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Search Results: 1 - 10 of 39128 matches for " LUO Tian-Xiang "
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(E)-5-[(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)iminomethyl]-2-methoxyphenyl 4-chlorobenzenesulfonate
Tian-Xiang Lei
Acta Crystallographica Section E , 2012, DOI: 10.1107/s160053681202627x
Abstract: In the title compound, C25H22ClN3O5S, the two N atoms in the pyrazole ring have a pyramidal environment, with the sums of the valence angles around them being 349.3 (2) and 357.5 (2)°. The phenyl ring is twisted by 50.97 (12)° from the pyrazole mean plane. In the crystal, pairs of weak C—H...O hydrogen bonds link the molecules into inversion dimers.
Optimization of clear liquid fermentation condition for ethanol production from Canna edulis Kerl  [PDF]
Ying Shen, Qing-li Tang, Tian-Xiang Wu
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.22019
Abstract: In this paper, clear liquid fermentation condition for ethanol production from Canna edulis Kerl with orthogonal design was studied. We have studied five factors that influenced clear liquid fermentation condition for ethanol production from Canna edulis Kerl by the single-factor test. The five factors were α-amylase amount, glu-coamylase amount, pH, nitrogen and auxiliary materials amount. Selected the best amounts of α-amylase, glucoamylase, pH, nitrogen source and auxiliary materials by means of the singe- factors test. And then, we used the Orthogonal test to optimize the fermentation process. The study showed that the best fermentation condi-tions were α-amylase amount 7 u/g C.eduli, glu-coamylase amount 145u/g C. edulis, pH 4.4 and the amount of urea 0.08%, 1% of rice bran as auxiliary materials. The rate of alcohol which was produced by the best fermentation conditions is 21.5% that increased by 1.3% than the rate of alcohol by the single-factor test.
Fine root biomass and its depth distribution across the primitive Korean pine and broad-leaved forest and its secondary forests in Changbai Mountain, northeast China
长白山原始阔叶红松(Pinus koraiensis)林及其次生林细根生物量与垂直分布特征

YANG Li-Yun,LUO Tian-Xiang,WU Song-Tao,
杨丽韫
,罗天祥,吴松涛

生态学报 , 2007,
Abstract: We measured the fine root biomass and its depth distribution of a more than 200-year-old primitive Korean pine and broad-leaved forest and its two 20-and 80-year-old secondary Populus davidiana and Betula platyphylla forests in the Changbai Mountain,northeast China.The soil core method was used for root sampling.The results indicated that the total fine root biomass increased with stand age,ranging from 561.8 g/m2 and 674.1 g/m2 for 20-year-old and 80-year-old secondary forests,respectively,to 827.8 g/m2 for the old primitive mixed forest.Fine root biomass increased in dominant tree species but decreased in the undergrowth other woody species and herbs.Along the successional development from young to old stands,the rooting depth exponentially increased though most of fine roots were distributed in the 0-10 cm soils.In the forests,the effects of soil bulk density,soil moisture,and soil organic C and N contents on fine-root depth distribution were more significant than that of soil temperature.
Characteristics of eco-climate at smith fir timberline in the Sergyemla Mountains, Southeast Tibetan Plateau
藏东南色季拉山急尖长苞冷杉(Abies georgei var. smithii)林线的生态气候特征

HE Ji-Cheng,LUO Tian-Xiang,XU Yu-Qing,
何吉成
,罗天祥,徐雨晴

生态学报 , 2009,
Abstract: 高山林线因其对气候因子的敏感性和自身结构的不稳定性而被视为气候变化的"监视器",通过自动微气象站对藏东南色季拉山急尖长苞冷杉(Abies georgei var. smithii)林线气象因子的连续监测,探讨了色季拉山高山林线的生态气候特征.结果表明:在色季拉山急尖长苞冷杉林线处,年平均温度为1.3℃,年平均相对湿度为79.4%,全年降水量为892.6 mm,主要集中在6、7、8、9月4个月份.林线最热月平均温度为9.4℃,最冷月平均温度为-6.4℃,年生物温度为3.1℃,温暖指数是11.6℃月,寒冷指数是-55.9℃月,生长季内平均温度为7.7℃,生长季长度为133d,大陆度指数为34.0,湿润指数为217.5.其温暖指数与我国两种山地森林树种祁连圆柏和喜马拉雅冷杉的分布上限较为接近.林线的最热月温度、年生物学温度和生长季平均温度与全国高山林线的平均值十分接近.从全球范围来看,色季拉山林线最热月平均温度9.4℃与全球均值10℃很接近.生长季内10cm深度的土壤均温为6.22℃,接近Krner观测的(6.7±0.8)℃全球均值.
Influence of nematodes and earthworms on the emission of atmospheric trace gases (CO2, N2O)
线虫和蚯蚓对土壤微量气体排放的影响

