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51.
A meta‐analysis of available data on dose response to dietary phosphorus (P) in fish from over 70 feeding trials reported in 64 published studies covering over 40 species of fish was performed. Broken‐line regression was used to model the data sets. The meta‐analysis showed that estimated minimal dietary P level varies with the response criterion and that estimates should preferably be expressed in terms of available P than in terms of total P. Estimates based on whole‐body P concentration (4.7 g available P kg?1 dry matter, DM) or vertebral P (5.2 g available P kg?1 DM) were greater than that for maximizing somatic weight gain (WG) (3.5 g available P kg?1 DM) or plasma P concentration (2.8 g available P kg?1 DM). P content of fish varies linearly with body mass (3.6 g kg?1 live weight). Use of ingredients rich in P or of diets with high basal P content or high levels of water P concentration can affect the estimations. Among the different response criteria tested, WG was found to be the most reliable and whole‐body P concentration to be the most stringent criterion to estimate P requirement of a given fish species. Expressing available P requirement as g P per unit DM or digestible energy (DE) in the diet was equally effective, but expressing in terms of g P intake per kg BW0.8 per day would be more precise.  相似文献   
52.
Population characteristics such as body size and reproductive condition are widely used by industry and resource managers as criteria for harvesting commercial species. Given the broad-scale approaches commonly adopted by managers to evaluate stocks, any spatial heterogeneity in the structure and functioning of those stocks may result in inaccurate assessments, interpretation and inappropriate management. Spatial heterogeneity in body size and reproductive condition has been shown in intertidal populations of Mytilus spp., but no assessment of subtidal structure has been made despite the importance of these populations as a mariculture resource. A spatially stratified sampling programme was used to test hypotheses of differences in bed structure depending on position within the bed. Commercial gears were used to harvest seed mussels and two condition indices were tested to identify a rapid accurate approach to evaluate reproductive condition for resource managers. Differences in the size and condition of mussels were dependent on spatial position within the population, with mussels exhibiting strong seasonal growth patterns. Edge-zone mussels showed both greater reproductive condition and body size than bed centre mussels. Reproductive condition also covaried with body size. Differences in spatial structure and function have the potential to confound stock assessments if appropriate sampling programmes are not utilised. Appropriate survey and reproductive condition assessment methods should be used to support subtidal stock persistence and optimal exploitation practices.  相似文献   
53.

Key message

Loblolly pine ( Pinus taeda ) logs can be evaluated using acoustic velocity whereby threshold acoustic velocity values can be set to ensure lumber meets specified mechanical property design values for modulus of elasticity.

Context

There is a need to better sort logs according to lumber quality for improved decision making and wood utilization because merchantable logs are being harvested from different stand types including natural forests, conventional plantations, and intensively managed plantations, all with differences in rotation ages, growth rates, and wood quality traits.

Aims

This study aimed to link tree- and lumber-length log acoustic velocity with the resulting lumber properties as tested in static bending from five intensively managed loblolly pine stands in the Atlantic Coastal Plain of Georgia.

Methods

Acoustic velocity was measured using the resonance-based approach on 87 tree-length logs and 244 lumber-length logs. The logs were then processed into 797 pieces of 38 mm by 89 mm (2×4), 140 mm (2×6), 184 mm (2×8), and 235 mm (2×10) dimension lumber, dried, and tested in static bending.

Results

Mean MOE of the lumber had moderate relationships with acoustic velocity of the logs (R 2 = 0.49) whereas MOR and acoustic velocity did not have a strong relationship (R 2 = 0.20). Accounting for log position increased the performance of the mean lumber MOE model (R 2 = 0.62) which was further increased by adding green density and small-end diameter (R 2 = 0.67). Utilization of acoustics was effective for segregating logs based on lumber modulus of elasticity and did not depend on knowing tree or stand information such as age, site quality, and silviculture history.

Conclusion

Acoustic velocity evaluation of tree- and lumber-length logs could be employed to segregate logs within the supply chain to ensure that lumber would meet specified design values.
  相似文献   
54.

