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21.
生物质气化炉在低于1 300℃情况下产生水煤气,并伴随有重质烃(焦油)、粉尘、烟尘颗粒、碱金属、酸和碱性气体等,这都会导致恶臭气味和排放问题。对于大多数污染物而言,先进的测量技术和减少/去除技术可以降低其排放。但就焦油而言,目前缺乏普遍可接受的、经济的减排技术。设计和开发的套式旋风分离器正是朝着这个方面努力。目前开发的套式旋风分离器利用旋风分离器外5℃、360 L/h流速的循环水可以从水煤气中除去99.60%的焦油。设备简单、便宜,由于循环水可再利用并且减少了冷凝水,因此套式旋风分离器是一种环境友好型设备。该文介绍了用于减少水煤气中焦油含量的套式旋风分离器的设计、开发和性能评价。  相似文献   
22.
A vast majority of the world buffalo resource is concentrated in tropical and subtropical countries. Apart from heat stress and poor nutritional availability, endometritis is one of the most commonly encountered reproductive problems limiting fertility and consequently productive potential of the species. As demonstrated recently, endometritis impairs growth and follicular fluid composition of the largest follicle in buffalo. In the present study, the effect of endometritis on luteal development, function, nitric oxide (NO), and ascorbic acid was investigated. Reproductive tracts were collected from 90 cyclic buffaloes at an abattoir and grouped into endometritic (n?=?36) or non-endometritic (n?=?54) buffaloes based on physical examination of uterine mucus, white side test, and uterine cytology. Samples with pus-containing mucus, positive reaction on white side test, and/or >5 % neutrophils were considered to be positive for endometritis. Corpora lutea were enucleated, weighed, classified into stages I to IV, and assayed for progesterone (P4), NO, and ascorbic acid concentrations. Endometritic buffaloes had lesser (P?<?0.0001) luteal weight and P4, NO, and ascorbic acid concentrations than non-endometritic buffaloes. The findings indicated that endometritis impairs corpus luteum development and function in buffalo. Reduced luteal NO and ascorbic acid concentrations during endometritis are novel findings.  相似文献   
23.
The mechanism of the entomocidal action of Bacillus thuringiensis var. israelensis (BTI) in Periplaneta americana has been studied. Cockroaches treated with the alkali-solubilized BTI crystal gradually became sluggish and immobile. A physiological examination of poisoned cockroaches indicated that BTI possessed both myotoxic and neurotoxic activity. Following hemocoel or foregut administration of BTI, myotoxic effects were observed within 10–20 min whereas the onset of neurotoxic effects was considerably delayed. The results of this study suggest that the myotoxic action of BTI is probably important for the initial manifestation of its toxicity. The neurotoxic effects of BTI were ascribed to its ability to interfere with transmitter release. BTI exerted a dual action on transmitter release in the cockroach sixth abdominal ganglion. At lower doses (2–4 μg/ml) BTI was found to suppress transmitter release by interfering with calcium uptake. At higher concentrations (12 μg/ml or higher), however, BTI caused blockage of synaptic transmission which was preceded by massive transmitter release. In either case, the synapse blocking action of BTI was probably due to its effects upon presynaptic terminals. Postsynaptic membranes and axons in the ventral nerve cord apparently remained unaffected.  相似文献   
24.
Background: An oviduct-specific glycoprotein, OVGP1, is synthesized and secreted by non-ciliated epithelial cells of the mammalian oviduct which provides an essential milieu for reproductive functions. The present study reports the effects of recombinant buffalo OVGP1 that lacks post-translational modifications, and native Buffalo OVGP1 isolated from oviductal tissue, on frozen-thawed sperm functions and in vitro embryo development.Results: The proportion of viable sperms was greater(P 0.05) in the recombinant OVGP1-treated group compared to the native OVGP1-treated group at 2 h, 3 h, and 4 h of incubation. The proportion of motile sperms at3 h and 4 h of incubation; and membrane-intact sperms at 4 h was greater(P 0.05) in the native OVGP1-treated group compared to the control and recombinant OVGP1-treated groups. The proportion of capacitated and acrosome-reacted sperms was greater(P 0.05) in the native OVGP1-treated group compared to the recombinant OVGP1 group at 4 h. The rates of cleavage of embryos and their development to the blastocyst stage were greater(P 0.05) in the presence of either native or recombinant OVGP1 in comparison to control at 10 μg/mL concentration as compared to 5 or 20 μg/mL.Conclusions: The study suggests that both native and recombinant OVGP1 impart a positive effect on various sperm features and in vitro embryo development. However, native OVGP1 was found to have a more pronounced effect in comparison to recombinant non-glycosylated OVGP1 on various sperm functions except viability. Hence,our current findings infer that glycosylation of OVGP1 might be essential in sustaining the sperm functions but not the in vitro embryo development.  相似文献   
25.
