期刊文献+
共找到18篇文章
< 1 >
每页显示 20 50 100
“在L”与“用N”连用格式的考察
1
作者 刘俊超 《黄山学院学报》 2008年第6期105-107,共3页
表处所的"在"字短语和"用"字短语连用的两种格式的区别主要体现在动作方向和动作终点的次范畴意义上,而影响"在L"与"用N"位序的制约因素主要有语义指向、义序、动作的语义角色、语用、时序、... 表处所的"在"字短语和"用"字短语连用的两种格式的区别主要体现在动作方向和动作终点的次范畴意义上,而影响"在L"与"用N"位序的制约因素主要有语义指向、义序、动作的语义角色、语用、时序、意欲这六大制约原则。 展开更多
关键词 “在L” “用n” 连用 语义功能 住序制约原则
下载PDF
“V—N”与“用N V”结构及其相关问题
2
作者 吴德新 《齐齐哈尔大学学报(哲学社会科学版)》 2009年第6期113-115,共3页
本文从句法和语用角度分析了"V—N"与"用N V"格式,探讨了它们的差异和区别。现代汉语中类似于"踢—脚"、"切—刀"的"V—N"格式可以转化为"用脚踢(—下)"、"用刀切(—... 本文从句法和语用角度分析了"V—N"与"用N V"格式,探讨了它们的差异和区别。现代汉语中类似于"踢—脚"、"切—刀"的"V—N"格式可以转化为"用脚踢(—下)"、"用刀切(—下)"的"用N V"的格式。但是这种转换是单项的,两者存在许多相异之处:格式对句法成分、相关句式都有特定要求;语用上存在着工具义隐现与否、语体风格的差异以及有无焦点的区别。 展开更多
关键词 “V—n” “用n V” 工具义
下载PDF
Advances in Research on Water and Fertilizer Coupling and Its Effects on Rice Growth and Utilization Rate of Nitrogen 被引量:1
3
作者 徐优 邓久英 王学华 《Agricultural Science & Technology》 CAS 2015年第4期737-744,共8页
At present, the shortage of agricuItural water resources is worsening. In order to reduce the rice irrigation water and improve the utiIization of fertiIizers so as to achieve the high and stabIe yielding of rice, thi... At present, the shortage of agricuItural water resources is worsening. In order to reduce the rice irrigation water and improve the utiIization of fertiIizers so as to achieve the high and stabIe yielding of rice, this report reviewed the research advances in water and fertiIizer coupIing, the conception of water and fertiIizer cou-pIing and its three kinds of effects (synergy, antagonism, superposition), mechanism of water and fertiIizer coupIing, effects of water and fertiIizer coupIing on growth, deveIopment, yield and quality of rice and effects of water and fertiIizer coupIing on utiIization rate of nitrogen in rice. In addition, the deveIopment prospects of water and fertiIizer coupIing in China were described. It was proposed that the water and fertiIizer coupIing mode is an effective measure to achieve the high yield and quality of rice. According to actual demand, referring to the ideas of promoting fertiIizer with water and reguIating water with fertiIizer, reasonabIe water and fertiIizer cou-pIing mode can be estabIished, thereby improving the utiIization efficiencies of water and fertiIizer. In the premise of saving irrigation water and no increasing fertiIization amount, both high yielding and Iess poI ution can be achieved, providing theoretical and technical basis for water-saving agricuIture and cuItivation and management of rice in future. 展开更多
关键词 Water and fertliizer coupling Rice yleId Utliizatlon rate of nitrogen
下载PDF
Design analysis and its application of M out of N in reactor protection system
4
作者 刘华 李军红 +1 位作者 文杰 阳武娇 《Journal of Measurement Science and Instrumentation》 CAS 2014年第3期60-63,共4页
The reliability and availability of the reactor protection system (RPS) can be improved by using M out of N judg- ment system. By analyzing two quantitative indicators, the rate of refusal to operate and mal-operati... The reliability and availability of the reactor protection system (RPS) can be improved by using M out of N judg- ment system. By analyzing two quantitative indicators, the rate of refusal to operate and mal-operation rate, a strict math- ematical formula and an approximate calculation are stated. The differences of a series of judgment systems are discussed on condition that the unsafe failure probability and the security failure probability are both 0.1. Based on given parameters (A, B,P, Q): A is upper limit of the refusal rate for the RPS, B is upper limit of the real-operation rate, P and Q are basic protection unit rates corresponding to refusal rate and mal-operation rate, respectively. According to these parameters, the values of N and M can be solved. 展开更多
关键词 reactor protection system (RPS) AVAILABILITY RELIABILITY M out of n system quantitative analysis
下载PDF
Nitrogen Status and Utilization in Rhizosphere of Rice 被引量:2
5
作者 HUANGJIAN-GUO YUANLING 《Pedosphere》 SCIE CAS CSCD 1995年第4期325-332,共8页
