检索结果-南通市图书馆

Nitrification Potential of Soils Under Liquid Incubation Conditions

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2005年第3期15卷 379-385页

作者： YUANFei RANWei shenqi-rong CollegeofResourcesandEnvironmentalSciences NanjingAgriculturalUniversityNanjing210095（China）

A red soil, a fluvo-aquic soil and a permeable paddy soil were used in a long-term investigation to study changes in nitrification with treatments: 1) soil incubation, 2) liquid incubation inoculated with soil samples, and 3) liquid incubation inoculated with ammonia-oxidizing bacteria (AOB) from the soils. There were significant differences (P < 0.001) in nitrification rates among the three soils when measured for 28 days by adding (NH4)SO4 at the rate of 154 mg N kg-1 dry soil to fresh soil. However, t…

关键词： ammonia-oxidizing bacteria nitrification pH soil type

The Measurement of Membrane Potential and NO3 Activity in Root Cells Using Ion-Selective Microelectrodes

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2003年第10期2卷 1097-1101页

作者： FANXiao-rong AnthonyJMiller shenqi-rong NanjingAgriculturalUniversity Nanjing210095P.R.China AgricultureandEnvironmentDivision RothamstedResearchHarpendenAL52JQUK）

Remobilisation of nitrate in plants, especially in vacuole of plant, is mostly related to the qua- lity of agricultural products and the high nitrogen use efficiency in plants. Ion-selective microelectrodes offer a non-destructive and non-interruptive method to measure NO 3 gradients and electric potential differences across both the plasma membrane and tonoplast. Thus, a double-barrelled microelectrode backfilled with a membrane sensor for NO 3 embedded in poly vinyl chloride (PVC) can record the NO 3 activity in cytoplasm and vacuole of a cell. This paper presented how to make this kind of microelectrode and how to do the intracellular measurements on intact plants. Our result showed that nitrate activity was about 2.7 mmol L 1 in cytoplasm while 70 mmol L 1 in vacuole, which implicated that vacuole was a pool of nitrate in plants.

关键词： Ion-selective microelectrodes Membrane potential NO 3 activity

Effect of NH_4^+-N/NO_3^--N Ratios on Growth and Some Physiological Parameters of Chinese Cabbage Cultivars

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2005年第3期15卷 310-318页

作者： CHENWei LUOJin-Kui shenqi-rong CollegeofResourceandEnvironmentalSciences NanjingAgriculturalUniversityNanjing210095（China）

The responses of three cultivars of Chinese cabbage (Brassica chmensis L.), one of the main vegetable crops in China, to different ratios of NH4+-N/NO3--N was investigated to find the optimal ratio of ammonium to nitrate for maximal growth and to explore ways of decreasing the nitrate content, increasing nitrogen use efficiency of Chinese cabbage, and determining distributions of nitrogen and carbon. Three cultivars of Chinese cabbage were hydroponically grown with three different NH4+-N/NO3--N ratios (0:10…

关键词： BEAN PHASEOLUS-VULGARIS NITRATE ACCUMULATION NITROGEN FORM MAIZE AMMONIUM EXPRESSION TRANSPORT NUTRITION CARBON ROOTS

Effect of Incorporation of Wheat Straw and Urea into Soil on Biomass Nitrogen and Nitrogen-Supplying Characteristics of Paddy Soil

在线全文

学校读者我要写书评

暂无评论

Pedosphere 1993年第3期3卷 201-205页

作者： shenqi－rong XUSHOU－MING 等 DepartmentofSoilScienceandAgrochemistry NanjingAgriculturalUniversityNanjing210014（China） NantongIns

Pot experiments were carried out to study the effect of incorporation of wheat straw and/ or urea into soil on biomass nitrogen and mineral nitrogen and its relation to the growth and yield of rice. The combined application of wheat straw and urea increased much more biomass nitrogen in soil than the application of wheat straw or urea alone and consequently increased the immobilization of urea nitrogen added and reduced the loss of urea nitrogen. An adequate nitrogen-supplying process to rice plant could be obtained if C / N ratio of the material added was about 20. The three yield components of rice were affected significantly by the status of nitrogen supplying. More than 30mg N / kg soil of mineral nitrogen at effective tillering stage, panicle initiation stage and filling stage should be maintained in order to get high rice yield, though the criteria varied with the different experimental conditions.

关键词： biomass nitrogen mineral nitrogen urea wheat straw

Effect of Different Water Management and Nitrogen Forms on Characteristics of Iron Nutrition of Rice Cultivated Under Aerobic Condition

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2003年第9期2卷 1014-1020页

作者： QIANXiao-qing shenqi-rong WANGJuan-juan： YANGJian-chang ZHOUMing-yao BAIYan-chao CollegeofResourcesandEnvironmentalSciences NanjingAgriculturalUniversityNanjing810095P.R.China CollegeofAgronomy YangzhouUniversityYangzhou225009P.R.China CollegeofHydraulicandCivilEngineering YangzhouUniversityYangzhou225009P.R.China

