全文获取类型
收费全文 | 260篇 |
免费 | 20篇 |
专业分类
林业 | 44篇 |
农学 | 12篇 |
基础科学 | 1篇 |
95篇 | |
农作物 | 12篇 |
水产渔业 | 52篇 |
畜牧兽医 | 44篇 |
园艺 | 6篇 |
植物保护 | 14篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 6篇 |
2019年 | 15篇 |
2018年 | 25篇 |
2017年 | 24篇 |
2016年 | 23篇 |
2015年 | 13篇 |
2014年 | 21篇 |
2013年 | 20篇 |
2012年 | 11篇 |
2011年 | 17篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 13篇 |
2005年 | 8篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1990年 | 2篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1976年 | 3篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有280条查询结果,搜索用时 62 毫秒
71.
Dr. Peter Hanelt Dr. Karl Hammer Dr. Jürgen Schultze-Motel Władysław Kulpa 《Genetic Resources and Crop Evolution》1982,30(2):215-244
Zusammenfassung Das während einer Reise in südliche Gebiete der VR Polen 1978 (vgl.Hanelt undSchultze-Motel 1979) gesammelte Kulturpflanzen-Material wird botanisch charakterisiert. Es handelt sich überwiegend um Landsorten und alte Sortentypen, die oft eine variable Zusammensetzung zeigen; ihr Anbau ist jedoch meist in raschem Rückgang begriffen. Charakteristische indigene Formen konnten u. a. beiTriticum aestivum, Secale cereale, Hordeum vulgare, Avena sativa, Vicia faba undPhaseolus vulgaris nachgewiesen werden. Besonders interessant sind zweiund mehrzeilige Nacktgersten, der hohe Anteil von Schüttmohnen innerhalb derPapaver-Kollektion, extrem kleinsamige, als Unkraut auftretende Formen vonPisum sativum convar.speciosum, der Nachweis eines reliktartigen Anbaues vonCamelina sativa sowie verschiedener, nur noch selten kultivierter Heilpflanzen. In morphologischer Hinsicht sehr variable Populationen von Landsorten wurden vor allem beiTriticum aestivum, Panicum miliaceum undPhaseolus vulgaris beobachtet. Die früher gegebene Einschätzung der südpolnischen Gebirgsregionen als Erhaltungsgebiet autochthoner Sippen von Kulturpflanzen konnte bestätigt werden; eine Fortführung der Sammeltätigkeit erscheint notwendig.
Herrn Prof. Dr. Dr. h. c. mult. H.Stubbe aus Anlaß der 80. Wiederkehr seines Geburtstages gewidmet.
Den Mitarbeitern der Genbank in Gatersleben sind wir für die bewährte Anzucht, Pflege und Bonitierung des Pflanzenmaterials zu großem Dank verpflichtet.An der Sammelreise beteiligten sich vom IHAR Radzikow ferner Mag. M.Górski, Mag. A.Jastrzbski und Ing. W.Doboszyski. 相似文献
Catalogue of indigenous taxa of cultivated plants collected 1978 in the PR Poland
Summary The material of cultivated plants collected during a mission to southern regions of PR Poland in 1978 has been characterized botanically. It is represented mainly by land-races and old varieties which are often rather variable; their cultivation is mostly decreasing rapidly. Typical indigenous types could be discovered e.g. forTriticum aestivum, Secale cereale, Hordeum vulgare, Avena sativa, Vicia faba andPhaseolus vulgaris. Especially interesting are two- and six-rowed naked barleys, a high percentage of poppies with shattering capsules among thePapaver collection, extremely small-grained weedy strains ofPisum sativum convar.speciosum, the discovery of a relic cultivation ofCamelina sativa and of some seldom cultivated medicinal plants. Morphologically very variable populations of land-races have been observed especially inTriticum aestivum, Panicum miliaceum andPhaseolus vulgaris. The characterization of the mountainous regions of southern Poland already formerly stated as a refugial area of autochthonous taxa of cultivated plants could be confirmed; a continuation of the collecting work seems to be necessary.