Objective

To evaluate analgesic efficacies of morphine and butorphanol in lame broiler chickens.

Study design

Double blind, randomized, controlled experimental study.

Animals

In study 1, 36 lame and 36 sound chickens. In study 2, 48 lame and 48 sound chickens.

Methods

Sound and lame chickens were gait scored and randomly assigned into four groups: sound-drug, sound-placebo, lame-drug, and lame-placebo in study 1. In study 2, an additional lame and sound handling control group was included. Chickens in drug groups were injected with either morphine or butorphanol 2 mg kg?1 intravenously. Chickens in placebo groups were injected with an equal volume of normal saline. All birds underwent an obstacle course (OC) and latency-to-lie (LTL) test before injection and at 30 minutes and 2 hours after injection, to assess their walking ability and their standing ability. The time taken to finish the OC and the standing time in the LTL test were recorded. Friedman tests with Dunn’s correction were used to identify significant differences.

Results

Lame chickens finished the OC faster (mean ± standard deviation 36 ± 8 c.f. 69 ± 18 seconds) after the injection of butorphanol. Morphine caused sedation with an increase in time taken to finish the OC, even in sound chickens. In the lame handling control and placebo groups the OC times increased and the LTL times decreased with each observation.

Conclusion

Intravenous butorphanol (2 mg kg?1) may be analgesic in chickens for up to 2 hours. Morphine caused sedation.  相似文献   
55.
Twenty-eight dogs with lymphoma were treated with a 12-week, 5-drug chemotherapy protocol concluding with high-dose cyclophosphamide supported by autologous bone marrow transplants. A dose escalation design was used to determine the maximum tolerated cyclophosphamide dose (MTD) in this setting. Three cyclophosphamide dose levels were given: 300 mg/ m2 IV (groupl, 3 dogs), 400 mg/m2 IV (group 2, 12 dogs), and 500 mg/m2 IV (group 3, 13 dogs); and the MTD was 500 mg/m2 IV. Toxicity was common but mild, and the dose-limiting toxicity was myelosuppression, specifically neutropenia. No dog died as a result of treatment-related toxicity. One dog in group 3 developed fever, neutropenia, and presumed sepsis and responded promptly to routine management. No other dog required hospitalization. Lower stage and higher cyclophosphamide dose (both increasing dose [study groups 1-3], and the highest dose [group 3]) compared with the lower doses combined (groups 1 and 2) were significantly associated with longer remission duration (all P < .0001). Median remission duration for dogs in group 3 was 54 weeks, compared with 21 weeks for dogs in groups 1 and 2 combined. Factors associated with longer survival time were lower stage (P = .042) and higher cyclophosphamide dose (both increasing dose [study groups 1-3], and the highest dose [group 3] compared with the lower doses combined [groups 1 and 2]) (P = .027). Median survival time for dogs in group 3 was 139 weeks, compared with 43 weeks and 68 weeks for dogs in groups 1 and 2, respectively.  相似文献   
56.
Noncellulosic polysaccharides from the cell walls of cereal grains are not digested by human small intestinal enzymes and so contribute to total dietary fiber intake. These polysaccharides are becoming recognized increasingly for their potential to lower the risk of serious diet‐related conditions such as type II diabetes, cardiovascular disease, colorectal cancer, and diverticular disease. The effectiveness of noncellulosic cell wall polysaccharides in improving health outcomes is related to the fine structure and associated physicochemical properties. The two most nutritionally relevant wall polysaccharides of cereal grains are the arabinoxylans and the (1‐3,1‐4)‐β‐d ‐glucans. These polysaccharides have high molecular mass values but are nevertheless soluble in aqueous media, at least in part, where they adopt highly asymmetrical conformations and consequently form high viscosity solutions. Thus, arabinoxylans and (1‐3,1‐4)‐β‐d ‐glucans contribute to the soluble fiber component of human diets. The molecular size, solubility, and viscosity of the polysaccharides vary widely not only between different cereals but also within a single species. The variability in these properties reflects differences in the chemical structure of the polysaccharides, which in turn influences the beneficial effects of arabinoxylans and (1‐3,1‐4)‐β‐d ‐glucans in human diets. Here, we summarize information on the variability of fine structures of the arabinoxylans and (1‐3,1‐4)‐β‐d ‐glucans in common cereals and relate these to solubility, viscosity, and health benefits. The recent identification of genes involved in the biosynthesis of the (1‐3,1‐4)‐β‐d ‐glucans opens the way for the genetic improvement of cereal quality parameters that are important in human health.  相似文献   
