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71.
LORRIE GASCHEN PATRICK KIRCHER ANJA STÜSSI KARIN ALLENSPACH FRÉDÉRIC GASCHEN MARCUS DOHERR ANDREA GRÖNE 《Veterinary radiology & ultrasound》2008,49(1):56-64
Intestinal wall thickness is neither a specific nor sensitive ultrasound parameter for detecting intestinal inflammation. We hypothesize that mucosal echogenicity, lymphadenomegaly, and secondary findings of the gastrointestinal tract would be more sensitive and specific markers for detecting and differentiating causes of chronic inflammatory bowel disease in dogs. Fifty-six client-owned dogs with chronic diarrhea and 10 control dogs were examined with two-dimensional, gray-scale ultrasound (time 0, 4, and 10 weeks post therapy) and small intestinal mucosal biopsies were performed at the 0- and 4-week time points. The clinical activity was assessed at each time point using the canine inflammatory bowel disease activity index (CIBDAI). Fifty-one dogs had inflammatory infiltration of the duodenal mucosa and were divided into three groups, food-responsive disease, idiopathic inflammatory bowel disease, and protein-losing enteropathy, based on their response to the different treatments and histology. Two different patterns of increased echogenicity of the mucosa were detected: hyperechoic speckles and hyperechoic striations. A normal, hypoechoic bowel mucosa in dogs with chronic diarrhea had a sensitivity of 80% and a specificity of 81% for the diagnosis of food-responsive disease. Hyperechoic striations had a sensitivity of 75% and a specificity of 96% for dogs with protein-losing enteropathy. Hyperechoic speckles were non-specific for diagnosing inflammatory bowel disease. There was a significant relationship between ultrasound score and CIBDAI at t0, but not following therapy. Mucosal echogenicity may be a better parameter for detecting inflammatory bowel disease than bowel wall thickness in dogs with chronic diarrhea. 相似文献
72.
Transpiration Sensitivity to Evaporative Demand Across 120 Years of Breeding of Australian Wheat Cultivars
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R. Schoppach D. Fleury T. R. Sinclair W. Sadok 《Journal of Agronomy and Crop Science》2017,203(3):219-226
Historically, wheat yields in drought‐prone Australian environments have been consistently increasing for over a century. There is currently an agreement that approximately half of that increase is attributable to breeding programmes, but their physiological basis remains poorly documented. In this investigation, we hypothesized that limited whole‐plant transpiration rate (TR) under high atmospheric vapour pressure deficit (VPD) could result in advantageous water conservation and crop yield increase under south Australian conditions. Therefore, TR response to VPD was measured in the 0.9–3.2 kPa range for a group of 23 wheat cultivars that were released from 1890 to 2008. Consistent with a water‐conservation hypothesis, all genotypes displayed a VPD break point (BP) in TR with increasing VPD such that TR was limited at VPD above a BP of about 2 kPa. The BP and slope of TR with increasing VPD above the break point were correlated with the year of release, although the changes were in different directions. Such changes in these transpiration parameters were independent of plant leaf area and only marginally correlated with Zadok's stages. These results indicated that selection over 120 years by breeders for yield increase unconsciously resulted in genotype selection for the expression of the limited‐TR trait. 相似文献
73.
74.
Latin American pastures usually include trees that may be important in sustaining productivity and conserving resources and
biodiversity. A participatory survey of trees in seasonally dry pastures of 54 farms in the Caribbean region of Colombia,
followed by cluster and correlation analyses, revealed a multistrata configuration. Trees of large stature (e.g., Tabebuia rosea, Albizia caribaea and Sterculia apelata) provided shade and produced timber. The most important fodder trees were those of medium stature (Albizia saman, Guazuma ulmifolia, and Cassia grandis) that produced fruits or pods, while other species were managed as shrubs producing green leaf fodder (e.g., Crescentia cujete and Gliricidia sepium, which was also ubiquitous as living fence posts). Trees were present on between 26 and 69% of the pastures on each farm,
at densities varying from less than 3 to more than 50 trees ha−1. There were more trees in drier areas, of lower fertility, with extensive grazing, where milk as well as meat was produced.
Most farmers planted timber trees, encouraged regeneration of fodder trees, and knew about fodder species preferences of cattle
and the effects of trees on pasture and animal productivity. Their knowledge of tree phenology was less certain and varied
even amongst farmers in similar locations. There is scope to develop silvopastoral systems with woody species familiar to
farmers, but it is critical to determine how important different vegetation strata are for sustainability of cattle production.
An experiment has been established to achieve this, with treatments based on an analysis of how trees are presently used on
farms in the region.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
75.
76.
V. Carpentieri-Pipolo A. E. Pipolo H. Abdel-Haleem H. R. Boerma T. R. Sinclair 《Euphytica》2012,186(3):679-686
Soybean (Glycine max (L.) Merr.) genotype PI 416937 has been identified as expressing a ‘slow-wilting’ phenotype in the field and this has been traced to a low hydraulic conductance in its leaves. The transpiration rate of de-rooted shoots of this genotype has been found to be insensitive to the aquaporin inhibitor silver nitrate compared to elite cultivars which are silver nitrate sensitive. These results indicated that PI 416937 might have a unique aquaporin population. The objective of this study was to determine if QTLs could be identified that are associated with the lack of sensitivity in PI 416937 to silver. To identify the genomic locations and genetic bases of this trait, a recombinant inbred line population was derived from a mating between PI 416937 and the cultivar ‘Benning’. The RILs were all phenotyped for their response to the silver inhibitor and the results were subjected to a QTL analysis. Four QTL were identified as putatively associated with the silver response (qSV). These QTL explained from 17.7 to 24.7% of the phenotypic variation with qSV_Gm12 explaining the greatest amount of phenotypic variation. The qSV_Gm03 and qSV_Gm10 QTL inherited their positive alleles from PI 416937, while qSV_Gm05 and qSV_Gm12 inherited their favorable alleles from Benning. Co-localized silver nitrate response QTL with other morpho–physiological traits could help to explain soybean plant’s ability to tolerate water-deficit stress. 相似文献
77.
