Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Ying Yong Sheng Tai Xue Bao ; 30(10): 3443-3451, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31621231

RESUMO

To tackle the issue of rainfall delay during dryland wheat sowing season and further examine the effects of seeding rate on water use and yield formation, a field experiment was conducted at Wenxi Experimental Station, Shanxi Province between 2015 and 2017. We used two sowing dates, i.e. September 20 and October 10 as early (EB) and late (LB) sowing in main plots, and each with three seeding rates as 67.5 (LD), 90 (MD) and 112.5(HD) kg·hm-2. The results showed that compared with LB, EB increased total soil water consumption by 11-22 mm over the entire growing season. With the increases of seeding density, total soil water consumption increased by 2-20 mm. Soil water consumption before anthesis tended to increase for LB, while there was a significant increase of soil water consumption after anthesis for EB. Compared with LB, the pre-anthesis nitrogen translocation and post-anthesis nitrogen accumulation amount in EB were increased under LD and MD, but decreased under HD. For EB, the pre-anthesis nitrogen translocation amount and post-anthesis nitrogen accumulation amount were highest at LD. Under LB, the pre-anthesis nitrogen translocation amount and post-anthesis nitrogen accumulation amount were greatest at high sowing density. EB significantly increased grain yield by 163-996 kg·hm-2 than LB. EB significantly increased grain yield and water use efficiency by 5%-26% and 2%-21% compared with LB, respectively. The nitrogen absorption efficiency and harvest index were 3%-36% and 11% higher under LB than that under EB. As for seeding rate, a low level tended to gain higher grain yield, water use efficiency, nitrogen uptake efficiency and nitrogen harvest index under EB, whereas a high level tended to gain higher values of grain yield, water use efficiency, nitrogen uptake efficiency and nitrogen harvest index under LB. In addition, the pre-anthesis nitrogen translocation was closely related with 100-200 cm soil water consumption before anthesis, especially for stem + sheath, glume + spike nitrogen translocation. The post-anthesis nitrogen accumulation was significantly correlated with 100-300 cm soil water consumption after anthesis. In conclusion, early sowing with a seeding rate of 67.5 kg·hm-2 and late sowing with a seeding rate of 112.5 kg·hm-2 could be promising options to boost dryland wheat production.


Assuntos
Solo , Triticum , Biomassa , Ingestão de Líquidos , Nitrogênio , Água
2.
J Inequal Appl ; 2017(1): 145, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28680248

RESUMO

In this paper, we present a QP-free algorithm for nonlinear semidefinite programming. At each iteration, the search direction is yielded by solving two systems of linear equations with the same coefficient matrix; [Formula: see text] penalty function is used as merit function for line search, the step size is determined by Armijo type inexact line search. The global convergence of the proposed algorithm is shown under suitable conditions. Preliminary numerical results are reported.

3.
Org Biomol Chem ; 14(46): 10833-10839, 2016 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-27805214

RESUMO

A novel method for the construction of allyl arylsulfone derivatives was developed by palladium catalyzed allylation of sulfonyl hydrazides with alkynes. A series of structurally diverse allyl arylsulfones can be regioselectively synthesized in high yields under mild conditions.

4.
Ying Yong Sheng Tai Xue Bao ; 27(1): 117-24, 2016 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-27228600

RESUMO

Field experiments were carried out to study the effects of different mulching times (30 or 60 d after previous wheat harvest) and mulching methods (whole-mulching, half-mulching and no- mulching) on wheat plant N absorption and assimilation after deep plowing in fallow period on dryland. The results showed that mulching improved water storage efficiency in fallow period and soil water storage of 0-300 cm at sowing stage significantly. Mulching in fallow period, especially the whole-mulching, increased the N accumulation amount of each growth stage, N translocation amount and rate before anthesis (NABA) , and N accumulation amount after anthesis (NAAA) and grain N. Yield, N uptake efficiency (NUPE), N partial factor productivity (NPFP) and N harvest index (NHI) were all significantly increased under mulching, and whole-mulching had better effects. Mulching at 30 d after previous wheat harvest significantly increased the soil water storage of 0-300 cm at sowing stage and the water storage efficiency in fallow period compared with mulching at 60 d after previous wheat harvest. Compared with mulching at 60 d after previous wheat harvest, mulching at 30 d increased the N accumulation amount of each growth stage, the N accumulation amount in leaf and shoot at maturity, the NABA of stem + sheath, leaf and shoot and the yield. The soil water at the depth of 0-300 cm at sowing stage was positively correlated to N mobilization amount before anthesis and N accumulation amount after anthesis. The N mobilization amount of stem + sheath had a remarkable direct effect on its yield with the direct path coefficient of 0.619. In summary, mulching in fallow period increased the soil moisture at sowing stage to promote N absorption and utilization, increase yield and improve quality, and whole-mulching in advance had better effects.


