全文获取类型
收费全文 | 252篇 |
免费 | 13篇 |
专业分类
林业 | 19篇 |
农学 | 4篇 |
基础科学 | 6篇 |
31篇 | |
综合类 | 24篇 |
农作物 | 19篇 |
水产渔业 | 23篇 |
畜牧兽医 | 110篇 |
园艺 | 7篇 |
植物保护 | 22篇 |
出版年
2022年 | 1篇 |
2021年 | 6篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 11篇 |
2012年 | 16篇 |
2011年 | 24篇 |
2010年 | 14篇 |
2009年 | 5篇 |
2008年 | 16篇 |
2007年 | 11篇 |
2006年 | 17篇 |
2005年 | 16篇 |
2004年 | 14篇 |
2003年 | 7篇 |
2002年 | 12篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有265条查询结果,搜索用时 0 毫秒
101.
Theresa A. MacNab Brent T. Newcomb Cornelia Ketz-Riley Robert D. Pechman Mark C. Rochat 《Journal of Exotic Pet Medicine》2010,19(4):313-316
Ectopic ureter is the most common cause of congenital urinary incontinence in the dog and cat. The occurrence of ectopic ureter in the dog has been estimated to be 0.016%. A 6-month-old ferret was evaluated for urinary incontinence and urine scalding around the perineal and inguinal areas. Ultrasonography showed a nondistended urinary bladder that contained a possible intraluminal blood clot. Excretory urography revealed a left ectopic ureter. The ferret was initially treated with oral amoxicillin-clavulanate and topical silver sulfadiazine ointment for the perineal and inguinal dermatitis associated with the incontinence. Because of the potential for complications and additional surgery with ureteral transplantation, a left nephroureterectomy was performed. Surgical recovery was uneventful and the incontinence improved, although a small amount of incontinence-associated dermatitis was still present 24 days after discharge. Phenylpropanolamine therapy was initiated to address a suspected dysfunction of the urethral sphincter. Urinary incontinence improved with the phenylpropanolamine therapy; however, a small amount of incontinence persisted throughout the 3 months in which the ferret was evaluated. To the authors' knowledge, this is the first report of an ectopic ureter in a domestic ferret. 相似文献
102.
Efficacy of postemergence herbicides tankmixes in aryloxyphenoxypropionate-resistant grain sorghum 总被引:1,自引:0,他引:1
M. Joy M. Abit Kassim Al-Khatib Brian L. Olson Phillip W. Stahlman Patrick W. Geier Curtis R. Thompson Randall S. Currie Alan J. Schlegel Johnathon D. Holman Kurt A. Hudson Douglas E. Shoup Michael J. Moechnig W. James Grichar Brent W. Bean 《Crop Protection》2011,30(12):1623-1628
The development of aryloxyphenoxypropionate (APP)-resistant grain sorghum could provide additional opportunities for postemergence herbicide grass control in grain sorghum. Field experiments were conducted in Texas (Bushland, and Yoakum), Kansas (Dodge City, Garden City, Hays, Manhattan, Colby, Ottawa, and Tribune), and South Dakota (Highmore) to evaluate the efficacy of quizalofop tank mixes in APP-resistant grain sorghum. Quizalofop was applied alone or in combination with dicamba, 2,4-D, prosulfuron, 2,4-D + metsulfuron methyl, or halosulfuron methyl + dicamba. Herbicides were applied when sorghum was 12–50 cm in height. Overall weed control was greater when quizalofop was applied with other herbicides than when applied alone. At 2 and 4 weeks after treatment (WAT), large crabgrass [Digitaria sanguinalis (L.) Scop.], giant foxtail (Setaria faberi Herrm.), and green foxtail [Setaria viridis (L.) Beauv.] control were greater than 90% when quizalofop was applied alone or in combination with dicamba, halosulfuron methyl + dicamba, or prosulfuron. Palmer amaranth (Amaranthus palmeri S. Wats.), puncturevine (Tribulus terrestris L.), and tumble pigweed (Amaranthus albus L.) control were greater than 90% in all treatments except when quizalofop was applied alone. Herbicide treatments, except those that included 2,4-D, caused slight to no sorghum injury. Grain sorghum yield was greater for all herbicide treatments compared to the weedy check. This research showed that application of quizalofop in combination with broadleaf weed herbicides provided excellent weed control in sorghum. 相似文献
103.
