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Search Results: 1 - 10 of 23352 matches for " ZHENG Zhihai "
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Comparison of Ion Balance and Nitrogen Metabolism in Old and Young Leaves of Alkali-Stressed Rice Plants
Huan Wang, Zhihai Wu, Jiayu Han, Wei Zheng, Chunwu Yang
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0037817
Abstract: Background Alkali stress is an important agricultural contaminant and has complex effects on plant metabolism. The aim of this study was to investigate whether the alkali stress has different effects on the growth, ion balance, and nitrogen metabolism in old and young leaves of rice plants, and to compare functions of both organs in alkali tolerance. Methodology/Principal Findings The results showed that alkali stress only produced a small effect on the growth of young leaves, whereas strongly damaged old leaves. Rice protected young leaves from ion harm via the large accumulation of Na+ and Cl? in old leaves. The up-regulation of OsHKT1;1, OsAKT1, OsHAK1, OsHAK7, OsHAK10 and OsHAK16 may contribute to the larger accumulation of Na+ in old leaves under alkali stress. Alkali stress mightily reduced the NO3? contents in both organs. As old leaf cells have larger vacuole, under alkali stress these scarce NO3? was principally stored in old leaves. Accordingly, the expression of OsNRT1;1 and OsNRT1;2 in old leaves was up-regulated by alkali stress, revealing that the two genes might contribute to the accumulation of NO3? in old leaves. NO3? deficiency in young leaves under alkali stress might induce the reduction in OsNR1 expression and the subsequent lacking of NH4+, which might be main reason for the larger down-regulation of OsFd-GOGAT and OsGS2 in young leaves. Conclusions/Significance Our results strongly indicated that, during adaptation of rice to alkali stress, young and old leaves have distinct mechanisms of ion balance and nitrogen metabolism regulation. We propose that the comparative studies of young and old tissues may be important for abiotic stress tolerance research.
Analogue-dynamical Prediction of Numerical Model Errors in the Mid-Lower Reaches of the Yangtze River
Qiguang Wang,Aixia Feng,Guolin Feng,Zhihai Zheng
Physics , 2011,
Abstract: A new prediction error correction scheme based on 74 circulation characteristics data provided by Weather Diagnostic Forecasting Division of National Climate Center, which is designed to develop the Operational Numerical Forecast Model (ONFM) of the National Climate Center of China, and the skill level of the precipitation prediction for rainy season in the midlower reaches (MLR) of the Yangtze River by ONFM is obviously raised. The approach use principal component(PC) analysis to prediction error of ONFM. And we used different factors to correct the different PCs of the error of precipitation field. The comparative study results indicate that the effectiveness of the new analogue error correction (AEC) scheme is better than system error correction (SEC) scheme.
Zircon U-Pb age and Hf isotope of Quanyishang A-type granite in Yichang: signification for the Yangtze continental cratonization in Paleoproterozoic
Qing Xiong,JianPing Zheng,ChunMei Yu,YuPing Su,HuaYun Tang,ZhiHai Zhang
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-008-0401-7
Abstract: Zircon U-Pb age and Hf isotope, and major and trace element compositions were reported for granite at Quanyishang, which intruded into the Kongling complex in Yichang, Hubei Province. The results show that the Quanyishang granite is rich in silicon and alkalis but poor in calcium and magnesium, and displays enrichment in Ga, Y, Zr, Nb but depletion in Sr and Ba, exhibiting the post-orogenic A-type affinity. 90% zircons from the granite are concordant, and give a middle Paleoproterozoic magmatic crystallization age (mean 1854 Ma). Initial Hf isotope ratios (176Hf/177Hf)i of the middle Paleoproterozoic zircons range from 0.280863 to 0.281134 and they have negative εHf(t) values with a minimum of 26.3. These zircons give the depleted mantle model ages (T DM) of 2.9–3.3 Ga (mean 3.0 Ga), and the average crustal model ages (T crust) of 3.6–4.2 Ga (mean 3.8 Ga). A Mesoarchean grain with 207Pb/206Pb age of 2859 Ma has a slightly high T DM (3.4 Ga) but similar T crust (3.8 Ga) to the Paleoproterozoic zircons. All these data suggest that the source materials of the Quanyishang A-type granite are unusually old, at least 2.9 Ga (even Eoarchean). The event of crustal remelting, which resulted in the formation of the Quanyishang granite in the middle Paleoproterozoic, recorded the cratonization of the Yangtze continent. The process may have relation to the extension and collapse of the deep crust with Archean ages, in response to the transition stage of the assembly and breakup of the Columbia supercontinent.
A Study of the Objective and Quantifiable Forecasting Based on Optimal Factors Combinations in Precipitation in the Middle and Lower Reaches of the Yangtze River in Summer
长江中下游汛期降水优化多因子组合客观定量化预测研究

