge of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China

It is a daunting task to develop a promising strategy at an industrial scale for simultaneously ameliorating ductility and gas barrier performance of poly(lactic acid)(PLA)films in the application of green *** this work,biaxial stretching and constrained annealing were employed to prepare transparent PLA films with superior ductility and barrier *** oriented nano-sized crystals induced by biaxial stretching were developed into regularαform during constrained annealing,which could not only serve as“nano-barrier wall”to impede the diffusion and dissolution of gas molecules,but also strengthen amorphous chain entanglement network as physical crosslink to enhance *** a result,the as-prepared PLA films exhibited an outstanding comprehensive performance with a low oxygen and water vapor permeability coefficient of 0.733×10^(-14) cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1) and 3.82×10^(-14) g·cm·cm^(-2)·s^(-1)·Pa^(-1),respectively,outstanding ductility with elongation at break of 66.0%,high yield strength of 84.2 MPa,and good transparency of more than 80%at 550 *** new insight in the relationship between microscopic amorphous and crystalline structure and macroscopic performance is conducive to alleviating the intrinsic defects of brittle and insufficient barrier PLA films without the aid of any heterogenous modifiers,facilitating their widespread commercialization in the booming sustainable packaging market.

关键词： Poly(lactic acid)films Biaxial stretching Constrained annealing Gas barrier properties Ductility

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NS Condition of Admissibility for the Linear Estimator of Normal Mean with Unknown Variance

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Acta Mathematica Sinica,English Series 2005年第5期21卷 1083-1086页

作者： Xing zhong xu Qi Guang WU Beijing Institute of Technology Beijing 100081 P. R. China Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 P. R. China

Suppose Y - N（β, σ^2 In）, where β ∈ R^n and σ^2 〉 0 are unknown. We study the admissibility of linear estimators of mean vector under a quadratic loss function. A necessary and sufficient condition of the admi... 详细信息

关键词： Multivariate normal distribution Mean vector Linear estimator Admissibility

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Phase-transfer catalysis of a new cationic gemini surfactant with ester groups for nucleophilic substitution reaction

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Chinese Chemical Letters 2014年第8期25卷 1169-1173页

作者： Dong-Qing xu zhong-Wen Pan Center of Analysis and Measurement Anhui Science and Technology University School of Chemistry and Chemical Engineering Anhui University

A highly effective phase transfer of a quaternary ammonium gemini surfactant with ester groups（（diethylhexanedioate） diyl-a,v-bis（dimethyl dodecyl ammonium bromide） referred to as 12-10-12）was synthesized with high yield and characterized by infrared spectroscopy, elemental analysis and1 HNMR. Then, 12-10-12 was used as a phase transfer catalyst to study the catalytic effect on the reaction of anhydrous sodium acetate and 4-methylbenzyl chloride. The possible catalytic mechanism and the influence of surfactant concentration, temperature and type are also discussed. The experimental results showed that the catalysis efficiency was more active than the traditional, single-chained surfactant,tetrabutyl ammonium bromide. It also revealed that the reaction was first-order with respect to the concentration of 4-methylbenzyl chloride. The concentration of 4-methylbenzyl chloride grew linearly with the concentration of 12-10-12 and as the reaction temperature increased. The optimum reaction time was 7 h.

关键词： Gemini surfactant Phase-transfer catalyst Kinetic model

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Error analysis on heading determination via genetic algorithms

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Journal of Systems Engineering and Electronics 2006年第3期17卷 673-676页

作者： zhong Bing xu Jiangning Ma Heng Dept. of Electric Naval Univ. of Engineering Wuhan 430033 P. R. China

A new error analysis method is presented via genetic algorithms for high precise heading determination model based on two total positioning stations （TPSs）. The method has the ability to search all possible solution space by the genetic operators of elitist model and restriction. The result of analyzing the error of this model shows that the accuracy of this model is precise enough to meet the need of calibration for navigation systems on ship, and the search space is only 0. 03% of the total search space, and the precision of heading determination is 4＂ in a general dock.

