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Search Results: 1 - 10 of 311684 matches for " 魏子栋br>XIE Xiao-hong "
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通过载体提高燃料电池催化剂的稳定性
Enhancing Stability of PEM Fuel Cell Catalysts via Support Changing

谢小红,<br>XIE Xiao-hong, WEI Zi-dong
- , 2015, DOI: 10.13208/j.electrochem.141052
Abstract: 摘要 Pt/C是目前质子交换膜燃料电池使用最广泛的一种催化剂,制约其实际应用的关键技术之一是稳定性,增强燃料电池催化剂稳定性研究一直是该领域的热点. 本文结合作者课题组的研究工作,综述了通过改进载体材料来提高Pt基催化剂稳定性的一些方法,指出采用更稳定的载体材料以及发展与金属催化剂纳米颗粒有强相互作用的载体材料,是增强催化剂稳定性的努力方向
Effects of conservation tillage on soil organic matter in paddy rice cultivation
保护性耕作对稻田土壤有机质的影响

SHAO Jing-An,TANG Xiao-Hong,WEI Chao-Fu,XIE De-Ti,<br>邵景安,唐晓红,朝富,谢德体
生态学报 , 2007,
Abstract: In this study, the effect of conservation tillage on soil organic matter (SOM) in paddy rice cultivation after 10 yr was investigated. Four treatments, disk till-fallow (DTF), disk till-wheat (DTW), conservation till-fallow (CTF) and conservation till-wheat (CTW) were used. The results indicated that the combinative application of no tillage, ridge culture and wheat cultivation was a sound conservation practice in paddy rice cultivation. It not only significantly increased the concentration of SOM in the topsoil, but also further affected humic acids (HA) optical and pyrolysis characteristics through changing the composition and structure of SOM. At 0-10 cm, the greatest SOM content was in CTW, but declined sharply with depth, while in DTF, DTW and CTF was not as high at the surface as in CTW, but the SOM content did not decline as fast as in CTW. The oxidation stabilization of SOM was generally greater in no tillage and ridge culture than that of disk till. The HA optical density in CTW at wavelength 665 nm and 465 nm was 0.122 and 0.705, while in DTF was 0.062 and 0.321, respectively. E4/E6 ratios in CTW were higher than that of in the other treatments. The enthalpy capacity of exothermal peak (360-365 ℃) for HA DTA curve in no tillage and ridge culture was lower than that of in disk till, while the HA absorption peaks in 1000-1050 cm-1 presented the reverse trend. The oxidation stabilization coefficient of HA in no tillage and ridge culture was higher than those in disk till, indicating that polycondensation degree and aromatization of HA were stronger. Those findings suggest that it may be possible to manipulate paddy soils through conservational tillage and crop practices and thereby maintain adequate SOM concentrations, mitigate soil organic carbon loss from soil to atmosphere.
Effects of Adulthood Exposure to Bisphenol-A on Behaviors in Mice
成年期双酚A暴露对小鼠行为的影响

TIAN Dong,XU Xiao-Hong,HONG Xing,CHEN Lei,XIE Ling-Dan,LI Tao,<br>田,徐晓虹,洪星,陈蕾,谢灵丹,李涛
心理学报 , 2011,
Abstract: Bisphenol-A (BPA), one of the well-known environmental endocrine disrupters with estrogen activity is a widely used industrial compound. With its expanded uses, BPA can be seen everywhere around us, and even has become an integral part of our daily life. As a result it makes more and more adult exposure to BPA in daily life. In recent years, many studies have focused on its toxicity to the reproductive system and development, but few studies on the adult brain and behaviors. It is reported that estrogen not...
CHEMICAL CONSTITUENTS IN ESSENTIAL OIL FROM THE LEAVES OF LITSEA ROTUNDIFOLIA VAR. OBLONGIFOLIA
豺皮樟叶挥发油化学成分的研究

