全文获取类型
收费全文 | 93篇 |
免费 | 8篇 |
专业分类
林业 | 8篇 |
农学 | 5篇 |
32篇 | |
综合类 | 2篇 |
农作物 | 5篇 |
水产渔业 | 14篇 |
畜牧兽医 | 23篇 |
园艺 | 1篇 |
植物保护 | 11篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 8篇 |
2020年 | 11篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 5篇 |
2016年 | 12篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 6篇 |
2012年 | 2篇 |
2011年 | 3篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有101条查询结果,搜索用时 31 毫秒
51.
Micha Kosma Marcin Studnicki Justyna Wjcik‐Seliga Beata Michalska‐Klimczak Zdzisaw Wyszyski Elbieta Wjcik‐Gront 《Journal of Agronomy and Crop Science》2019,205(4):414-421
While evaluating plant response to biotic or abiotic stress and genotype–environment interactions and searching causes of yield gap, very often are observed data with non‐normal distributions. One of the commonly encountered types of variables with a non‐normal distribution is count data. Count data are defined as the type of observations which have a positive, non‐zero, integer value. The selection of appropriate probability distributions and model types is very important due to the risk of estimating the variance incorrectly—the phenomenon of over‐dispersion. Increasingly, biologists and agronomists have been using methods based on generalized linear models. However, sometimes, when including count data, they are not aware of or disregard their over‐dispersion. One of the solutions for over‐dispersed count data is to use probability distributions and model types which assume a more flexible mean and variance relationship. Thus, the aim of this study is to present various ways of assessing over‐dispersion. Additionally, we present alternative distributions and discuss other approaches to solve the problem of over‐dispersion in count data sets. As examples in this study are used real data sets from different agricultural experiments. In our study, in one out of the two data sets used, this phenomenon occurred. Thus, in the analysis of count data, instead of using default distribution (usually Poisson distribution), other distributions should be considered because of the possible occurrence of over‐dispersion. We also observed that there is not one universal distribution to use and each data set might need a separate assessment to choose its distribution. For an efficient and proper count data analysis, with potential over‐dispersion, it is important to explore several options, i.e. evaluate models with an alternative to Poisson probability distributions and then make an informed choice. 相似文献
52.
Beata Irena Cejko Beata Sarosiek Radosław Kajetan Kowalski Sławomir Krejszeff Dariusz Kucharczyk 《Journal of the World Aquaculture Society》2013,44(3):466-472
The common carp, Cyprinus carpio L., sperm motility parameters were analyzed by using computer‐assisted sperm analysis system. The percentage of motile sperm (MOT, %), progressively motile sperm (PRG, %), curvilinear velocity (VCL, µm/sec), average path velocity (VAP, µm/sec), the wobbling index (WOB, %), movement linearity (LIN, %), beat cross frequency (BCF, Hz), and amplitude of lateral head displacement (ALH, µm) were determined. Five activation solutions (As) were used to activate sperm movement. As 1 solution: 68 mM NaCl, 50 mM urea, 0.5% bovine serum albumin (BSA), pH: 7.7, 181 mOsm/kg; As 2 buffer: 100 mM NaCl, 10 mM Tris, 0.5% BSA, pH: 9.0, 199 mOsm/kg; As 3 solution: 86 mM NaCl, 0.5% BSA, pH: 7.4, 167 mOsm/kg; As 4 buffer: 5 mM KCl, 45 mM NaCl, 30 mM Tris, 0.5%, pH: 8.0, 160 mOsm/kg; and As 5 solution: distilled water with the addition of 0.5% BSA, pH: 7.3, <3 mOsm/kg. Among five tested solutions, a buffer with a pH of 9.0 and osmolality of approximately 200 mOsm/kg (As 2) was the most suitable. After its activation, a significant increase in MOT and ALH values was observed, which can be of importance to the effectiveness of egg fertilization . 相似文献
53.
Summary The water content of pollen has a decisive influence on its storability in liquid nitrogen. Pollen with an initial high water content cannot be stored successfully at extremely low temperatures, so a certain degree of drying must be carried out before storage. Provided the viability of the pollen is not significantly reduced during drying, the pollen remains viable and fertile when kept at –196°C. 相似文献
54.
The fate of cadmium in field soils of the Danubian lowland 总被引:1,自引:0,他引:1
Lubomir Lichner Pavel Dlapa Miloslav Sir Andrea Cipakova Beata Houskova Pavol Fasko Viliam Nagy 《Soil & Tillage Research》2006,85(1-2):154-165
The susceptibility of soils to deep penetration of cadmium was assessed by measuring cadmium adsorption on soil particles <0.01 mm, easily mobile in soil macropores, and bypassing ratio. The latter is defined as a ratio of the rate of macropore flow to the rate of total (macropore and matrix) flow. Measurements were made on soils from the Danubian lowland, which is a large (1260 km2) agriculturally managed area situated in the south-west of Slovakia, with a shallow (0.5–3.8 m deep) underlying aquifer containing about 10 km3 of freshwater. In this study, the susceptibility of soils to deep penetration of cadmium was assessed on light, loamy-sand soil in Kalinkovo, medium heavy, loamy soil in Macov, and heavy, clay soil in Jurova. It was found that when the interaction between soil and cadmium lasted 1 min, more than 35, 32, and 48% of cadmium was adsorbed on the particles <0.01 mm in soils from Kalinkovo, Macov, and Jurova, respectively. In the case of ponding infiltration, more than 50% of water can flow via topsoil macropores in Kalinkovo, about 70% in Macov, and 96% in Jurova. This value of bypassing ratio can be met during an irrigation/rain with higher intensity then the infiltration rate into the soil matrix of studied soils. As the rains resulting in the macropore flow can occur 24 times on average in south-western Slovakia during the vegetation season, the probability of deep penetration of cadmium is very high, mainly during an initial stage of rainfall. For this reason, some mitigative agricultural practices (e.g. subsurface fertilizer banding or shallow ploughing) should be used in this region to prevent soils from the deep penetration of cadmium. 相似文献
55.