关键词： heading determination SGA genetic algorithms.

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FDR Control for Pairwise Comparisons of Normal Means Based on Goodness of Fit Test

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Acta Mathematicae Applicatae Sinica 2016年第3期32卷 701-712页

作者： Pei JIN Xing-zhong xu Na LI School of Mathematics and Statistics Beijing Institute of Technology School of Economics and Management University of the Chinese Academy of Sciences

This study is undertaken to apply a bootstrap method of controlling the false discovery rate （FDR） when performing pairwise comparisons of normal means. Due to the dependency of test statistics in pairwise comparisons, many conventional multiple testing procedures can＇t be employed directly. Some modified pro- cedures that control FDR with dependent test statistics are too conservative. In the paper, by bootstrap and goodness-of-fit methods, we produce independent p-values for pairwise comparisons. Based on these indepen- dent p-values, plenty of procedures can be used, and two typical FDR controlling procedures are applied here. An example is provided to illustrate the proposed approach. Extensive simulations show the satisfactory FDR control and power performance of our approach. In addition, the proposed approach can be easily extended to more than two normal, or non-normal, balance or unbalance cases.

关键词： multiple testing false discovery rate goodness-of-fit test pairwise comparisons p-value resampling

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Thermodynamic analysis of carbon migration in W1-1.0C steel in plasma surface chromizing

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Journal of University of Science and Technology Beijing 2006年第2期13卷 131-134页

作者： Chengzhong Chi Zhiyong He Yuan Gao zhong xu College of Materials Science and Engineering Taiyuan University of Technology Taiyuan 030024 China Research Institute of Surface Engineering Taiyuan University of Technology Taiyuan 030024 China

W 1-1.0C steel was chromized at 1173 K with double glow plasma surface alloying process, and the distribution of Fe, Cr, and C contents in the chromized layer was measured using glow discharge spectrum analysis （GDA）. The behavior and mechanism of carbon migration during the formation of chromized layer were studied through thermodynamic analysis and calculation. The gradient of carbon chemical potential was regarded as the driving force of carbon migration. An equation was derived to describe the carbon content varying with the chromium content within the carbon-rich region. The calculated results from the equation approximated closely to the experimental ones.

关键词： carbon steel chromizing thermodynamic analysis surface alloying carbon migration

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Tropical Cyclone Size Change under Ocean Warming and Associated Responses of Tropical Cyclone Destructiveness: Idealized Experiments

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Journal of Meteorological Research 2020年第1期34卷 163-175页

作者： Zanmin xu Yuan SUN Tim LI zhong zhong Jia LIU Chen MA Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environmental Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 210044China College of Meteorology and Oceanography National University of Defense TechnologyNanjing 211101China Department of Atmospheric Sciences School of Ocean and Earth Science and TechnologyUniversity of HawaiiHonoluluHI 96822USA

The power dissipation index(PDI),which is defined as the sum of the cube of tropical cyclone(TC)maximum wind speed during TC lifetime,is widely used to estimate the TC destructive ***,due to the lack of high-resolution observations,little attention has been paid to the contribution of TC size change to TC destructive potential in response to ocean *** this study,sensitivity experiments are performed by using the high-resolution Weather Research and Forecasting(WRF)model to investigate the responses of TC size and TC destructive potential to prescribed sea surface temperature(SST)increase under the present climate *** results show that TC size increases with the ocean *** reasons for TC size change are investigated with a focus on the outer air–sea moisture difference(ASMD).As SST increases,ASMD in the outer zone of the TC is larger than that in the inner zone,which increases the surface entropy flux(SEF)of the outer *** change in the radial distribution of SEF causes the increase of tangential wind in the outer zone,which further increases SEF,resulting in a positive feedback between outer-zone SEF and outer-zone tangential *** feedback leads to the increase of the radius of gale-force wind,leading to the expansion of TC ***,to estimate the contribution of TC size change to TC destructiveness,we calculate TC size-dependent destructive potential(PDS)as the storm size information is available in the model outputs,as well as PDI that does not consider the effect of TC size *** find that PDS increases exponentially as SST increases from 1 to 4°C,while PDI increases linearly;hence the former is soon much greater than the *** suggests that the growth effect of TC size cannot be ignored in estimating destructiveness under ocean warming.