A greenhouse pot experiment was conducted with hybrid rice (Ocyza Sativa L.) in order to stndy Nstatus and utilization in the rhizosphere of rice. The experiment was composed of three treatments: withoutN,  ̄(15)NH_(4... A greenhouse pot experiment was conducted with hybrid rice (Ocyza Sativa L.) in order to stndy Nstatus and utilization in the rhizosphere of rice. The experiment was composed of three treatments: withoutN,  ̄(15)NH_(4-) N and  ̄(15) NO_(3-) N. Plant roots were separated from the soil by a nylon cloth, and 1 mm incrementsof soil, moving laterally away from the roots, were taken and analyzed for various N froms. The labelled Nin the plants ranged from 67.51% to 69.24% of the total amount of N absorbed by the rice seedlings withthe labelled fertilizer N treatments. This shows that the N in the plants came mainly from the fertilizers.However, the N absorbed by the rice seedlings accounted for less than 35% of the total amount of the Ndepletion in the soil near the rice roots, indicating an important N loss in the rhizosphere of rice. The soilredox potential (all treatments) and the concentration of the labelled NO_3-N (the labelled NH_(4-_)N treatmentonly) decreased as the distance from the rice roots increased in the rhizosphere of rice. In contrast, theconcentration of the labelled NH_(4-) N increased a.s the distance increased in the same soil zone. These resultssuggested that nitrification occurred in the soil around the rice roots. Therefore, the reason for the N lossin the rhizosphere of rice might be the NO_3 movement into the reductive non-rhizosphere soil (submerged)where denitrification can take place. 展开更多
关键词 nITRIFICATIOn nITROGEn RHIZOSPHERE RICE
下载PDF
Zinc phthalocyanine as an efficient catalyst for halogen-free synthesis of formamides from amines via carbon dioxide hydrosilylation under mild conditions 被引量:3
6
作者 Rongchang Luo Xiaowei Lin +2 位作者 Jing Lu Xiantai Zhou Hongbing Ji 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第8期1382-1389,共8页
The combination of a zinc phthalocyanine(ZnPc)catalyst and a stoichiometric amount of dimethyl formamide(DMF)provided a simple route to formamide derivatives from amines,CO2,and hydrosilanes under mild conditions.We d... The combination of a zinc phthalocyanine(ZnPc)catalyst and a stoichiometric amount of dimethyl formamide(DMF)provided a simple route to formamide derivatives from amines,CO2,and hydrosilanes under mild conditions.We deduced that formation of an active zinc‐hydrogen(Zn‐H)species promoted hydride transfer from the hydrosilane to CO2.The cooperative activation of the Lewis acidic ZnPc by strongly polar DMF,led to formation of activated amines and hydrosilanes,which promoted the chemical reduction of CO2.Consequently,the binary ZnPc/DMF catalytic system showed excellent yields and superior chemoselectivity,representing a simple and sustainable pathway for the reductive transformation of CO2into valuable chemicals as an alternative to conventional halogen‐containing process. 展开更多
关键词 Carbon dioxide Zinc phthalocyanine Cooperative effect n‐formylation HYDROSILAnES
下载PDF
The Inhibitory Effects of Arresten Protein on Tumor Formation 被引量:3
7
作者 Yi Lv Jin-ping Zheng 《Chinese Medical Sciences Journal》 CAS CSCD 2012年第1期11-17,共7页
Objective To examine the inhibitory effects of recombinant purified arresten on tumor formation. Methods Purified arresten protein was incubated with human umbilical vein endothelial cells (HUVECs) and HeLa cells in v... Objective To examine the inhibitory effects of recombinant purified arresten on tumor formation. Methods Purified arresten protein was incubated with human umbilical vein endothelial cells (HUVECs) and HeLa cells in vitro. The effect on proliferation of HUVECs and HeLa cells was examined using 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide assay, and apoptosis of these cells monitored by flow cytometry. The effect on migration of HUVECs and HeLa cells was examined by Boyden chamber. Twenty colon carcinoma-bearing C67BL/6 mice were used to investigate the antitumor effects of arresten protein. The mice were randomly divided into