检索结果-南通市图书馆

Design considerations for re-functionalizing electrocatalytic materials

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2023年第12期66卷 3355-3368页

作者： ZHANG DanTong peng chao XUE DongFeng Multiscale Crystal Materials Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Electrocatalytic materials are a critical bottleneck for the development of new energy *** review summarizes the unique physicochemical properties of topological,magnetic,and rare earth materials and their applications in the functionalization of *** materials have unique band structures and geometric structures,and the interface difference in charge transport structures can give rise to topological insulators,topological superconductors,and Dirac *** materials possess distinctive electron spin-splitting configurations,and varying spin strengths induce disparate impacts on the intermediate equilibrium adsorption *** earth materials have unique f-electron roaming properties,broad atomic radius,and f-orbital configurations,which typically confer notable advantages in oxygen reduction ***,the catalytic performance exhibits significant differences under an external alternating electric,thermal,and magnetic *** new materials show great potential in the re-functionalization of electrocatalytic materials and are expected to lead the development of the next generation of emerging energy materials.

关键词： electrocatalysis topological materials magnetic materials rare earth materials

Poverty alleviation through e-commerce:Village involvement and demonstration policies in rural China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2021年第4期20卷 998-1011页

作者： peng chao MA Biao ZHANG Chen Administration and Management Institute Ministry of Agriculture and Rural AffairsBeijing 102208P.R.China School of Agricultural Economics and Rural Development Renmin University of ChinaBeijing 100872P.R.China Institute of Population and Labor Economics Chinese Academy of Social SciencesBeijing 100006P.R.China

The diffusion of e-commerce has played a significant role in recent rural economic development in China.E-commerce is also considered as an efficient channel to alleviate poverty in rural *** studies have investigated the contribution of e-commerce to agricultural development,yet it is lacking empirical evidence as to the effects of e-commerce on rural poverty *** the year of 2014,in order to develop rural e-commerce,Chinese government launched the National Rural E-commerce Comprehensive Demonstration *** gradual involvement policy offered a natural experiment for evaluation of *** on village-level survey data from rural China and Heckit method,our study finds that rural e-commerce has a significantly positive effect on rural ***,the effect is inverted U-shaped for the relative-poverty *** estimation of the propensity scores matching model confirms that the results are *** following policy recommendations are proposed:(1)policy support to rural e-commerce should prioritize the povertystricken *** doing so,the marginal income effects of e-commerce will be maximized.(2)Investment in internet infrastructure and establishment of human resources for e-commerce in rural areas will have spillover effects,increasing rural income through the"digital dividend".

关键词： poverty alleviation income National Rural E-commerce Comprehensive Demonstration Project Heckit method

Separation/degradation behavior and mechanism for cationic/anionic dyes by Ag-functionalized Fe_(3)O_(4)-PDA core-shell adsorbents

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2022年第11期16卷 153-164页

作者： Qingqing Li chao Lv Xiangwei Xia chao peng Yan Yang Feng Guo Jianfeng Zhang College of Mechanics and Materials Hohai UniversityNanjing 210098China Sinosteel Maanshan General Institute of Mining Research Co. LtdMaanshan 243004China Productivity Centre of Jiangsu Province Nanjing 210042China Engineering Research Center on Utilization of Alternative Water Resources Nanjing 210000China

High-performance adsorbents have been well-studied for the removal of organic dye pollutants to promote environment *** this study,an Ag nanoparticle-functionalized Fe_(3)O_(4)-PDA nanocomposite adsorbent(PDA-Fe_(3)O_(4)-Ag)was synthesized,and the adsorption/separation performance of commonly used cationic and anionic organic dyes by the PDA-Fe_(3)O_(4)-Ag adsorbent were ***,PDA-Fe_(3)O_(4)-Ag exhibited a significantly higher adsorption capacity for cationic dyes compared to anionic dyes,the highest of which was more than 110.0 mg/g(methylene blue(MB)),which was much higher than not only the adsorption capacities of the anionic dyes in this study but also other dye adsorption capacities reported in the *** dye adsorption kinetics data fitted well to both the pseudo second-order kinetics model and the Langmuir isotherm model,suggesting a monolayer-chemisorption-dominated adsorption *** analysis indicated that the adsorption process was both endothermic and ***,the PDAFe_(3)O_(4)-Ag adsorbent achieved high photodegradation removal rates of the dyes,especially neutral red(NR)and methyl orange(MO),which were 91.2%and 87.5%,*** the addition of PDA-Fe_(3)O_(4)-Ag,the degradation rate constants of NR and MO increased from 0.08×10^(−2)and 0 min^(−1)to 2.11×10^(−2)and 1.73×10^(−2)min−1,*** high adsorption and photocatalytic degradation performance of the PDA-Fe_(3)O_(4)-Ag adsorbent make it an excellent candidate for removing cationic and anionic dyes from the industrial effluents.