, HP 1978
, 1978 HP (.Hanelt undSchultze-Motel 1979). , , ë , . , , Triticum aestivum, Secale cereale, Hordeum vulgar e, Avena saliva, Vicia faba PhaseoLus vulgaris. ë , (Pisum sativum convar.speciosum); Camelina sativa . Triticum aestivum, Panicum miliaceum, Phaseolus vulgaris. - , .
Herrn Prof. Dr. Dr. h. c. mult. H.Stubbe aus Anlaß der 80. Wiederkehr seines Geburtstages gewidmet.
Den Mitarbeitern der Genbank in Gatersleben sind wir für die bewährte Anzucht, Pflege und Bonitierung des Pflanzenmaterials zu großem Dank verpflichtet.An der Sammelreise beteiligten sich vom IHAR Radzikow ferner Mag. M.Górski, Mag. A.Jastrzbski und Ing. W.Doboszyski. 相似文献
72.
Bolesław P. Salmanowicz 《Genetic Resources and Crop Evolution》1999,46(4):409-417
Seed globulins isolated from 58 accessions representing 12 Old World Lupinus species were studied using two techniques of high-performance liquid chromatography (HPLC): reversed-phase (RP-HPLC) and ion-exchange (IE-HPLC). Differences in quantitative and qualitative composition of globulins between smooth-seeded and rough-seeded lupins appear to be significant. Each investigated species/subspecies is distinguished by its specific protein HPLC pattern of globulins. The number of globulin peaks recorded in particular species varied from four to eight. In total, 72 retention times of protein peaks were distinguished in the investigated taxa. Chromatographic data were subjected to statistical analysis using hierarchical UPGMA grouping of the examined taxa. Heterogeneous smooth-seeded lupins proved to be distantly related to rather homogeneous rough-seeded lupins except for the new species L. anatolicus. Within the rough-seeded lupins three subgroups are distinguished: (1) L. atlanticus, L. cosentinii and L. digitatus, (2) L. palaestinus and L. pilosus and (3) L. princei. The obtained data are discussed with reference to taxonomic relationships in the Old World lupins. 相似文献
73.
Hanna Jaworska Halina Dąbkowska-Naskręt Mirosław Kobierski 《Journal of Soils and Sediments》2016,16(2):396-404
Purpose
The aim of the research was to determine the effect of lithogenic and pedogenic processes on the formation of Luvisols from the area of Vistula glaciation on the base of profile distribution of iron oxides and total iron in relation to texture and physicochemical properties. The indices of weathering of the soil material in genetic horizons were calculated, and changes in the content and forms of iron oxides were evaluated.Materials and methods
The predominant type of soil in the study area is Luvisols under agricultural use, formed from silt formations on loam. The analyses were made applying the following methods: grain size composition using the sieve method and hydrometer method, the interpretation of the results was performed according to the World Reference Base for Soil Resources classification, the pH of soils was measured with the potentiometric method, C-organic with the Walkley-Black dichromate method, the content of the following iron forms was determined (total iron (Fet) after the mineralization of soils in the mixture of HF and HClO4 acids), free iron oxides were extracted using dithionite-citrate-bicarbonate method, and amorphous iron oxides after the ammonium oxalate extraction (using the Philips 9100PU apparatus). The clay mineralogy was estimated by X-ray diffraction analysis.Results and discussion
It was observed that total iron enrichment occurs in argic horizons accompanied by iron depletion in luvic horizons, while the profile distribution of iron is similar to the distribution of clay. The (Fed/Fet) ratio indicates a low degree of weathering; the highest values were observed in argic (Bt) horizons, which confirms the effect of the process of pedogenesis on the value of that index. In the soils investigated, crystalline iron oxides generally dominate over the amorphous forms. The mineralogical composition of clay fraction separated from the upper part of soils was different as compared to the underlying material.Conclusions
The results of the study showed that iron contents (together with the other indicators) and its forms can be used to distinguish soil layers of different origin. The depth distribution of Fed, Feo and Fet within soil profiles indicates that the soil material may be of different lithogenic origin in the studied pedons.74.