arresten treatment group (n=10) and control group (n=10). The microvessel densities of the tumors were measured by immunohistochemical staining with anti-CD31 monoclonal antibody. Results Arresten inhibited the proliferation and migration of HUVECs in a dose-dependent manner while promoting apoptosis. However, arresten had no significant effects on the proliferation and apoptosis of HeLa cells. The migration of HeLa cells was modestly inhibited by arresten. The arresten treatment group of mice showed no weight loss or unusual behavior during the course of treatment, and the tumor growth was significantly decreased; in contrast, the control group of mice exhibited rapidly growing tumors and cachexia. A dramatically decreased microvessel density in tumor tissues was found in arresten-treated mice compared with that in the control mice. Conclusion Arresten can inhibit tumor growth through inhibition of tumor angiogenesis. 展开更多
关键词 ARRESTEn prokaryotic expression PURIFICATIOn TUMOR
下载PDF
Synergistic Catalytic Action of Cobalt(Ⅱ) Hydroxamates and N-Hydroxyphthalimide in the Aerobic Oxidation of p-Xylene 被引量:1
8
作者 JianLIANG JianZhangLI BoZHOU ShengYingQIN 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第1期111-114,共4页
The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-... The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-toluic acid (PTA) were investigated. The results showed that the existing synergistic action in the catalytic oxidation can shorten the induction period of the radical reaction and improve the yield of PTA. 展开更多
关键词 Catalysis n-hydroxyphthalimide (nHPI) cobalt(Ⅱ) hydroxamates oxidation of p-xyl- ene.
下载PDF
Soil animals and nitrogen mineralization under sand-fixation plantations in Zhanggutai region,China 被引量:8
9
作者 CHEN Fu-sheng ZENG De-hui +2 位作者 HU Xiao-fei CHEN Guang-sheng YU Zhan-yuan 《Journal of Forestry Research》 SCIE CAS CSCD 2007年第1期73-77,共5页
The effects of soil animals on soil nitrogen (N) mineralization and its availability were studied by investigating soil animal groups and their amounts of macro-faunas sorted by hand, and middle and microfaunas distin... The effects of soil animals on soil nitrogen (N) mineralization and its availability were studied by investigating soil animal groups and their amounts of macro-faunas sorted by hand, and middle and microfaunas distinguished with Tullgren and Baermann methods under three Pinus sylvestris var. mongolica Litv. plantations in Zhanggutai sandy land, China. In addition, soil N mineralization rate was also measured with PVC closed-top tube in situ incubation method. The soil animals collected during growing season belonged to 13 orders, 5 groups, 4 phyla, whose average density was 86 249.17 individuals·m^(-2). There were significant differences in soil animal species, densities, diversities and evenness among three plantations. Permanent grazing resulted in decrease of soil animal species and diversity. The average ammonification, nitrification and mineralization rates were 0.48 g·m^(-2)·a^(-1), 3.68 g·m^(-2)·a^(-1) and 4.16 g·m^(-2)·a^(-1), respectively. The ammonification rate in near-mature forest was higher than that in middle-age forests, while the order of nitrification and net mineralization rates was: middle-age forest without grazing < middle-age forest with grazing < near-mature forest with grazing (P<0.05). Soil N mineralization rate increased with soil animal amounts, but no significant relationship with diversity. The contribution of soil animals to N mineralization was different for different ecosystems due to influences of complex factors including grazing, soil characteristics, the quality and amount of litter on N mineralization. 展开更多
关键词 Soil animals n mineralization Pinus sylvestris var. mongolica Litv. Zhanggutai sandy land
下载PDF
SOME USEFUL FORMULAE IN SU(N) ALGEBRA
10
作者 宗红石 冯世祥 王子兴 《Nuclear Science and Techniques》 SCIE CAS CSCD 1995年第4期225-225,共1页
Some useful relations in SU(N) algebra are given in this paper. These relations may be useful in deriving the many-body interaction in QCD.
