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81.
居华  哈益明  王锋  刘书亮 《核农学报》2010,24(4):761-765
采用ATP发光法检测辐照对冷却猪、鸡肉ATP发光强度的影响,并对其他试验因素是否对样品ATP发光强度产生影响进行了分析。结果表明:ATP标准品的浓度与发光强度呈显著的正相关,ATP标准品发光强度与辐照剂量表现为显著的负相关;辐照冷却肉的细菌ATP发光强度随辐照剂量的变化趋势呈现为倒"S"形特征,其中6.0kGy辐照时发光强度最大,4.0、8.0kGy剂量辐照时强度最小;无菌水、灭菌样品未对ATP发光强度造成干扰,而未辐照大肠杆菌浓度与ATP发光强度之间呈显著线性正相关,相关系数达到0.9437。  相似文献   
82.
The motility outcomes of boar semen frozen with newly developed freezing techniques using a new unique freezing technology (UFT) compared with traditional liquid nitrogen methodology were investigated with the intent of improving current fertility outcomes using semen. The UFT is an electronically controlled cooling chamber that houses an organic fluid bath that can be maintained at temperatures below 0 degrees C without solidifying to freeze samples. Four ejaculates from four different boars were collected for this trial. Samples were handled consistently during the pre- and post-freeze processing. From each ejaculate, samples were separated into eight cryopreservation treatment groups, six UFT variations and two control liquid nitrogen groups, immediately before freezing, in replicates of two. After the initial cryopreservation was complete, all samples were stored in liquid nitrogen for at least 48 h. Post-thaw motilities and original motility return percentages were assessed on a random, individual-sample basis. After the initial evaluations, samples from two boars were recollected and frozen using the UFT for breeding purposes. Four sows were bred with the UFT frozen semen to confirm fertility capability. When assessing the individual UFT techniques, all of six UFT techniques had improved post-thaw motilities. However, treatments F (micro = 29%, return micro = 37%) and J (micro = 27%, return micro = 34%) showed the highest statistical improvement for post-thaw (p < 0.05) and original motility percent returns (p < 0.05) when compared with either the control cryo-tube (micro = 15%, return micro = 19%) or straw groups (micro = 12%, return micro = 16%). The UFT semen had a 50% conception rate, with an average of seven piglets from the sows that farrowed. Our preliminary data suggest a higher motility return with a slower pre-freeze phase below the freezing point before the acceleration to liquid nitrogen temperatures. The preliminary data suggest that the UFT could be utilized as a potential cryopreservation option for boar semen.  相似文献   
83.
In the study, the relationship of follicular growth waves, oestradiol and pregnancy rates were investigated during oestrus cycle in cows. A total of 22, Brown Swiss cows (3-5 years old) were used for the study. The ovaries of animals were examined from sixth day of cycle to next oestrus by ultrasound. The follicles that were present in the ovarium were recorded. Follicular growth was observed every day by means of ultrasound examination. The blood samples were taken for analysis of oestradiol simultaneously with ultrasound examinations. The oestrus animals were inseminated. Each animal that inseminated was examined by ultrasound on day 28 after insemination for pregnancy diagnosis. Two follicular growth waves were observed in nine of 22 (40.9%), three waves in 13 of 22 (59.1%) animals. The oestradiol was found in the same concentration but in different release patterns between two and three waves animals. Pregnancy rate in cows with three and two follicular waves did not differ. In conclusion, emergence of three waves of follicular growth was higher in Brown Swiss cows, the analysis of oestradiol could be used for determination of the wave numbers and the animals with different waves may have had the same pregnancy rates.  相似文献   
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AIM: To explore the expression and significance of receptor tyrosine kinase anexelekto (Axl) in nasopharyngeal carcinoma (NPC). METHODS: Immunohistochemistry was used to detect the Axl protein expression of 78 patients with NPC and 32 patients with nasopharyngeal chronic inflammation (NPI). The correlations between the Axl protein levels and the clinical parameters of NPC patients were analyzed. NPC cells were cultured in vitro, and the expression of Axl in well differentiated CNE1 cells, poorly-differentiated CNE2Z cells and undifferentiated C666-1 cells was detected by immunofluorescence staining. After treatment of the CNE1and C666-1 cells with Axl specific inhibitor TP-0903, CCK-8 assay was used to detect cell viability, flow cytometry was adopted to analyze the cell cycle distribution, qPCR was used to examine the mRNA levels of Axl and proliferating cell nuclear antigen (PCNA), and Western blot was used to examine the protein expression of Axl and p-Axl. RESULTS: Axl protein was localized in the cell membrane and cytoplasm. The rate of high expression of Axl in NPC was significantly higher than that in NPI (P<0.01). High Axl expression showed no correlations with NPC patients' age, gender and M stage, while positively correlated with the clinical stage, T stage and N stage (P<0.05). Axl protein showed a low level in the CNE1 cells, but showed a high level in CNE2Z and C666-1 cells. TP-0903 inhibited cell viability in concentration and time dependent manners. TP-0903 at 2 nmol/L showed significant inhibitory effects, as evidenced by arresting the cell cycle at G0 phase and reducing Axl activity and PCNA expression. CONCLUSION: High expression of Axl promotes the clinical progress of NPC.TP-0903 significantly inhibits the viability of NPC cells, suggesting that Axl may be a valuable target in the NPC treatment.  相似文献   
87.
