全文获取类型
收费全文 | 227篇 |
免费 | 4篇 |
专业分类
林业 | 8篇 |
农学 | 4篇 |
基础科学 | 3篇 |
25篇 | |
综合类 | 16篇 |
农作物 | 3篇 |
水产渔业 | 4篇 |
畜牧兽医 | 150篇 |
园艺 | 12篇 |
植物保护 | 6篇 |
出版年
2020年 | 1篇 |
2019年 | 9篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 11篇 |
2011年 | 13篇 |
2010年 | 10篇 |
2009年 | 7篇 |
2008年 | 10篇 |
2007年 | 13篇 |
2006年 | 16篇 |
2005年 | 16篇 |
2004年 | 12篇 |
2003年 | 10篇 |
2002年 | 13篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有231条查询结果,搜索用时 15 毫秒
11.
Kazuya KUSHIDA Urs GIGER Toshihiko TSUTSUI Megumi INABA Yoshio KONNO Kureha HAYASHI Kana NOGUCHI Akira YABUKI Keijiro MIZUKAMI Moeko KOHYAMA Yasuyuki ENDO Osamu YAMATO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(6):743-746
Erythrocyte pyruvate kinase (PK) deficiency is an inherited glycolytic erythroenzymopathy
caused by mutations of the PKLR gene. A causative mutation of the feline
PKLR gene was originally identified in Abyssinian and Somali cats in
the U.S.A. In the present study, a TaqMan probe-based real-time PCR genotyping assay was
developed and evaluated for rapid genotyping and large-scale screening for this mutation.
Furthermore, a genotyping survey was carried out in a population of four popular purebred
cats in Japan to determine the current mutant allele frequency. The assay clearly
displayed all genotypes of feline PK deficiency, indicating its suitability for
large-scale survey as well as diagnosis. The survey demonstrated that the mutant allele
frequency in Abyssinian and Somali cats was high enough to warrant measures to control and
prevent the disease. The mutant allele frequency was relatively low in Bengal and American
Shorthair cats; however, the testing should still be carried out to prevent the spread of
the disease. In addition, PK deficiency should always be considered in the differential
diagnosis of anemia in purebred cats in Japan as well as worldwide. 相似文献
12.
Juraj Lieskovský Pavol Kenderessy Jana Špulerová Tibor Lieskovský Peter Koleda Felix Kienast Urs Gimmi 《Landscape Ecology》2014,29(5):867-877
Collectivization of agriculture (1950s–1970s) was one of the most important periods in landscape development in Slovakia. Traditionally managed agricultural landscapes, that covered more than half of the Slovak territory, were transformed into large-scale fields and only fragments of traditional agricultural landscapes survived. We mapped the remaining traditional agricultural landscapes using aerial photos and historical maps. We then statistically analyzed the various geographical factors and their influence on the transformation process of traditional and collectivized fields, i.e., slope steepness, soil fertility, distance from settlements and isolation from regional capital cities. The comparison was performed using classification tree analysis. We constructed a set of decision rules that explain why fields were managed traditionally or collectivized. Our findings show that traditional agricultural fields were more likely to persist on steep terrain, less fertile soils, and on locations that were closer to the settlements, but more isolated from the regional capital cities. Steepness played the most important role: small-scale fields located on steep areas were not accessible to heavy machinery and therefore, frequently survived the collectivization. We show that the selected geographical factors are good explanatory variables for the collectivization of arable fields and orchards. For vineyards and grasslands, however, the explanatory power of the selected geographical factors is lower, and we suspect that other factors, not depicted in the analysis play an important role. 相似文献
13.
Kormann Urs G. Scherber Christoph Tscharntke Teja Batáry Péter Rösch Verena 《Landscape Ecology》2019,34(5):1045-1056
Landscape Ecology - Global change pressures (GCPs) imperil species and associated ecosystem functions, but studies investigating interactions of landscape-scale pressures remain scarce. Loss of... 相似文献
14.