Giacomo Gianotti Alexander Valverde Melissa Sinclair Doris H. Dyson Thomas Gibson Ron Johnson 《Canadian journal of veterinary research》2012,76(4):261-267
The objective of this study was to compare the effect on the minimum alveolar concentration (MAC) of isoflurane when ketamine was administered either after or without prior determination of the baseline MAC of isoflurane in rabbits. Using a prospective randomized crossover study, 8 adult, female New Zealand rabbits were allocated to 2 treatment groups. Anesthesia was induced and maintained with isoflurane. Group 1 (same-day determination) had the MAC-sparing effect of ketamine [1 mg/kg bodyweight (BW) bolus followed by a constant rate infusion (CRI) of 40 μg/kg BW per min, given by intravenous (IV)], which was determined after the baseline MAC of isoflurane was determined beforehand. A third MAC determination was started 30 min after stopping the CRI. Group 2 (separate-day determination) had the MAC-sparing effect of ketamine determined without previous determination of the baseline MAC of isoflurane. A second MAC determination was started 30 min after stopping the CRI. In group 1, the MAC of isoflurane (2.15 ± 0.09%) was significantly decreased by ketamine (1.63 ± 0.07%). After stopping the CRI, the MAC was significantly less (2.04 ± 0.11%) than the baseline MAC of isoflurane and significantly greater than the MAC during the CRI. In group 2, ketamine decreased isoflurane MAC (1.53 ± 0.22%) and the MAC increased significantly (1.94 ± 0.25%) after stopping the CRI. Minimum alveolar concentration (MAC) values did not differ significantly between the groups either during ketamine administration or after stopping ketamine. Under the study conditions, prior determination of the baseline isoflurane MAC did not alter the effect of ketamine on MAC. Both methods of determining MAC seemed to be valid for research purposes. 相似文献
78.
79.
The echocardiographic effects of romifidine in dogs with and without prior or concurrent administration of glycopyrrolate 总被引:1,自引:0,他引:1
Objective To determine the cardiopulmonary response to romifidine (RO) in the dog with or without prior or concurrent administration of glycopyrrolate. Study Design Randomized, cross‐over experimental study. Animals Six (three male, three female) cross‐bred dogs weighing 23 ± 2.4 kg. Methods Two‐dimensional guided M‐mode echocardiography was performed in conscious dogs simultaneously with measurement of systolic arterial blood pressure (SBP) and heart rate (HR). Dimensions of the left ventricle (LVID), interventricular septum (IVS), and left ventricular free wall (LVFW) were obtained in systole (S) and diastole (D). Amplitude of motion (Amp) of the IVS and LVFW were also measured. From these, measures of wall stress (WS) and fractional shortening (FS) of the left ventricle were derived. Baseline echocardiographic measurements were recorded, following which one of the five treatments was administered. Glycopyrrolate (G) 0.01 mg kg?1, or saline (S) 0.5 mL, was administered IM as pre‐medication (Gp or Sp), or G was administered concurrently (Gc) with romifidine (RO). Treatments were: T1, Sp + RO (40 μg kg?1); T2, Gp + RO (40 μg kg?1); T3, Sp + RO (120 μg kg?1); T4, Gp + RO (120 μg kg?1); and T5, Sp + Gc +RO (120 μg kg?1). Romifidine or RO + Gc was administered SC 20 minutes after pre‐medication (time 0), and further measurements were taken 10, 20, 30, 60, and 90 minutes after RO. Results Echocardiographic indices of cardiac systolic function (LVID‐S, FS, Amp‐LVFW) and HR were decreased in RO‐sedated dogs (p < 0.0001) . The magnitude of change in cardiac indices was least with low‐dose RO. At most sampling times, high‐dose RO produced significantly more alteration in cardiac indices. Systolic blood pressure increased in all treatment groups, with the greatest increases in those groups receiving G. Glycopyrrolate significantly increased HR; however, cardiac indices were further reduced. Wall stress significantly increased, with a more dramatic increase in groups receiving G. Conclusions Indices of LV systolic function were reduced in RO‐sedated dogs in a dose‐related manner. Glycopyrrolate further reduced these indices and dramatically increased measurements of wall stress in dogs sedated with RO. Clinical relevance Use of low‐dose RO minimizes cardiac dysfunction; however, it should still be used cautiously in dogs with cardiomyopathy or heart failure. The routine use of G is not recommended to alleviate the bradycardia associated with RO in conscious dogs. 相似文献
80.
KR Arrigo DH Robinson DL Worthen RB Dunbar GR DiTullio M VanWoert MP Lizotte 《Science (New York, N.Y.)》1999,283(5400):365-367
Data from recent oceanographic cruises show that phytoplankton community structure in the Ross Sea is related to mixed layer depth. Diatoms dominate in highly stratified waters, whereas Phaeocystis antarctica assemblages dominate where waters are more deeply mixed. The drawdown of both carbon dioxide (CO2) and nitrate per mole of phosphate and the rate of new production by diatoms are much lower than that measured for P. antarctica. Consequently, the capacity of the biological community to draw down atmospheric CO2 and transport it to the deep ocean could diminish dramatically if predicted increases in upper ocean stratification due to climate warming should occur. 相似文献