Satoru Inoue Toshiro Kato Victor W. L. Jordan Keith J. Brent 《Pest management science》1987,19(2):145-152
The effects of rice blast fungicides known to inhibit melanisation or penetration on the adhesion of Pyricularia oryzae to the leaf surface of barley were investigated. Adhering appressoria were counted after shaking inoculated leaves vigorously with water. On untreated leaves, appressoria began to adhere at the time when appressorial melanisation was initiated. The number of adhering appressoria then increased gradually, and most were melanised. On chlobenthiazone-treated leaves, appressoria were not melanised and were easily detached from the surface. Similar results were obtained with tricyclazole. However, after treatment with tetrachlorophthalide or pentachlorobenzyl alcohol, which are also known to prevent penetration of P. oryzae, melanised appressoria still remained after shaking in water. It is suggested that appressorial melanisation in P. oryzae is involved in appressorial adhesion. The antipenetrant action of the melanin biosynthesis inhibitors chlobenthiazone and tricyclazole may be ascribed to the lack of adhesive intensity necessary to support the mechanical shearing of the cuticle of rice plants. 相似文献
104.
A high incidence of Diplodia shoot blight (site means ranging 85-100%) was observed on recently planted red pine (Pinus resinosa) seedlings where mature red pine stands previously had been clearcut. An investigation of the potential of harvest debris as a source of inoculum of Diplodia pathogens then was conducted. Cones, bark, needles, stems from shoots bearing needles, and stems from shoots not bearing needles (both suspended above the soil and in soil contact) were collected from harvest debris left at sites where clearcutting occurred. Conidia were quantified, and their germination rate was assessed, and Diplodia species were identified using PCR. Conidia of Diplodia species were found at all study sites and conidia counts increased from samples collected from 6 to 18 months after harvest. Germinable conidia were obtained from debris collected 6 months to 5 years after harvest. Fewer conidia were obtained from debris collected at intervals of up to 4-5 years after harvest and the percentage of germinable conidia was lower after longer intervals following harvest. More conidia were obtained and a greater percentage germinated from debris collected above the soil than from debris in soil contact. The host substrate also influenced the number of conidia and the percentage that germinated. Planting red pine seedlings next to debris infested with Diplodia pathogens could provide a persistent source of inoculum. Results should prompt further consideration by land managers and researchers of the potential forest health risks, in addition to benefits, that may be associated with harvest debris. 相似文献
105.
Reimer SB Kittleson MD Kyles AE 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2006,20(2):290-296
The purpose of this prospective clinical trial was to evaluate the safety and efficacy of a commercially available rheolytic thrombectomy system in the treatment of naturally occurring feline aortic thromboembolic disease. All 6 cats enrolled in the investigation were affected at the level of the distal aorta and had signs of the disease affecting both pelvic limbs. Cats were anesthetized and an arteriotomy was performed on 1 carotid artery to gain access to the arterial system. Selective arterial angiography was used to confirm the presence of thromboembolic disease. The thrombectomy system was advanced to the level of the thrombus using fluoroscopic guidance. Repeat angiography was used intermittently to assess progress of thromboembolus dissolution throughout the procedure. The use of the rheolytic thrombectomy system resulted in successful thrombus dissolution in 5 of 6 cats. Three of 6 cats survived to discharge. Both of these results compare favorably with conventional therapies used in the treatment of this disease. Feline distal aortic thromboembolism is a frustrating disease that warrants a guarded to poor prognosis. Rheolytic thrombectomy may provide veterinarians with an alternative therapy in the treatment of thromboembolic diseases, including feline distal aortic thromboembolism. 相似文献
106.
Murray R. Woodbury Brent Wagner Elad Ben-Ezra Dale Douma Wendy Wilkins 《The Canadian veterinary journal. La revue veterinaire canadienne》2014,55(9):870-874
An egg count survey using environmental fecal samples obtained in spring or early summer was conducted to estimate the apparent prevalence of Toxocara vitulorum in unweaned bison calves and of other intestinal parasites in adult bison on 98 farms in Manitoba and Saskatchewan. Calf samples were pooled (maximum 5 samples per pool) by farm and positive pools were examined to determine individual T. vitulorum counts. Toxocara vitulorum eggs were found on 4 farms in Manitoba and none in Saskatchewan. Apparent herd-level prevalence estimates were 12% [95% confidence interval (95% CI): 3.4% to 28.2%] and 0% (95% CI: 0% to 5.7%) respectively. Samples from adult bison contained eggs/oocysts from trichostrongyle species, Eimeria sp., Monieza sp., Capillaria sp., Nematodirus sp. and Trichuris sp. in 100%, 95%, 72%, 13%, 13%, and 5% of herds, respectively. Strongyloides sp. were not found in any herd. Further studies are needed to assess parasite distribution patterns in bison and to evaluate the risk that T. vitulorum may pose to bison, cattle, and wildlife. 相似文献
107.
