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Search Results: 1 - 10 of 68107 matches for " SHI Yan-Xia "
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2-(1H-Benzotriazol-1-yl)acetohydrazide
Yan-Xia Zhang,Zhi-Qiang Shi
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809021199
Abstract: The title compound, C8H9N5O, was synthesized by the reaction of ethyl 2-(benzotriazol-1-yl)acetate with hydrazine hydrate in ethanol. In the amide group, the C—N bond is relatively short [1.3283 (16) ], suggesting some degree of electronic delocalization in the molecule. In the crystal structure, molecules are linked into infinite chains along the a axis by intermolecular O—H...N hydrogen bonding.
Chloridobis[2-(1,3-thiazol-4-yl-κN)-1H-benzimidazole-κN3]cobalt(II) chloride dihydrate
Zhan-Wang Shi,Yan Qin,Yan-Xia Lin,Wei Wu
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812030371
Abstract: In the title compound, [CoCl(C10H7N3S)2]Cl·2H2O, the CoII atom is five-coordinated by four N atoms from two chelating 2-(1,3-thiazol-4-yl)-1H-benzimidazole ligands and one Cl atom in a distorted trigonal–bipyramidal geometry. In the crystal, N—H...O and O—H...Cl hydrogen bonds and π–π interactions between the thiazole, imidazole and benzene rings [centroid-to-centroid distances 3.546 (2), 3.683 (2) and 3.714 (2) ] link the complex cations, chloride anions and uncoordinating water molecules into a three-dimensional network.
Silver Nanoparticles Confined in SBA-15 Mesoporous Silica and the Application as a Sensor for Detecting Hydrogen Peroxide
Dong-Hai Lin,Yan-Xia Jiang,Ying Wang,Shi-Gang Sun
Journal of Nanomaterials , 2008, DOI: 10.1155/2008/473791
Abstract: Silver nanoparticles within the pore channels of selectively grafted mesoporous silica SBA-15 were synthesized. Silanols on the external surface of as-SBA-15 were first capped by –Si(CH3)3 groups. After removal of the template of capped SBA-15 by calcination, silanols on the internal surface of SBA-15 were modified by 3-aminopropyltrimethoxysilane (APTMS), and then formaldehyde was grafted by amino groups of APTMS, and further Ag(NH3)2NO3SBA-15). High-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR), nitrogen adsorption/desorption isotherms, and UV-vis spectra confirm that the silver nanoparticles have been confined inside the channels of SBA-15. In addition, the Ag-mSBA-15 modified electrode (Ag-mSBA-15/GC) exhibited an excellent electrocatalytic activity toward the reduction of hydrogen peroxide (H2O2). The proposed H2O2 sensor exhibits a linear range of 48.5 M–0.97 M with a detection limit of 12 M (S/N=3 ) and analytical time of 10 seconds per sample.
N′-(Furan-2-ylmethylene)-2-hydroxybenzohydrazide
Yan-Xia Zhang
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808034636
Abstract: In the title molecule, C12H10N2O3, the aromatic and furan rings form a dihedral angle of 8.89 (1)° and an intramolecular N—H...O hydrogen bond occurs. In the crystal structure, intermolecular O—H...O hydrogen bonds link the molecules into zigzag chains running along the c axis.
The Real Estate Bubble’s Forming and Precaution
Yan-xia WU
Canadian Social Science , 2007,
Abstract: “Bubble” is the excessive growth of the fictitious capital in brief. “The real estate bubble” is one kind of the bubble, and the bubble economy taking real estate as carrier. This paper begin with concept of the bubble of the real estate, analyses the reason which can arouse the real estate bubble, from psychology of investor and speculation, etc. The paper summarize kinds of danger that it will be brought to economy once real estate foam evaporate, and has put forward some effective precautionary measures at the end of the article. Key words: The real estate bubble, Forming reason, The damage, The precaution Résumé: La bulle désigne de manière générale la croissance excessive du capital virtuel. La propriété immobilière est une sorte de bulle, et l’économie en bulle prend pour vecteur l’immobilier. L’article présent, débutant par le concept de la bulle dans l’immobilier, analyse les raisons qui provoquent la bulle de la proriété immobilière sous les perspectives de la psychologie des investisseurs et de la spéculation, etc. L’article résume toutes sortes de dangers qui seront entra nés une fois la bulle évanouie, et avance finalement des précautions effectives. Mots-Clés: bulle de la propriété immobière, raison, dommage, précaution
The effect of acid-alkali in the microenvironment on three major fungal pathogens in cucumber
酸碱微环境对三种黄瓜主要真菌病原菌的影响