关键词 SU(n) algebra Many body interaction Quantum chromodynamics Hermitian operators Many-dimensional calculations
下载PDF
Predicting GM(1,N) Model for the Coefficient of Variation of Hectometer Yarn's Weight 被引量:1
11
作者 李晓峰 《Journal of Donghua University(English Edition)》 EI CAS 2010年第3期391-394,共4页
The Coefficient of Variation(CV)of hectometer yarn's weight is one of the guidelines to evaluate its intrinsic quality.In the spinning manufacturing,the control of cotton yarn's weight unevenness is accomplish... The Coefficient of Variation(CV)of hectometer yarn's weight is one of the guidelines to evaluate its intrinsic quality.In the spinning manufacturing,the control of cotton yarn's weight unevenness is accomplished mainly in terms of a spot-check on semi-product and a succedent adjust in process parameters during spinning based on technicians' experience.However,it is theoretically believed among manufacturers that with fixed technical levels and parameters in the spinning process,the quality parameters of assorted cotton have a certain influence on the CV.In order to find out a rule of the influence that assorted cotton has on the CV,a GM(1,N)model,correlated raw cotton's quality parameter with the CV,has firstly been developed according to the modeling theory of grey system,and then been applied in the designing step to predict the CV.It has been approved by practical modeling and validation that the model could fit preferably an accrual CV value,and provide a method of quantitative predicting analysis for textile manufacturers to design cotton yarn's quality. 展开更多
关键词 cotton yarn coefficient of variation(CV) raw cotton's quality GM(1 n PREDICTIOn
下载PDF
Studies on characteristics of nanostructure of N-TiO_2 thin films and photo-bactericidal action 被引量:1
12
作者 XU Ming-fang LIN Shan +1 位作者 CHEN Xin-man PENG Yan-zhi 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2006年第7期586-590,共5页
Pseudomonas aeruginosa strain (AS 1.50) and Bacillus subtilis strain (AS 1.439) from Ming lake were decomposed by photocatalytic nanostructure N-TiO2 thin films in a photo-reactor under UV irradiation. The differe... Pseudomonas aeruginosa strain (AS 1.50) and Bacillus subtilis strain (AS 1.439) from Ming lake were decomposed by photocatalytic nanostructure N-TiO2 thin films in a photo-reactor under UV irradiation. The different thickness nanostructure N-TiO2 thin films coated on mesh grid were prepared by sol-gel method and immobilized at 500 ℃ (films A) or 350 ℃ (films B) for 1 h in a muffle furnace. The results showed that N-TiO2 thin film B (8.18 nm thickness, 2.760 nm height and 25.15 nm diameter) has more uniform granular nanostructure and thinner flat texture than N-TiO2 thin film A (12.17 nm thickness, 3.578 nm height and 27.50 nm diameter). The bactericidal action of N-TiO2 thin film A and film B for Pseudomonas aeruginosa strain (AS 1.50) and Bacillus subtilis varniger strain (AS1.439) were investigated in this work. More than 95% of photocatalytic bactericidal efficiency for Pseudomonas aeruginosa strain (AS 1.50) and 75% for Bacillus subtilis strain (AS 1.439) were achieved by using N-TiO2 thin films-B for 70-80 rain of irradiation during the photo-bactericidal experimental process. The results indicated that the photo-induced bactericidal efficiency of N-TiO2 thin films probably depended on the characteristics of the films. 展开更多
关键词 Photocatalytic degradation Photo-bactericidal action n-TiO2 thin film
下载PDF
Protective effect of low dose of melatonin against cholestatic oxidative stress after common bile duct ligation in rats 被引量:6
13
作者 Mukaddes Esrefoglu Mehmet Gül +2 位作者 Memet Hanifi Emre Alaattin Polat Mukadder Ayse Selimoglu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第13期1951-1956,共6页
