A Dynamic Semi Parametric Panel Spatial Lag Model for Brain Drain and Economic Stability Based on the Security Perspective

Shengming Chen,Yabin Zhang,Azhong Ye 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.10

In this article, the authors research on the effect of international mobility of talent impact on Chinese economic development based on nonlinear relationship. From the perspective of the heterogeneity of human capital, this article introduces brain drain into a production function and analyzes the relationship between brain drain and economic development of the home country, and this paper draws an conclusion that moderate brain drain enhance the economic development of home country, but the unlimited brain drain will weaken the home country’s production capacity. On the contrary, it will cause the loss of economic of the home country. On the other hand, this article use Chinese Provincial Panel Data during 1997-2014 to construct the indicators of brain drain, and then use dynamic semi-parametric spatial lag model to empirical test the above inference. And find that there is indeed optimal level of brain drain in our country, but the level of the eastern coastal provinces is too high which inhibit the economic development of this region. Therefore, develop differentiated brain drain policies for coastal and inland, be a reasonable guide to the transnational flow of talent is important to increase China's economic.

Early IL-17A Prevention Rather Than Late IL-17A Neutralization Attenuates Toluene Diisocyanate-Induced Mixed Granulocytic Asthma

Chen Shuyu,Yu Li,Deng Yao,Liu Yuanyuan,Wang Lingwei,Li Difei,Yang Kai,Liu Shengming,Tao Ailin,Chen Rongchang 대한천식알레르기학회 2022 Allergy, Asthma & Immunology Research Vol.14 No.5

Purpose: Interleukin (IL)-17A plays a critical role in the pathogenesis of allergic airway inflammation. Yet, the exact roles of IL-17A in asthma are still controversial. Thus, the aim of this study was to dissect the roles of IL-17A in toluene diisocyanate (TDI)-induced mixed granulocytic asthma and to assess the effects of neutralizing antibody in different effector phases on TDI-induced asthma. Methods: IL-17A functions in allergic airway inflammation were evaluated using mice deficient in IL-17A (Il17a−/−) or IL-17A monoclonal antibody (IL-17A mab, intraperitoneally, 50 μg per mouse, 100 μg per mouse). Moreover, the effects of exogenous recombinant IL (rIL)-17A in vivo (murine rIL-17A, intranasally, 1 μg per mouse) and in vitro (human rIL-17A, 100 ng/mL) were investigated. Results: TDI-induced mixed granulocytic airway inflammation was IL-17A-dependent because airway hyperreactivity, neutrophil and eosinophil infiltration, airway smooth muscle thickness, epithelium injury, dysfunctional T helper (Th) 2 and Th17 responses, granulocytic chemokine production and mucus overproduction were more markedly reduced in the Il17a−/− mice or by IL-17A neutralization during the sensitization phase of wild-type (WT) mice. By contrast, IL-17A neutralization during the antigen-challenge phase aggravated TDI-induced eosinophils recruitment, with markedly elevated Th2 response. In line with this, instillation of rIL-17 during antigen sensitization exacerbated airway inflammation by promoting neutrophils aggregation, while rIL-17A during the antigen-challenge phase protected the mice from TDI-induced airway eosinophilia. Moreover, rIL-17A exerted distinct effects on eosinophil- or neutrophil-related signatures in vitro. Conclusions: Our data demonstrated that IL-17A was required for the initiation of TDI-induced asthma, but functioned as a negative regulator of established allergic inflammation, suggesting that early abrogation of IL-17A signaling, but not late IL-17A neutralization, may prevent the progression of TDI-induced asthma and could be used as a therapeutic strategy for severe asthmatics in clinical settings.

Color center of YAlO3 with cation vacancies

Jianyu Chen,Dunhua Cao,Guangjun Zhao,Shengming Zhou 한국물리학회 2010 Current Applied Physics Vol.10 No.2

High quality pure YAlO3 crystal with dimension of Ø 30 × 50 ㎟ was grown by Czochralski technique. UV irradiation and air annealing bring additional absorption in the region 200–800 nm. The absorption spectra of perfect YAlO3 and YAlO3 containing cation vacancy (aluminium vacancy and yttrium vacancy)were calculated using density functional theory code CASTEP. Comparison of the simulated absorption spectra with the experimental absorption spectra of YAlO3 after UV irradiation and air annealing treatments shows that cation vacancies are responsible for part of the coloration on YAlO3 crystal.