关键词： tropical cyclone destructive potential tropical cyclone size surface entropy flux air–sea moisture difference sea surface temperature

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The　First　Conference　of　the　4th　Session　of　the　Special　Committee　on　Seismology，SSC　held　in　Chengdu

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Acta Seismologica Sinica(English Edition) 1995年第4期8卷 661-662页

作者： zhong-Huai xu

ＴｈｅＦｉｒｓｔＣｏｎｆｅｒｅｎｃｅｏｆｔｈｅ４ｔｈＳｅｓｓｉｏｎｏｆｔｈｅＳｐｅｃｉａｌＣｏｍｍｉｔｔｅｅｏｎＳｅｉｓｍｏｌｏｇｙ，ＳＳＣｈｅｌｄｉｎＣｈｅｎｇｄｕ￥／／Ｔｈｅ４ｔｈＳｅｓｓｉｏｎｏｆｔｈｅＣｏｍｍ... 详细信息

ＴｈｅＦｉｒｓｔＣｏｎｆｅｒｅｎｃｅｏｆｔｈｅ４ｔｈＳｅｓｓｉｏｎｏｆｔｈｅＳｐｅｃｉａｌＣｏｍｍｉｔｔｅｅｏｎＳｅｉｓｍｏｌｏｇｙ，ＳＳＣｈｅｌｄｉｎＣｈｅｎｇｄｕ￥／／Ｔｈｅ４ｔｈＳｅｓｓｉｏｎｏｆｔｈｅＣｏｍｍｉｔｔｅｅｏｎＳｅｉｓｍｏｌｏｇｙ...

关键词： Conference the held Chengdu First Session SSC

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Resolution of ghost imaging with entangled photons for different types of momentum correlation

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Science China(Physics,Mechanics & Astronomy) 2016年第7期59卷 9-13页

作者： MaLin zhong Ping xu LiangLiang Lu ShiNing Zhu National Laboratory of Solid State Microstructures and School of Physics Nanjing University

We present an analytical analysis of the spatial resolution of quantum ghost imaging implemented by entangled photons from a general, spontaneously parametric, down-conversion process. We find that the resolution is affected by both the pump beam waist and the nonlinear crystal length. Hence, we determined a method to improve the resolution for a certain imaging setup. It should be noted that the resolution is not uniquely related to the degree of entanglement of the photon pair since the resolution can be optimized for a certain degree of entanglement. For certain types of Einstein-Podolsky-Rosen(EPR) states——namely the momentum-correlated or momentum-positively correlated states——the resolution exhibits a simpler relationship with the pump beam waist and crystal length. Further, a vivid numerical simulation of ghost imaging is presented for different types of EPR states,which supports our analysis. This work discusses applicable references to the applications of quantum ghost imaging.

关键词： resolution of ghost imaging entangled photons momentum correlation

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Pollen wall pattern in Arabidopsis

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Science Bulletin 2016年第11期61卷 832-837页

作者： Te xu Cheng Zhang Que Zhou zhong-Nan Yang College of Life and Environmental Sciences Shanghai Normal University

The pollen wall is a solid and variously sculptured structure. This pattern is determined inside a tetrad. During meiosis, the callose wall is formed outside of the meiocyte/microspore to form a tetrad. Then, primexine is deposited between the callose wall and the microspore plasma membrane which will become undulated. The sporopollenin deposits on top of the undulated membrane and develops into the pollen wall pattern, while the callose wall is gradually degraded. In recent years, much progress has been made in the study of pollen wall pattern formation, at both molecular and genetic levels. In this review,we summarize these achievements mainly in Arabidopsis.

关键词： Pollen wall pattern Sexine Callose Primexine - Plasma membrane undulation Sporopollenin

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