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Search Results: 1 - 10 of 28841 matches for " Sheng Qiang "
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Impacts of oasis on the atmospheric hydrological cycle over the nearby desert  [PDF]
Qiang Zhang, Yuhe Nan, Sheng Wang
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.27084
Abstract: Using the data of “A field experiment on landatmosphere interaction over arid region in Northwest China” carried out in Dunhuang of Gansu Province from May to June 2000; Characteristics of the atmospheric humidity over desert and Gobi near oasis in the Northwest China Arid Region are analyzed. According to the difference of the characteristics in different wind directions, the impacts of oasis on atmospheric hydrological cycle over desert and Gobi near it are revealed. The relation of atmosphere inverse humidity and negative water vapor flux to wind direction and atmospheric stability is studied. It shows that distribution of the atmosphere inverse humidity is inconsistent with that of the negative water vapor flux; sometimes 1-hour-average value demonstrates the characteristic of counter-gradient transfer. And the diurnal variation of distribution of the counter-gradient transfer and the effect of atmospheric stability on the counter-gradient transfer are also given.
BF3.OEt2-Mediated Benzylation of Arenes and Heteroarenes with Benzyl Ether Derivatives  [PDF]
Ling Dang, Qiang Li, Tongmei Ma, Sheng Sheng, Wei Zeng
International Journal of Organic Chemistry (IJOC) , 2011, DOI: 10.4236/ijoc.2011.14026
Abstract: An efficient BF3.OEt2-promoted benzylation of arenes and heteroarenes with various benzyl ether derivatives has been developed. This method provided alternative access to valuable diarylmethane in good yields under mild conditions via an easy work-up procedure.
Inversion and Feedback Research on the Temperature Control and Crack Prevention for Concrete Crane Beam on Rock Wall
Yang Zhang,Sheng Qiang
International Journal of Image, Graphics and Signal Processing , 2011,
Abstract: Concrete crane beam on a rock wall on a new structure used in underground building has become more common in recent year. But the concrete beam cracking problem always perplexes scientists and engineers. In order to solve this, the construction information inversion and feedback analysis method is applied. A beam section was taken as a prototype experiment. The temperature and construction data was collected to inverse some necessary thermal parameters. According to the characteristics of concrete temperature field, the basic accelerating genetic algorithm was improved. The improved accelerating genetic algorithm has the merits of high precision and fast calculation. With this algorithm, the calculation temperature and measured value are very close, which shows the method is efficiency. Then inversed parameters were applied in the feedback simulation. According to the simulation results, the proper temperature control method was suggested. By this way, the concrete temperature was controlled well and the beams appear no crack in recent two year. The successful application shows that the inversion and feedback analysis of concrete temperature field can reflect the factual performance of concrete and give important direction to engineering construction.
Effects of Winter Harvesting and Salinity on the Structure of Regrowing Reed Stands  [PDF]
Mingyao Huang, Qiang Sheng, Jihua Wu, Xiaoyun Pan
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.521339
Abstract: Harvest and salinity are two important factors of the growth of common reed (Phragmites australis). We here examined the different impact of winter harvest treatment on the Phragmites australis between high and low salinity (mean soil electrical conductivity is 7.87 ms/cm and 0.91 ms/cm) areas in Dongtan wetland of Yangtze River estuary, China. We measured phenology, Shoot density, stem diameter and height, biomass (total, aboveground and belowground biomass) and spike weight. At high salinity areas, harvest significantly inhibited the individual growth of stem height yet enhanced ramet density, and consequently led to an insignificant change in aboveground biomass. The belowground parts of reed were significantly inhibited. The root shoot ratio and the proportion of asexual reproduction decreased significantly. At low salinity areas, however, winter harvest generally has no significant influence on reed growth. Our results suggest that the winter harvest management may cause a decline of reed populations in the long term under condition of high salinity; however winter harvesting can be suggested as a proper management for sustainable utilization of reed communities at low salinity areas.
Quantitative analysis of weed communities in cotton fields in cotton-growing regions of Jiangsu Province
江苏省棉区棉田杂草群落发生分布规律的数量分析