Role of Myocardial Extracellular Volume Fraction Measured with Magnetic Resonance Imaging in the Prediction of Left Ventricular Functional Outcome after Revascularization of Chronic Total Occlusion of Coronary Arteries

Yinyin Chen,Xinde Zheng,Hang Jin,Shengming Deng,Daoyuan Ren,Andreas Greiser,Caixia Fu,Hongxiang Gao,Mengsu Zeng 대한영상의학회 2019 Korean Journal of Radiology Vol.20 No.1

Objective: The purpose of this study was to prospectively investigate the value of the myocardial extracellular volume fraction (ECV) in predicting myocardial functional outcome after revascularization of coronary chronic total occlusion (CTO). Materials and Methods: Thirty patients with CTO underwent cardiovascular magnetic resonance (CMR) before and 6 months after revascularization. Three baseline markers of functional outcome were evaluated in the dysfunctional segments assigned to the CTO vessels: ECV, transmural extent of infarction (TEI), and unenhanced rim thickness (RIM). At the global level, the ECV values of the whole myocardium with and without a hyperenhanced region (global and remote ECV) were respectively measured. Results: In per-segment analysis, ECV was superior to TEI and RIM in predicting functional recovery (area under receiver operating characteristic curve [AUC]: 0.86 vs. 0.75 and 0.73, all p values < 0.010), and it emerged as the only independent predictor of regional functional outcome (odds ratio [OR] = 0.83, 95% confidence interval [CI]: 0.77–0.89; p < 0.001) independent of collateral circulation. In per-patient analysis, global baseline ECV was indicative of ejection fraction (EF) at the follow-up examination (β = -0.61, p < 0.001) and changes in EF (β = -0.57, p = 0.001) in multivariate regression analysis. A patient with global baseline ECV less than 30.0% (AUC, 0.93; sensitivity 94%, specificity 80%) was more likely to demonstrate significant EF improvement (OR: 0.38; 95% CI: 0.17–0.85; p = 0.019). Conclusion: Extracellular volume fraction obtained by CMR may provide incremental value for the prediction of functional recovery both at the segmental and global levels in CTO patients, and may facilitate the identification of patients who can benefit from revascularization.

Experimental studies on elastic cooling and pyromagnetic effect of polyvinyl chloride sheets with defects

Luo, Yingshe,Chen, Shengming,Zhang, Liang,Su, Jianxin,Zhang, Yongzhong,Luo, Shuling 한국유변학회 2012 Korea-Australia rheology journal Vol.24 No.3

Polyvinyl Chloride (PVC) sheets were made into samples with precast defects for uniaxial tensile test. The tests are carried out under room temperature with conditions of same displacement rate but different defect sizes or of same defect but different displacement rates. The local nonuniform temperature field on whole deformation area of specimen is recorded with a thermal infrared imager and the whole coupling magnetic field with thermal changes in experiments is detected and measured by a self-developed sensors system. The experimental results show that, in a complete tensile test process of PVC samples, the temperature reduction phenomenon emerges firstly in its elastic deformation stage (areas) that temperature of specimen is cooler than room temperature. And then in viscoplastic deformation period (areas), the temperature increases sharply to be obviously higher than room temperature due to the thermo-mechanical coupling effection of tensile load and viscoplastic deformation heat. These thermal variations lead a coupling pyromagnetic effect occur and the effect intensity is dependent strongly on the strain rate and/or the size of defects. The temperature prejudgment conditions for materials yield are preliminary discussed based on this effect.

Experimental studies on elastic cooling and pyromagnetic effect ofpolyvinyl chloride sheets with defects

Yingshe Luo,Shengming Chen,Liang Zhang,Jianxin Su,Yongzhong Zhang3,Shuling Luo 한국유변학회 2012 Korea-Australia rheology journal Vol.24 No.3

Polyvinyl Chloride (PVC) sheets were made into samples with precast defects for uniaxial tensile test. The tests are carried out under room temperature with conditions of same displacement rate but different defect sizes or of same defect but different displacement rates. The local nonuniform temperature field on whole deformation area of specimen is recorded with a thermal infrared imager and the whole coupling magnetic field with thermal changes in experiments is detected and measured by a self-developed sensors system. The experimental results show that, in a complete tensile test process of PVC samples, the temperature reduction phenomenon emerges firstly in its elastic deformation stage (areas) that temperature of specimen is cooler than room temperature. And then in viscoplastic deformation period (areas), the temperature increases sharply to be obviously higher than room temperature due to the thermo-mechanical coupling effection of tensile load and viscoplastic deformation heat. These thermal variations lead a coupling pyromagnetic effect occur and the effect intensity is dependent strongly on the strain rate and/or the size of defects. The tem\-perature prejudgment conditions for materials yield are preliminary discussed based on this effect.

Removal of malachite green in aqueous solution by adsorption on sawdust

Yinghua Song,Sheguang Ding,Shengming Chen,Hui Xu,Ye Mei,Jianmin Ren 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.12

A new adsorbent was synthesized from sawdust, a forest residue, in which methanol was used as a solvent and triethylamine as a modification agent under the following optimum conditions: 25 oC of reaction temperature, 1 : 8.75 of the ratio of sawdust to triethylamine (g :mL) and 1 hour of reaction time. The adsorption capacity of this adsorbent for malachite green was improved by 632.98% in contrast to that of the unmodified sawdust under the same adsorption conditions. Factors affecting the adsorption behavior of this adsorbent for malachite green, such as pH value, adsorption time, temperature and initial dye concentration, were evaluated through experiments in a batch system. The results indicated that the maximum adsorption capacity can be achieved at 5.08 of pH value and adsorption equilibrium can be reached in 6 hours. It was also found that the higher the temperature, the higher the adsorptive capacity would be. The Freundlich isotherm model provides a better description for the adsorption equilibrium when compared with the Langmuir equation in the conditions of the present study. Additionally, to examine the controlling mechanisms of the process, kinetic equations of the mass transfer and chemical reaction, the pseudo-first order model, the pseudo-second order model and the intraparticle diffusion model were used to correlate the experimental data respectively. The adsorption process of malachite green on sawdust tended to be controlled simultaneously by film mass transfer and intra-particle diffusion and it accompanied chemical reactions. It showed that the sawdust modified with triethylamine had good performance for cationic dye and can be used as a biomass adsorbent to treat dyes-containing wastewater with high quality.

