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51.
骨质疏松症是以骨量减少、骨的微观结构退化为特征,致使骨的脆性增加并易于发生骨折的一种全身性骨骼疾病,是当前严重危害人类特别是绝经妇女和老人的疾病之一.近年来出现了许多预防和治疗骨质疏松症的药物,极大地推动了骨质疏松症理论基础的完善和临床治疗研究.就该领域的研究进展进行了简要综述.  相似文献   
52.
Isoflavonoids isolated from Cuban propolis   总被引:3,自引:0,他引:3  
Chemical investigation of a red-type Cuban propolis sample has led to the isolation of 11 isoflavonoids (2 isoflavones, 3 isoflavans, and 6 pterocarpans), together with gallic acid, isoliquiritigenin, and (-)-liquiritigenin. Structural determination, including the absolute stereochemistry, was accomplished by spectroscopic analysis, particularly CD and 2D NMR techniques. The fragmentation behavior of pterocarpans was studied by electrospray ionization (ESI) tandem mass spectrometry (MS/MS) using an ion-trap analyzer, and a generalized fragmentation pathway, useful in the identification and structural characterization of pterocarpans, is proposed. Isoflavonoids are reported for the first time from propolis samples.  相似文献   
53.
The bursting of the mining dam of Aznalcollar (Seville, Spain) triggered an increase in the concentration of heavy metals in the soils of the river Guadiamar valley as a result of the leaching of the pyritic sludge deposited on them. After the cleaning operations which included, as well as mechanical clearing, the addition of different amendments, some areas with residual sludge remained, from which some heavy metals are being mobilized by the cyclical recharge and discharge processes of water in the profiles. This paper analyzes the effect of the soil recovery operations and the climatology on the concentration of metals and their distribution in the soil profile in an area affected by the toxic spill. Fourteen points have been selected in a plot in which acidity persists, there is no vegetation, and residual sludge stains can be seen at a glance. The temporal and spatial evolution of the extractable metals: Fe, Cu, Mn and Zn, the pH and the oxidable fraction has been measured in-depth. The results obtained up to now indicate a leaching of the pollutant towards deeper horizons, finding, at a depth of 757 cm, pH values of 3.5 and very high Fe and Mn concentrations available, especially in the profiles with large sized pores, with a big fraction of sand. On the surface, seasonally, there are low pH values of around 2.5 and extractable Fe contents of over 4000 ppm, which might have an influence on the quality of surface runoff or underground water.  相似文献   
54.
55.
Blood samples from 13 cases of snakebite, 6 in dogs and 7 in cats, were tested for activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrin/fibrinogen degradation products (FDP). Four cases were tested for fibrinogen concentration. Based on the results of a commercially available ELISA test, 9 cases were caused by tiger snakes (Notechis scutatus) and 1 case by a brown snake (Pseudonaja textilis). Three other cases had clinical signs and increased creatine phosphokinase values which suggested tiger snake envenomation. Although the period post-envenomation varied, results indicated a marked prolongation of the APTT and PT in 5 of 6 dogs. Three of these 5 dogs also had increased FDP values and 3 (of 3 examined) were hypofibrinogenaemic. Clinical manifestations of this coagulopathy were: haematoma formation after venepuncture (3 cases), gingival petechiae (1 case) and hyphaema (1 case). In contrast, there was minimal or no prolongation of the APTT and PT values, and no increase in FDP, in all 7 cats. Furthermore, no cat exhibited clinical signs of a coagulopathy.  相似文献   
56.