关键词： PDA Fe_(3)O_(4) Magnetic adsorbent Cationic dyes Anionic dyes

Effects of simulated on-fire processing conditions on the microstructure and mechanical performance of Q345R steel

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第1期23卷 49-56页

作者： Yi-chao peng Hao-hao Xu Mai-cang Zhang Department of Materials Technology Zhejiang Energy Technology & Research Co.Ltd. Department of Materials Science and Engineering University of Science and Technology Beijing

A series of simulated on-fire processing experiments on Q345R steel plates was conducted, and the plates＇ Brinell hardness, ten- sile strength, and impact energy were tested. Microstructure morphologies were systematically analyzed using a scanning electron micro- scope with the aim of investigating the effect of the steel＇s microstructure on its performance. All examined performance parameters exhib- ited a substantial decrease in the cases of samples heat-treated at temperatures near 700℃. However, although the banded structure decreased with increasing treatment temperature and holding time, it had little effect on the performance decline in fact. Further analysis revealed that pearlite degeneration near 700℃, which was induced by the interaction of both subcritical annealing and conventional spherical annealing, was the primary reason for the degradation behavior. Consequently, some nonlinear mathematical models of different mechanical perform- ances were established to facilitate processing adjustments.

关键词： low alloy steels heat treatment mechanical properties microstructure nonlinear mathematical models

Insight into evolution of invasive patterns on fingering phenomenon during immiscible two-phase flow through pore structure

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第5期21卷 3307-3325页

作者： Yu Li Hui-Qing Liu chao peng peng Jiao Wai Lam Loh Qing Wang State Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing102249China Department of Mechanical Engineering National University of Singapore117575Singapore Oil and gas production Business Department Kunlun Shuzhi Technology Co.LTDBeijing100040China

Understanding fingering, as a challenge to stable displacement during the immiscible flow, has become a crucial phenomenon for geological carbon sequestration, enhanced oil recovery, and groundwater protection. Typically governed by gravity, viscous and capillary forces, these factors lead invasive fluids to occupy pore space irregularly and incompletely. Previous studies have demonstrated capillary numbers,describing the viscous and capillary forces, to quantificationally induce evolution of invasion *** the evolution mechanisms of invasive patterns have not been deeply elucidated under the constant capillary number and three variable parameters including velocity, viscosity, and interfacial *** research employs two horizontal visualization systems and a two-phase laminar flow simulation to investigate the tendency of invasive pattern transition by various parameters at the pore scale. We showed that increasing invasive viscosity or reducing interfacial tension in a homogeneous pore space significantly enhanced sweep efficiency, under constant capillary number. Additionally, in the fingering crossover pattern, the region near the inlet was prone to capillary fingering with multi-directional invasion, while the viscous fingering with unidirectional invasion was more susceptible occurred in the region near the outlet. Furthermore, increasing invasive viscosity or decreasing invasive velocity and interfacial tension promoted the extension of viscous fingering from the outlet to the inlet, presenting that the subsequent invasive fluid flows toward the outlet. In the case of invasive trunk along a unidirectional path, the invasive flow increased exponentially closer to the outlet, resulting in a significant decrease in the width of the invasive interface. Our work holds promising applications for optimizing invasive patterns in heterogeneous porous media.

关键词： Immiscible two-phase flow Fingering phenomenon Invasive pattern Capillary number Parameters optimization

Hierarchical Porous Polymer Beads Prepared by Polymerization-induced Phase Separation and Emulsion-template in a Microfluidic Device

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2014年第12期32卷 1646-1654页

作者： Wei-cai Wang Yan-xiong Pan Kai Shi chao peng 姬相玲 State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences

Porous polymer beads（PPBs） containing hierarchical bimodal pore structure with gigapores and meso-macropores were prepared by polymerization-induced phase separation（PIPS） and emulsion-template technique in a glass capillary microfluidic device（GCMD）. Fabrication procedure involved the preparation of water-in-oil emulsion by emulsifying aqueous solution into the monomer solution that contains porogen. The emulsion was added into the GCMD to fabricate the（water-in-oil）-in-water double emulsion droplets. The flow rate of the carrier continuous phase strongly influenced the formation mechanism and size of droplets. Formation mechanism transformed from dripping to jetting and size of droplets decreased from 550 μm to 250 μm with the increase in flow rate of the carrier continuous phase. The prepared droplets were initiated for polymerization by on-line UV-irradiation to form PPBs. The meso-macropores in these beads were generated by PIPS because of the presence of porogen and gigapores obtained from the emulsion-template. The pore morphology and pore size distribution of the PPBs were investigated extensively by scanning electron microscopy and mercury intrusion porosimetry（MIP）. New pore morphology was formed at the edge of the beads different from traditional theory because of different osmolarities between the water phase of the emulsion and the carrier continuous phase. The morphology and proportion of bimodal pore structure can be tuned by changing the kind and amount of porogen.

