全文获取类型
收费全文 | 91篇 |
免费 | 5篇 |
专业分类
林业 | 5篇 |
农学 | 2篇 |
7篇 | |
综合类 | 14篇 |
农作物 | 17篇 |
水产渔业 | 2篇 |
畜牧兽医 | 45篇 |
植物保护 | 4篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 5篇 |
2011年 | 4篇 |
2010年 | 3篇 |
2009年 | 7篇 |
2008年 | 3篇 |
2007年 | 9篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 2篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1938年 | 1篇 |
排序方式: 共有96条查询结果,搜索用时 31 毫秒
11.
Studies were conducted to determine the efficacy of K salts in alleviating lime‐induced chlorosis. Greenhouse studies using a Gibbon silt loam [fine‐silty, mixed (calcareous), mesic Typic Haplaquoll] and a 1: 1 mixture of Gibbon soil and washed sand were conducted with KCl, KNO3, K2SO4, K2HPO4, or KHCO3 applied at rates of 0, 250, and 500 mg K/kg soil. An FeEDDHA treatment was included for comparison. Similar studies were conducted at two field sites known to produce lime‐induced chlorosis. Potassium salts were applied at 0, 20, and 40 g K/m of row. In the greenhouse, plants treated with KCl, KNO3, and K2SO4 on Gibbon soil were less chlorotic than controls or plants treated with K2HPO4, or KHCO3. No K treatment totally alleviated chlorosis except FeEDDHA. Chlorophyll correlated positively with chlorosis rating. No relationship was found between leaf Fe uptake and chlorosis. Plants grown in soil/sand exhibited no chlorosis and had lower Fe uptake than plants grown in Gibbon soil. Thus chlorosis was not due strictly to low soil‐Fe availability or inadequate Fe uptake. Bicarbonate in the soil solutions of both growth media treated with KCl was lower than controls which may explain the reduced chlorosis associated with this treatment. One field site showed positive effects of K treatments on chlorosis rating, chlorophyll concentration, and seed yield. No treatment was as effective as FeEDDHA in influencing plant growth or yield. Total leaf Fe concentration was unrelated to leaf chlorophyll concentration. Inorganic cation/anion ratios in the plant were from 4.4–8.4 which could cause net H+ efflux by the plant and alkalinization of plant tissues. One possibility is that H+ efflux solubilizes P in the rhizosphere, which after uptake could immobilize Fe in the plant. Application of KCl, KNO3, and K2SO4 generally lowered HCO3 content of the upper 15 cm of both soils. High bicarbonate could increase rhizosphere P availability and increase immobilization of Fe in the plant. 相似文献
12.
A fast and efficient approach was established to identify bacteria possessing the potential to biosynthesize phenazines, which are of special interest regarding their antimicrobial activities. Sequences of phzE genes, which are part of the phenazine biosynthetic pathway, were used to design one universal primer system and to analyze the ability of bacteria to produce phenazine. Diverse bacteria from different marine habitats and belonging to six major phylogenetic lines were investigated. Bacteria exhibiting phzE gene fragments affiliated to Firmicutes, Alpha- and Gammaproteobacteria, and Actinobacteria. Thus, these are the first primers for amplifying gene fragments from Firmicutes and Alphaproteobacteria. The genetic potential for phenazine production was shown for four type strains belonging to the genera Streptomyces and Pseudomonas as well as for 13 environmental isolates from marine habitats. For the first time, the genetic ability of phenazine biosynthesis was verified by analyzing the metabolite pattern of all PCR-positive strains via HPLC-UV/MS. Phenazine production was demonstrated for the type strains known to produce endophenazines, 2-hydroxy-phenazine, phenazine-1-carboxylic acid, phenazine-1,6-dicarboxylic acid, and chlororaphin as well as for members of marine Actinobacteria. Interestingly, a number of unidentified phenazines possibly represent new phenazine structures. 相似文献
13.
14.
William Muir DVM PhD Diplomate ACVA Diplomate ACVECC Phillip Lerche DVM PhD Diplomate ACVA Ashley Wiese DVM MS Laura Nelson DVM Kirby Pasloske† DVM DVSc Diplomate ACVCP & Ted Whittem† BVSc PhD DACVCP 《Veterinary anaesthesia and analgesia》2009,36(1):42-54
ObjectiveTo determine the cardiorespiratory and anesthetic effects of 0, 5, 15, and 50 mg kg?1 intravenous (IV) alfaxalone in hydroxypropyl beta cyclodextrin (Alfaxan; Jurox Pty Ltd, Rutherford, NSW, Australia) in cats.Study designFour treatments of alfaxalone were administered in sequential order.AnimalsEight healthy adult cats (four male; four female) weighing between 3.71 and 5.91 kg.MethodsCats were instrumented for hemodynamic measurements. Four (0, 5, 15, and 50 mg kg?1) IV doses of alfaxalone were administered over one minute, with a 3-hour washout period between doses 0, 5, and 15 mg kg?1 on Day 0. The 50 mg kg?1 treatment was administered 24 hours later. Measurements of heart rate, aortic systolic, mean, and diastolic blood pressures, pulmonary arterial and right atrial mean pressures, cardiac output, respiratory rate, tidal and minute volumes, and arterial blood pH and blood gases (PaO2, PaCO2) were performed at pre-determined intervals. Systemic vascular resistance and rate pressure product were calculated. The quality of induction, maintenance, and recovery from anesthesia and the response to noxious stimulation were categorically scored.ResultsAlfaxalone administration resulted in dose-dependent cardiorespiratory depression. Decreases in arterial blood pressure and increases in heart rate occurred at higher doses. Most variables returned to baseline by 15-30 minutes. Respiratory rate, minute volume, and PaO2 decreased. Apnea was the most common side effect. Induction and maintenance quality were judged to be good to excellent at all doses and quality of recovery good to excellent at all but the 50 mg kg?1 dose. The duration of anesthesia and unresponsiveness to noxious stimulation increased with dose. The administration of the 50 mg kg?1 dose produced marked cardiorespiratory depression and apnea.Conclusions and clinical relevanceAlfaxalone produced dose-dependent anesthesia, cardiorespiratory depression and unresponsiveness to noxious stimulation in unpremedicated cats. Hypoventilation and apnea were the most common side effects. 相似文献
15.
