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131.
Calcium ions play an important role in the activation of fish sperm movement. The mechanism of their binding in semen is still unknown. The goal of this study was the development of a method for identifying calcium-binding proteins in fish seminal plasma. Two methods of calcium-binding proteins detection were tested with the use of Quin2 and Stains-all dyes. The first method was useful for the identification of calcium-binding proteins of fish seminal plasma. It consisted of proteins separation using SDS–PAGE, transfer on PVDF membrane, incubation with CaCl2, staining with Quin2 and illumination with UV light to reveal calcium-binding protein bands. Using Quin2 allowed the detection of calcium-binding proteins with low and high molecular weight. Electrophoretic species-specific profiles of calcium-binding proteins were identified in the seminal plasma of carp, whitefish, roach, brook trout, brown trout and rainbow trout. Staining of calcium-binding proteins with Quin2 is a quick and safe method, allowing the identification of calcium-binding proteins in fish semen.  相似文献   
132.
Summary Since in these studies wood is used as basic material for the isolation of cellulose the structure and the composition of this planty substance were considered in greater detail. New measurements of the fiber dimensions and the thickness of the cell wall layers of typical springwood and summerwood tracheids in combination with data obtained from literature led to a model showing the most probable distribution of cellulose, polyoses, and lignin within the cell wall. The ultrastructural composition of the wood cell wall has been deduced from the properties and the behaviour of the cell wall components. The described model will be the basis for subsequent considerations.
Zusammenfassung Da bei diesen Untersuchungen Holz das Ausgangsmaterial zur Isolierung von Cellulose bildet, wurden die Struktur und die Zusammensetzung dieser pflanzlichen Substanz näher betrachtet. Neue Messungen der Faserdimensionen und der Dicke der einzelnen Wandschichten typischer Früh- und Spätholztracheiden in Verbindung mit Literaturwerten führten zu einem Modell, das die wahrscheinlichste Verteilung von Cellulose, Polyosen und Lignin innerhalb der Zellwand zeigt. Die ultrastrukturelle Zusammensetzung der verholzten Zellwand wurde aus den Eigenschaften und dem Verhalten der Zellwandkomponenten abgeleitet. Das beschriebene Modell wird die Grundlage für nachfolgende Betrachtungen bilden.


Dedicated in appreciation to my esteemed teacher Prof. Dr.-Ing. Georg Jayme, on the occasion of his 70th birthday.  相似文献   
133.
Summary Aging of wood begins with the cutting of a tree. The subsequent changes of the wood substance proceed very slowly and depend on environmental conditions. In a hot, dry desert climate wooden objects and cellulose textiles are preserved for several millenia, whereas their degradation is accelerated by conditions which favor the attack of microorganisms.Two conditions under which aging processes take place can be distinguished: a) aerobic conditions as prevailing in wooden buildings, sculptures etc.; b) anaerobic conditions valid for wooden items buried in the ground or submerged in water such as foundation pillars, ships etc. Submersion and underground embedding initiate the very slow process of fossilization in which the cell wall substance is transformed into highly condensed compounds (coalification) or is substituted by minerals (silicification).The various wood components are subjected to different kinds of degradation and conversion. The polysaccharides disappear with aging and seem to be more sensitive than lignin. Although more resistant, the lignin is converted chemically and its structure differs increasingly from its original state. Even extractives may survive millions of years.Academy Lecture presented at the IAWA IUFRO Wood Anatomy Symposium 1990, in Zürich, Switzerland, on 24th July 1990I wish to express my gratitude to members of my staff who have been involved in the study of ancient and fossilized wood as well as of Egyptian linen for the past 23 years: Monika Friedl, Margarete Przyklenk, Manfred Stoll, Ulrike Wegener, Maria Wenzkowski. Many thanks to the guests in my laboratory who worked in this field and whose results were included in this report: Yoon Soo Kim (Kwangju, Korea), Renzo Tomellini (Rome, Italy). And last but not least I am much indebted to several colleagues who provided me with slides or gave permission to reproduce their figures for the Academy Lecture: Takeshi Furuno (Matsue, Shimane, Japan) Dietger Grosser (Munich, FRG), John I. Hedges (Seattle, Wash., USA), Per Hoffmann (Bremerhaven, FRG), John R. Obst (Madison, Wisc., USA). Sylvia Schoske (Munich, FRG)  相似文献   
134.
Summary Wood samples that had been ball-milled and extracted with dioxane under various conditions were observed in the scanning electron microscope. Ball milling causes not only a reduction in size of the cells and cell walls but also an internal disruption of the particles. The intensity of milling has a larger influence on the particle size than a prolongation of the milling time. A direct relation was established between particle size and the previously determined yield of purified milled wood lignin.Submitted by Erwin-Riesch-Stiftung zur Förderung der wissenschaftlichen Forschung.  相似文献   
135.
136.
