Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 30 )

2019 ( 198 )

2018 ( 1208 )

2017 ( 1072 )

Custom range...

Search Results: 1 - 10 of 78275 matches for " Quanzhen Chen "
All listed articles are free for downloading (OA Articles)
Page 1 /78275
Display every page Item
耿全震 Geng Quanzhen,陈受钧 Chen Shoujun
大气科学 , 1996, DOI: 10.3878/j.issn.1006-9895.1996.03.05
Abstract: 根据ECMWF1980~1988年的全球资料,确定了南北两半球对流层上层定常的辐散风所形成的定常涡源的位置、定常波能量传播路径及它们的位置关系,讨论了涡源的形成机制。由此揭示了热带西太平洋积云对流加热、风暴路径上的潜热释放、欧亚大陆冷源及青藏高原热力和动力作用等主要外源在冬夏南北半球定常波形成中的作用。
Modeling Analysis on Germination and Seedling Growth Using Ultrasound Seed Pretreatment in Switchgrass
Quanzhen Wang, Guo Chen, Hayixia Yersaiyiti, Yuan Liu, Jian Cui, Chunhui Wu, Yunwei Zhang, Xueqing He
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0047204
Abstract: Switchgrass is a perennial C4 plant with great potential as a bioenergy source and, thus, a high demand for establishment from seed. This research investigated the effects of ultrasound treatment on germination and seedling growth in switchgrass. Using an orthogonal matrix design, conditions for the ultrasound pretreatment in switchgrass seed, including sonication time (factor A), sonication temperature (factor B) and ultrasound output power (factor C), were optimized for germinating and stimulating seedling growth (indicated as plumular and radicular lengths) through modeling analysis. The results indicate that sonication temperature (B) was the most effective factor for germination, whereas output power (C) had the largest effect on seedling growth when ultrasound treatment was used. Combined with the analyses of range, variance and models, the final optimal ultrasonic treatment conditions were sonication for 22.5 min at 39.7°C and at an output power of 348 W, which provided the greatest germination percentage and best seedling growth. For this study, the orthogonal matrix design was an efficient method for optimizing the conditions of ultrasound seed treatment on switchgrass. The electrical conductivity of seed leachates in three experimental groups (control, soaked in water only, and ultrasound treatment) was determined to investigate the effects of ultrasound on seeds and eliminate the effect of water in the ultrasound treatments. The results showed that the electrical conductivity of seed leachates during either ultrasound treatment or water bath treatment was significantly higher than that of the control, and that the ultrasound treatment had positive effects on switchgrass seeds.
Models Analyses for Allelopathic Effects of Chicory at Equivalent Coupling of Nitrogen Supply and pH Level on F. arundinacea, T. repens and M. sativa
Quanzhen Wang, Bao Xie, Chunhui Wu, Guo Chen, Zhengwei Wang, Jian Cui, Tianming Hu, Pawel Wiatrak
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0031670
Abstract: Alllelopathic potential of chicory was investigated by evaluating its effect on seed germination, soluble sugar, malondialdehyde (MDA) and the chlorophyll content of three target plants species (Festuca arundinacea, Trifolium repens and Medicago sativa). The secretion of allelochemicals was regulated by keeping the donor plant (chicory) separate from the three target plant species and using different pH and nitrogen levels. Leachates from donor pots with different pH levels and nitrogen concentrations continuously irrigated the target pots containing the seedlings. The allelopathic effects of the chicory at equivalent coupling of nitrogen supply and pH level on the three target plants species were explored via models analyses. The results suggested a positive effect of nitrogen supply and pH level on allelochemical secretion from chicory plants. The nitrogen supply and pH level were located at a rectangular area defined by 149 to 168 mg/l nitrogen supply combining 4.95 to 7.0 pH value and point located at nitrogen supply 177 mg/l, pH 6.33 when they were in equivalent coupling effects; whereas the inhibitory effects of equivalent coupling nitrogen supply and pH level were located at rectangular area defined by 125 to 131 mg/l nitrogen supply combining 6.71 to 6.88 pH value and two points respectively located at nitrogen supply 180 mg/l with pH 6.38 and nitrogen supply 166 mg/l with pH 7.59. Aqueous extracts of chicory fleshy roots and leaves accompanied by treatment at different sand pH values and nitrogen concentrations influenced germination, seedling growth, soluble sugar, MDA and chlorophyll of F. arundinacea, T. repens and M. sativa. Additionally, we determined the phenolics contents of root and leaf aqueous extracts, which were 0.104% and 0.044% on average, respectively.
Synergistic and Antagonistic Effects of Salinity and pH on Germination in Switchgrass (Panicum virgatum L.)
Yuan Liu, Quanzhen Wang, Yunwei Zhang, Jian Cui, Guo Chen, Bao Xie, Chunhui Wu, Haitao Liu
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0085282
Abstract: The effects of salt-alkaline mixed stress on switchgrass were investigated by evaluating seed germination and the proline, malondialdehyde (MDA) and soluble sugar contents in three switchgrass (Panicum virgatum L.) cultivars in order to identify which can be successfully produced on marginal lands affected by salt-alkaline mixed stress. The experimental conditions consisted of four levels of salinity (10, 60, 110 and 160 mM) and four pH levels (7.1, 8.3, 9.5 and 10.7). The effects of salt-alkaline mixed stress with equivalent coupling of the salinity and pH level on the switchgrass were explored via model analyses. Switchgrass was capable of germinating and surviving well in all treatments under low-alkaline pH (pH≤8.3), regardless of the salinity. However, seed germination and seedling growth were sharply reduced at higher pH values in conjunction with salinity. The salinity and pH had synergetic effects on the germination percentage, germination index, plumular length and the soluble sugar and proline contents in switchgrass. However, these two factors exhibited antagonistic effects on the radicular length of switchgrass. The combined effects of salinity and pH and the interactions between them should be considered when evaluating the strength of salt-alkaline mixed stress.
Advance in the toxic effects of petroleum water accommodated fraction on marine plankton