QIANG Sheng,
强胜

生态学报 , 1999,
Abstract: The outputs of a principal component analysis (PCA) were ecologically interpreted, after the overall weed infestation indexes of all weed populations occurred in 82 sampling sites amounted to 57 5hm 2 cotton fields was assessed by visual scoring the level of weed infestation to cotton in seven scales. There was a close correlationship among the structure of weed community, crop rotation system and geographical factors. The marked difference in water content of soil resulted from the different crop rotation system with rice or dry crop significantly diversified weed distribution and occurrence in the cotton fields. The cropping rotation system with cotton rice resulted in identity of weed communities in the cotton fields. While soil and climate factors determined by geographical regions significantly influenced the communities in the cotton fields with succession of dry cropping system. All sampling sites were divided into four groups by PCA. The group of cotton cropping of rotation with rice had such dominants as Echinochloa crusgalli, Digitaria sanguinalis, Eclipta prostrata and Leptochloa chinensis. Three dry cropping succession groups respectively were Huaibei cotton growing region group with dominant weed Eleusine indica, Digitaria sanguinalis and Portulaca oleracea, Yanhai cotton growing group with Digitaria sanguinalis, Acalypha australis and Cephalanoplos segetum, and Yanjiang cotton growing group with Digitaria sanguinalis, Setaria viridis and Acalypha australis from the north to the south. According to the above weed distribution and occurrence pattern, weed control strategy was suggested.
Quantitative analysis of weed communities in cotton fields in cotton growing regions of Jiangsu Province
江苏省棉区棉田杂草群落发生分布规律的数量分析

QIANG Sheng,
强胜

生态学报 , 1999,
Abstract: The outputs of a principal component analysis (PCA) were ecologically interpreted, after the overall weed infestation indexes of all weed populations occurred in 82 sampling sites amounted to 57 5hm 2 cotton fields was assessed by visual scoring the level of weed infestation to cotton in seven scales. There was a close correlationship among the structure of weed community, crop rotation system and geographical factors. The marked difference in water content of soil resulted from the different crop rotation system with rice or dry crop significantly diversified weed distribution and occurrence in the cotton fields. The cropping rotation system with cotton rice resulted in identity of weed communities in the cotton fields. While soil and climate factors determined by geographical regions significantly influenced the communities in the cotton fields with succession of dry cropping system. All sampling sites were divided into four groups by PCA. The group of cotton cropping of rotation with rice had such dominants as Echinochloa crusgalli, Digitaria sanguinalis, Eclipta prostrata and Leptochloa chinensis. Three dry cropping succession groups respectively were Huaibei cotton growing region group with dominant weed Eleusine indica, Digitaria sanguinalis and Portulaca oleracea, Yanhai cotton growing group with Digitaria sanguinalis, Acalypha australis and Cephalanoplos segetum, and Yanjiang cotton growing group with Digitaria sanguinalis, Setaria viridis and Acalypha australis from the north to the south. According to the above weed distribution and occurrence pattern, weed control strategy was suggested.
THE HISTORY AND STATUS OF THE STUDY ON CROFTON WEED(EUPATORIUM ADENOPHORUM SPRENG. )A WORST WORLDWIDE WEED
世界性恶性杂草──紫茎泽兰研究的历史及现状

Qiang Sheng,
强胜

植物科学学报 , 1998,
Abstract: 紫茎泽兰又名破坏草,其学名为Eupalo,。u。。ade;;opho;、。nSprengel,[Age。t。naade。;opho;a(Spreng.)K.&R,E.glandulosumH.B.K.nonMichx.j,英文名为Croftonweed或Pamakani,菊科泽兰属多年生杂草。原产美洲的墨西哥至哥斯达黎加一带,后作为观赏植物被引种到欧洲"',后再引到澳洲和亚洲'"。显然,长距离的传播是借助于人的力量。不过,短距离传播扩散都是由其自身的瘦果扩散能力,经风力完成的'"。现已广泛分布在世界热带、亚热带地区30多个国家和地区。除中美洲原产地外,其中还包括美国'"'、澳大利亚","…
Effect of Essential Oil Extracted from Acorus tatarinowii Rhizomes on Germination and Growth of Barnyardgrass, Eclipta and Rice(Oryza sativa)
石菖蒲根茎挥发油对稗、鳢肠和水稻的萌发与生长的影响