Dirikolu L Mollett BA Troppmann A Woods WE Bratton C Cashman CP Schroedter D Mayer B Lehner AF Karpiesiuk W Hughes C Boyles J Harkins JD Tobin T 《Veterinary therapeutics : research in applied veterinary medicine》2002,3(3):297-307
Single doses of one, three, and six actuations (120 micro g albuterol/actuation) and multiple daily doses (six actuations per dose four times daily) for 5 days of aerosol albuterol sulfate were sequentially administered to each of six horses using an equine inhaler device (Torpex, 3M Animal Care Products, St. Paul, MN [corrected] and Boehringer Ingleheim Vetmedica, Inc., St. Joseph, MO [corrected]). A 2-week washout period was allowed between each dose. ELISA testing revealed no evidence of albuterol in urine at 24 hours after any single-dose administration. Results indicated that 48 hours or longer should be allowed for albuterol to be cleared from urine after single doses. When given at the maximum recommended rate of six actuations per dose four times a day for 5 days, urine samples tested by ELISA showed no evidence of albuterol at 48 hours after the final dose. Testing of nasal swabs by ELISA demonstrated the presence of albuterol for 8 hours after each single dose, and some horses might have detectable levels of albuterol in nasal swabs for several days following administration of multiple doses. As a guideline for withdrawal time, 72 hours or longer should be allowed after administration of aerosol albuterol sulfate to horses before participation in equestrian competitions that are regulated for detection of certain performance-enhancing substances. However, these recommendations were based on a small sample of horses and the specific ELISA test used and interpreted as described. Factors specific to individual horses may influence these detection times. 相似文献
108.
White Emma L. Thomasson J. Alex Auvermann Brent Kitchen Newell R. Pierson Leland Sandy Porter Dana Baillie Craig Hamann Hendrik Hoogenboom Gerrit Janzen Todd Khosla Rajiv Lowenberg-DeBoer James McIntosh Matt Murray Seth Osborn Dave Shetty Ashoo Stevenson Craig Tevis Joe Werner Fletcher 《Precision Agriculture》2021,22(1):306-315
Precision Agriculture - Data-centric technology has not undergone widespread adoption in production agriculture but could address global needs for food security and farm profitability. Participants... 相似文献
109.
Allister Holmes Karin Müller Brent Clothier Markus Deurer 《Communications in Soil Science and Plant Analysis》2015,46(4):122-136
Management practices designed to increase carbon sequestration via perennial tree crops are potential tools to mitigate the consequences of climate change. Changes in orchard management could enable growers to meet eco-verification market demands for products with a low carbon footprint and potentially exploit the emerging business opportunity in carbon storage, while enhancing the delivery of ecosystem services that depend on soil carbon stocks. However, there is no standard methodology to verify any potential claims of carbon storage by perennial vine crops. We developed a robust methodology to quantify carbon storage in kiwifruit orchards. Soil carbon stocks (SCS) were determined in six depth increments to 1 m deep in two adjacent kiwifruit blocks, which had been established 10 (“young”) and 25 (“old”) years earlier. We used a space-for-time analysis. Our key results were the young and old kiwifruit block stored about 139 and 145 t C/ha to 1 m depth. Between 80–90 percent of the SCS were stored in the top 0.5 m, and 89–95 percent in the top 0.7 m; there was no significant difference between the SCS in row and alley to a depth of 0.5 m; a CV of 5–15 percent indicates that 4–10 cores are needed for 80 percent confidence in the estimated SCS; we recommend separating each core into the depths 0–0.1, 0.1–0.3, 0.3–0.5, and 0.5–1 m to allow the assessment of SCS dynamics; we detected a weak spatial pattern of the SCS only for the old kiwifruit block with a range of about 3 m. A sampling bay along a vine row should have a maximum length of 3 m. We then assessed SCS in more than sixty kiwifruit orchards throughout New Zealand. They stored on average 174.9 ± 3 t C ha?1 to 1 m depth. On average, 51 percent of the SCS down to 1 m depth were stored in the top 0.3 m, which is the standard depth according to the Kyoto protocol. About 72 percent of the SCS to 1 m depth were captured when increasing the sampling depth to 0.5 m. These results underscore the necessity to analyze SCS in an orchard to at least 0.5 m deep. Using the same methodology to 1 m deep, we determined SCS in two wine grape vineyards on shallow, stony alluvial soils. We found a difference between vineyard and adjacent pasture SCS of nearly 16 t/ha. As the vines are 25 years old, this equates to carbon sequestration rates of 640 kg ha?1 yr?1. Our results of the space-for-time analysis also showed that all sequestration had occurred below 0.5 m. Therefore, we decided to sample C to a greater depth. In a 30-year old kiwifruit orchard and an adjacent pasture, SCS was measured to 9 m deep. In the kiwifruit orchard, we found a sequestration rate of 6.3 tons of C per hectare per year greater than in the adjacent pasture that was the antecedent land use. 相似文献
110.