Zhibing Jiang,Yijun Huang,Xiaoqun Xu,Yibo Liao,Lu Shou,Jingjing Liu,Quanzhen Chen,Jiangning Zeng,

生态学报 , 2010,
The impact of oil pollution on marine phytoplankton community growth change

HUANG Yijun,CHEN Quanzhen,ZENG Jiangning,JIANG Zhibing,

生态学报 , 2011,
Abstract: Increasing demands for and utilizations of petrochemicals have resulted in an increase in levels of petroleum hydrocarbons in marine,coastal and estuarine environment.Maritime oil contamination usually caused by maritime incidents has catastrophic impacts on the marine environment.More generally,merchant ships can have a significant environmental impact due to on-going human activities,e.g.air and sea pollutions caused by oil,fuel,waste disposal,and the effects of ballast water exchange processes.The oil co...
Influences of the Extratropical Pacific SST on the Precipitation of the North China Region

Geng Quanzhen,Ding Yihui,Huang Chaoying,

大气科学进展 , 1997,
Abstract: The influences of the extratropical Pacific SST on the precipitation of the North China region are reexamined with the observational data and studied with numerical simulations by using NCAR CCM2. It is found that there ex-ist high positive correlations between the annual precipitation of the North China region and the extratropical Pacific SST in late spring, especially in two regions, e.g., the Kuroshio Current region and the midlatitude central Pacific re-gion. The numerical simulations with NCAR CCM2 show that the warmer SSTs in the Kuroshio Current region and the midlatitude central Pacific in late spring can generate a large-scale circulation pattern over the Asia-Pacific re-gion that is favorable to the precipitation of the North China region.
Community pattern and diversity of macrozoobenthos in an intertidal flat, Jiaojiang Estuary