Qiang Sheng,
强胜

植物科学学报 , 2003,
Abstract: The laboratory and glasshouse experiments were conducted to evaluate the effect of fraction 4 on seed germination and seedling growth of barnyardgrass (Echinochloa crusgalli (L.) Beauv.), eclipta(Eclipta prostrata(L.) L.) and rice(Oryza sativa L.), which was separated from the essential oil of rhizomes of grass-leaved sweetflag(Acorus tatarinowii) that was dephlegmated at low pressure. A common phenomenon was observed in both laboratory and greenhouse trials, that is, seed germination and seedling growth was inhibited at higher concentration but slightly increased at 50 mg/L or lower concentration. Under laboratory conditions, inhibition was observed at concentration from 50~400 mg/L and more than 90% inhibition with >400 mg/L. However, under glasshouse conditions, inhibition occurred at 3000 mg/L or higher while increase of the growth was observed at 1000 mg/L or lower concentration.
A Data Compression Algorithm for Wireless Sensor Networks Based on an Optimal Order Estimation Model and Distributed Coding
Peng Jiang,Sheng-Qiang Li
Sensors , 2010, DOI: 10.3390/s101009065
Abstract: In many wireless sensor network applications, the possibility of exceptions occurring is relatively small, so in a normal situation, data obtained at sequential time points by the same node are time correlated, while, spatial correlation may exist in data obtained at the same time by adjacent nodes. A great deal of node energy will be wasted if data which include time and space correlation is transmitted. Therefore, this paper proposes a data compression algorithm for wireless sensor networks based on optimal order estimation and distributed coding. Sinks can obtain correlation parameters based on optimal order estimation by exploring time and space redundancy included in data which is obtained by sensors. Then the sink restores all data based on time and space correlation parameters and only a little necessary data needs to be transmitted by nodes. Because of the decrease of redundancy, the average energy cost per node will be reduced and the life of the wireless sensor network will obviously be extended as a result.
Adaptive Responses of Birch-Leaved Pear (Pyrus betulaefolia) Seedlings to Salinity Stress
Qiang Sheng WU,Ying Ning ZOU
Notulae Botanicae Horti Agrobotanici Cluj-Napoca , 2009,
Abstract: One-year-old birch-leaved pear (Pyrus betulaefolia Bunge) seedlings were subjected to 0, 50, 100, 150, and 200 mmol/L NaCl solutions for 27 days in order to study the effects of salinity stress on photosynthesis, ion accumulation and enzymatic and non-enzymatic scavenging of reactive oxygen species in the seedlings. The research was performed in a greenhouse using potted trees. Salinity stress reduced photosynthetic rates, stomatal conductance and water use efficiency of leaves of the pear seedlings, but increased transpiration rates and leaf temperature. Hydrogen peroxide and superoxide anion radical contents increased with increasing NaCl concentrations, a phenomena also observed for malondialdehyde, suggesting that leaves of the pear seedlings suffered from oxidative injury. Superoxide dismutase (SOD) and catalase (CAT) activities quickly responded by increasing when the pear seedlings were subjected to salinity stress. Total protein content in leaves of the seedlings was restrained by salinity stress, whereas ascorbate content increased. Salinity stress reduced glutathione content once the birch-leaved pear seedlings were exposed to a low level (50 or 100 mmol/L) of NaCl, whereas a high level (150 or 200 mmol/L NaCl) of salinity stress stimulated the accumulation of glutathione. Salinity stress increased the accumulation of Na+, Cl-, K+ and Mg2+ in the seedlings, but reduced Ca2+ levels and the ratio of other ions to Na+ except K+/Na+ under 50 mmol/L NaCl conditions. This suggests that leaves of birch-leaved pear seedlings possess the capacity for salt exclusion only under 50 mmol/L NaCl conditions, and Ca2+ does not play a fundamental role as a secondary messenger under salinity stress conditions.
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