LUO Tian-Xiang,LI Hui-Xin,WANG Tong,HU Feng,
罗天相
,李辉信,王同,胡锋

生态学报 , 2008,
Abstract: To determine effects of soil fauna on greenhouse gas emissions, soil inoculated with different populations of nematodes and earthworms was incubated for 15 d. Soil with greater populations of nematodes and earthworms enhanced CO2 and N2O emissions. Cumulative emission fluxes of the two gases in the treatment of greater populations of nematodes and the treatment of greater populations of nematodes and earthworms were increased by 4.3 and 5.2 times for CO2, 1.8 and 2.7 times for N2O, respectively in comparison of the nematode-killed treatment. The emission fluxes of CO2 and N2O in soil treated with greater populations of nematodes were 19% for CO2 and 21% for N2O higher than those in soil treated with lower populations of nematodes. Meanwhile, the emission fluxes of the two gases in soil treated with greater populations of nematodes and earthworms were 12% for CO2 and 27% for N2O higher than those in soil treated with lower populations of nematodes and earthworms. The two gas fluxes were significantly correlated (R2 = 0.9414; p < 0.001). Cumulative emissions of CO2 and N2O from soil treated with different populations of nematodes were positively correlated with DOC (dissolved organic carbon) concentration measured at the start of gas sampling (p < 0.05).
Distribution characteristics of δ13C values in different organs of Abies georgei growing at alpine timberline
高山林线急尖长苞冷杉不同器官的稳定碳同位素组成分布特征

LI Ming-cai,LUO Tian-xiang,LIU Xin-sheng,KONG Gao-qiang,
李明财
,罗天祥,刘新圣,孔高强

应用生态学报 , 2007,
Abstract: Based on the analysis of the distribution characteristics of delta13C values in the needle, twig, branch, trunk, and root of different age Abies georgei growing at the timberline of Sergyemla Mountain on the southeast edge of Tibetan Plateau, this paper studied the process or extent of post-photosynthetic delta13C fractionation and its affecting factors. The results showed that the organ-specific difference in delta13C values was highly significant (P < 0.001), with the sequence of trunk (-24.19 per thousand +/- 0.34 per thousand) > branch (-24.56 per thousand +/- 0.62 per thousand) > root (-25.05 per thousand +/- 1.08 per thousand) > twig (-25.12 per thousand +/- 0.54 per thousand) > needle (-7.25 per thousand +/- 0.63 per thousand), which suggested that an obvious post-photosynthetic delta13C fractionation was existed between photosynthetic and non-photosynthetic organs. With increasing age of needle and twig, the delta13C value in needle decreased significantly, while that in twig showed a reverse pattern (P < 0.01). The delta13C value in needle increased significantly (P < 0.01) from lower canopy to higher canopy, whereas no significant difference (P > 0.05) of delta13C value in twig was observed among different canopy heights. A significant vertical gradient of delta13C value existed in the branches at a distance of 2.5 m from trunk (P < 0.01), but disappeared at a distance of 1.5 m or 0.5 m. At the same canopy height, the delta13C value in twig decreased with increasing distance from trunk, which was most obvious in the twigs of middle and lower canopies. All of these suggested that post-photosynthetic delta13C fractionation occurred in alpine A. georgei, and the carbon need for the growth of height-specific tree stems or branches was not wholly supplied by the corresponding segment of the tree crown at the same height.
Variations in leaf functional traits of Stipa purpurea along a rainfall gradient in Xizang,China
西藏紫花针茅叶功能性状沿降水梯度的变化