YAN Xiao-hong,ZHANG Feng-xian,WEI Xiao-yi,XIE Hai-Hui,LIU Mei-fang,<br>严小红,张凤仙,孝义,谢海辉,刘梅芳
热带亚热带植物学报 , 2001,
Abstract: Twenty-seven constituents in essential oil from the leaves of Litsea rotundifolia var. oblongifolia were identified by means of GC-MS-DS. The content of these compounds amounted to 88.75% of the essential oil. The main compounds are dodecanoic acid (43.68%), myristic acid (14.61%), n-undecanoic acid (4.70%) and palmitic acid (4.15%).
APORPHINE ALKALOIDS OF LITSEA ROTUNDIFOLIA AND L. ROTUNDIFOLIA VAR. OBLONGIFOLIA
豺皮樟和圆叶豺皮樟中的阿朴啡生物碱成分

YAN Xiao-hong,WEI Xiao-yi,XIE Hai-hui,LIU Meifang,ZHANG Feng-xian,<br>严小红,孝义,谢海辉,刘梅芳,张凤仙
热带亚热带植物学报 , 2000,
Abstract: Three aporphine alkaloids, laurolitsine, boldine and N-acetyllaurolitsine were isolated from the stems of both Litsea rotundifolia and L. rotundifolia var. oblongifolia. Their structures were identified on the basis of spectral analysis and chemical correlation. Among them, N-acetyllaurolitsine was found as a naturally occurring compound for the first time.
Effects of conservational tillage on aggregate composition and organic carbon storage in purple paddy soil.
保护性耕作对紫色水稻土团聚体组成和有机碳储量的影响

TANG Xiao-hong,SHAO Jing-an,GAO Ming,WEI Chao-fu,XIE De-ti,PAN Gen-xing,<br>唐晓红,邵景安,高明,朝富,谢德体,潘根兴
应用生态学报 , 2007,
Abstract: A 13 year experiment was conducted to study the effects of conservational tillage on the aggregate composition and organic carbon storage in purple paddy soil of Sichuan Basin. The results showed that under no-tillage and ridge culture (rice-rape) (NR-RR), no-tillage and plain culture (rice-rape) (NP-RR), no-tillage and ridge culture (rice-green manure) (NR-RGM), tillage and ridge culture (rice-rape) (TR-RR), and tillage and plain culture (rice-rape) (TP-RR), the proportion of macroaggregates in 0-10 cm soil layer was 23%, 69%, 9%, 36%, and 28% higher than that under conventional tillage (CT) (12%), respectively, while in 10-20 cm soil layer, this proportion under conservational tillage was 9%-38% lower than that under CT. The organic carbon storages in the macroaggregates at the depth of 0-10 cm were 13%, 31% and 32% higher under no-tillage and ridge culture (rice-fallow) (NR-RF), NR-RR and NR-RGM than under CT, respectively, while that at the depth of 10-20 cm was 28%-54% lower. The differences in organic carbon storage between macro- and microaggregates were smaller in 10-20 cm layer than in 0-10 cm layer. Under conservational tillage, the organic carbon storage was 8%-28% higher in 0-10 cm layer but 4%-22% lower in 10-20 cm layer, compared with that under CT. After converted from CT to conservational tillage for 13 years, the mean organic carbon sequestration rate was 53 g x m(-2) x a(-1) and 25 g x m(-2) x a(-1) at the depths of 0-10 cm and 10-20 cm, while under CT, it was 26 g x m(-2) x a(-1) and 33 g x m(-2) x a(-1), respectively. Conservational tillage was favorable to the formation of macroaggregates in surface soil layer and the enhancement of soil total organic carbon storage.
GIS-fuzzy neural network-based evaluation of tobacco ecologicalsuitability in southwest mountains of China
基于GIS和模糊神经网络的西南山地烤烟生态适宜性评价