Yongqiang Zhao,Jiangning Zeng,Aigen Gao,Quanzhen Chen,Yibo Liao,Lu Shou,

生物多样性 , 2009,
Abstract: 为了解椒江口滩涂大型底栖动物群落格局与多样性, 揭示其对环境变化的响应规律, 作者于2007年10月、2008年1月、4月和7月在椒江口南岸和北岸潮间带, 沿河流到海洋方向共布设6条采样断面进行大型底栖动物调查。分析了大型底栖动物种类组成、栖息密度和生物量的时空变化特征, 在此基础上运用α, β和γ多样性测度方法对大型底栖动物多样性进行分析, 同时探讨了大型底栖动物群落结构对环境变化的响应方向及程度, 结果显示: (1) 6条断面共记录到大型底栖动物78种, 总种数随季节变化显著, 在空间上沿河流到海洋方向呈升高趋势; (2) 栖息密度的季节变化不显著(P=0.145>0.05), 但空间变化显著(P=0.017<0.05), 生物量的季节变化显著(P=0.012<0.05), 空间变化极显著(P=0.004<0.01); (3) β和γ多样性指数定量显示了椒江河口区域滩涂环境的多变性和大型底栖动物群落的多样性和更替性。
A simulation of the combined effects of temperature increase and chlorination on phytoplankton in a coastal power plant cooling system

JIANG Zhibing,ZENG Jiangning,CHEN Quanzhen,ZHENG Ping Laboratory of Marine Ecosystem Biogeochemistry,Second Institute of Oceanography State Oceanic Administration,Hangzhou College of Environmental,Resource Science,Zhejiang University,Hangzhou,

环境科学学报 , 2009,
Abstract: 为探明当前滨海电厂冷却系统热冲击和加氯对浮游植物的影响程度,于室内对采自乐清湾的浮游植物进行短期(15、30 min)温升(0、4、8、12℃)和加氯(O、1.0、1.8、3.2 mg·L-1)胁迫的模拟研究.结果表明,加氯、暴露时间、加氯和温升间的交互作用对叶绿素a(Chl-a)浓度有显著影响(P<0.01).但温升对Chl-a浓度无显著影响(P>0.05).热冲击和加氯胁迫后.浮游植物细胞活性显著降低(P<0.05).加氯对Chl-a浓度及浮游植物细胞活性影响最大.目前,滨海电厂浓度为1-2 mg·L-1的加氯处理对浮游植物影响较大,但温升8-12℃的热冲击对浮游植物影响不大.
Diversity of microorganisms in sediments of the Jiaojiang Estuary as estimated by Biolog and PCR-DGGE

DU Ping,LIU Jingjing,SHEN Lidong,HU Baolan,ZENG Jiangning,CHEN Quanzhen,SHOU Lu,LIAO Yibo,

环境科学学报 , 2012,
Abstract: Biolog and PCR-DGGE methods were used to estimate the catabolic and genetic diversity of microorganisms in the surface sediments at six sites in the Jiaojiang Estuary. The package CANOCO was used to determine the correlation between microbial diversity and physiochemical parameters. It was shown by Biolog that the microbial metabolic activity was in the order of intertidal zone and mouth of the estuary>within the mouth>outside the mouth.The values of Shannon-Wiener index for microbial carbon sources ranged from 2.09 to 3.25 in the order of intertidal zone and mouth of the estuary>within the river course > near the mouth > outside the mouth. The use efficiency of different carbon sources for microorganisms was similar in the intertidal zone, mouth of the estuary and within the estuary. However, different use efficiencies of carbon sources were observed near and outside the mouth, where the use efficiency of polymers for microorganisms was much higher than those of amino acids or amine. The DGGE results indicated high spatial heterogeneity of bacterial community structures along the salinity gradient and high similarity (82.27%) of the bacterial community structure between the two sampling sites in the intertidal zone. The values of Shannon-Wiener index for bacterial community structure ranged from 1.68 to 2.87 in the order of intertidal zone > mouth of the estuary > outside the mouth > near the mouth > within the river course. Redundancy gradient analysis (RDA) showed that the distribution of organic matter and nitrobenzene mainly explained the change of microbial catabolism. On the other hand, Canonical correspondence analysis (CCA) showed that the bacterial community structure might be significantly influenced by nitrobenzene and PAHs. Therefore, we concluded that the diversity of microbial catabolism and community structure in the surface sediments of Jiaojiang Estuary was influenced by both the estuarine physicochemical conditions and anthropogenic pollution.
Page 1 /78275
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.