Simplified AFLP procedure as a tool for identification of strawberry cultivars and advanced breeding lines 总被引:7,自引:0,他引:7
DNA polymorphisms among 6 cultivars of Fragaria × ananassa (Duch.) and 13salinity tolerant clones were evaluated using simplified – PstI based Amplified Fragment Length Polymorphism
procedure(PstIAFLP). Out of 129 amplification products obtained with 10 selective primers, 116 markers were polymorphic and could be used
to distinguish all analyzed materials. Coordinate and cluster analyses revealed 2 main groups of clones and divided strawberry
cultivars (CUL) and tested F1 hybrids of ‘Sweet Heart’(HYB). Mean genetic similarities in groups of cultivars and selected breeding lines (SEL) were significantly
higher (0.722 and0.706, respectively, p < 0.05) than in group of SH hybrids (0.485). Results suggest that PstIAFLP method is sufficient for effective identification and useful for assessing the level of genetic diversity in strawberry
cultivars and breeding lines. The presented method can bean alternative multilocus marker system to widespread RAPD method.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
75.
Summary The doubled haploid (DH) system and the single seed descent (SSD) technique are frequently applied in breeding of self-pollinated crops to rapidly obtain homozygous lines from heterozygous hybrids. This study presents a comparison of populations of barley DH and SSD lines in terms of traits of stem structure. The SSD and DH lines derived from F1 and F2 hybrids Roland x Apex were examined in a field experiment. On the basis of a comparison of means, variances and correlations between traits in the F1DH, F2DH and SSD populations the occurrence/absence of linkage between genes responsible for the analysed traits was inferred. Independent inheritance was found for 1000-grain weight and the length of particular internodes, spike length and stem wall thickness. Moreover, no linkage was found for stem wall thickness and spike length, length of internodes I, II and thickness of stem walls, stem diameter and thickness of stem walls. The results obtained for the other pairs of traits indicate the presence of linkage. 相似文献
76.
Chmura Daniel J. Barzdajn Władysław Kowalkowski Wojciech Guzicka Marzenna Rożkowski Roman 《European Journal of Forest Research》2021,140(6):1457-1467
European Journal of Forest Research - In multisite forest genetic experiments, the presence of genotype?×?environment interaction (GEI) is common. GEI may negatively affect the... 相似文献
77.
The studies conducted in 2003–2004 focused on the possibilities of applying a tannic solution to remove adhesiveness from pikeperch eggs. Spawners were caught in Lake P?tnowskie (central Poland) and then transported to the Gos?awice Fish Farm. After initial selection, the fish were weighed, measured and stimulated with human chorionic gonadotropin. Gametes were obtained 5 days after the first injection. The weight and diameter of the eggs, and the commercial fecundity of individual females were determined. The eggs were fertilized with the dry method. After the addition of water, the eggs were mixed for 4 min, and then divided into 20 g portions. After determining the number of eggs in the various portions, the adhesiveness removal procedure was performed. Three concentrations of tannic acid solution (500, 1000, 1500 mg L?1) and three exposure times (0.5, 2, 5 min) were applied. The eggs were incubated in Weiss jars. The studies indicated that both the solution concentration and the exposure time significantly (P<0.05) impacted pikeperch egg hardening, the degree of adhesive removal and embryo survival. The tannic acid solution concentration of ≤500 mg L?1 applied for 0.5–2 min was not effective; the eggs clumped and it was impossible to separate them even with intensive mixing. Better results were obtained using higher tannic acid concentrations and/or by lengthening exposure time. The adhesiveness of pikeperch eggs disappeared completely after 5 min exposure to tannic acid solution concentrations of 500–1500 mg L?1 or after 2 min exposure to solution concentrations of 1000–1500 mg L?1. In these variants, the embryo survival rate to the eyed‐egg stage was 78.0–84.0% (2003) and 82.3–84.7% (2004). However, high tannic acid concentration had a negative impact on the pikeperch larvae hatching. The greatest decrease in survival rate was observed in groups exposed to a tannic acid solution of 1500 mg L?1 for 2 and 5 min periods. Thus, the optimum method for removing pikeperch egg adhesiveness was to apply a solution of tannic acid at a concentration of 500 mg L?1 for 5 min or 1000 mg L?1 for 2–5 min. 相似文献
78.