Landscape Ecology - Ecological design used for stormwater management—referred to as Water Sensitive Urban Design (WSUD)—exemplifies how urban environments can benefit from mimicking... 相似文献
56.
Beata?Krasnod?bska-Ostr?gaEmail author Hendrik?Emons Jerzy?Golimowski 《Journal of Soils and Sediments》2004,4(1):43-48
Background Goal and Scope
The application of solid-liquid extraction is proposed to assess extractable fractions of components in soil. The application of a several step scheme could give a lot of information about mobility of metals associated with specific solid phases, especially after separation of top and bottom layers of studied soil. In this study, it was aimed to take into solution metal fractions of major (Ca, Mg, Mn, Fe) and trace elements (Cr, Co, Cu, Zn, As, Cd, Pb) from soil collected in urban areas. The fractions were defined by using chemical extraction operationally. The extraction behavior of studied elements in a six-step sequential extraction procedure is discussed with respect to the properties of the reagents used. 相似文献57.
Tae-Won Kim Irene Sartini Beata Łebkowska-Wieruszewska Andrzej Lisowski Amnart Poapolathep Mario Giorgi 《Journal of veterinary pharmacology and therapeutics》2020,43(1):13-18
Use of drug in lactating animal should be carefully considered due to its possibility of changes in pharmacokinetics as well as drug penetration in milk. The aim of this study was to assess the effect of lactation on pharmacokinetics of meloxicam after IV and IM administrations in goats. A crossover design (2 × 2) was used for each lactating and nonlactating group of goats with a 3-week washout period. Meloxicam (0.5 mg/kg) was administered into the jugular vein and upper gluteal muscle by IV and IM routes, respectively. The plasma and milk drug concentrations were determined by high-performance liquid chromatography with diode array detector, and the pharmacokinetic analysis was carried out by noncompartmental analysis. The pharmacokinetic parameters of meloxicam in lactating and nonlactating goats were not significantly different. The IM bioavailability of meloxicam was relatively lower in lactating (75.3 ± 18.6%) than nonlactating goats (103.8 ± 34.7%); however, the difference was not statistically significant. Moreover, AUC ratio between milk and plasma, which represent drug milk penetration, for both IV and IM administrations was less than 1 (about 0.3). In conclusion, pharmacokinetic parameters of meloxicam are not significantly altered by lactation for either the IV or IM routes of administration and this drug does not require a different dosage regimen for lactating animals. 相似文献
58.
During the development and maturation of cereal grains, storage proteins are accumulated in the starchy endosperm. The enzymes responsible for the mobilisation of stored proteins during seed germination are cysteine endopeptidases and serine carboxypeptidases. In our previous study, we purified the major gliadin-degrading cysteine, endopeptidase EP8, from germinating triticale kernels. We confirmed in an experiment with exogenous gibberellic acid (GA3) that this enzyme is synthesised in aleurone during germination. In this study, the nucleotide sequence of EP8, a barley EP-A (HvEPA) homologue, and the expression pattern during grain development and germination have been analysed. Additionally, by comparing the activity of purified EP8 with the activity pattern of crude enzymatic extracts, the lack of enzyme activity in some tissues and during certain developmental stages has been demonstrated. The correlation of the results of the EP8 expression analysis with the activity pattern of this endopeptidase allowed us to formulate a hypothesis regarding the mechanism of EP8 activity regulation. We believe that the absence of active EP8 until the third day of germination may be associated with high levels of endogenous cystatin TrcC-4, which has the ability to inhibit EP8 in vitro. 相似文献
59.
Inge M. Hanssen Rick Mumford Dag-Ragnar Blystad Isabel Cortez Beata Hasiów-Jaroszewska Dimitrinka Hristova Israel Pagán Ana-Maria Pereira Jeff Peters Henryk Pospieszny Maja Ravnikar Ineke Stijger Laura Tomassoli Christina Varveri René van der Vlugt Steen Lykke Nielsen 《European journal of plant pathology / European Foundation for Plant Pathology》2010,126(2):145-152
60.
Abundance of some skeletal muscle mitochondrial proteins is associated with increased blood serum insulin in bovine fetuses 总被引:1,自引:0,他引:1
Beata Pajak Patrycja Pawlikowska Isabelle Cassar-Malek Brigitte Picard Jean-Franois Hocquette Arkadiusz Orzechowski 《Research in veterinary science》2010,89(3):445-450
The aim of this study was to investigate the evolution of the abundance of cytochrome oxidase c subunit IV (NCOIV) and beta subunit of ATP synthase (β-ATP) during the last third of gestation in bovine skeletal muscles. Semitendinosus, longissimus thoracis and rectus abdominis muscles were chosen for the immunoblotting of the respective protein levels. Muscle and blood samples from bovine fetuses of randomly selected breeds were collected at 180, 210, and 260 days post-conception (dpc). The muscle tissue expressions of NCOIV, β-ATP were compared to blood glucose and insulin. At 260 dpc, protein levels of NCOIV raised in skeletal muscles. Additionally, β-ATP in semitendinosus and longissimus thoracis were elevated and paralleled by higher concentrations of blood serum insulin. It corroborates our previous observations indicating that accelerated metabolic differentiation of bovine skeletal muscles is associated with elevated blood insulin and occurs during the last trimester of gestation. Our observations point to the connection between insulin-sensitivity and the molecular mechanisms of mitochondrial contribution to ontogenesis of skeletal muscles. 相似文献