全文获取类型
收费全文 | 173篇 |
免费 | 9篇 |
国内免费 | 3篇 |
专业分类
林业 | 3篇 |
农学 | 6篇 |
31篇 | |
综合类 | 26篇 |
农作物 | 8篇 |
水产渔业 | 15篇 |
畜牧兽医 | 67篇 |
园艺 | 4篇 |
植物保护 | 25篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 12篇 |
2011年 | 6篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 5篇 |
2003年 | 10篇 |
2002年 | 4篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1983年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1954年 | 1篇 |
1948年 | 1篇 |
1937年 | 1篇 |
1896年 | 1篇 |
排序方式: 共有185条查询结果,搜索用时 15 毫秒
141.
A. MacLeod H. Anderson D. J. Van Der Gaag J. Holt O. Karadjova H. Kehlenbeck G. Labonne O. Pruvost P. Reynaud G. Schrader J. Smith R. Steffek N. Viaene I. Vloutoglou 《EPPO Bulletin》2010,40(3):435-439
In late 2009, a European Food Safety Authority (EFSA)‐funded project (Prima phacie) began work to review and test methodologies for conducting pest risk assessment by means of case studies on three phytoplasmas (Candidatus Phytoplasma mali, Ca. P. prunorum, Ca. P. pyri); two bacteria (Acidovorax avenae subsp. citrulli, Xanthomonas citri [=X. axonopodis] pv. citri); two fungi (Guignardia citricarpa, Mycosphaerella dearnessii); two nematodes (Meloidogyne chitwoodi, M. fallax); and an insect (Anoplophora glabripennis). Multiple risk assessment schemes and methods will be applied to each of the case study pests, allowing for a comparative assessment of methods. Methods to assess the effectiveness of possible risk management options for each pest will also be evaluated. The project will further develop the scientific basis for pest risk assessment within the European Community and identify methodologies most suitable for conducting risk assessments and for evaluating the effectiveness of possible risk management options by the EFSA Panel on Plant Health in order to support European decision making. The project lasts 29 months, and is being conducted by an international consortium of 11 partners consisting of phytosanitary organizations, research institutes and a university. Results will be disseminated via conventional publications and at a workshop in March 2012. 相似文献
142.
特木 《内蒙古林业调查设计》2007,30(2):17-18,74
文章通过对伊图里河林业局1994年、2005年两次二类调查数据的分析,详细阐述了森林资源消长变化总趋势,在此基础上对伊图里河林业局森林资源现状及其特点进行了分析,提出了对森林资源管理利用的建议。 相似文献
143.
Evaluation of Limnocorrals for Studying the Effects of Phytotoxic Compounds on Plankton and Water Chemistry in Aquaculture Ponds 总被引:1,自引:0,他引:1
Kevin K. Schrader Craig S. Tucker Marjan Q. de Regt Susan K. Kingsbury 《Journal of the World Aquaculture Society》2000,31(3):403-415
Abstract.— Two studies were conducted to evaluate the potential use of limnocorrals (in situ enclosures) for evaluating the effects of phytotoxic compounds on phytoplankton community structure and water quality. Limnocorrals consisted of open‐bottomed, fiberglass cylinders that were 2.44 m in diameter and 1.53 m high. The enclosures were placed in an aquaculture pond and allowed to settle 10–20 cm into the bottom mud, forming a watertight seal that isolated approximately 5.5 m3 of pond water. The first study evaluated the effect of water mixing on environmental conditions within limnocorrals. Mixing was accomplished by injecting air through airstones suspended inside the enclosures. Conditions in unmixed limnocorrals rapidly deviated from conditions in the pond and in aerated enclosures, with overall phytoplankton biomass decreasing while abundance of cyanobacteria and concentrations of soluble reactive phosphorus increased. Conditions in limnocorrals with continuous mixing also deviated from conditions in the pond. Environmental conditions among replicate mixed enclosures were, however, relatively consistent and stable for at least 2 wk. The second study evaluated the use of limnocorrals for testing the effects of phytotoxic compounds on phytoplankton community structure and water quality. A commercial chelated copper algicide was added to randomly selected, mixed limnocorrals at the label‐recommended rate. The algicide killed nearly all phytoplankton in the treated enclosures within 1 wk; however, treated limnocorrals were rapidly recolonized by green algae and diatoms. Conditions in untreated limnocorrals remained relatively stable and consistent among replicates for 16 d, after which total phytoplankton biomass began to decrease, possibly due to nutrient depletion within the enclosures. Although conditions inside the enclosures deviated with time from those in the surrounding pond water, mixed limnocorrals appear to provide a convenient and reliable method for short‐term studies of algicides and other water quality manipulations. 相似文献
144.
Precambrian sponges with cellular structures 总被引:2,自引:0,他引:2
Sponge remains have been identified in the Early Vendian Doushantuo phosphate deposit in central Guizhou (South China), which has an age of approximately 580 million years ago. Their skeletons consist of siliceous, monaxonal spicules. All are referred to as the Porifera, class Demospongiae. Preserved soft tissues include the epidermis, porocytes, amoebocytes, sclerocytes, and spongocoel. Among thousands of metazoan embryos is a parenchymella-type of sponge larvae having a shoe-shaped morphology and dense peripheral flagella. The presence of possible amphiblastula larva suggests that the calcareous sponges may have an extended history in the Late Precambrian. The fauna indicates that animals lived 40 to 50 million years before the Cambrian Explosion. 相似文献
145.
