全文获取类型
收费全文 | 206篇 |
免费 | 6篇 |
专业分类
林业 | 42篇 |
农学 | 5篇 |
基础科学 | 1篇 |
38篇 | |
综合类 | 11篇 |
农作物 | 14篇 |
水产渔业 | 6篇 |
畜牧兽医 | 66篇 |
园艺 | 1篇 |
植物保护 | 28篇 |
出版年
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 10篇 |
2014年 | 10篇 |
2013年 | 25篇 |
2012年 | 8篇 |
2011年 | 17篇 |
2010年 | 8篇 |
2009年 | 12篇 |
2008年 | 15篇 |
2007年 | 13篇 |
2006年 | 10篇 |
2005年 | 10篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 11篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1991年 | 2篇 |
1983年 | 1篇 |
排序方式: 共有212条查询结果,搜索用时 312 毫秒
181.
Yoshiyuki Ohashi Hirofumi Saneoka Kounosuke Fujita 《Soil Science and Plant Nutrition》2013,59(2):417-425
Siratro (Macroptilium atropurpureum) and soybean (Glycine max) were grown in pots with or without irrigation for 3 weeks at the vegetative stage to examine the effect of water stress on plant biomass production, biological N2 fixation, CO2 assimilation rate, stomatal conductance, leaf water potential, and the partition of 14CO2 to plant parts. Biomass production decreased by water stress and the decrease was less conspicuous in siratro, mainly due to the maintenance of a relatively higher growth rate in stem plus petioles and roots. Siratro maintained a higher stomatal conductance and CO2 assimilation rate at a lower leaf water potential compared to soybean. Water stress decreased the biological N2 fixation in both species, and the decrease was more appreciable in siratro than in soybean under stress conditions. Water stress affected the export of photoassimilates from leaves in both species. The translocation of 14CO2 photoassimilates to nodules and roots was less substantial in siratro than in soybean under water stress conditions. Translocation of photoassimilates from leaves to stem plus petioles in siratro enables the maintenance of growth of stem and petioles under water stress conditions. 相似文献
182.
Mariko?YoshiokaEmail author Atsushi?Miyata Tadashi?Yagi Yoshiyuki?Nishio 《Journal of Wood Science》2004,50(6):511-518
A ring-opening polymerization of cyclic esters -caprolactone (CL) and/or l-lactide (LACD) was carried out in the presence of methyl--d-glucoside (m-Glc) as an activated substrate and tin(II) 2-ethylhexanoate (SnEht2) as a catalyst. This led to successful synthesis of an armed polyester polyol with m-Glc as the core. These polyols were characterized through gel permeation chromatography, hydroxyl value assessment, differential scanning calorimetry, and viscosity measurements. It was clarified that the thermal properties and tractability of the synthesized polyols are closely related to the structural characteristics of the side chain polyesters, such as their length and chemical composition. Polyurethane foams were also prepared by mixing an appropriate amount of the polyols with diphenyl methane diisocyanate, a foaming agent (water), and other additives, and their mechanical properties were examined. Two polyurethane foams manufactured from polycaprolactone-polyols that were synthesized at a CL/m-Glc ratio of 2 or 5, were used in a biodegradation test in a closed system of activated sludge suspension. Evidence of their biodegradation is presented based on data showing oxygen consumption by the pulverized samples. 相似文献
183.
Yuliati Indrayani Tsuyoshi Yoshimura Yoshiyuki Yanase Yuji Imamura 《Journal of Wood Science》2007,53(3):239-248
Five Japanese timbers, four timbers from the USA, and one Malaysian timber were evaluated for their resistance to the invasive
dry-wood termite Incisitermes minor (Hagen) using laboratory choice and no-choice feeding tests with holed specimens. The highest survival rates of I. minor in both the heartwood and sapwood no-choice feeding tests were more than 70% after 3 months. When offered sapwood and heartwood
choice feeding tests and the combined choice feeding tests, the highest survival rates of I. minor were more than 75% after 3 months. With regards to the percentage of wood mass losses in the no-choice and choice feeding
tests, karamatsu (Larix leptolepsis), buna (Fagus crenata), and Douglas fir (Pseudotsuga menziesii) were classified as “resistant” species among the ten sapwood specimens. In the heartwood no-choice and choice feeding tests,
the resistant species were buna, karamatsu, Douglas fir, sugi (Cryptomeria japonica), akamatsu (Pinus densiflora), and western red cedar (Thuja plicata). The ranking of the resistance of the ten commercial timbers against I. minor was buna > karamatsu > sugi > western red cedar > Douglas fir > rubber > western hemlock > hinoki > spruce. 相似文献
184.