Although available iron is usually abundant for the growth of rice cultivated in waterlogged condition, the rice crop may suffer from its deficiency when cultivated in aerobic soil since the soil properties are totally different from waterlogged. Solubility of iron is very low in soils with high Eh and/or high pH. A field experiment with five different depth (10, 20, 30, 40 and 50 cm) of groundwater, and a pot experiment with five treatments of ammonium nitrate ratio (100/0, 75/25, 50/50, 25/75 and 0/100) were conducted to study the characteristics of iron nutrition of rice in non full irrigation condition. Moreover, the contents of iron extracted by 1 mol L 1 HCl of rice plant samples of 8 cultivars from both aerobic and waterlogged cultivation were analyzed to study the effect of water regimes on iron content of rice plants. The results were as follows: (1) The average content of available Fe (2.70 mg kg 1 ) of 5 layers of the soil treated with 10 cm depth of groundwater was significantly higher than that (0.83 mg kg 1 ) with 50 cm depth of groundwater, and the iron concentration of rice plant of the former was much higher than that of the later. (2) Iron deficiency of rice became much severe when high ratio of nitrate (more than 75 percent) in nitrogen fertilizer applied at different intervals in aerobic cultivation. (3) The iron concentrations of 3 cultivars, Wuyujing3 (99 mg kg 1 ), Yangdao4 (87 mg kg 1 ) and 9520 (95 mg kg 1 ), of rice plants cultivated in aerobic condition were significantly less than those(195, 197 and 175 mg kg 1 ) respectively in waterlogged condition at tillering stage. And even much significant differences existed in the iron concentrations of different cultivars growing in the aerobic and waterlogged condition at maturity.

关键词： Water stress Rice Iron nutrition

Effect of Initial Soluble Salt Composition of Saline Soil on Salinity Tolerance of Barley Plant

在线全文

学校读者我要写书评

暂无评论

Pedosphere 1991年第4期1卷 355-362页

作者： shenqi－rong LIUZHAO－PU 等 DepartmentofSoilScienceandAgrochemistry NanjingAgriculturalUniversityNanjing210014（China） Department

A pot experiment was carried out on a marine saline soil to study the effect of initial soluble Na/Ca ratio of saline soil on the salinity tolerance of barley *** results showed that (1) the Na/Ca ratio affected significantly the dry weight of the plant at an earlier stage of growth,the critical values of initial Na/Ca ratio at which the plant could grow normally on soils containing salts of 2.5,3.5 and 4.5g kg^-1 were 30,20 and 15,respectively;(2)smaller Na/Ca ratio resulted in a considerable decrease in Na accumulation but a great increase in K accumulation in the barley plant;and (3) the plasmallema of barley leaf were badly injured when the Na/Ca ratio was more than 30 and the increase of Na content of plant caused an exudation of K from the leaf *** critical indexes were suggested for the cultivation of barley plant on marine saline soils and could be used as reference in the biological reclamation of marine saline soils.

关键词： barley initial soluble Na/ Ca ratio marine saline soil salinity tolerance salt content

Empirical likelihood for spatial cross-sectional data models with matrix exponential spatial specification

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 125-139页

作者： LIU Yan rong Jian-rong QIN Yong-song Nanning University Nanning 530200China Center for Applied Mathematics of Guangxi and College of Mathematics and Statistics Guangxi Normal UniversityGuilin 541004China

In this paper,we study spatial cross-sectional data models in the form of matrix exponential spatial specification(MESS),where MESS appears in both dependent and error *** empirical likelihood(EL)ratio statistics are established for the parameters of the MESS *** is shown that the limiting distributions of EL ratio statistics follow chi-square distributions,which are used to construct the confidence regions of model *** experiments are conducted to compare the performances of confidence regions based on EL method and normal approximation method.

关键词： MESS empirical likelihood con dence region

Some convergence theorems of fuzzy concave integral on fuzzyσ-algebra

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2024年第3期39卷 438-447页

作者： SUN rong School of Mathematics and Statistics Chongqing Technology and Business UniversityChongqing 400067China Chongqing Key Laboratory of Statistical Intelligent Computing and Monitoring Chongqing Technology and Business UniversityChongqing 400067China

In this paper,we consider the extension of the concave integral from classical crispσ-algebra to fuzzyσ-algebra of fuzzy ***,the concept of fuzzy concave integral on a fuzzy set is ***,some important properties of s... 详细信息

关键词： convergence theorems fuzzy concave integral fuzzyσ-algebra

Petrogenesis and Tectonic Significance of Shenxianshui Alkaline Granite in Gejiu,Yunnan Province,China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2024年第2期98卷 368-385页

作者： YANG rong CHEN Yongqing School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China

The Shenxianshui granites in the western Gejiu area were formed in the Late *** ablation inductively coupled plasma mass spectrometry indicates zircon U-Pb ages ranging from 90.67±0.7 to 85.97±0.6 *** intrusive rocks are peraluminous(A/CNK=1.03 to 1.33)and calc-alkaline,showing an affinity towards I-type *** ion lithophilic elements are enriched in K and Rb,while high field strength elements are ***,light rare earth elements are significantly enriched,showing a slight negative Eu anomaly(Eu/Eu^(*)=0.39 to 0.58).Shenxianshui granite has a relatively high initial Sr isotope ratio(^(87)Sr/^(86)Sr)_(i)(0.7098-0.7105),negative ε_(Nd)(t)values(−7.99 to−7.44)and negative ε_(Hf)(t)values(−8.37 to−2.58).Combined with previous studies,these characteristics suggest that the Shenxianshui alkaline granites were formed in a post-collision extensional *** alkaline granitic magma possibly originated from the partial melting of the lower crust during the Mesoproterozoic era and may have contained mantle source *** alkaline granite was formed from mixed magma with a high degree of crystal *** abundance of ore-forming elements indicates that Shenxianshui granite has the potential to mineralize key metals and rare earth elements.

关键词： I-type granite zircon U-Pb geochronology Sr-Nd-Pb isotopes Hf isotope Gejiu