WANG Li,LI Bao-Ju,SHI Yan-xia,
王莉
,李宝聚,石延霞

生态学报 , 2005,
Abstract: 以引起黄瓜灰霉病(Botrytis cinerea)、黑星病(Cladosporium cucumerium)、霜霉病(Pseudoperonospora cubensis)的3种真菌病害病原菌为代表,通过对病菌栖息微环境酸碱度的调节,达到控制病害的目的。研究看出,黄瓜的3种主要病害病原菌在p H=3.4~10 .4间孢子萌发和致病力表现基本一致:偏酸性环境(p H=4 .2~6 .2 )促进孢子萌发率和致病力增强而偏碱性环境(p H=7.5~10 .4 )则对其明显抑制;降低叶面微环境的酸度,大大减轻了病害的发生、扩展,特别是对黄瓜灰霉病菌的防治有明显效果
Effects of light intensity and temperature on the growth and pigment accumulation of ultraviolet radiation mutagenized productive Dunaliella salina Mutants
光照与温度对紫外筛选盐生杜氏藻藻株的生长及色素积累的影响

MENG Zhen,ZHANG Xue-cheng,SHI Yan-xia,
孟振
,张学成,时艳侠

海洋科学 , 2008,
Abstract: 利用紫外线诱变方法进行盐生杜氏藻(Dunaliella salina)的藻种选育,并研究了所选择的3株诱变株(OUC21,OUC36,OUC66)对光照和温度的反应.结果表明,光照实验中诱变株和出发株(BJ38)的生长与β-胡萝卜素积累的最适光照强度相同,都是0.88×104 lx,此光强下诱变株的生长速率要高于出发株,其中OUC36生长速率最快,藻细胞密度比出发株高25%;3株诱变株中只有OUC36单位体积藻液中β-胡萝卜素的积累量(10.76 mg/L)高于出发株(10.10 mg/L),而OUC21(6.68 mg/L)则低于出发株,各光强下3株诱变株单位体积藻液叶绿素的积累量都高于出发株.诱变株与出发株在最适生长温度上表现出差异性,出发株生长的最适温度为22℃,诱变株OUC66与之相同,而OUC21和OUC36生长的最适温度是28℃,实验中同一温度条件下诱变株的生长速率高于出发株,最大的也是OUC36;适于β-胡萝卜素积累的温度诱变株与出发株相同,都是22℃,3株诱变株中同样是OUC36单位体积藻液中β-胡萝卜素积累量(7.9 mg/L)最大,略高于BJ38(7.84 mg/L),而OUC21(5.31 mg/L)最低,各温度下诱变株单位体积藻液中叶绿素含量高于出发株.OUC36具有生长速率快和积累β-胡萝卜素能力强的优点,可能成为适用于大规模培养的藻种.
Responses of PSII photochemistry efficiency and photosynthetic pigments of Saussurea superba to short-term UV-B-supplementation
高山植物美丽风毛菊PSII光化学效率和光合色素对短期增补UV-B辐射的响应