Tan CX Schrader KK Mizuno CS Rimando AM 《Journal of agricultural and food chemistry》2011,59(11):5977-5985
In a continuing effort to discover natural products and natural product-based compounds for the control of columnaris disease in channel catfish (Ictalurus punctatus), 17 lycorine analogues were synthesized, including new benzoyl analogues 6-16, and evaluated for antibacterial activity against two isolates (ALM-00-173 and BioMed) of Flavobacterium columnare using a rapid bioassay. Two of the lycorine analogues had greater antibacterial activity than 1-O-acetyllycorine, an analogue of lycorine evaluated previously that is highly active against both isolates. Carbamate analogue 18 (1S,2S,3a(1)S,12bS)-2,3a(1),4,5,7,12b-hexahydro-1H-[1,3]dioxolo[4,5-j]pyrrolo[3,2,1-de]phenanthridin-1,2-diylbis(o-tolylcarbamate) had the strongest antibacterial activity toward both F. columnare isolates ALM-00-173 and BioMed, with 24-h IC(50) values of 3.0 ± 1.3 and 3.9 ± 2.2 mg/L, respectively, and a MIC of 5.5 ± 0 mg/L for both isolates. Compound 18 appears to be the most promising lycorine analogue for future efficacy studies to determine its potential for use as an alternative to the currently used compounds to control columnaris disease in channel catfish. 相似文献
146.
[目的]旨在研究和牛杂交牛(日本和牛♀×西门塔尔牛♂)与西门塔尔牛的肉品质性能。[方法]选择相同月龄、体重相近的和牛杂交牛和西门塔尔牛各5头,屠宰后选取背最长肌分析肉品质特性。[结果]结果表明,和牛杂交牛的粗脂肪显著高于西门塔尔牛(P0.05);粗蛋白、成人必需氨基酸和鲜味氨基酸相比西门塔尔牛表现出良好的优势(P0.05);饱和脂肪酸含量降低,单不饱和脂肪酸和多不饱和脂肪酸含量相比西门塔尔牛有所升高(P0.05)。[结论]说明和牛杂交牛具有较好的营养价值,其肉品质略优于西门塔尔牛。 相似文献
147.
A Schrader O Schulz H V?lker H Puls 《Berliner und Münchener tier?rztliche Wochenschrift》2001,114(5-6):218-221
It is reported of botanical intoxications in 1379 ruminants (dairy cattle, beef cattle and ewes) in north-eastern Germany. The intoxications of these animals were caused by consumption of the following plants: meadow saffron (Colchicum autumnale L.), cowbane (Cicuta virosa L.), sweet clover (Melilotus alba MED.), sheep's sorrel (Rumex acetosella L.), bracken (Pteridium aquilinum KUHN) and St. John's wort (Hypericum perforatum L.). In all the five described cases animals died as a result of plant intoxications. The authors come to the conclusion that periodical inspections of the meadows are necessary, checking the plants in cooperation with veterinary surgeons. 相似文献
148.
Objectives To describe the morbidity and mortality patterns and identify factors associated with morbidity in pre-weaning llamas and alpacas.
Design Cross-sectional observational study of 287 crias born on four farms in Ohio, USA
Procedure Historical data representing all crias born over a 6-year period were obtained from two llama farms and two alpaca farms in Ohio. Multivariable generalised linear mixed effects regression models were used to identify factors associated with morbidity outcomes.
Results In total, 105 (37%) of the llamas and alpacas had some reported morbidity during the pre-weaning period, and mortality rate was 2.1%. In addition, 51 (18%) of llamas and alpacas experienced morbidity because of infectious disease, and 47 (16%) experienced morbidity during the neonatal period. The three most commonly reported morbidity events were undifferentiated diarrhoea (23%), umbilical hernia (16%) and unspecified infectious disease (15%). Difficult birth was an important risk factor for pre-weaning morbidity in this population.
Conclusions Camelid veterinarians and their clients can expect that pre-weaning health events are common among crias, although mortality is low. Crias experiencing difficult births may require additional monitoring for health events during the pre-weaning period. 相似文献
Design Cross-sectional observational study of 287 crias born on four farms in Ohio, USA
Procedure Historical data representing all crias born over a 6-year period were obtained from two llama farms and two alpaca farms in Ohio. Multivariable generalised linear mixed effects regression models were used to identify factors associated with morbidity outcomes.
Results In total, 105 (37%) of the llamas and alpacas had some reported morbidity during the pre-weaning period, and mortality rate was 2.1%. In addition, 51 (18%) of llamas and alpacas experienced morbidity because of infectious disease, and 47 (16%) experienced morbidity during the neonatal period. The three most commonly reported morbidity events were undifferentiated diarrhoea (23%), umbilical hernia (16%) and unspecified infectious disease (15%). Difficult birth was an important risk factor for pre-weaning morbidity in this population.
Conclusions Camelid veterinarians and their clients can expect that pre-weaning health events are common among crias, although mortality is low. Crias experiencing difficult births may require additional monitoring for health events during the pre-weaning period. 相似文献
149.
Automated chemical synthesis of a protein growth factor for hemopoietic cells, interleukin-3 总被引:20,自引:0,他引:20
I Clark-Lewis R Aebersold H Ziltener J W Schrader L E Hood S B Kent 《Science (New York, N.Y.)》1986,231(4734):134-139
Interleukin-3 (IL-3), a protein of 140 amino acids, was chemically synthesized by means of an automated peptide synthesizer and was shown to have the biological activities attributed to native IL-3. Assays of synthetic analogues established that an amino terminal fragment has detectable IL-3 activity, but that the stable tertiary structure of the complete molecule was required for full activity. The results demonstrate that automated peptide synthesis can be applied to the study of the structure and function of proteins. 相似文献
150.