AIM: To investigate the role of oxidative injury and the effect of exogenous melatonin administration on liver damage induced by bile duct ligation (BDL), and second, to evaluate the role of nitric oxide (NO), a free ... AIM: To investigate the role of oxidative injury and the effect of exogenous melatonin administration on liver damage induced by bile duct ligation (BDL), and second, to evaluate the role of nitric oxide (NO), a free oxygen radical, in oxidative injury. METHODS: Thirty-two Sprague-Dawley rats were assigned to four groups: sham operation (SO), BDL, BDL+melatonin, and BDL+vehicle. Cholestasis was achieved by double ligature of the common bile duct. Melatonin was injected intraperitoneally 500 μg/(kg·d) for 8 d. Hepatic oxidative stress markers were evaluated by changes in the amount of lipid peroxides, measured as malondialdehyde (MDA), and reduced GSH. Total nitrite (NOx) concentrations were determined in hepatic homogenates. Histopathological examination was performed using a histological scoring system. RESULTS: The histopathological changes including portal inflammation, necrosis,apoptosis, focal inflammation and fibrosis were severe in the BDL and BDL+vehicle groups. There were numerous large areas of coagulation necrosis. Histological Activity Index scores of these groups were significantly higher than that of the SO group. Treatment with melatonin reduced these alterations significantly. The degree of necro-inflammation and fibrosis showed significant difference between the BDL and BDL+melatonin groups. BDL was accompanied by a significant increase in MDA and NOx, and a significant decrease in GSH levels. Mean±SE values of MDA, GSH and NOx levels of SO group were 147.47±6.69, 0.88±0.33 μmol/g and 180.70±6.58 nm/g, respectively. The values of BDL group were 200.14±21.30, 0.65±0.02 μmol/g, and 400.46±48.89 nm/g, respectively, whereas the values of BDL+melatonin group were 115.93±6.8,0.74±0.02 μmol/g, and 290.38±32.32 nm/g, respectively. Melatonin treatment was associated with a significant recovery of MDA, GSH and NOx levels. CONCLUSION: We have concluded that oxidative stress is associated with the pathogenesis of cholestatic liver damage and NO contributes to oxidative damage. Melatonin, even at low dose, is an efficient agent in reducing negative parameters of cholestasis. 展开更多
关键词 CHOLESTASIS MELATOnIn Oxidative stress Free radicals Hepatic injury
下载PDF
Expression and correlation of Ezrin and survivin in non-small cell lung cancer
14
作者 Jinghua Wang Min Zhang +2 位作者 Longbang Chen Weisun Huang Henghui Ma 《The Chinese-German Journal of Clinical Oncology》 CAS 2010年第7期381-384,共4页
Objective: The aim of this study was to explore expression and correlation of Ezrin and survivin in non-small cell lung cancer (NSCLC). Methods: Expression of Ezrin and survivin were detected and analyzed by Envision ... Objective: The aim of this study was to explore expression and correlation of Ezrin and survivin in non-small cell lung cancer (NSCLC). Methods: Expression of Ezrin and survivin were detected and analyzed by Envision method of immu- nohistochemical staining in 86 NSCLC. Results: The strong expression rate of Ezrin in NSCLC was 60.5% and significantly correlated with lymph node metastasis (P < 0.05), but no associated with gender, histologic subtype, TNM stages, differen- tiation and smoking. Meanwhile, the positive expression rate of survivin in NSCLC was 65.1% and significantly correlated with TNM stages and lymph node metastasis (P < 0.05), but no associated with gender, histologic subtype, differentiation and smoking. And expression of Ezrin and survivin were positively correlated in NSCLC (r = 0.384). Conclusion: Ezrin and survivin may play synergetic roles in the process of carcinogenesis of NSCLC, and their expression may be significantly associated with NSCLC metastasis. Detection of Ezrin and survivin may be valuable for diagnosing lung cancer metastasis and providing evidence for clinical treatment. 展开更多
关键词 lung cancer EZRIn SURVIVIn METASTASIS IMMUnOHISTOCHEMISTRY
下载PDF