Echocardiographic Evaluation of Myocardial Changes Observed After Closure of Patent Ductus Arteriosus in Dogs
下载免费PDF全文
![点击此处可从《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
L. Hamabe S. Kim R. Yoshiyuki T. Fukayama T.M. Nakata R. Fukushima R. Tanaka 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(1):126-131
Background
Closure of PDA can be associated with echocardiographic changes including deterioration of LV systolic function. Although PDA is commonly encountered in dogs, few comprehensive reports of echocardiographic changes in dogs with PDA closure are available.Objectives
To evaluate the short‐term echocardiographic changes observed after PDA closure in dogs using strain analysis.Animals
Seventeen client‐owned dogs with left‐to‐right PDA.Methods
Echocardiographic evaluations, including standard echocardiography and two‐dimensional tissue tracking (2DTT), were performed before and within 3 days of PDA closure.Results
Preclosure examination showed LV and left atrial dilatation indicating volume overload as a result of PDA. Closure of PDA resulted in significant reduction of LVIDd (<.0001) and LA/Ao (0.01) without change in LVIDs, suggestive of decreased preload. Postclosure LV systolic dysfunction was observed with significant decreased in FS (<.0001) and strain values (P = .0039 for radial strains, P = .0005 for circumferential strains). Additionally, significant LV dyssynchrony (P = .0162) was observed after closure of PDA.Conclusions and Clinical Importance
Closure of PDA resulted in decreased preload as a result of alleviation of LV volume overload, which in turn caused transient deterioration of LV systolic function. Additionally, this study demonstrated that strain analysis is load dependent. Therefore, care should be taken when interpreting strain measurements as an indicator of LV systolic function. 相似文献185.
Nagano M Hishinuma M Katagiri S Takahashi Y 《The Journal of reproduction and development》2007,53(4):953-958
We investigated the relationships between oocyte morphology, follicular size and follicular waves using bovine ovaries derived from local abattoirs. Ovaries at the recruitment and selection phases contained larger numbers of oocytes with good developmental ability, although ovaries at the recruitment phase contained the largest numbers of follicles compared with ovaries at the selection and dominant phases. Dominant phase ovaries contained a high percentage of oocytes with as good developmental ability as selection phase ovaries; however, they contained the lowest total number of oocytes with good developmental ability. Small follicles under 3.0 mm in diameter contained large numbers of small and degenerating oocytes. In contrast, follicles more than 3.0 mm in diameter contained a higher percentage of oocytes with good developmental ability. 相似文献
186.
Nagate T Chino T Nishiyama C Okuhara D Tahara T Maruyama Y Kasahara H Takashima K Kobayashi S Motokawa Y Muto S Kuroda J 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(11):1137-1143
Despite its explosive properties and toxicity to both animals and humans, diethyl ether is an agent long used in Japan in the anaesthesia jar method of rat anaesthetises. However, in response to a recent report from the Science Council of Japan condemning diethyl ether as acceptable practice, we searched for an alternative rat anaesthesia method that provided data continuous with pre-existing regular toxicology studies already conducted under diethyl ether anaesthesia. For this, we examined two candidates; 30% isoflurane diluted with propylene glycol and pentobarbitone. Whereas isoflurane is considered to be one of the representatives of modern volatile anaesthetics, the method of propylene glycol-diluted 30% isoflurane used in this study was our modification of a recently reported method revealed to have several advantages as an inhalation anaesthesia. Intraperitoneal pentobarbitone has long been accepted as a humane method in laboratory animal anaesthesiology. These 2 modalities were scrutinized in terms of consistency of haematology and blood chemistry with previous results using ether. We found that pentobarbitone required a much longer induction time than diethyl ether, which is suspected to be the cause of fluctuations in several haematological and blood chemical results. Conversely, only calcium ion concentration showed a slight difference from traditional results in the case of 30% isoflurane. Additionally, serum prolactin and corticosterone levels indicated that 30% isoflurane induced less stress than ether, confirming that 30% isoflurane can both provide results consistent with diethyl ether, while at the same time remove its disadvantages. As such 30% isoflurane appears to be a strong alternative anaesthetic agent for future regular toxicology studies in Japan. 相似文献
187.
