全文获取类型
收费全文 | 337篇 |
免费 | 22篇 |
国内免费 | 4篇 |
专业分类
林业 | 20篇 |
农学 | 24篇 |
基础科学 | 4篇 |
134篇 | |
综合类 | 32篇 |
农作物 | 29篇 |
水产渔业 | 10篇 |
畜牧兽医 | 70篇 |
园艺 | 9篇 |
植物保护 | 31篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 14篇 |
2020年 | 15篇 |
2019年 | 14篇 |
2018年 | 27篇 |
2017年 | 23篇 |
2016年 | 17篇 |
2015年 | 9篇 |
2014年 | 16篇 |
2013年 | 33篇 |
2012年 | 19篇 |
2011年 | 16篇 |
2010年 | 23篇 |
2009年 | 10篇 |
2008年 | 15篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 9篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1970年 | 1篇 |
排序方式: 共有363条查询结果,搜索用时 15 毫秒
1.
Susan J. Holcombe VMD MS Alicia L. Bertone DVM PhD David S. Biller DVM Valerie Haider DVM 《Veterinary radiology & ultrasound》1995,36(2):119-125
The purpose of this study was to define normal gross anatomic structures in the equine stifle with magnetic resonance images. Magnetic resonance (MR) images were made in sagittal, 15° supinated, transverse, and dorsal planes of two equine stifles. The MR images were scrutinized by comparing MR images to dissection specimens and frozen cross sections of stifle joints. Sagittal and 15° supinated images were the most valuable in assessing articular cartilage, subchondral bone, and soft tissue structures within the joint. Cranial and caudal cruciate ligaments, medial and lateral menisci, meniscotibial and meniscofemoral ligaments, long digital extensor tendon, and patellar ligaments were easily evaluated. MR images provided substantially more gross anatomical information than the currently available imaging modalities. 相似文献
2.
Integration of pharmacokinetic–pharmacodynamic for dose optimization of doxycycline against Haemophilus parasuis in pigs 下载免费PDF全文
Y. Wang A. Sajid S. Ahmed X. Li 《Journal of veterinary pharmacology and therapeutics》2018,41(5):706-718
The aims of this study were to establish optimal doses of doxycycline (dox) against Haemophilus parasuis on the basis of pharmacokinetic–pharmacodynamic (PK‐PD) integration modeling. The infected model was established by intranasal inoculation of organism in pigs and confirmed by clinical signs, blood biochemistry, and microscopic examinations. The recommended dose (20 mg/kg b.w.) was administered in pigs through intramuscular routes for PK studies. The area under the concentration 0‐ to 24‐hr curve (AUC0–24), elimination half‐life (T½ke), and mean residence time (MRT) of dox in healthy and H. parasuis‐infected pigs were 55.51 ± 5.72 versus 57.10 ± 4.89 μg·hr/ml, 8.28 ± 0.91 versus 9.80 ± 2.38 hr, and 8.43 ± 0.27 versus 8.79 ± 0.18 hr, respectively. The minimal inhibitory concentration (MIC) of dox against 40 H. parasuis isolates was conducted through broth microdilution method, the corresponding MIC50 and MIC90 were 0.25 and 1 μg/ml, respectively. The Ex vivo growth inhibition data suggested that dox exhibited a concentration‐dependent killing mechanism. Based on the observed AUC24 hr/MIC values by modeling PK‐PD data in H. parasuis‐infected pigs, the doses predicted to obtain bacteriostatic, bactericidal, and elimination effects for H. parasuis over 24 hr were 5.25, 8.55, and 10.37 mg/kg for the 50% target attainment rate (TAR), and 7.26, 13.82, and 18.17 mg/kg for 90% TAR, respectively. This study provided a more optimized alternative for clinical use and demonstrated that the dosage 20 mg/kg of dox by intramuscular administration could have an effective bactericidal activity against H. parasuis. 相似文献
3.