The substance secreted by mussels, also known as nature’s glue, is a type of liquid protein that hardens rapidly into a solid water-resistant adhesive material. While in seawater or saline conditions, mussels can adhere to all types of surfaces, sustaining its bonds via mussel adhesive proteins (MAPs), a group of proteins containing 3,4-dihydroxyphenylalanine (DOPA) and catecholic amino acid. Several aspects of this adhesion process have inspired the development of various types of synthetic materials for biomedical applications. Further, there is an urgent need to utilize biologically inspired strategies to develop new biocompatible materials for medical applications. Consequently, many researchers have recently reported bio-inspired techniques and materials that show results similar to or better than those shown by MAPs for a range of medical applications. However, the susceptibility to oxidation of 3,4-dihydroxyphenylalanine poses major challenges with regard to the practical translation of mussel adhesion. In this review, various strategies are discussed to provide an option for DOPA/metal ion chelation and to compensate for the limitations imposed by facile 3,4-dihydroxyphenylalanine autoxidation. We discuss the anti-proliferative, anti-inflammatory, anti-microbial activity, and adhesive behaviors of mussel bio-products and mussel-inspired materials (MIMs) that make them attractive for synthetic adaptation. The development of biologically inspired adhesive interfaces, bioactive mussel products, MIMs, and arising areas of research leading to biomedical applications are considered in this review.  相似文献   
26.
From five paddy rice cultivars grown in Taiwan and harvested in the summers of 1997, 1998, and 1999, five calibrated models were established by backpropagation neural network program through different morphological and color features selection for classifying paddy rice harvested in the summer of 2000. With 60 features, the average classification rates of Model 1 and Model 5 were 92 and 99.8%, respectively. With the most effective 50 features, by loading in the first principal component, the average classification rate of Model 2 was 90.0%. With 35 features selected from the correlation coefficient matrix, the average classification rate of Model 3 was 91.0%. With the most effective 20 features of area, area/perimeter, 48th width, shape factor, maximum length/maximum width, average intensity of blue, maximum length, average intensity of green, 47th width, 50th width, average intensity of red, 1st width, 19th width, 5th width, 6th width, 29th width, perimeter, 46th width, 42nd width, and 4th width based on the contribution of the training model, the average classification rate of Model 4 was 91.8% and would be recommended for classifying five paddy rice cultivars of set trading prices because it required fewer features and held a stable classification rate.  相似文献   
27.
Stripe rust of wheat caused by the fungal pathogen is a destructive foliar disease of wheat. Thus, it is crucial step to characterize the resistant germplasm for stripe rust in a diverse germplasm pool for their ultimate utilization in efficient crop rust resistance breeding. In the present study, we followed two pronged strategies involving integrated phenotypic and molecular characterization of 440 diverse wheat germplasm lines for rust resistance. The germplasm panel was extensively evaluated in field epiphytotic conditions during two consecutive years. After rigorous screening, 72 accessions were successfully revealed as resistant to moderately resistant to stripe rust. Subsequently, entries were then evaluated for their field agronomicperformances, considering prerequisites for serving as a donor germplasm,particularly for yield and 33 potential rust-resistant accessions were identified. Furthermore, to detect the sources of resistance, accessions were molecular characterized for potential race-specific resistance genes Yr5, Yr10,Yr15, and effective adult plant resistance (APR) gene Lr34/Yr18/pm38. We identified the 22 accessions possessing one or more single resistance genes and two accessions were observed with at least three of them. Moreover, Lr34/Yr18/pm38 was determined to confer resistance when observed along with any of the race-specific genes. Thus, the study not only provides proof of concept methodology to identify candidate resistant sources from large germplasm collections but simultaneouslyconfirmed the contribution of combining race-specific andnon-specific APR genes. The finding could further assist in the potential deployment of resistant genes directly into the stripe rust breeding program by involving marker-assisted approaches.  相似文献   
28.