Influence of CeO2 morphology on the catalytic oxidation of ethanol in air

Guilin Zhou,Baoguo Gui,Hongmei Xie,Fang Yang,Yong Chen,Shengming Chen,Xuxu Zheng 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.1

Nano-CeO2 catalysts of different shapes were synthesized at different hydrothermal crystallizationtemperatures from an alkaline aqueous solution. X-ray diffraction (XRD), transmission electronmicroscope (TEM), and H2 temperature-programmed reduction (H2-TPR) were used to study thesynthesized nano-CeO2 catalyst samples. The catalytic properties of the prepared nano-CeO2 catalystsfor the catalytic oxidation of ethanol in air were also investigated. TEM analysis showed that CeO2nanorod and nanocube catalysts have been synthesized at hydrothermal crystallization temperatures of373 K and 453 K, respectively. XRD results showed that the synthesized nano-CeO2 catalysts have similarcubic fluorite structures. H2-TPR results indicated that CeO2 nanorod and nanocube catalysts exhibitdifferent reduction behaviors for H2 and that the nanorod catalyst has better low-temperature reductionperformance than the nanocube catalyst. Ethanol catalytic oxidation results indicated that oxidation andcondensation products (including acetaldehyde, acetic acid, CO2, and ethyl acetate) have been producedfrom the prepared catalysts. The ethyl acetate and acetic acid can be ignited by ethanol at lowtemperature on the CeO2(R) catalyst to give low catalytic combustion temperature for ethyl acetate andacetic acid molecules. CeO2 nanorods gave ethanol oxidation conversion rates above 99.2% at 443 K andCO2 selectivity exceeding 99.6% at 483 K, while CeO2 nanocubes gave ethanol oxidation conversion ratesof about 95.1% until 508 K and CO2 selectivity of only 93.86% at 543 K. CeO2 nanorod is a potential lowcostand effective catalyst for removing trace amounts of ethanol to purify air.

Catalytic combustion of volatile aromatic compounds over CuO-CeO2 catalyst

Hongmei Xie,Qinxiang Du,Hui Li,Guilin Zhou,Shengming Chen,Zhaojie Jiao,Jianmin Ren 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.7

Ce1−xCuxO2 oxide solid solution catalysts with different Ce/Cu mole ratios were synthesized by the one-pot complex method. The prepared Ce1−xCuxO2 catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and H2 temperature-programmed reduction (H2-TPR). Their catalytic properties were also investigated by catalytic combustion of phenyl volatile organic compounds (PVOCs: benzene, toluene, xylene, and ethylbenzene) in air. XRD analysis confirmed that the CuO species can fully dissolve into the CeO2 lattice to form CeCu oxide solid solutions. XPS and H2-TPR results indicated that the prepared Ce1−xCuxO2 catalysts contain abundant reactive oxygen species and superior reducibility. Furthermore, the physicochemical properties of the prepared Ce1−xCuxO2 catalysts are affected by the Ce/Cu mole ratio. The CeCu3 catalyst with Ce/Cu mole ratio of 3.0 contains abundant reactive oxygen species and exhibits superior catalytic combustion activity of PVOCs. Moreover, the ignitability of PVOCs is also affected by the respective physicochemical properties. The catalytic combustion conversions of ethylbenzene, xylene, toluene, and benzene are 99%, 98.9%, 94.3%, and 62.8% at 205, 220, 225, and 225 oC, respectively.

Reduction of CO2 to CO via reverse water-gas shift reaction over CeO2 catalyst

Bican Dai,Shiquan Cao,Hongmei Xie,Guilin Zhou,Shengming Chen 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.2

CeO2 catalysts with different structure were prepared by hard-template (Ce-HT), complex (Ce-CA), and precipitation methods (Ce-PC), and their performance in CO2 reverse water gas shift (RWGS) reaction was investigated. The catalysts were characterized using XRD, TEM, BET, H2-TPR, and in-situ XPS. The results indicated that the structure of CeO2 catalysts was significantly affected by the preparation method. The porous structure and large specific surface area enhanced the catalytic activity of the studied CeO2 catalysts. Oxygen vacancies as active sites were formed in the CeO2 catalysts by H2 reduction at 400 oC. The Ce-HT, Ce-CA, and Ce-PC catalysts have a 100% CO selectivity and CO2 conversion at 580 oC was 15.9%, 9.3%, and 12.7%, respectively. The highest CO2 RWGS reaction catalytic activity for the Ce-HT catalyst was related to the porous structure, large specific surface area (144.9m2∙g−1) and formed abundant oxygen vacancies.