Mahmoud Alagawany Shaaban S. Elnesr Mayada R. Farag Ruchi Tiwari Mohd. Iqbal Yatoo Kumaragurubaran Karthik Izabela Michalak Kuldeep Dhama 《The Veterinary quarterly》2021,41(1):1
Nutraceuticals have gained immense importance in poultry science recently considering the nutritional and beneficial health effects of their constituents. Besides providing nutritional requirements to birds, nutraceuticals have beneficial pharmacological effects, for example, they help in establishing normal physiological health status, prevent diseases and thereby improve production performance. Nutraceuticals include amino acids, vitamins, minerals, enzymes, etc. which are important for preventing oxidative stress, regulating the immune response and maintaining normal physiological, biochemical and homeostatic mechanisms. Nutraceuticals help in supplying nutrients in balanced amounts for supporting the optimal growth performance in modern poultry flocks, and as a dietary supplement can reduce the use of antibiotics. The application of antibiotic growth enhancers in poultry leads to the propagation of antibiotic-resistant microbes and drug residues; therefore, they have been restricted in many countries. Thus, there is a demand for natural feed additives that lead to the same growth enhancement without affecting the health. Nutraceuticals substances have an essential role in the development of the animals’ normal physiological functions and in protecting them against infectious diseases. In this review, the uses of amino acids, vitamins and minerals as well as their mode of action in growth promotion and elevation of immune system are discussed. 相似文献
4.
5.
Malik Muniba Abid Munir Haider Muhammad Saleem Zhai Ying Khan Muhammad Azmat Ullah Pappu Hanu R. 《植物病害和植物保护杂志》2023,130(1):23-33
Journal of Plant Diseases and Protection - Mastreviruses are an emerging group of viruses transmitted by leafhoppers and infect both monocot and dicot plants. Chickpea chlorotic dwarf virus... 相似文献
6.
The factors influencing the decision of smallholder farmers to adopt new farming technologies were studied with reference to rubber–tea intercropping in Sri Lanka. Rubber–tea intercropping has been recommended previously to rubber farmers as a means to improve productivity and income during the early pre-tapping phase of rubber growth. Although crop trials have shown that the two crops are agronomically compatible and potentially produce a combined economic yield superior to the yield of a sole crop grown on the same area of land, there is little evidence of widespread adoption of this practice among smallholder farmers in Sri Lanka. The aim of the study was to determine the major factors that influence the decision to undertake rubber–tea intercropping and to construct a predictive model that describes the likelihood of adoption of intercropping by traditional smallholder rubber growers. A rapid rural appraisal (RRA) was undertaken based on semi-structured interviews of 90 smallholder farmers in the main rubber growing low wet zone of Sri Lanka. Among a number of factors shown to significantly influence the decision to intercrop tea with rubber, three were shown to operate independently, namely level of income, source of income (i.e. solely from own farm or from farm plus additional off-farm enterprises), and availability of land considered suitable for tea cultivation. A statistical model developed through correlation and logistic analysis, which predicts the likelihood of a smallholder adopting intercropping based on these factors, is presented and discussed. The most likely combination of circumstances (82% probability) under which rubber–tea intercropping is practiced is shown to be where the farmer’s income is greater than Rs. 10,000 per month, where the farmer’s income is based solely on own farm enterprises, and where more than 80% of the farmer’s land area was judged to be suitable for tea cultivation. Conversely, 30% of smallholder farmers that chose not to intercrop did possess land suitable for tea cultivation. Qualitative responses to the RRA indicated that limitation of technical knowledge was the main problem subsequently faced by rubber farmers who had adopted rubber–tea intercropping. Results indicate that there is need for both income support through farm subsidies and further agricultural extension services, if rubber–tea intercropping is to be adopted more widely in Sri Lanka. The wider usefulness of the developed logistic model in determining the likelihood of adoption of intercropping by smallholder farmers is discussed. 相似文献
7.
Genome-wide association analysis for stripe rust resistance in spring wheat(Triticum aestivum L.) germplasm 下载免费PDF全文
Sher MUHAMMAD Muhammad SAJJAD Sultan Habibullah KHAN Muhammad SHAHID Muhammad ZUBAIR Faisal Saeed AWAN Azeem Iqbal KHAN Muhammad Salman MUBARAK Ayesha TAHIR Muhammad Umer Rumana KEYANI Muhammad Inam AFZAL Irfan MANZOOR Javed Iqbal WATTOO Aziz-ur REHMAN 《农业科学学报》2020,19(8):2035-2043
Stripe rust is a continuous threat to wheat crop all over the world. It causes considerable yield losses in wheat crop every year. Continuous deployment of adult plant resistance(APR) genes in newly developing wheat cultivars is the most judicious strategy to combat this disease. Herein, we dissected the genetics underpinning stripe rust resistance in Pakistani wheat germplasm. An association panel of 94 spring wheat genotypes was phenotyped for two years to score the infestation of stripe rust on each accession and was scanned with 203 polymorphic SSRs. Based on D' measure, linkage disequilibrium(LD) exhibited between loci distant up to 45 c M. Marker-trait associations(MTAs) were determined using mixed linear model(MLM). Total 31 quantitative trait loci(QTLs) were observed on all 21 wheat chromosomes. Twelve QTLs were newly discovered as well as 19 QTLs and 35 previously reported Yr genes were validated in Pakistani wheat germplasm. The major QTLs were QYr.uaf.2 AL and QYr.uaf.3 BS(PVE, 11.9%). Dissection of genes from the newly observed QTLs can provide new APR genes to improve genetic resources for APR resistance in wheat crop. 相似文献
8.