Assuntos
Agricultura/métodos , Conservação dos Recursos Naturais/métodos , Nitrogênio/análise , Triticum , Água , Grão Comestível , Folhas de Planta , Caules de Planta , Solo
5.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(11): 1993-5, 2006 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-17260739

RESUMO

In the FEL experiment, when electron beam passes through the wiggler, the movement of electron beam will be changed to wiggle in the wiggler due to the periodical magnet field. Meanwhile the electron beam will spontaneously emit the radiation with a wavelength similiar to the FEL radiation. This radiation is influenced by the parameters of both the electron beam and the wiggler. The gain of FEL was determined by the spontaneous emission spectrometer, and the spectrum width mainly determined by the periods of wiggler and electron energy homogeneity (deltaE/E). According to the measured parameters of electron beam and the wiggler, the spontaneous emission was studied. In the experiment, the spectrum of the spontaneous emission was measured by far infrared 100 microm spectrometer with Ge:Ga detector.

6.
Zhongguo Zhong Yao Za Zhi ; 30(19): 1513-5, 2005 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-16335821

RESUMO

OBJECTIVE: To develop an HPLC method for determination of the four effective components (genistin; rutin; quercetin; genistein) in Huaijiao pill. METHOD: The chromatographic separation was performed on a Shim-packODS (4.6 mm x 150 mm, 5.0 microm) eluted with a mobile phase of MeOH-H2O-HAc (40:60:0.25). The detection wavelength was set at 256 nm and column temperature was set at 30 degrees C . RESULT: Nice linear relation between the peak area and injected amount exists when the amount is within 0.059-0.352 microg for genistin, within 0.435-2.610 microg for rutin, within 0.020-0.121 microg for quercetin and within 0.053-0.319 microg for genistein. The correlation coefficient of each component is 0.999 6, 0.998 2, 0.998 9 and 0.999 9 respectively. The average recoveries of the four components are from 98.7% to 100.2%. The RSD of each group are 1.21%, 1.36%, 0.47% and 1.54% (n = 5). CONCLUSION: The method was accurate, repeatable and suitable to determine four effective components in Huaijiao pill. It can be use for quality control of Huaijiao pill.


Assuntos
Genisteína/análise , Isoflavonas/análise , Quercetina/análise , Rutina/análise , Sophora/química , Cromatografia Líquida de Alta Pressão/métodos , Combinação de Medicamentos , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Plantas Medicinais/química , Reprodutibilidade dos Testes
7.
Molecules ; 10(6): 634-9, 2005 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-18007332

RESUMO

Some novel beta-biarylacryl ferrocene derivatives were synthesized via Pd-catalytic Suzuki cross-coupling reactions of beta-(2-bromophenyl)acrylferrocene and arylboronic acids. The structures were determined with elemental analyses, IR spectra, and (1)H-NMR spectra.


Assuntos
Compostos Ferrosos/síntese química , Paládio/química , Compostos de Boro/química , Catálise , Metalocenos , Estrutura Molecular , Análise Espectral
8.
Zhongguo Zhong Yao Za Zhi ; 28(11): 1044-7, 2003 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-15615413

RESUMO

OBJECTIVE: To study the methods of determining the amount of Isoflavones in red clover extractive. METHOD: RP-HPLC is employed to determine the Isoflavones, with a C18 RP Column, a moble phase of MeOH-CH3CN-0.1%H3PO4 and a detection wavelength of 260 nm. RESULT: After being water-solved, the four groups of flavoes elements satisfactorily separated, the amount of feeding in a range of 0.024-0.336 microg which has a good linear relationship with the peaks, and the total isoflavones determining results repetition, RSD=10.1%. CONCLUSION: A simple, reliable and effective quality-control method is given.


Assuntos
Medicamentos de Ervas Chinesas/isolamento & purificação , Isoflavonas/análise , Plantas Medicinais/química , Trifolium/química , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/química , Hidrólise , Isoflavonas/química , Controle de Qualidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...