全文获取类型
收费全文 | 407篇 |
免费 | 28篇 |
专业分类
林业 | 41篇 |
农学 | 15篇 |
基础科学 | 4篇 |
102篇 | |
综合类 | 14篇 |
农作物 | 33篇 |
水产渔业 | 38篇 |
畜牧兽医 | 113篇 |
园艺 | 30篇 |
植物保护 | 45篇 |
出版年
2023年 | 6篇 |
2022年 | 13篇 |
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 16篇 |
2018年 | 24篇 |
2017年 | 25篇 |
2016年 | 20篇 |
2015年 | 19篇 |
2014年 | 15篇 |
2013年 | 44篇 |
2012年 | 32篇 |
2011年 | 27篇 |
2010年 | 19篇 |
2009年 | 31篇 |
2008年 | 27篇 |
2007年 | 17篇 |
2006年 | 16篇 |
2005年 | 14篇 |
2004年 | 12篇 |
2003年 | 10篇 |
2002年 | 13篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有435条查询结果,搜索用时 31 毫秒
11.
Menşure Özgüven Bilge Şener Ilkay Orhan Nazım Şekeroğlu Muzaffer Kirpik Murat Kartal Ipek Peşin Zülküf Kaya 《Industrial Crops and Products》2008,27(1):60-64
Artemisia annua L. is an aromatic-antibacterial herb that destroys malarial parasites, lowers fevers and checks bleeding, and of which the secondary compound of interest is artemisinin. The objective of the present study was to determine yield, yield components and artemisinin content of A. annua L. grown under four nitrogen applications (0, 40, 80 and 120 kg ha−1) in the Çukurova region of Turkey in 2004 and 2005. Field trials were conducted at Çukurova University, Agricultural Faculty Field Crops Department. In the study, plant height, number of branches, fresh herbage yield, dry herbage yield, fresh leaf yield, dry leaf yield, essential oil content and artemisinin content (by high performance liquid chromatography, HPLC) were examined. By analysis of variance, nitrogen doses had no any statistical effect on the traits investigated except for artemisinin content. Artemisinin content of the dried leaves were significantly affected by nitrogen applications, which varied from 6.32 to 27.50 mg 100 g−1. Contents were from 120 and 80 kg ha−1 nitrogen for the years of 2004 and 2005, respectively. 相似文献
12.
Veterinary Research Communications - The current study aimed at estimating the direct (condemned offal) and indirect (meat, milk, and fecundity losses) production losses due to cystic... 相似文献
13.
Onur Yilmaz Mehmet Kizilaslan Yunus Arzik Sedat Behrem Nezih Ata Orhan Karaca Cengiz Elmaci Ibrahim Cemal 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2022,139(1):26-39
Sheep are considered as a major contributor of global food security. Moreover, sheep preweaning growth traits as well as in vivo carcass composition traits such as ultrasonic measurements of Longissimus dorsi muscle depth (UMD) and back-fat thickness (UFD) are crucially important indicators of meat yield and hot carcass composition. Despite their relative importance for productivity and profitability of a sheep production system, detected QTL for these traits are quite scarce. Therefore, we implemented GWAS for these traits using animal mixed model-based association approach provided by GenABEL in Esme sheep. Three genome-wide and 14 individual chromosome-wide associated SNPs were discovered. As a result, ESRP1, LOC105613082, ZNF641, DUSP5, TEAD1, SMOX, PTPRT, RALYL, POM121C, PHIP, LOC101106051, ZIM3, PEG3, TRPC7, FBXL4, LOC105610397, LOC105616489 and DNAAF2 were suggested as candidates. Some of the discovered genes and involved pathways were already annotated to contribute growth and development in various species including human, mice and cattle. All in all, the results of this study are expected to strongly contribute to shed a light on the underlying molecular mechanisms behind growth and carcass composition traits, with potential implications on studies aiming faster genetic improvement, targeted low-resolution SNP panel designs and genome-editing studies. 相似文献
14.
V. Gunes A. C. Onmaz A. Pavaloiu G. Kaya Karasu R. van den Hoven 《Equine Veterinary Education》2022,34(9):467-472
The aim of our retrospective study was to produce and analyse epidemiological data on gastrointestinal (GI) disorders of Austrian leisure horses. Case records of horses referred to the Equine Clinic of the Veterinary University of Vienna were collected from an electronic hospital information system using its search options. All cases reported to have suffered a GI disorder between March 2003 and February 2015 were selected. In this period of 4314 days, data of 1833 GI cases, mostly accompanied by colic signs, were analysed. The vast majority of our GI cases appeared in the abdominal parts of the GI tract 96% (1760/1833) while just 1.3% (24/1833) could be definitively attributed to oesophageal disorders, whereas in 2.7% (49/1833) of the cases a definitive diagnosis could not be made. The highest prevalence of GI disorders was seen in July and October/November. A breakdown of figures for cases clustered under the colic syndrome showed that colon impactions in left ventral large and/or pelvic flexure (35%) were the major problem followed by gastric disorders (18%), spasmodic colic (9%), enteritis (7%), caecal tympany (6%); caecal impaction (4%), colitis (3%), abnormal anatomical positions of large colon including complete and partial strangulation/volvulus, nephrosplenic entrapment of the left ventral and dorsal colon and right dorsal displacement of the large colon (3%) and small intestinal volvulus (2.7%). In 12% of the cases, the cause of the abdominal discomfort was likely idiopathic paralytic ileus. The searching tool of the electronic patient data also brought up cases with malabsorbtion/IBD syndrome and GI ruptures, both these contributed less than 1% of the referred GI cases. Results suggested that the causes of colic are diverse, but the major reasons for referred cases of colic in the east Austrian horse population are large colon impaction or displacements. Seasonal distribution and specific causes of gastrointestinal disorders should be considered essential components of the initial clinical assessment of horses presenting with colic. 相似文献
15.