Andrzej K Siwicki Zdzisaw Zak John C Fuller Jr Steven Nissen Sylwia Trapkowska Edward Gbski Krzysztof Kazu Agata Kowalska & Elbieta Terech-Majewska 《Aquaculture Research》2005,36(1):16-21
The present study examined the influence of leucine metabolite β‐hydroxy‐β‐methylbutyrate (HMB), a natural product HMB, on nonspecific cell‐mediated defence mechanisms and protection against enteric redmouth disease (ERM) in pikeperch (Sander lucioperca). β‐hydroxy‐β‐methylbutyrate was fed in a pelletted ration at 50 mg kg?1 of the feed for 8 weeks. The phagocytic ability and potential killing activity of blood and pronephric phagocytes were examined in HMB‐ and control‐fed fish before and after 8 weeks of feeding HMB. Simultaneously, the proliferative response of blood and pronephric lymphocytes stimulated by mitogens concanavaline A and lipopolisaccharide were examined in experimental and control groups. Following 8 weeks of HMB feeding, a challenge test was performed by injecting the fish with live pathogenic bacteria Yersinia ruckeri. β‐hydroxy‐β‐methylbutyrate applied in the diet for 8 weeks prompted a statistically significant (P<0.05) increase in phagocytic ability and potential killing activity of the blood and pronephric phagocytes and the proliferative response of blood and pronephric lymphocytes. The changes in these mechanisms correlated with protection against Y. ruckeri, the ERM pathogen. The results showed that feeding HMB increased the nonspecific cell‐mediated defence mechanisms and protection against ERM by reducing cumulative mortality (30%) following the challenge with pathogenic bacteria. Future studies will include determination of optimal doses and protocols of oral application of HMB to maximize the immunomodulatory effects and protection against viral diseases in intensive pikeperch culture. 相似文献
79.
Mirosaw Krzemieniewski Mariusz Teodorowicz Marcin Debowski & Jarosaw Pesta 《Aquaculture Research》2004,35(6):568-573
The influence of a constant magnetic field with an intensity ranging from 0.4 to 0.6 T (Tesla) was determined on physicochemical parameters of water and on rearing of larvae of the European sheatfish Silurus glanis L. larvae. In the experiment, feeding brood of European sheatfish was reared in two groups. One was kept in tanks supplied with magnetically treated water. The second group was kept in tanks supplied with water without treatment with a magnetic field (control). The fish tanks were supplied with circulating river water. Rearing was conducted for 15 days at an initial stocking density for both groups of 8 fish per litre. The mean fish mass obtained was 0.46 g, and in the control group – 0.78 g (P<0.05). Stocking mortality was 19.1% in the tanks with a constant magnetic field, and 13.5% in the control group. No changes were observed in water phosphate, ammonium, organic compounds or chloride concentrations. 相似文献
80.
Phenolic acid profiles in some small berries 总被引:1,自引:0,他引:1
Zadernowski R Naczk M Nesterowicz J 《Journal of agricultural and food chemistry》2005,53(6):2118-2124
The composition of phenolic acids in several small berries grown in Northeastern Poland, namely, low-bush blueberries, black mulberries, European juneberries, black currants, fruits of blue-berried honeysuckle, and blackberries, was determined by gas chromatography (GC) and mass spectrometry (MS). The total content of phenolic acids, identified by GC-MS, ranged from 2845.8 +/- 141.0 (black mulberries) to 5418.2 +/- 228.0 (blue-berried honeysuckle). Twenty phenolic acids were identified in the berries. Of these, hydroxycaffeic, m- and p-coumaric, and 3,4-dimethoxycinnamic acids were the major phenolic acids in blackberries and blueberries, m-coumaric acid was the major phenolic acid in blue-berried honeysuckle and black currant fruits, while salicylic, caffeic, and m- and p-coumaric acids were the predominant phenolic acids in European juneberries. Syringic and veratric acids were detected only in blueberries, while p-hydroxybenzoic and sinapic acids were present only in black currants and o-coumaric acid was present in blueberries and black mulberries. The phenolic acids liberated from esters and glycosidic bonds were the major fractions of phenolic acids in the berries. 相似文献