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排序方式: 共有235条查询结果,搜索用时 15 毫秒
1.
应用多重PCR检测人工感染鸡呼吸道疾病的研究 总被引:3,自引:0,他引:3
本文报道了IBV,NDV,ILTV,MG人工感染4周龄SPF鸡和非免疫鸡后,用多重PCR检测试验鸡的咽喉棉拭子和器官组织样品,并与传统的病原分离鉴定,血清学方法进行比较,多重PCR无论是对单一感染病原,还是对两种以上混合感染病原,其敏感性和检测速度都优于传统的鉴别诊断方法,具有较高的实用价值,可以直接应用于临床检测,服务于生产。 相似文献
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从臭蜣螂中提取甲壳素/壳聚糖的研究 总被引:9,自引:0,他引:9
甲壳素作为自然界中产量仅次于纤维素的第二大生物资源 ,近年来其开发和应用日益受到重视 ,但目前甲壳素的生产原料来源有限 ,生产成本较高。而昆虫是世界上最大的优势动物种类 ,昆虫的总生物量超过了地球上所有动物总生物量 ;但被人类利用的昆虫资源却很少。昆虫是当今地球上未被利用的最大生物资源 ,特别是昆虫的甲壳素资源尚未开发。鉴于目前对于昆虫甲壳素资源的开发尚在尝试阶段 ,本文以臭蜣螂为材料 ,进行了提取甲壳素和壳聚糖的工艺以及其理化特性研究。研究发现 ,臭蜣螂体中甲壳素含量高出目前甲壳素生产常规原料虾蟹壳数倍 ,且从其体中提取的甲壳素与壳聚糖的品质在残留灰分、粘度和色泽等方面优于虾蟹壳。并以单因素试验方法进行了提取甲壳素和壳聚糖提取工艺的研究 ,提出了从臭蜣螂中提取甲壳素和壳聚糖的提取工艺 :①脱矿物质 :用 0 8mol·L- 1 HCl预先 70℃加热 30min ,然后室温条件下浸泡 12h ;②脱蛋白质、脂类 :用 2 0~ 2 5mol·L- 1 NaOH ,在 90~ 10 0℃条件下 ,处理 4~ 5h ;③脱乙酰基 :用 10 0 0~ 11 2 5mol·L- 1 NaOH ,在 130℃条件下 ,处理 3h。 相似文献
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Summary Ninety Chinese rice landraces were examined with special reference to the indica-japonica differentiation in terms of traditional criteria, isozyme analysis and PCR analysis of the chloroplast DNA (cpDNA). Cultivars were separated into indica and japonica defined by a discriminant function (Z) based on key characters, as well as by isozyme genotypes. Most indica landraces had chloroplast DNAs with a deletion at the Pst-12 fragment, while most japonica landraces had cpDNAs without the deletion. Two traditionally recognized varietal groups in China, keng and hsien, corresponded largely to the respective japonica and indica revealed in our study. The results obtained in this study showed good agreement for classification of indica and japonica types by the three methods: discriminant analysis by Z value, isozyme analysis, and PCR analysis for cpDNA. 相似文献
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Rotfinder is a non-destructive decay-sensing apparatus based on resistance measurements in standing trees. The accuracy of Rotfinder in detecting decay was evaluated in 500 standing trees in three Norway spruce (Picea abies) plots. Trees were measured at three heights, 0.30, 0.66 and 1.30 m. Sections were later inspected for the presence of decay and reaction zones. Inspected trees were mostly infected by Heterobasidion annosum and showed a large variation in the amount of decay present, ranging from 0.1% to 88.0% of the section. Correctly and incorrectly classified trees were compared in terms of ion and element concentration, density and moisture. Measurements at stump level (0.30 m) were more accurate than measurements at breast height (1.30 m) where the reaction zone and decay columns showed lower moisture content. The accuracy of Rotfinder increased when trees with small decay columns were regarded as ‘non-decayed’. When only trees with more than 15% of the section decayed were regarded as ‘decayed’, Rotfinder had an accuracy of 0.86 when performing assessments at stump level. False negatives, as opposed to true positives, corresponded to trees with smaller and drier decay columns, drier reaction zones and lower K+ (potassium) concentration in the decay column. False positives corresponded to trees with large sapwood and high sodium content in the sapwood. Rotfinder represents an alternative to the standard method of using increment core observations to assess decay in living trees. 相似文献