16.
Erisman J. W. Hogenkamp J. E. M. van Putten E. M. Uiterwijk J. W. Kemkers E. Wiese C. J. Mennen M. G. 《Water, air, and soil pollution》1999,109(1-4):237-262
In 1990 a project to develop a dry deposition monitoring method of SO2, NH3 and NO2 to Speulder forest in the Netherlands began. Detailed annual deposition fluxes for these gases were measured throughout November 1992 to December 1995. This paper describes the measurement set-up and the analysis of the deposition parameters for SO2. The dry deposition velocity was usually smaller than the maximum Vd, showing a resistance to surface uptake, except for periods when the canopy is wet and surface resistance is negligible. Several methods were tested to estimate annual average fluxes from the gradient measurements. Annual fluxes were estimated by selecting the data for periods fulfilling gradient theory and extending the data by using an inferential method for the other periods. The surface resistance parametrisation used in the inferential method was tested using the selected data and was found to yield systematic larger fluxes of the order of 20%. Annual fluxes were 465 mol ha-1 a-1 in 1992/1993, 460 mol ha-1 a-1 in 1994 and 330 mol ha-1 a-1 in 1995. The uncertainty in the annual flux was estimated to be 25%. The annual average dry deposition velocity was 1.5 cm s-1. No large differences were found in deposition parameters between each of the three years. 相似文献
17.
蒙药是蒙医师用于防治疾病的药物,是蒙医药事业发展的物质基础。蒙医药事业的可持续发展必须保障药材的质量和供应。随着蒙药资源使用量的增加和蕴藏量的减少,蒙药资源的可持续利用显得越来越重要。因此,一定要重视蒙药资源的可持续利用研究。文章着重介绍了蒙药资源可持续利用情况。 相似文献
18.
19.
JH Waite GR Gladstone WS Lewis P Drossart TE Cravens AN Maurellis BH Mauk S Miller 《Science (New York, N.Y.)》1997,276(5309):104-108
Observations with the High Resolution Imager on the Rontgensatellit reveal x-ray emissions from Jupiter's equatorial latitudes. The observed emissions probably result from the precipitation of energetic (>300 kiloelectron volts per atomic mass unit) sulfur and oxygen ions out of Jupiter's inner radiation belt. Model calculations of the energy deposition by such heavy ion precipitation and of the resulting atmospheric heating rates indicate that this energy source can contribute to the high exospheric temperatures(>800 kelvin at 0.01 microbar) measured by the Galileo probe's Atmospheric Structure Instrument. Low-latitude energetic particle precipitation must therefore be considered, in addition to other proposed mechanisms such as gravity waves and soft electron precipitation, as an important source of heat for Jupiter's thermosphere. 相似文献
20.
Boué SM Wiese TE Nehls S Burow ME Elliott S Carter-Wientjes CH Shih BY McLachlan JA Cleveland TE 《Journal of agricultural and food chemistry》2003,51(8):2193-2199
Seven legume extracts containing phytoestrogens were analyzed for estrogenic activity. Methanol extracts were prepared from soybean (Glycine max L.), green bean (Phaseolus vulgaris L.), alfalfa sprout (Medicago sativa L.), mung bean sprout (Vigna radiata L.), kudzu root (Pueraria lobata L.), and red clover blossom and red clover sprout (Trifolium pratense L.). Extracts of kudzu root and red clover blossom showed significant competitive binding to estrogen receptor beta (ERbeta). Estrogenic activity was determined using an estrogen-dependent MCF-7 breast cancer cell proliferation assay. Kudzu root, red clover blossom and sprout, mung bean sprout, and alfalfa sprout extracts displayed increased cell proliferation above levels observed with estradiol. The pure estrogen antagonist, ICI 182,780, suppressed cell proliferation induced by the extracts, suggesting an ER-related signaling pathway was involved. The ER subtype-selective activities of legume extracts were examined using transiently transfected human embryonic kidney (HEK 293) cells. All seven of the extracts exhibited preferential agonist activity toward ERbeta. Using HPLC to collect fractions and MCF-7 cell proliferation, the active components in kudzu root extract were determined to be the isoflavones puerarin, daidzin, genistin, daidzein, and genistein. These results show that several legumes are a source of phytoestrogens with high levels of estrogenic activity. 相似文献