Wang Qiguang,Feng Guolin,Zheng Zhihai and,
王启光
,封国林,郑志海,

大气科学 , 2011,
Abstract: A new approach to improve precipitation in the Yangtze River in summer by using the useful historical data is suggested. The outcomes of the model can be improved by determining the years in which there are similar prediction error fields of precipitation based on 74 circulation characteristic indexes of Weather Diagnostic Forecasting Room of National Climate Center and 40 climate indexes of NOAA, and then the fields are integrated to revise the output errors of the model. The results show that the revised errors using the above method are better than system ones. On the basis of the above conclusions, the objective and quantifiable forecasting (OQF) technique can be established. The steps are selecting pre-factors, determining optimal factor combinations (OFC) of the analogy forecasting error fields, and using the method of weighted average integration. It shows that the technique of OQF based on OFC has a better prediction skill to the regression results of independent samples between 2003 and 2009. Finally, the anomaly correlation coefficient (ACC) of historical data in the error field is analyzed. It is found that the determining of the analogy error field in different years can be improved more, and the possible way to improve is to be discussed.
Improvements to dynamical analogue climate prediction method in China
近年来我国短期气候预测中动力相似预测方法研究与应用进展

LI Weijing,ZHENG Zhihai,SUN Chenghu,
李维京
,郑志海,孙丞虎

大气科学 , 2013,
Abstract: Because the dynamical climate prediction model is ineffective for skillful forecasting on a weekly to intra-annual scale in the East Asia region, the combination of a dynamical and statistical prediction method has been suggested as an optimal strategy. To realize the technique, a forecasting error correction method by utilizing historical analogue information was developed in China. The current applications show that this new method can significantly improve prediction skill in extended range, monthly, seasonal, and El Ni o-Southern Oscillation (ENSO) prediction and hence have encouraged us to further explore operational applications for this method in the future.
Zircon U-Pb age and Hf isotope of Quanyishang A-type granite in Yichang: Signification for the Yangtze continental cratonization in Paleoproterozoic