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保存二年以上的过二硫酸铵固体试剂,因逐渐分解而使溶液酸度过低,无法定量测出过二硫酸铵与碘化钾反应级数,改变各反应物量并加入适量氟化氢铵,可使反应顺利进行. 相似文献
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芨芨草基因组DNA提取与RAPD反应体系优化 总被引:1,自引:0,他引:1
本文选出适合芨芨草Achnatherum splendens (Trin.) Nevski基因组DNA提取方法,对RAPD反应体系中的一些重要参数进行优化,包括模板浓度、Mg2+、dNTP、引物和Taq酶浓度,建立了适合芨芨草RAPD分析的PCR反应体系.即在12.5uL的反应总体积中Mg2+浓度为1.5mmol·L-1,dNTPs 浓度0.2mmol·L-1,Taq酶0.5U,20ng模板DNA,10bp附机引物3.2pmol.反应程序为:前6个循环为95℃变性30s,35℃复性45s,72℃延伸80s,后36个循环为94℃ 45s,36℃ 40s,72℃ 70s,最后72℃延伸10 min.该反应体系具有良好的稳定性和重复性. 相似文献
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聚合酶链反应检测猪细小病毒的研究 总被引:18,自引:1,他引:17
本研究成功地建立了检测猪细小病毒(PPV)的聚合酶链反应(PCR)技术。以16个核苷酸引物对首次完成了PPVDNA结构蛋白VP1编码区228bp片段的扩增。同样数目的另一引物对,也成功扩增了Vp2编码区158bpDNA片段。PPVBM-1株与其它国内分离株(广西株、天津株和哈尔滨株)均出现相同扩增结果。琼脂糖凝胶电泳显示了特异条带(VP1228bp.Vp2158bp),而伪狂犬病病毒、犬细小病毒均未扩增,表明了本方法的特异性。同时,限制性内切酶分析(Vp1228bp及Vp2158bp分别含单一PvuⅡ、EcoRⅠ位点),也证实了特异性。本方法敏感性高,可检出10fg模板DNA。既可作样品的快速检测,又能检查细胞系的污染。具有特异、简便、快速的优点。 相似文献
10.
Blikslager AT Yin C Cochran AM Wooten JG Pettigrew A Belknap JK 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2006,20(5):1191-1196
BACKGROUND: Recent reports indicate increased amounts of mRNA from inflammation-related genes in the prodromal stage of laminitis. HYPOTHESIS: Cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) undergo distinct patterns of expression in equine laminae in the developmental stage (DEV) and acute clinical stage (LAM) of laminitis. ANIMALS: Horses selected from an outbred population were placed into 1 of 4 groups: DEV (n = 5), CON-3h (control group for DEV, n = 5), LAM (n = 5) and CON-10h (control group for LAM, n = 5). METHODS: Laminar and skin samples were obtained from (1) animals either undergoing leukopenia (DEV) or the onset of clinical signs of laminitis (LAM) after black walnut extract (BWE) administration and (2) animals either 3 (CON-3h) or 10 (CON-10h) hours after administration of water. Real-time quantitative polymerase chain reaction (RT-qPCR), immunoblotting, and immunohistochemical analysis were performed for COX-1 and COX-2. RESULTS: Upon immunohistochemical analysis of all 4 groups, COX-2 was expressed by most viable epithelial cells in both laminae and skin. COX-1 exhibited similar epithelial expression to COX-2 in skin epidermis, but was expressed exclusively in the basal layer of laminar epidermis. COX-1 protein was not detectable in dermal vasculature of equine skin or laminae, whereas COX-2 was present in endothelial and vascular smooth muscle cells of dermal vasculature in both skin and laminae in all groups. A marked increase in laminar COX-2 protein concentrations was detected on immunoblotting in the DEV group, although a lesser increase was observed in the LAM group. CONCLUSIONS AND CLINICAL IMPORTANCE: COX-2 protein expression is markedly increased in the resident laminar cell types in the developmental stage of BWE-induced laminitis. 相似文献