关键词： Porous polymer beads Hierarchical Polymerization-induced phase separation Emulsion-template Microfluidic device.

Artifacts in two-dimensional shear wave elastography of liver

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2023年第21期29卷 3318-3327页

作者： Hui-peng Wang peng-chao Zheng Xue-Mei Wang Liang Sang Department of Ultrasound The First Hospital of China Medical UniversityShenyang 110001Liaoning ProvinceChina

BACKGROUND Artifacts are common when using two-dimensional shear wave elastography(2-D SWE)to measure liver stiffness(LS),but they are poorly *** To investigate the presence and influence of artifacts in 2-D SWE of *** We included 158 patients with chronic liver disease,who underwent 2-D SWE examination by a novice and an expert.A cross line at the center of the elastogram was drawn and was divided it into four locations:top-left,top-right,bottom-left,and *** occurrence frequency of artifacts in different locations was *** influence of artifacts on the LS measurements was evaluated by comparing the elastogram with the most artifacts(EMA)and the elastogram with the least artifacts(ELA).RESULTS The percentage of elastograms with artifacts in the novice(51.7%)was significantly higher than that of the expert(19.6%)(P<0.001).It was found that both operators had the highest frequency of artifacts at bottom-left,followed by top-left and bottom-right,and top-right had the lowest *** LS values(LSVs)and standard deviation values of EMAs were significantly higher than those of ELAs for both *** intraclass correlation coefficient value of 0.96 was found in the LSVs of EMAs of the two operators,and it increased to 0.98 when the LSVs of the ELAs were *** operators had lower stability index values for EMAs than ELAs,but the difference was only statistically significant for the *** Artifacts are common when using 2-D SWE to measure LS,especially for the *** may lead to the overestimation of LS and reduce the repeatability and reliability of LS measurements.

关键词： Ultrasound Elastography Artifact Liver

Reachable domain for spacecraft with ellipsoidal Delta-V distribution

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Astrodynamics 2018年第3期2卷 265-288页

作者： Changxuan Wen chao peng Yang Gao Chinese Academy of Sciences Beijing 100094China

Conventional reachable domain(RD)problem with an admissible velocity increment,Δv,in an isotropic distribution,was extended to the general case withΔv in an anisotropic ellipsoidal *** an extension enables RD to describe the effect of initial velocity uncertainty because a Gaussian form of velocity uncertainty can be regarded as possible velocity deviations that are confined within an error *** specify RD in space,the boundary surface of RD,also known as the envelope,should be *** this study,the envelope is divided into two parts:inner and outer ***,the problem of solving the RD envelope is formulated into an optimization *** inner and outer reachable boundaries that are closest to and farthest away from the center of the Earth,respectively,were found in each *** optimal control policy is then formulated by using the necessary condition for an optimum;that is,the first-order derivative of the performance function with respect to the control variable becomes *** properties regarding the optimal control policy is ***,an algorithm to solve the RD envelope is *** general,the proposed algorithm does not require any iteration,and therefore benefits from quick *** examples,including two coplanar cases and two 3D cases,are provided,which demonstrate that the proposed algorithm works efficiently.

关键词： reachable domain maneuverability orbit uncertainty

Development and application of the multi-wavelength cavity ring-down aerosol extinction spectrometer

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2019年第2期31卷 227-237页

作者： Junling Li Weigang Wang Kun Li Wenyu Zhang Maofa Ge chao peng State Key Laboratory for Structural Chemistry of Unstable and Stable Species CAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of Sciences University of Chinese Academy of Sciences Air Quality Research Division Environment and Climate Change Canada Center for Excellence in Urban Atmospheric Environment (CEUAE) Institute of Urban EnvironmentChinese Academy of Sciences

To better characterize the optical properties of atmospheric aerosols, the multi-wavelength cavity ring-down aerosol extinction spectrometer(MCRD-AES) is developed and applied in this study. By using tunable light source and four parallel cavities, the MCRD-AES covers a wide and atmospherically relevant wavelength range from 360 to 663 nm. Four wavelengths(375 nm, 440 nm, 532 nm, and 620 nm) are particularly tested with ammonium sulfate and nigrosine. The refractive index values obtained from this study agree well with literature data. The stability and accuracy of the MCRD-AES are tested, and the minimum detectable extinction coefficient is 0.5 1/Mm. The high sensitivity, high precision, and wavelength changeable of MCRD-AES indicate its great application prospect in comprehensively quantifying the optical properties of atmospheric aerosols.

关键词： MCRD-AES Optical property Refractive indices Wavelength dependence