Farid Menaa P. A. U. I. Wijesinghe Gobika Thiripuranathar Bushra Uzair Haroon Iqbal Barkat Ali Khan Bouzid Menaa 《Marine drugs》2020,18(12)
Seaweeds are broadly distributed and represent an important source of secondary metabolites (e.g., halogenated compounds, polyphenols) eliciting various pharmacological activities and playing a relevant ecological role in the anti-epibiosis. Importantly, host (as known as basibiont such as algae)–microbe (as known as epibiont such as bacteria) interaction (as known as halobiont) is a driving force for coevolution in the marine environment. Nevertheless, halobionts may be fundamental (harmless) or detrimental (harmful) to the functioning of the host. In addition to biotic factors, abiotic factors (e.g., pH, salinity, temperature, nutrients) regulate halobionts. Spatiotemporal and functional exploration of such dynamic interactions appear crucial. Indeed, environmental stress in a constantly changing ocean may disturb complex mutualistic relations, through mechanisms involving host chemical defense strategies (e.g., secretion of secondary metabolites and antifouling chemicals by quorum sensing). It is worth mentioning that many of bioactive compounds, such as terpenoids, previously attributed to macroalgae are in fact produced or metabolized by their associated microorganisms (e.g., bacteria, fungi, viruses, parasites). Eventually, recent metagenomics analyses suggest that microbes may have acquired seaweed associated genes because of increased seaweed in diets. This article retrospectively reviews pertinent studies on the spatiotemporal and functional seaweed-associated microbiota interactions which can lead to the production of bioactive compounds with high antifouling, theranostic, and biotechnological potential. 相似文献
9.
Imdad Ullah ZAID Sajid Hanif MUHAMMAD Na ZHANG Xin ZHENG Likun WANG Xiaofang LI 《土壤圈》2022,32(4):555-564
Understanding the genetic mechanisms for cadmium(Cd) uptake and translocation in common wheat(Triticum aestivum) is of significance in food Cd contamination control. In this study, a diverse panel of 132 wheat cultivars was collected from the North China Plain. The cultivars were evaluated in terms of their phenotypic variations in response to Cd stress and subjected to a genome-wide association study(GWAS) to identify single nucleotide polymorphisms(SNPs) associated with the phenotypic variatio... 相似文献
10.
Qudsia Nazir Muhammad Javed Akhtar Muhammad Imran Azhar Hussain Sajid Mahmood 《Journal of plant nutrition》2017,40(9):1339-1350
This study was conducted to evaluate the simultaneous use of plant growth promoting rhizobacterium (QS1) and different combinations of urea-nitrogen and biogas slurry-nitrogen for improving growth, yield, and nutritional quality of field grown okra. The isolate QS1 was identified as Bacillus sp. QS1 based on its ribosomal ribonucleic acid (rRNA) sequence analysis. Results revealed that among the combinations, the application of 50% urea-nitrogen + 50% biogas slurry-nitrogen was optimal for improving crop performance. This combination significantly (p ≤ 0.05) promoted okra growth viz. plant height (69.63–80.03 cm), no of branches per plant (14–18), shoot fresh weight (86.66–136.25 g/plant), root fresh weight (22.5–26.58 g/plant), and fruit yield (8.5–13.5 kg/plot) compared to the plants receiving 100% urea-nitrogen. The interactive effective of this nitrogen combination and QS1 inoculation produced the highest growth and yield response. Similarly, the same treatment improved nitrogen, phosphorus, potassium, and protein contents in shoot and fruit of okra compared to other treatments. 相似文献