McIntosh MP Narita H Kameyama Y Rajewski RA Goto H 《Veterinary anaesthesia and analgesia》2007,34(3):149-156
OBJECTIVE: To evaluate and compare the effects of the aqueous sulfobutyl ether beta-cyclodextrin (SBE-CD) etomidate formulation and the commercial etomidate formulation on mean arterial pressure (MAP), heart rate, and sympathetic outflow using neuraxis-intact and baro-denervated rabbits. STUDY DESIGN: Prospective experimental study. ANIMALS: Twenty-seven male New Zealand white rabbits. METHODS: Under basal anesthesia (urethane) and ventilation with intermittent positive pressure (IPPV), the New Zealand white rabbits underwent surgical preparation including isolation of the left renal sympathetic nerve and, in the baro-denervated models, additional combined denervation of bilateral carotid sinus, aortic, and vagal nerves. After hemodynamic stabilization, both neuraxis-intact and baro-denervated animals received bolus intravenous (IV) injection (0.6 mg kg(-1)) of either the SBE-CD or commercial etomidate formulation over 5 seconds (n = 6 animals per group). RESULTS: Mean arterial pressure decreased significantly in all four groups to the same extent. However, the rate of MAP decrease was lower in the SBE-CD-treated groups relative to the commercial formulation. Renal sympathetic nerve activity was decreased significantly less in the SBE-CD group in the baro-denervated studies. Independent pharmacokinetic evaluation demonstrated that the two formulations had comparable plasma concentration-time profiles. CONCLUSIONS AND CLINICAL RELEVANCE: Etomidate in the commercial drug product is solubilized with propylene glycol, a cosolvent associated with adverse side effects on injection. An aqueous formulation of etomidate has been developed, which utilizes SBE-CD as a solubilizing agent. The data suggest that the SBE-CD etomidate formulation may be a safer IV induction formulation than the commercial etomidate drug product. 相似文献
188.
Yutaka Sato Katsutoshi Tsuda Yoshiyuki Yamagata Hiroaki Matsusaka Hiromi Kajiya-Kanegae Yuri Yoshida Ayumi Agata Kim Nhung Ta Sae Shimizu-Sato Toshiya Suzuki Misuzu Nosaka-Takahashi Takahiko Kubo Shoko Kawamoto Ken-Ichi Nonomura Hideshi Yasui Toshihiro Kumamaru 《Breeding Science》2021,71(3):291
Biological resources are the basic infrastructure of bioscience research. Rice (Oryza sativa L.) is a good experimental model for research in cereal crops and monocots and includes important genetic materials used in breeding. The availability of genetic materials, including mutants, is important for rice research. In addition, Oryza species are attractive to researchers for both finding useful genes for breeding and for understanding the mechanism of genome evolution that enables wild plants to adapt to their own habitats. NBRP-RICE contributes to rice research by promoting the usage of genetic materials, especially wild Oryza accessions and mutant lines. Our activity includes collection, preservation and distribution of those materials and the provision of basic information on them, such as morphological and physiological traits and genomic information. In this review paper, we introduce the activities of NBRP-RICE and our database, Oryzabase, which facilitates the access to NBRP-RICE resources and their genomic sequences as well as the current situation of wild Oryza genome sequencing efforts by NBRP-RICE and other institutes. 相似文献
189.
190.
应用RAPD分子标记分析“晚绿”品种的杂交亲本 总被引:39,自引:6,他引:33
应用随机扩增多态性DNA (RAPD)技术对茶树无性系品种“晚绿”进行亲子关系分析。所用 10 8条随机引物中的 93条引物对日本静冈和枕畸两地取样的 6个无性系茶树品种的 8份材料的基因组DNA分别扩增出 1- 8条谱带 ,平均每条引物 3 5条。其中 19条引物扩增出“晚绿”与其母本“数北”不同的RAPD分子标记 30个。从中选择 6条引物对 8份供试材料的基因组DNA鉴定表明 ,其中 4个RAPD分子标记显示出“晚绿”品种特异性 ,说明包括“静在 16”在内的 4个供试品种都不是“晚绿”的真正父本。本文还证明 ,不同生态条件下生长的同一无性系茶树品种的基因组DNA具有遗传保守性 相似文献