HU Meng-Yao,ZHANG Lin,LUO Tian-Xiang,SHEN Wei,
胡梦瑶
,张林,罗天祥,沈维

植物生态学报 , 2012,
Abstract: Aims Stipa purpurea is the dominant species in alpine arid and semi-arid grasslands on the Tibetan Plateau. Our objectives are to determine if this species exhibits a strategy shift in its specific leaf area (SLA) to nitrogen (N) concentration relationship along a rainfall gradient and to detect possible effects of environmental factors on related leaf traits. Methods We investigated variations in leaf traits of S. purpurea associated with climatic and soil factors along an east-west transect with a rainfall gradient (69–479 mm) but similar altitudes (4 300–4 700 m). Five locations from east to west are Damxung, Namco, Gêrzê, Mount Qomolangma and Rutog. We measured SLA, mass- and area-based leaf N concentration (Nmass, Narea), leaf density and thickness and soil total N along the transect. Important findings In pooled data, SLA and Nmass varied little with the growing season mean temperature and precipitation and the soil total N concentration. The SLA-Nmass relationship in S. purpurea did not shift between the semi-humid areas (ratio of rainfall to evaporation > 0.11) and the arid and semi-arid areas (ratio < 0.11), although there was a positive correlation between SLA and Nmass across the five locations. Variation in SLA was mainly determined by leaf density in the semi-humid areas and by leaf thickness in the arid and semi-arid areas; both were negatively correlated with SLA. With increasing temperature or declining precipitation, leaf density decreased and leaf thickness increased, leading to non-significant relationships between SLA and climatic factors. The increase of leaf density in the semi-humid areas was correlated with the increase of Narea, but the increase of leaf thickness in the arid and semi-arid areas did not lead to change of Narea, resulting in unchanged Narea along the rainfall gradient. A positive correlation was detected between aboveground biomass and Narea in S. purpurea, indicating that increased Narea may increase plant productivity. Our findings suggest that alpine plants in arid and semi-arid areas may maintain a constant Narea by increased leaf thickness in order to achieve a similar photosynthetic productivity and water use efficiency compared to the relatively humid areas. The relative impacts of leaf density and leaf thickness on SLA shifted between the semi-humid areas and the arid and semi-arid areas, which may provide insight in detecting the threshold of water limitation in alpine grasslands.
A THEORETICAL MODEL OF VIBRATIONAL PREDISSOCIA-TION VIA INTERMEDIATE STATE COUPLING
分子聚合物中间态耦合振动预离解理论

XIANG TIAN-XIANG,
向天翔

物理学报 , 1990,
Abstract: In this paper, a theoretical model for vibrational predissociation (VP) of molecular clusters via intermediate states is proposed. It is shown that molecular intermediate states play an important role in inducing VP processes of molecular clusters. Based on this theory, a statistical dynamics model is established to describe and interpret qualitatively and semiquantatively the experimental line-broadening effects in various molecular clusters. Finally, we discuss the effects of a variety of coupling mechanisms on the energetic structures and the state relaxation processes in molecular clusters.
ECOSYSTEM STABILITY AND ITS ANALYSING MODEL
生态系统稳定性研究

Yue Tian-Xiang,
岳天祥

生态学报 , 1991,
Abstract:
A New Method for Evaluating the Complexity of Enterprise Management Structure--Entropy Vector Projection
企业管理结构复杂度评价的新方法—熵正交投影法

HE Tian-xiang,
何天祥

系统工程理论与实践 , 2005,
Abstract: A comprehensive method for evaluating the complexity of enterprise management is proposed. Based on the hierarchy theory and the structure entropy theory, considering the state of organization structure and information flow within the structure, the paper puts forth the concepts of layer entropy vector and entropy space. Then a modified orthogonalized projection method is put forward and applied to calculate the values of entropy vector projection as indexes to measure of the complexity of inner layers within the system and the whole management system. Moreover, a method for calculating the factors' weight is expatiated in order to find out the key factors, which determine the complexity of enterprise management structure. Finally, a case of Yinchuan Rubber Plant is studied to verify the conclusion that the proposed method is feasible and valid, and is worthwhile to be popularized.
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