Eight mature Angora wethers (average BW 47.2 kg) were used in a 4 x 4 replicated Latin square design to evaluate responses to intraperitoneal (IP) administration of amino acids. The IP treatments consisted of saline (Control), methionine 1 g/d (Met), lysine 2 g/d (Lys), and methionine + lysine (Met + Lys). The amino acids dissolved in Control were infused continuously for the first 14 d of each 28-d period using peristaltic infusion pumps. Average d-28 grease and clean mohair yields (grams/100 square centimeters), and fiber diameter (micrometers) and length (centimeters) measurements during Control administration were 8.8, 7.6, 40, and 2.3, respectively. Mean clean mohair yield and fiber diameter increased by 5.3% (P less than .039) and 2.5% (P less than .067), respectively, with Met administration but were decreased by 9.2% (P less than .033) and 3.8% (P less than .001), respectively, by Lys administration; however, mean fiber length was increased (P less than .014) 21.7% by Lys infusion. The goats did not exhibit increased grease (P greater than .939) and clean (P greater than .477) mohair yields and fiber diameter (P greater than .619) when treated with Met+Lys. A N balance trial was conducted during d 10 through 14 of each period. Total retained N (grams per day) during Control administration was 18.4 and 24% greater than Met (P greater than .281) and Lys (P less than .061), respectively. When expressed as a proportion of N intake, retained N was lowest (P less than .127) in the Lys infusion group. Jugular blood ammonia N and plasma glucose and total protein concentrations were not affected (P greater than .10) by treatment.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
57.
The distribution of various sugars, that contribute to the composition of the carbohydrate components of the glycoprotein in the ultimobranchial tubule and the thyroid C-cells has been studied, using eight peroxidase-labelled lectins (Dolichos biblorus, Glycine max, Bauhinia purpurea, Helix pomatia, Arachis hipogaea, Ulex europaeus I, Limax flavus and Sophora japonica). The results obtained seem to show that there are receptors for Dolichos biflorus, Glycine max, Bauhinia purpurea, Helix pomatia, Arachis hipogaea, Ulex europaeus I and Limax flavus in the ultimobranchial tubule, suggesting the existence of N-acetylgalactosamine, galactose, L-fucose and sialic acid. However, the C-cells show only a positive reaction with Ulex europaeus I indicating the existence of fucosyl residues in those cells. All these findings support the contention that the ultimobranchial body might contribute decisively not only to the formation of C-cells but also, partially, to the constitution of certain follicular cells.  相似文献   
58.
The present study was designed to determine whether reactivity toward humans can be used to predict a pig's reactivity to the slaughter procedure as measured by postmortem muscle metabolism. Forty-two pigs were group-reared in six pens with straw-bedding. Pigs received regular positive (HI) or mildly negative (RC) handling training in a separate pen for 40 d before slaughter. Control pigs remained in their home pens throughout rearing. Pigs were slaughtered at a commercial packing plant, and half of each treatment group (HI, RC, or controls) was accompanied by the handler throughout mixing and transportation, as well as a portion of the lairage time and introduction to the holding pens situated before the slaughter room, whereas the other half was not accompanied by the handler. Muscle pH and temperature, objective color (L*, a*, and b* values), and drip loss were measured on the LM, biceps femoris, semimembranosus, and adductor femoris. Prior handling experience did not in itself influence ultimate meat quality (P > 0.37); however, the presence of the negative handler (RC pigs) at slaughter accelerated (P < 0.06) preslaughter glycogen breakdown in the LM. Fighting behavior during mixing explained between 13 and 32% of the variability of lightness (L* values) of the LM, biceps femoris, and semimembranosus. Visual contact with the handler at the start of the handling training and number of fights initiated explained between 31 and 42% of the variability in ultimate muscle pH. Latency to approaching the handler during human exposure tests explained 20% of the variability in initial muscle temperature of two muscles. Fighting behavior during mixing could be partly predicted from fighting during a food competition test conducted at the start of the rearing period. Results indicate that reactivity to humans and the tendency to fight determined, in part, meat quality in pigs of similar genetic and rearing backgrounds. These behavioral characteristics were, to some extent, determined early in life. Handling experience modified behavior toward the handler but correlations between behavioral characteristics and meat quality were not influenced by prior handling experience.  相似文献   
59.