SHI Sheng-Bo,SHANG Yan-Xia,SHI Rui,ZHANG Bo,
师生波
,尚艳霞,师瑞,张波

植物生态学报 , 2012,
Abstract: Aims Native alpine plants that have grown and evolved on the Qinghai-Tibetan Plateau of China for a long time have developed a strong adaptation capacity for harsh environmental factors,such as low temperature,low air pressure,strong sunlight and solar UV-B radiation.The objective of this study was to determine the response of PSII photochemistry efficiency to short-term enhanced solar UV-B intensity in alpine plants.We examined whether UV-B-absorbing compounds were sufficiently efficient to protect the photosynthetic apparatus from UV-B photo-inactivation or photo-damage and evaluated the influence of UV-B radiation on photosynthetic pigments.Methods Field experiments were conducted during the 2008 and 2009 growing seasons in alpine Kobresia humilis meadow near Haibei Alpine Meadow Ecosystem Research Station(37°29’-37°45’ N,101°12’-101°33’ E;alt.3 200 m) using the native alpine plant Saussurea superba.Short-term UV-B-supplementation studies were performed over 5 days using UV-B-313 fluorescence lamps,which were filtered with a cellulose diacetate film to get increased UV-B treatment and a Mylar film as a control.Pulse-modulated in-vivo chlorophyll fluorescence was used to obtain rapid information of UV-B on photosynthetic processes.The 3-min dark-adapted maximum quantum efficiency of PSII photochemistry,F(v)/F(m),and PSII photochemistry efficiency were measured under natural sunlight.The contents of photosynthetic pigments and UV-B-absorbing compounds were analyzed based on leaf area unit.Important findings Although there was no significant difference,F(v)/F(m) showed a decreasing trend after short-term exposure to enhanced UV-B radiation in all measurements throughout the growing season.The reduction of the actual photochemical quantum efficiency and photochemical quenching as well as the increase of non-photochemical quenching in UV-B supplemented treatment,when compared to the control,indicated therewas a decrease in PSII photochemistry efficiency and an increase in non-photochemical quenching.These phenomena indicated photo-inactivation or photo-damage of photosynthesis occurred in the PSII reaction center.The photosynthetic pigments showed a small decrease in the UV-B supplemented treatment,which may be related to the enhancement of photo-oxidation,a reduction of pigment synthesis and small variation of leaf thickness.The UV-B-absorbing compounds were not influenced by short-term enhancement of UV-B radiation when analyzed based on leaf area unit.This demonstrated that higher contents of UV-B-absorbing compounds in the epidermal layer of alpine plant S.superba were efficient for defense against UV-B radiation and stabilized for further enhancement of UV-B radiation
Mechanisms of high temperature-induced Pseudoperonospora cubensis resistance of cucumber
高温诱导黄瓜抗霜霉病机理

SHI Yan-xia,LI Bao-ju,LIU Xue-min,
石延霞
,李宝聚,刘学敏

应用生态学报 , 2007,
Abstract: This paper studied the effects and control efficiency of high temperature on the pathogenicity and occurrence of Pseudoperonospora cubensis. The results showed that the P. cubensis resistance of cucumber was most obvious after treated at 40 degrees C for 2 h or at 45 degrees C for 1 h, with the control efficiency being 58. 40% and 45. 81% at the forth day, and 39. 35% and 37. 65% at the sixth day after P. cubensis inoculation, respectively. Under high temperature, the activities of peroxidase (POD), phenylalanine ammonia lyase (PAL) , chitinase (Cht), beta-1,3-glucanase (Glu) in cucumber leaf were significantly higher, and large amount of lignin was deposited on the cell wall of leaf tissue, indicating that after treated with high temperature, cucumber plant manifested an induced P. cubensis resistance.
Effects of strong solar UV-B radiation on photosynthesis and photosynthetic pigment contents of Saussurea superba on Qinghai-Tibet Plateau
青藏高原强UV-B辐射对美丽风毛菊光合作用和色素含量的影响

SHI Sheng-bo,SHANG Yan-xia,ZHU Peng-jin,ZHANG De-gang,
师生波
,尚艳霞,朱鹏锦,张德罡

应用生态学报 , 2011,
Abstract: 以青藏高原矮嵩草草甸的主要伴随种美丽风毛菊为材料,通过滤除太阳辐射光谱中UV-B成分的模拟试验,研究了强太阳UV-B辐射对高山植物光合作用、光合色素和紫外吸收物质的影响.结果表明:与对照相比,弱UV-B处理能促使美丽风毛菊叶片净光合速率增加和提高稳态PSⅡ光化学效率;对照中叶片厚度的相对增加能弥补单位叶面积光合色素的光氧化损失,是高山植物对强UVB辐射的一种适应方式.短期滤除UV-B辐射处理时紫外吸收物质含量几乎没有变化,说明高山植物叶表皮层中该类物质受环境波动的影响较小.强UV-B环境下光合色素的相对增加是一种表象,而青藏高原强太阳UV-B辐射对高山植物美丽风毛菊的光合生理过程仍具有潜在的负影响.
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