P. Mäder Stephan Edenhofer Thomas Boller Andres Wiemken Urs Niggli 《Biology and Fertility of Soils》2000,31(2):150-156
Arbuscular mycorrhizal (AM) root colonization was studied in a long-term field trial in which four farming systems currently
in use in Switzerland were continuously applied to a randomized set of plots at a single field site from 1978 till 1993. There
were two low-input farming systems (organic and bio-dynamic) and two high-input (conventional) farming systems (according
to Swiss guidelines of integrated plant production with and without farmyard manure). The systems had an identical 7-year
crop rotation and tillage scheme and differed essentially only in the amount and type of fertilizer supplied and in plant
protection management. The percentage of root colonization by AM fungi was determined in field samples 2–3 times over the
growing season in crops in the rotation, namely in winter wheat (Triticum aestivum L. cv. Sardona), vetch-rye and grass-clover. We found the percentage of root length colonized by AM fungi to be 30–60% higher
(P≤0.05) in the plants grown in soils from the low-input farming systems than in those grown in conventionally farmed soils.
Approximately 50% of the variation of AM root colonization was explained by chemical properties of the soils (pH, soluble
P and K, exchangeable Mg), the effect of soluble soil P being most pronounced. The potential of the field soils from the differently
managed plots to cause symbiosis with AM fungi was tested in a glasshouse experiment, using wheat as a host plant. Soils from
the low-input farming systems had a greatly enhanced capacity to initiate AM symbiosis. The relative differences in this capacity
remained similar when propagules of the AM fungus Glomus mosseae were experimentally added to the soils, although overall root colonization by AM fungi was 2.8 times higher.
Received: 27 August 1999 相似文献
15.
First morphological characterization of 'Candidatus Mycoplasma turicensis' using electron microscopy
Willi B Museux K Novacco M Schraner EM Wild P Groebel K Ziegler U Wolf-Jäckel GA Kessler Y Geret C Tasker S Lutz H Hofmann-Lehmann R 《Veterinary microbiology》2011,149(3-4):367-373
At least three haemotropic mycoplasmas have been recognized in cats: Mycoplasma haemofelis (Mhf), 'Candidatus Mycoplasma haemominutum' (CMhm) and 'Candidatus M. turicensis' (CMt). The latter was originally identified in a Swiss pet cat with haemolytic anaemia and shown to be prevalent in domestic cats and wild felids worldwide using molecular methods. So far, there has been no confirmatory morphological evidence of the existence of CMt presumably due to low blood loads during infection while CMhm has only been characterized by light microscopy with discrepant results. This study aimed to provide for the first time electron microscopic characteristics of CMt and CMhm and to compare them to Mhf. Blood samples from cats experimentally infected with CMt, CMhm and Mhf were used to determine copy numbers in blood by real-time PCR and for transmission and scanning electron microscopy. High resolution scanning electron microscopy revealed CMt and CMhm to be discoid-shaped organisms of 0.3 μm in diameter attached to red blood cells (RBCs). In transmission electron microscopy of CMt, an oval organism of about 0.25 μm with several intracellular electron dense structures was identified close to the surface of a RBC. CMhm and CMt exhibited similar morphology to Mhf but had a smaller diameter. This is the first study to provide morphological evidence of CMt thereby confirming its status as a distinct haemoplasma species, and to present electron microscopic features of CMhm. 相似文献
16.
Irrigation rate and plant density effects on yield and water use efficiency of drip-irrigated corn 总被引:3,自引:0,他引:3
Salah E. El-Hendawy Essam A. Abd El-Lattief Mohamed S. Ahmed Urs Schmidhalter 《Agricultural Water Management》2008,95(7):836-844
The efficient use of water by modern irrigation systems is becoming increasingly important in arid and semi-arid regions with limited water resources. This study was conducted for 2 years (2005 and 2006) to establish optimal irrigation rates and plant population densities for corn (Zea mays L.) in sandy soils using drip irrigation system. The study aimed at achieving high yield and efficient irrigation water use (IWUE) simultaneously. A field experiment was conducted using a randomized complete block split plot design with three drip irrigation rates (I1: 1.00, I2: 0.80, and I3: 0.60 of the estimated evapotranspiration), and three plant population densities (D1: 48,000, D2: 71,000 and D3: 95,000 plants ha−1) as the main plot and split plot, respectively. Irrigation water applied at I1, I2 and I3 were 5955, 4762 and 3572 m3 ha−1, respectively. A 3-day irrigation interval and three-way cross 310 hybrid corn were used. Results indicated that corn yield, yield components, and IWUE increased with increasing irrigation rates and decreasing plant population densities. Significant interaction effects between irrigation rate and plant population density were detected in both seasons for yield, selected yield components, and IWUE. The highest grain yield, yield components, and IWUE were found for I1D1, I1D2, or I2D1, while the lowest were found for I3D2 or I3D3. Thus, a high irrigation rate with low or medium plant population densities or a medium irrigation rate with a low plant population density are recommended for drip-irrigated corn in sandy soil. Crop production functions with respect to irrigation rates, determined for grain yield and different yield components, enable the results from this study to be extrapolated to similar agro-climatic conditions. 相似文献
17.