XIONG Qing,ZHENG JianPing,YU ChunMei,SU YuPing,TANG HuaYun &|ZHANG ZhiHai,

科学通报(英文版) , 2009,
Abstract: Zircon U-Pb age and Hf isotope, and major and trace element compositions were reported for granite at Quanyishang, which intruded into the Kongling complex in Yichang, Hubei Province. The results show that the Quanyishang granite is rich in silicon and alkalis but poor in calcium and magnesium, and displays enrichment in Ga, Y, Zr, Nb but depletion in Sr and Ba, exhibiting the post-orogenic A-type affinity. 90% zircons from the granite are concordant, and give a middle Paleoproterozoic magmatic crystallization age (mean 1854 Ma). Initial Hf isotope ratios (176Hf/177Hf)i of the middle Paleoproterozoic zircons range from 0.280863 to 0.281134 and they have negative εHf(t) values with a minimum of 26.3. These zircons give the depleted mantle model ages (T DM) of 2.9–3.3 Ga (mean 3.0 Ga), and the average crustal model ages (T crust) of 3.6–4.2 Ga (mean 3.8 Ga). A Mesoarchean grain with 207Pb/206Pb age of 2859 Ma has a slightly high T DM (3.4 Ga) but similar T crust (3.8 Ga) to the Paleoproterozoic zircons. All these data suggest that the source materials of the Quanyishang A-type granite are unusually old, at least 2.9 Ga (even Eoarchean). The event of crustal remelting, which resulted in the formation of the Quanyishang granite in the middle Paleoproterozoic, recorded the cratonization of the Yangtze continent. The process may have relation to the extension and collapse of the deep crust with Archean ages, in response to the transition stage of the assembly and breakup of the Columbia supercontinent. Supported by National Natural Science Foundation of China (Grant Nos. 90714002 and 40772042) and National Basic Research Program of China (Grant No. 2006CB403502)
The Metastasis Suppressor, N-myc Downregulated Gene 1 (NDRG1), Is a Prognostic Biomarker for Human Colorectal Cancer
Zhihai Mao, Jing Sun, Bo Feng, Junjun Ma, Lu Zang, Feng Dong, Daohai Zhang, Minhua Zheng
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068206
Abstract: Metastasis remains to be one of the most prevalent causes leading to poor long-term survival of colorectal cancer (CRC) patients. The clinical significances of tumor metastatic suppressor, N-myc downregulated gene 1 (NDRG1), have been inconsistently reported in a variety of cancerous diseases. In this study with 240 CRC clinical specimens, we showed that NDRG1 expression was significantly decreased in most of CRC tissues compared to the paired non-tumor counterparts. Statistical analysis revealed a significant inverse correlation of NDRG1 expression with tumor stage, differentiation status and metastasis. Compared with NDRG1-negative group, NDRG1-positve group had better disease-free/overall survival (p = 0.000) over 5 years’ follow-up. Furthermore, NDRG1 was considered to be an independent prognostic factor for overall survival (p = 0.001) and recurrence (p = 0.003). Our study concludes that NDRG1 is a novel favorable predictor for the prognosis in CRC patients.
华北汛期降水多因子相似订正方案与预报试验
杨杰 YANG Jie,赵俊虎 ZHAO Junhu,郑志海 ZHENG Zhihai,等 et al
大气科学 , 2012, DOI: 10.3878/j.issn.1006-9895.2012.01.02
Abstract: 本文基于动力—相似预报的基本原理,在已初步建立的华北汛期降水模式的动态最优多因子组合相似订正方案工作基础上,研究前期关键因子之间的相互配置对夏季降水的影响,挑选关键的大气环流预报因子。根据预报年前期气候因子的异常状况,通过EOF压缩自由度进行相似年选取,进一步构建了基于前期异常信号的汛期降水相似订正预报方案。研究发现,预报年前期大气环流中异常因子个数的偏多或偏少与该年华北降水的多寡呈现较好的对应关系,并以异常因子的个数状况作为判断该年是否为异常年的标准,将异常多因子方案与动态最优多因子方案相结合,建立模式误差相似订正的多因子综合预报方案。通过诊断分析发现,该方案对降水异常年有着较好的针对性。2003~2009年7年的独立样本回报结果表明:该方法进一步提高了模式对华北汛期降水的预报能力,将华北汛期降水预报的距平相关系数(ACC)平均分从系统订正结果的0.38提高至0.61,具有良好的业务应用前景。
近年来我国短期气候预测中动力相似预测方法研究与应用进展
李维京 LI Weijing,郑志海 ZHENG Zhihai,孙丞虎 SUN Chenghu
大气科学 , 2013, DOI: 10.3878/j.issn.1006-9895.2012.12311
Abstract: 鉴于当前短期气候预测中,纯粹使用动力学方法尚不能完全满足气候预测业务的需要,因此有必要在策略上采取动力和统计相结合的办法。在具体实现手段上,简要介绍了从历史资料中提炼预测信息,发展了一种基于历史相似误差订正的相似—动力短期气候预测新方法。分别在月、季节以及ENSO等短期气候预测领域相继开展了试验和应用,取得了一些令人鼓舞的初步结果,为下一步深入开展有关短期气候预测科学的研究提供了些许借鉴。
长江中下游汛期降水优化多因子组合客观定量化预测研究
王启光 Wang Qiguang,封国林 Feng Guolin,郑志海 Zheng Zhihai,等 et al
大气科学 , 2011, DOI: 10.3878/j.issn.1006-9895.2011.02.08
Abstract: 针对长江中下游区域汛期降水模式预报误差,利用历史资料的有用信息订正模式预报误差。根据国家气候中心预测室提供的74项环流特征量和美国国家海洋和大气管理局发布的40项气候指数,确定降水预报误差场的相似年份,利用相似年的降水误差场对模式结果进行相似误差订正,有别于传统的模式系统误差订正。研究发现,相似误差订正效果明显优于系统误差订正。在此基础上,对前期因子进行筛选,确定相似误差场的多因子优化组合,并结合加权集合平均的方法,提出了基于优化多因子组合的客观定量化预测(OQF)技术。2003~2009年7年的独立样本回报结果表明,基于优化多因子组合的OQF方案具有较高的预报技巧,平均距平相关系数为0.43。最后对历史资料中误差场间的距平相关系数进行分析,发现确定误差场相似年的关键技术还有待于进一步完善,并指出了改进方法的可能途径。
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