We have recently reported that Salmonella enterica serovar Enteritidis (S. Enteritidis) strains circulating in Uruguay, are unevenly distributed among different genetic subtypes, with a predominant genotype that is a common contaminant of poultry-derived food and that accounts for the vast majority of human cases of food-borne disease. Herein, we describe the construction of a genetically-defined aroC derivative (LVR02) of a local strain of S. Enteritidis belonging to the major genetic type. We demonstrated the attenuation and the immunogenicity of that strain in a mouse model, and evaluated it as a vaccine for commercial layer chickens. LVR02 proved to be stable, attenuated, innocuous, immunogenic and to induce protective immunity against a S. Enteritidis challenge when used for oral vaccination. A single oral dose of LVR02 administered to newly hatched chickens induced protection against oral challenge with the parental virulent strain, preventing systemic and persistent intestinal infection and significantly reducing the shedding of the challenge strain in birds' feces. A second vaccine dose at 15 days post-hatching boosted the immunogenicity of the vaccine, and strengthened the protection achieved with a single dose. This strain may represent the basis of a live vaccine to be included in national control programs to reduce circulation of this pathogen in the country.  相似文献   
60.
Twenty geldings (five groups; similar age and BW) were used in a completely randomized design experiment to determine effects of grain supplementation of an alfalfa-cube diet on apparent nutrient digestibility and hindgut fermentation. The geldings were housed individually, fed their diets in two equal meals (0600 and 1800), and adapted to five dietary treatments over 6 wk. The treatments were alfalfa cubes (1% of BW; DM basis) without (control) or with one of four rolled cereal grains (i.e., barley, corn, naked oats, or oats) to provide a target level of 0.4% of BW as total nonstructural carbohydrates (TNC). Due to acute laminitis, three geldings (one in the control group and two in the barley group) were excluded. Because of this and multiple incidents of gas colic, TNC level was decreased to 0.2% of BW to ensure the geldings' health throughout the adaptation (7 d) and sample collection (5 d) periods. Grain intakes varied (P < 0.05) and reflected the different TNC concentrations. Apparent digestibilities of DM, OM, CP, NDF, ADF, and cellulose were not affected (P > 0.05) by grain supplementation and averaged 63.2, 63.1, 79.5, 42.7, 39.9, and 50.3%, respectively. Regardless of the source, grain supplementation increased (P < 0.05) apparent digestibility of TNC (from 85.6 to 94.6%) and decreased (P < 0.05) fecal pH (from 7.04 to 6.74). Fecal concentrations of total VFA (mg/g of DM) were greatest for the barley and naked oats diets (averaging 11.73), intermediate for the oats diet (8.00), and least for the control and corn diets (averaging 5.00; P < 0.05). Fecal concentrations of lactate (microg/g of DM) were greatest for the barley diet (254), intermediate for the oats diet (138), and least for the remaining diets (averaging 100; P < 0.05). Fecal concentrations of NH3 N (mg/g of DM) were greatest for the naked oats diet (1.68), intermediate for the barley and oats diets (averaging 0.86), and least for the remaining diets (averaging 0.63; P < 0.05). Serum concentration of lactate was 46% higher (P < 0.05) for the control than for the grain diets (averaging 0.05 mg/100 mL). Feeding barley, corn, naked oats, and oats contributed to 13, 15, 8, and 20% higher (P < 0.05) serum NH3 N concentrations than the control diet (0.25 mg/100 mL). Higher (P < 0.05) serum concentrations of urea N (mg/100 mL) were detected for the control, barley, and naked oats diets (averaging 25.28) than for the corn or oats diets (averaging 22.21). Results suggest that horses consuming alfalfa cubes could be supplemented with rolled barley, corn, naked oats, or oats at levels not exceeding 0.2% of BW as TNC without affecting nutrient digestion or overall health negatively.  相似文献   
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