The dusuns of Central Maluku which improve fallows by planting spice trees such as clove (Syzygium aromaticum syn. Eugenia aromatica), nutmeg (Myristica fragrans), or coconut (Cocos nucifera) and tending spontaneous regeneration, are an example of a species-rich forest garden system in the eastern hemisphere of
the Indonesian archipelago. In this paper we report the influence of site conditions, as slope inclination, soil type, and
soil depth, on species composition, tree species diversity, and stand structure in old dusuns in four villages on Saparua, a small island south of Seram. In addition, we compared the floristic composition and stand
structure of old dusuns with those of primary forest and advanced fallow vegetation (∼15-yr old). Soil conditions, particularly the depth of the
mineral soil layer, and the relief have a major influence on species selection in dusuns. The most common species in old dusuns were absent both in primary forest and forest fallow. Floristic similarity between old dusuns and the unmanaged stands was low. However, in two study villages species richness of old dusuns was similar to that of the primary forest. Old dusuns showed an open structure with an average reduction of basal area by about half compared to the primary forest. Less than
half of all individuals found above 10 cm DBH in old dusuns were planted. Only very few species were exclusively planted. Most species were both planted and emerged from spontaneous
regeneration. The results indicate the important role of spontaneous regeneration in this forest garden system.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
16.
Fikret Kaya BScFE MScFE. Ph. D. candidate Ian Smith BSc. MSc. PhD. PEng. FIWSc. 《Wood Science and Technology》1993,27(3):229-239
Summary Below-crown radial and height variations in maximum crushing strength parallel to grain, relative density and tracheid length of an immature, 55 year old, red pine were studied. All properties showed pronounced trends with radial age and increased from pith to bark. A radial age of 16 years was estimated as the age from which mature stem wood is formed. All properties studied varied with height above ground. Strong correlations were observed among properties. The study tree exhibited noticeably lower average crushing strength than is reported in the literature for wood from mature red pines.This work was undertaken with financial support from Karadeniz Technical University, Trabzon, Turkey, and the Natural Sciences and Engineering Research Council of Canada, Operating Grant 0GP0004417 相似文献
17.
The aim of this study was to determine changes in crystallinity and crystalline unit cell type of heat-treated Scots pine
(Pinus sylvestris L.) and Uludağ fir (Abies nordmanniana stev. subsp. bornmuelleriana Mattf.) wood samples by means of FT-IR spectroscopic method. Heat treatment was applied on the test samples in an oven at
three different temperatures (120, 150, and 180°C) and for two different periods of time (6 and 10 h) under atmospheric pressure.
It was designated that crystallinity of both Scots pine and Uludağ fir wood samples increased during heat treatment depending
on the duration. However, monoclinic structure in crystalline unit cells of Scots pine and Uludağ fir wood samples converted
to triclinic structure when heat treated. It was estimated that monoclinic structure was dominant in the crystalline unit
cell. It was established that the crystalline structure of Scots pine wood samples was more affected by heat treatment than
that of Uludağ fir wood samples. 相似文献
18.
19.
Erkut Turan Cengiz Unsal Mehmet Utkan Oren Omer Gurkan Dilek Ismail Gokce Yildirim Murat Sarierler 《Veterinary research communications》2014,38(3):229-235
The aim of this study was to test the applicability of electrical stimulation of lumbar spinal nerve roots and obtain normative electrical root stimulation (ERS) data for L7 nerve root and sciatic nerve in dogs. For that purpose ERS and sciatic nerve stimulations were performed consecutively, in totally 40 healthy dogs. ERS was applied in the L7/S1 intervertebral space via monopolar needle electrodes. Muscle responses were recorded from the gastrocnemius muscles on the left and right hind limbs. Sciatic nerve stimulation was performed at the greater trochanter level on the left hind limb, with records obtained from the left gastrocnemius muscle. Mean root latencies of the left and right side were 5.22?±?0.49 ms and 5.29?±?0.53 ms, respectively. There was no significant difference in root latency between the right and left sides. The mean terminal latency was 3.82?±?0.46 ms. The proximal motor nerve conduction velocity of the sciatic nerve was 63.15?±?3.43 m/s. The results of this study show that ERS provides objective data about the integrity of lumbar spinal nerve roots by evaluating the entire population of motor fibres and total length of the motor axon in dogs. ERS can be considered a useful diagnostic method for confirmation of diagnoses of lumbosacral diseases. 相似文献
20.
Bladder eversion is a rare condition and may occur in mares as a result of excessive straining during pregnancy or in the postpartum period. In the present case, bladder eversion was caused by chronic cystitis in a nonpregnant mare. An Arabian racehorse (mare, 3 years old) was admitted to The Racehorse Hospital of the Turkish Jockey Club with a history of lumbar pain, excessive straining, and frequently assuming the urination position. Physical examination revealed the presence of tenesmus, stranguria, passing of small amounts of urine, and a visible mucosal structure at the ventral vulvar commissure during tenesmus. Laboratory findings revealed leucocytosis, increased urine pH, proteinuria, pyuria, and hematuria. Streptococcus equi subsp. zooepidemicus and Escherichia coli were isolated and identified in urine culture. Transrectal ultrasonography revealed thickening of the bladder wall and prolapse of the bladder corpus into the bladder. In the cystoscopic examination, performed following bladder reduction, severe hyperemia, erosion, and ulcers were determined in the bladder mucosa. Chronic cystitis was treated using antibiotics, based on urine culture test results, together with steroids and non-steroidal anti-inflammatory drugs. Twenty-four hours after the start of treatment, the severity of straining was observed to have decreased, ceasing completely on Day 4, and the bladder returned to its normal position. 相似文献