An easily recoverable thermo-sensitive polyelectrolyte as draw agent for forward osmosis process 被引量:4
15
作者 Yanni Wang Hairong Yu +5 位作者 Rui Xie Kuangmin Zhao Xiaojie Ju Wei Wang Zhuang Liu Liangyin Chu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第1期86-93,共8页
As a potential solution to the crises of energy and resources, forward osmosis(FO) has been limited by the development of draw agents. An ideal draw agent should be able to generate high osmotic pressure and can be ea... As a potential solution to the crises of energy and resources, forward osmosis(FO) has been limited by the development of draw agents. An ideal draw agent should be able to generate high osmotic pressure and can be easily recovered. In this study, a thermo-sensitive polyelectrolyte of poly(N-isopropylacrylamide-co-acrylic acid)(PNA)is developed as an efficient draw agent, and two easy and simple methods are proposed to effectively recover the polyelectrolytes. After adjusting the pH value of polyelectrolyte solutions to around 6.0, the polyelectrolyte can generate relatively high osmotic pressure, and induce average water fluxes of 2.09 and 2.95 L·m^(-2)·h^(-1) during12 h FO processes when the polyelectrolyte concentrations are 0.20 and 0.38 g·ml^(-1) respectively. After acidifying and heating to 70 °C, the PNA-10 polyelectrolyte can aggregate together because of hydrophobic association and separate from water, so it can be easily recovered by either simple centrifugation or gravitational sedimentation. The recovery ratios of PNA-10 polyelectrolyte in both methods are as high as 89%, and the recovered polyelectrolytes can be reused with almost the same FO performance as fresh ones. The results in this study provide valuable guidance for designing efficient and easily recoverable draw agents for FO processes. 展开更多
关键词 Forward osmosis Draw agent Thermo-sensitive polyelectrolyte Recovery method Poly(n-isopropylacrylamide-co-acrylic acid)
下载PDF
Responses of Agronomic Benefit and Soil Quality to Better Management of Nitrogen Fertilizer Application in Greenhouse Vegetable Land 被引量:8
16
作者 JIANG Hui-Min ZHANG Jian-Feng +3 位作者 SONG Xiao-Zong LIU Zhao-Hui JIANG Li-Hua YANG Jun-Cheng 《Pedosphere》 SCIE CAS CSCD 2012年第5期650-660,共11页
As a result of intensive greenhouse vegetable production in northern China, the potential risk of nitrogen (N) fertilizer over-applied is increasingly apparent and is threatening ecosystem and the sustainability of ... As a result of intensive greenhouse vegetable production in northern China, the potential risk of nitrogen (N) fertilizer over-applied is increasingly apparent and is threatening ecosystem and the sustainability of food production. An experiment was carried out in Shouguang, Shangdong Province, China to evaluate agronomic benefit and soil quality under different N applications, including the conventional chemical N rate (1000 kg N ha^(-1) season^(-1), N1), 70% of N1 (N2), 70% of N1 + maize straw (N3), 50% of N1 + maize straw + drip irrigation (N4), and 0% of N1 (NO), during two successive growing seasons of autumn-winter (AW) and winter-spring (WS). The maximum yields for N4 were 1.1 and 1.0 times greater than those for N1 in the AW and WS seasons, respectively. N agronomic efficiency (AEN) and apparent N recovery efficiency (REN) were greatest with the N4. A significant relationship was found between soil NO3-N content and electrical conductivity (EC) (R^2 = 0.61 in the AW season and R^2= 0.29 in the WS season). Reducing N fertilizer decreased soil NO3-N accumulation (20.9%-37.8% reduction in the AW season and 11.7%-20.1% reduction in the WS season) relative to the accumulation observed for N1 within the 0-100 cm soil layer. Soil urease and invertase activities were not significantly different among N treatments. The N4 treatment would be practical for reducing excess N input and maintaining the sustainability of greenhouse-based intensive vegetable systems in Shouguang. 展开更多