Effect of wheeling on stress distribution and changes in the macro- and microstructure of a cambic phaeozem derived from loess The determination of stress induced changes in the poresystem due to repeated wheeling of a cambic phaeozem derived from loess as well as in the aggregate size distribution, arrangement, and stage are reported. It could be shown, that repeated wheeling always results in a further stress distribution to deeper depths and that the vertical stresses dominate with repeated wheeling. Furthermore the octahedral shear stresses and mean normal stresses exceed the maximum strength defined by the Mohr Coulomb failure line and define a further soil deformation. The process of aggregate deterioration can be verified by radiographs from which not only the changes in bulk density on a mesoscale can be derived but from which also the crack patterns can be defined for the different stages of structure deterioration. Under the well known assumption that pore water pressure is increased due to wheeling, soil compaction and consecutive soil homogenisation by kneading can be differentiated. The consequences for ecological parameters will be discussed.  相似文献   
137.
Characterization of soil structure by X-ray analysis Frequently the use of morphological observation of soil structure to assess effects of tillage operations has been restricted by the extreme slowness of sample preparation. A method for rapid analysis of structure with the help of X-ray radiographs is described. The method is based on differences in attenuation of transmitted X-rays by soil pores and the adjoining soil mass. After digitizing X-ray pictures of unimpregnated soil cores using a video scanner and digitizer we found a close relationship between the average bulk density of soil within a core and the mean greylevel value of the digital image when sample thickness, origin and organic matter content of soil material, energy of radiation and sensitivness of X-ray film are the same. Application of a universal image processing system (DIAS) for the quantification of image parameters by procedures of binarization, skeletonization and direction coding demonstrated that radiographs are useful for analyzing spatial distribution, shape and orientation of soil structure elements. Results are illustrated by examples of soil tillage experiments.  相似文献   
138.
Cereal samples were collected in 1998 from Bulgarian villages without [control village (C), n = 20] or with [endemic villages (E); E1, n = 21; E2, n = 30; E3, n = 23] a history of Balkan endemic nephropathy (BEN). Sampling included foods (wheat, corn) and feeds (barley, oats, wheat bran). Analysis of ochratoxin A and citrinin was done by enzyme immunoassays (EIA), with detection limits of 0.5 and 5 ng/g, respectively. Ochratoxin A-positive results were confirmed by HPLC after immunoaffinity chromatography. Highest toxin levels were found in wheat, wheat bran, and oats. For ochratoxin A, the percentages of positives were 35% (C), 29% (E1), 30% (E2), and 47% (E3), the mean/median values of positives were 1.5/1.3 ng/g (C), 11/1.6 ng/g (E1), 18/1.6 ng/g (E2), and 3.5/1.5 ng/g (E3). For citrinin, 5.0% (C), 14% (E1), 3.3% (E2), and 13% (E3) were positive, and the mean/median values were 6.1/6.1 ng/g (C), 180/83 ng/g (E1), 10/10 ng/g (E2), and 84/20 ng/g (E3). Highest concentrations of ochratoxin (maximum = 140 ng/g) and citrinin (maximum = 420 ng/g) were found in samples from endemic villages. Co-contamination with ochratoxin A and citrinin was found for one sample (14% of positives) from village C and for six samples (22% of positives) from villages E1-E3. Citrinin levels in these samples were 2-200 times higher than those of ochratoxin A.  相似文献   
139.
Resource degradation in rice farming systems in Thailand endangers food security, but the systems may become more sustainable by combining them with aquaculture and livestock farm enterprises by capitalization of their synergies in resource use and re-use, i.e. by adopting integrated farming systems. Most empirical studies that assess this potential have focused on a few specific aspects, but not on the multiple social, economic, and ecological functions of resource integration. This study uses the framework of multifunction agriculture to assess the performance of integrated farming systems in Thailand and compares its performance with that of ‘normal-rice’ or non-integrated farming systems. Surveys were conducted in Khon Kaen province of Northeast Thailand using a combination of quantitative and qualitative survey methods.  相似文献   
140.
A wide and homogenous viticultural area traverses the border between Friuli Venezia Giulia (Italy) and the western part of Slovenia. Despite similar agricultural, climatic and geographical conditions on each side of the border, the management of agricultural activities and, in particular, the organization of phytosanitary campaigns is carried out separately and differently between the two countries incurring a waste of money, time and energy. The project P. Rada (EU Interreg IIIA Italy Slovenia 2000–06) was set up with the aim of establishing a common expert agrometeorological system to evaluate the development of Plasmopara viticola on a territorial scale. The required agrometeorological data are collected by a network of weather stations and spatially interpolated in a grid with a resolution of 500 × 500 m. The spatial dataset obtained is integrated with rainfall images processed by a polarimetric radar located in Fossalon di Grado (Gorizia, Italy). Once the territorial dataset has been completed, data are used to feed two agrometeorological models: SWEB, for the estimation of leaf wetness, and PLASMO for the simulation of grapevine downy mildew. The main output of the system is represented by meteorological (temperature, rainfall, leaf wetness) and epidemiological (total and current number of infections, days for the outbreak of the current infection) maps capable of supplying end users with detailed information useful for planning and management of grapevine protection activity.  相似文献   
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