Soil salinity over root zone usually demonstrates temporal and spatial variations. By changing irrigation management practices
it is possible to change both the frequency of salinity fluctuations and its distribution over the root zone. The objective
of this study was to experimentally investigate how plants integrate soil salinity over its rooting depth when irrigated with
saline water. Consequently, detailed experiments with alfalfa were conducted in some lysimeters containing packed loamy sand
soil. The target soil salinities were created by changing quantity and quality of applied saline water. Results indicated
that the uptake rate preliminary reacts to soil salinity. But at given water content and salinity, the “evaporative demand”
and “root activity” become more important to control the uptake pattern. The obtained results also indicate that root activity
is inconstant during the stress period. By increasing salinity, the activity of that part of the root system is also increased.
Thus, most water is taken from the less saline part and the uptake at other parts with higher salinities never stops. Consequently,
the reduced uptake in one compartment resulting from high salinity is not only compensated from other parts with less salinities,
but also from the same increment by increasing root activity. 相似文献
18.
Waddle JR Giger U 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1990,19(3):80-85
Pleural effusions from 23 dogs and 25 cats hospitalized between November 1986 and April 1987 at the Veterinary Hospital of the University of Pennsylvania (VHUP) were classified as chylous (chylomicrons present) or nonchylous (chylomicrons absent) by the presence or absence, respectively, of a chylomicron band on lipoprotein electrophoresis gels of the effusions. Triglyceride concentrations, cholesterol concentrations, and cholesterol/triglyceride (C/T) ratios were compared between the chylous and nonchylous groups in each species. Cholesterol concentrations were not significantly different between chylous and nonchylous effusions in both dogs and cats. Cholesterol/triglyceride ratios of less than 1 were present in all dogs and cats with chylous effusions; however, 12% of dogs with nonchylous effusions and 50% of cats with nonchylous effusions also had a C/T ratio less than 1. Triglyceride concentrations accurately classified all effusions as chylous or nonchylous in both dogs and cats. Pleural effusions with triglyceride concentrations greater than l00 mg/dl were chylous in all cases, whereas, effusions with triglyceride concentrations less than l00 mg/dl were nonchylous in all cases. 相似文献
19.
Larenza MP Bergadano A Iff I Doherr MG Schatzmann U 《American journal of veterinary research》2005,66(12):2135-2141
OBJECTIVE: To compare the cardiopulmonary effects of anesthesia maintained by continuous infusion of ketamine and propofol with anesthesia maintained by inhalation of sevoflurane in goats undergoing magnetic resonance imaging. ANIMALS: 8 Saanen goats. PROCEDURES: Goats were anesthetized twice (1-month interval) following sedation with midazolam (0.4 mg/kg, IV). Anesthesia was induced via IV administration of ketamine (3 mg/kg) and propofol (1 mg/kg) and maintained with an IV infusion of ketamine (0.03 mg/kg/min) and propofol (0.3 mg/kg/min) and 100% inspired oxygen (K-P treatment) or induced via IV administration of propofol (4 mg/kg) and maintained via inhalation of sevoflurane in oxygen (end-expired concentration, 2.3%; 1X minimum alveolar concentration; SEVO treatment). Cardiopulmonary and blood gas variables were assessed at intervals after induction of anesthesia. RESULTS: Mean +/- SD end-expired sevoflurane was 2.24 +/- 0.2%; ketamine and propofol were infused at rates of 0.03 +/- 0.002 mg/kg/min and 0.29 +/- 0.02 mg/kg/min, respectively. Overall, administration of ketamine and propofol for total IV anesthesia was associated with a degree of immobility and effects on cardiopulmonary parameters that were comparable to those associated with anesthesia maintained by inhalation of sevoflurane. Compared with the K-P treatment group, mean and diastolic blood pressure values in the SEVO treatment group were significantly lower at most or all time points after induction of anesthesia. After both treatments, recovery from anesthesia was good or excellent. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that ketamine-propofol total IV anesthesia in goats breathing 100% oxygen is practical and safe for performance of magnetic resonance imaging procedures. 相似文献