Despite being targeted as a conservation flagship species for several decades, the tiger (Panthera tigris) grows ever more imperiled. Debate exists as to where tiger conservation should focus: on protected nature reserves or larger landscapes. We developed a landscape scale, density-based model to assess whether reasonably effective management of current reserves is adequate to ensure the survival of tiger populations. We focused on the Indian subcontinent, the region likely to harbor most tigers. Using tiger density estimates and vegetation data, we set tiger population targets that could be attained through reasonable management of the subcontinent’s nature reserves. Depending on the quality of the surrounding landscape matrix, our model indicated that the subcontinent could potentially hold ∼3500-6500 tigers, in up to 150 reserves. Strikingly, just 21 reserves can hold most (58-95%) of this tiger capacity. These high-population target reserves were relatively insensitive to the hostility of the surrounding matrix to tigers, as their aggregate capacity varied by <10% across a wide range of matrix conditions. In contrast, the remaining 129 reserves were highly sensitive to matrix quality, as they were unable to sustain populations with a tiger-hostile matrix, even with reasonable management. Our results suggest that reasonably improved management of the subcontinent’s reserves can sustain multiple tiger populations based on two differing conservation strategies. Conservation within the 21 reserves with the largest population targets should focus primarily on the reserves themselves. In contrast, tiger conservation in the remaining reserves can succeed only with additional management of the unprotected landscapes that surround them.  相似文献   
29.
The enzymatic conjugation of arginine to the N-termini of proteins is a part of the ubiquitin-dependent N-end rule pathway of protein degradation. In mammals, three N-terminal residues-aspartate, glutamate, and cysteine-are substrates for arginylation. The mouse ATE1 gene encodes a family of Arg-tRNA-protein transferases (R-transferases) that mediate N-terminal arginylation. We constructed ATE1-lacking mouse strains and found that ATE1-/- embryos die with defects in heart development and in angiogenic remodeling of the early vascular plexus. Through biochemical analyses, we show that N-terminal cysteine, in contrast to N-terminal aspartate and glutamate, is oxidized before its arginylation by R-transferase, suggesting that the arginylation branch of the N-end rule pathway functions as an oxygen sensor.  相似文献   
30.
Fisheries have had major negative impacts on marine ecosystems, and effective fisheries management and governance are needed to achieve sustainable fisheries, biodiversity conservation goals and thus good ecosystem status. To date, the IndiSeas programme (Indicators for the Seas) has focussed on assessing the ecological impacts of fishing at the ecosystem scale using ecological indicators. Here, we explore fisheries ‘Management Effectiveness’ and ‘Governance Quality’ and relate this to ecosystem health and status. We developed a dedicated expert survey, focused at the ecosystem level, with a series of questions addressing aspects of management and governance, from an ecosystem‐based perspective, using objective and evidence‐based criteria. The survey was completed by ecosystem experts (managers and scientists) and results analysed using ranking and multivariate methods. Results were further examined for selected ecosystems, using expert knowledge, to explore the overall findings in greater depth. Higher scores for ‘Management Effectiveness’ and ‘Governance Quality’ were significantly and positively related to ecosystems with better ecological status. Key factors that point to success in delivering fisheries and conservation objectives were as follows: the use of reference points for management, frequent review of stock assessments, whether Illegal, Unreported and Unregulated (IUU) catches were being accounted for and addressed, and the inclusion of stakeholders. Additionally, we found that the implementation of a long‐term management plan, including economic and social dimensions of fisheries in exploited ecosystems, was a key factor in successful, sustainable fisheries management. Our results support the thesis that good ecosystem‐based management and governance, sustainable fisheries and healthy ecosystems go together.  相似文献   
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