57.
Benzothiadiazole (BTH) enhanced the accumulation of soluble and cell-wall-bound phenolics in strawberry leaves and also improved the resistance to powdery mildew infection under greenhouse conditions. The most pronounced change was seen in the levels of ellagitannins, which increased up to 2- to 6-fold 4 days after the BTH application, but persisted only in the inoculated plants. The induction of phenolic metabolism by BTH was also reflected in the fruits, several compounds being increased in inoculated, BTH-treated plants. Basal salicylic acid (SA) content was high in strawberry leaves, but increased in a similar fashion to other phenolics after the treatments. Several phenolic compounds were identified in strawberries for the first time. For example, ellagic acid deoxyhexose, three agrimoniin-like ellagitannins, sanguiin H-10- and lambertianin C-like ellagitannins in the leaves, ellagic acid, p-coumaric acid, gallic acid, and kaempferol hexose in the cell-wall-bound fraction of the leaves, and kaempferol malonylglucoside in the fruits. The findings show that BTH can enhance the accumulation of phenolics in strawberry plants which may then be involved in the BTH-induced resistance to powdery mildew.  相似文献   
58.
Comparative efficacy of faecal culture and IS900 Polymerase chain reaction (PCR) assay of faecal samples was investigated in 40 clinically suspected cases of Johne’s disease in dairy cattle. The sensitivity of faecal culture and PCR assay in this study was 52.5% (21/40) and 90% (36/40) respectively. All isolates appeared only on the mycobactin J supplemented Herrold’s egg yolk medium (HEYM) at 8–16 weeks post-inoculation, were acid-fast and were positive for IS900 PCR yielding a single amplicon of 217 bp. A total of 28 faecal samples out of 40 were positive by IS900 primary PCR assay for Mycobacterium avium subsp. paratuberculosis (Map) yielding an expected product of size 217 bp. Twelve faecal samples, which gave negative results in the primary PCR, were subjected to secondary PCR assay. Of the 12 samples, 8 gave positive results in the IS900 nested PCR (nPCR), which yielded a PCR product of 167 bp, proving better sensitivity of nPCR assay than single amplification PCR. PCR could detect additionally 15 samples as positive which were negative by faecal culture. The chi-square analysis showed a highly significant difference between the tests (P< 0.01). This study suggests that IS900-PCR-based detection of Map could be used as a potential diagnostic tool for rapid and effective Johne’s disease surveillance.  相似文献   
59.
Vincristine Therapy for Mast Cell Tumors in Dogs   总被引:1,自引:0,他引:1  
Twenty-seven dogs with naturally occurring mast cell tumors were treated with weekly IV injections of vincristine (0.75 mg/m2) for 4 treatments. Two dogs (7%) had a partial response. Nine dogs (32%) had treatment stopped prematurely because of toxicity or a perceived deterioration in their quality of life. We conclude that vincristine is ineffective as a sole treatment for measurable mast cell tumors in dogs and produces an undesirable number of adverse reactions.  相似文献   
60.
Thirty-eight cats with lymphoma were treated with vincristine, cyclophosphamide, and prednisone (COP). They were randomized at entry to receive maintenance chemotherapy consisting of either single-agent doxorubicin or continued COP therapy, starting on week 4 of treatment and continuing for 6 months or until relapse. Eighteen cats achieved complete clinical remission after COP induction chemotherapy. The median remission duration for 11 cats continuing to receive COP was 83 days, which was significantly shorter than for 7 cats that received doxorubicin (281 days). Thus, doxorubicin should be considered a well-tolerated and efficacious agent for the maintenance of remission in cats with lymphoma.  相似文献   
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