In Belgium, pseudorabies in swine has been the subject of a mandatory eradication programme since 1993. From December 1995 to February 1996, a survey was conducted in the five provinces of northern Belgium to estimate the provincial pseudorabies virus (PRV) herd seroprevalence. Seven hundred and twenty randomly selected herds were included in this survey. To detect recently infected animals, only young sows were sampled. The results show that 44% of these herds had an important number of PRV-seropositive young sows. The highest herd seroprevalence was observed in West Flanders (68%), followed by Antwerp (60%), East Flanders (43%), Limburg (18%), and Flemish Brabant (8%). Assuming a diagnostic test sensitivity and specificity of 95% and 99%, respectively, and a true PRV within-herd prevalence of 43%, the overall true PRV herd prevalence was estimated to be 35%. A logistic multiple-regression revealed that the presence of finishing pigs was associated with a two-fold increase in odds of a herd being seropositive (odds ratio (OR)=2.07, 95% confidence interval (CI)=1.31–3.26); a breeding herd size ≥70 sows was associated with a four-fold increase in odds of a herd being seropositive (OR=4.09, 95% CI=2.18–7.67); a pig density in the municipality of ≥455 pigs/km2 was associated with a 10-fold increase in odds of a herd being seropositive (OR=9.68, 95% CI=5.17–18.12). No association was detected between the PRV herd seroprevalence and purchase policy of breeding pigs (purchased gilts, or use of homebred gilts only).  相似文献   
88.
四种野生植物对天津盐碱地土壤改良效果的研究   总被引:2,自引:2,他引:0  
选择天津市蓟县、西青和大港的荒地土壤和耐盐碱的4种野生植物(猪毛菜、草木樨、艾蒿和补血草)进行盆栽试验.植株生长5个月后,测定土壤的各项理化指标.结果显示:4种植物均大大降低土壤总盐量,猪毛菜可以不同程度地降低土壤中CO23-、SO24-和有效磷;补血草对降低土壤SO24-和水溶性钙较有效;草木樨和艾篙可以明显增加土壤有效氮含量.综合分析表明,这4种野生耐盐植物对改良盐碱地土壤效果明显.  相似文献   
89.
为研究山地丘陵地区土地利用格局在地形差异上的演变规律,明确自然和人文因素在土地利用变化中的作用,基于RS和ArcGIS空间分析技术,利用地形位指数和分布指数,研究了河北省怀来县1993—2013年土地利用变化在地形差异上的时空分异特征。结果表明:六种土地利用类型空间分布及其变化均受到地形因子的影响和制约。水域的优势位主要分布在高程为300~500m、坡度0°~6°以及地形位级别为二级的区域;建设用地和耕地多分布于高程为500~700m、坡度0°~6°以及地形位级别为一级的区域;园地的地形适应性强于耕地,其分布的区域相对于耕地更加广泛,林地和未利用地则主要分布于高程900 m以上、坡度6°以上的区域,林地在地形位较高的级别更有优势。该文为今后怀来县土地资源的合理利用和科学规划提供依据与指导。  相似文献   
90.
鸡公山自然保护区森林生态系统服务功能及其价值初步研究   总被引:12,自引:1,他引:12  
从生态系统服务功能的概念入手,根据调查和研究,采用替代工程、市场价值等方法,从2个方面评价了鸡公山自然保护区森林生态系统服务功能的价值.结果表明,面积3000hm2的鸡公山自然保护区森林生态系统的生态服务功能价值70548.6万元·a-1,其中涵养水源价值8593.9万元·a-1,净化水质价值1265.3万元·a-1,保持土壤价值57754.1万元·a-1,固碳制氧价值2114.2万元·a-1,净化环境价值(吸收SO2量)26.1万元·a-1,游憩价值550万元·a-1,林产品价值245万元·a-1.  相似文献   
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