关键词 maize straw n use efficiency soil enzyme soil nO3-n accumulation tomato yields
原文传递
Site-Specific Nitrogen Management in Dry Direct-Seeded Rice Using Chlorophyll Meter and Leaf Colour Chart 被引量:5
17
作者 Ali Mohamed ALI Harmit Singh THIND +1 位作者 Sandeep SHARMA YADVINDER-SINGH 《Pedosphere》 SCIE CAS CSCD 2015年第1期72-81,共10页
The need to maintain high rice yields and improve fertilizer nitrogen(N)-use efficiency has fueled the use of tools such as leaf colour chart(LCC) and chlorophyll meter(SPAD meter) in managing fertilizer N based on co... The need to maintain high rice yields and improve fertilizer nitrogen(N)-use efficiency has fueled the use of tools such as leaf colour chart(LCC) and chlorophyll meter(SPAD meter) in managing fertilizer N based on colour of the leaf. Field experiments were conducted during 2011 to 2013 at Ludhiana, India to assess the need for basal N application and to establish critical threshold values of leaf greenness as measured by LCC and SPAD meter for formulating strategies for in-season management of fertilizer N in dry direct-seeded rice(DDSR). Avoiding application of N at sowing did not adversely affect rice grain yield, indicating that basal N application in DDSR was not necessary and might lead to reduced N-use efficiency. Monitoring N uptake rate during the growing season of DDSR suggested that N uptake rate peaked at the two growth stages: maximum tillering(42 to 56 days after sowing(DAS))and panicle initiation stages(70 to 84 DAS). Using the Cate-Nelson procedure, critical LCC and SPAD meter values for fertilizer N application worked out to be 4 and 37, respectively. Real-time fertilizer N management strategy based on applying 30 kg N ha-1whenever SPAD meter or LCC readings fell below the critical values maintained optimum rice yields along with higher N-use efficiency than that observed by following blanket recommendation for fertilizer N in the region. The fixed-time variable-dose strategy consisted of applying prescriptive doses of 20 kg N ha-1at 14 DAS and 30 kg N ha-1at 28 DAS and corrective doses of 30, 40 or 50 kg N ha-1at 49 and 70 DAS depending upon LCC shade to be ≥ 4, 4–3.5, or < 3.5 and SPAD meter readings to be ≥ 40, 40–35, or< 35, respectively. This strategy also resulted in optimal rice yield along with higher N-use efficiency as compared to the blanket recommendation. This study revealed that in DDSR, fertilizer N could be managed more efficiently using the tools of LCC and SPAD meter than the current blanket recommendation. 展开更多
关键词 basal n application critical value grain yield leaf greenness n-use efficiency
原文传递
Ru(Ⅱ)-catalyzed ortho-amidation and decarboxylation of aromatic acids: a versatile route to meta-substituted N-aryl benzamides 被引量:1
18
作者 Xian-Ying Shi Xue-Fen Dong +3 位作者 Juan Fan Ke-Yan Liu Jun-Fa Wei Chao-Jun Li 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第8期1286-1291,共6页
Carboxylate as a promising and valuable directing group has attracted a great deal of attention.However,employing it as a traceless direction group has rarely been reported.We developed the ruthenium-catalyzed amidati... Carboxylate as a promising and valuable directing group has attracted a great deal of attention.However,employing it as a traceless direction group has rarely been reported.We developed the ruthenium-catalyzed amidation of substituted benzoic acids with isocyanates via directed C–H functionalization followed by decarboxylation to afford the corresponding metasubstituted N-aryl benzamides,in which the carboxylate serves as a unique,removable directing group.Notably,this protocol can provide an efficient alternative to access meta-substituted N-aryl benzamides,which are much more difficult to prepare than ortho-substituted analogues. 展开更多
关键词 AMIDES DECARBOXYLATIOn AMIDATIOn C-H functionalization homogeneous catalysis
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部