WANG Xuan,XU Xiao-Hong,LV Jia-Ke,WEI Chao-Fu,XIE De-Ti,<br>汪璇,徐小洪,吕家恪,朝富,谢德体
中国生态农业学报 , 2012,
Abstract: Evaluation of tobacco ecological suitability is important for the scientific tobacco planting and mountain agro-resources utilization in the southwest mountains of China. In this study, Qianjiang County tobacco plantation in southeast Chongqing was used as a case to evaluate tobacco ecological suitability. After analysis of tobacco biological characteristics, thirteen ecological factors with strong influence on local tobacco growth were selected to construct a tobacco planting ecological suitability evaluation indexes system. The spatial distributions of the factors of temperature, precipitation, sunshine and soil were modeled by gridded interpolation, multi-factor sunshine simulation and co-Kriging on GIS platform. This was followed by evaluation of Qianjiang tobacco planting suitability using the fuzzy neural network approach. The results showed that the average acreage of the most suitable regions was 648.63 km2. This accounted for 27.03% of the total study area and mainly covered the moderate hillslope and middle mountain areas within altitude 800~1 100 m. The combined acreage of suitable and sub-suitable regions was 964.13 km2, which covered 40.18% of the total area and mainly distributed in the hilly, low mountains within altitude 600~800 m. Unsuitable region with an acreage coverage of 775.16 km2 mainly covered the mountain areas above 1 600 m of altitude or 25 degree of slope. The study not only provided guidance for adjustments of local tobacco planting but also offered a new evaluation mode of crop planting ecological suitability in mountain terrains.
Nonideal effects in quantum field-effect directional coupler

Xie Yue-E,Yan Xiao-Hong,Chen Yuan-Ping,<br>
中国物理 B , 2006,
Abstract: The nonideal effects in a quantum field-effect directional coupler where two quantum wires are coupled through a finite potential barrier are studied by adopting the lattice Green function method. The results show that the electron energy distribution, asymmetric geometry and finite temperature all have obvious influence on the electron transfer of the coupler. Only for the electrons with energies in a certain region, can the complete periodic transfer between two quantum wires take place. The conductance of these electrons as a function of the barrier length and potential height exhibits a fine periodic or quasi-periodic pattern. For the electrons with energies beyond the region, however, the complete periodic transfer does not hold any more since many irregular oscillations are superimposed on the conductance profile. In addition, the finite temperature and asymmetric geometry both can reduce the electron transfer efficiency.
Surface Properties and Adsorption Characteristics for Fluoride of Goethite,Kaolinite and Their Association
针铁矿-高岭石复合体的表面性质和吸附氟的特性

WEI Shi-yong,YANG Xiao-hong,<br>世勇,杨小洪
环境科学 , 2010,
Abstract: 采用X-射线衍射(XRD)、扫描电镜(SEM)、红外(FT-IR)光谱、质子电位滴定、比表面及微孔分析等方法对针铁矿、高岭石及其复合体的基本性质进行了表征;研究了供试样品对氟的吸附容量及吸附模型.结果表明,在悬浮液体系中,针铁矿可包被在高岭石表面形成二元复合体.复合体的孔径主要分布在0.42 nm和0.61 nm左右,BET表面积为34.08 m2/g,表面分形度D=2.726,质子电荷零点(pHPZNPC)位于5.50~6.50间.初始pH=6.00时,针铁矿对氟的吸附容量(qmax)为4.506 mg/g,高岭石的吸附容量为0.608 mg/g,复合体的吸附容量为3.520 mg/g.用Langmuir和Freundlich方程拟合了针铁矿、高岭石及复合体对氟的等温吸附数据,其中Langmuir方程拟合的相关系数(R2)分别为0.964、0.991和0.799,Freundlich方程拟合的相关系数分别为0.925、0.886和0.995.3种矿物吸附氟的主要机制有阴离子配体交换、表面配位和静电作用;此外,"F-键桥"对复合体吸附氟也有重要贡献.与2种单体的平均值比较,针铁矿-高岭石复合体的孔体积和孔径分布无明显变化,比表面积和表面分形度增加,表面羟基含量和质子电荷量减少,吸附氟的能力增强.针铁矿和高岭石单体埘氟的吸附属于单层吸附模式,适合用Langmuir方程拟合;多层吸附模型Freundlich方程可很好地描述复合体对氟的吸附.
STUDY ON MAGNETIZATION REVERSAL OF BARIUM FERRITE PARTICLES
钡铁氧体粒子反磁化研究

LI XIAO-HONG,WEI FU-LIN,YANG ZHENG,<br>李晓红,福林,杨正
物理学报 , 2001,
Abstract: A model of a chain of oblate ellipsoids is proposed for magnetization reversal of barium ferrite particles. The angular dependences of coercivity and critical field were calculated with the consideration of the uniaxial magnetocrystalline anisotropy, the shape anisotropy, the interaction anisotropy of the ellipsoids, as well as the number of ellipsoids. This model could be used to explain the magnetization reversal mechanism of the oriented Ba ferrite particulate media.
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