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71.
Expert opinions were elicited about the characteristics at the commercial-farm level of on-line information technology (IT) applications that are able to detect oestrus and mastitis in dairy cows. Since actual data of these characteristics are not available, judgmental data provided an alternative means to interpret the implications of research results for commercial farms. Applications included were activity measurement, milk-production measurement, electrical conductivity of quarter milk, automated concentrate feeders and milk-temperature measurement. Sensitivity and specificity of detection of oestrus (OD), clinical-mastitis (CMD) and subclinical-mastitis (SCMD) were ascertained. Conjoint-analysis was used to assess the effect of each application indirectly by decomposing the evaluated overall detection characteristics of a predefined number of IT combinations. The individual experts were consistent in evaluating the alternatives, but there was variation in estimates among experts. Estimations of the main effects of the applications and important first-order interactions were incorporated into the detection models. Implementation of all applications under study resulted in overall sensitivities and specificities of 82% and 90%, 73% and 87%, 58% and 82% for OD, CMD and SCMD, respectively. Further research is necessary that should take into account costs and benefits of the different detection systems based on the current status of farm performance (e.g. OD and mastitis incidence) and farm structure (e.g. farm size, years in operation of the milking parlour and parlour layout). Research to do this is currently in progress.  相似文献   
72.
Pharmacological study of Phe-Met-Leu-Phe-amide (FMRFa) receptors is hindered by the lack of selective ligands. The classification of these selective ligands is further hampered by the limited availability of functional assays. In this study, we evaluated several synthetic FMRFa analogs for agonist and antagonist activity by measuring their abilities to produce [35-S]-GTP-gamma-S stimulation or to inhibit FMRFa-induced [35S]-GTP-gamma-S binding in squid optic lobes. Analogs included acetyl-Phe-norLeu-Arg-Phe-amide (acFnLRFa), desamino-Tyr-Phe-Leu-Arg-amide (daYFLRa), desamino Tyr-Phe-norLeu-Arg-Phe-amide (daYFnLRFa), desamino Tyr-Phe-norLeu-Arg-[TIC]-amide (daYFnLR[TIC]a), desamino Tyr-Trp-norLeu-Arg-amide (daYWnLRa), (D)-Tyr-Phe-norLeu-Arg-Phe-amide (D)-YFnLRFa), Phe-Leu-Arg-Phe-amide (FLRFa), and the D-amino acid analogs of FMRFa (D-FMRFa, F-(D)-MRFa and FM-(D)-RFa). For agonist studies, full dose-response curves were generated and analyzed for potency and efficacy (maximal percent effect). FMRFamide as well as analogs ac-FnLRFa, daYFnLRFa, daYFnLR[TIC]a, D-YFnLRFa, FLRFa, and (D)-FMRFa stimulated [35S]-GTP-gamma-S binding. Analogs daYWnLRa, daYFLRa, F-(D)-MRFa, and FM-(D)-RFa failed to stimulate either [35S]-GTP-gamma-S binding or to inhibit FMRFa-induced [35S]-GTP-gamma-S binding. The rank order of potency was daYFnLRFa > or = daYFnLRF[TIC]a > acFnLRFa > (D)YFnLRFa > FLRFa > or = FMRFa > (D)-FMRFa. The order of efficacy was daYFnLRFa = acFnLRFa = (D)-YFnLRFa > FLRFa = FMRFa > or = (D)-FMRFa > or = daYFnLRF[TIC]a. Peptide analog daYFnLR[TIC]a was less efficacious (59% maximal stimulation) than analogs daYFnLRFa, acFnLRFa, and (D)-YFnLRFa (113-146% maximal stimulation). A maximal concentration of daYFnLR[TIC]a (10 microM) reduced daYFnLRFa, acFnLRFa, and (D)-YFnLRFa induced [35S]-GTP-gamma-S stimulation, indicating that daYFnLR[TIC]a is a partial agonist at the receptor stimulated by the FMRFamide analogs. Analysis of the structural requirements needed for promoting [35S]-GTP-gamma-S binding show that elongation (i.e., daYFnLRFa, D-YFnLRFa) or modification of Phe1 (ac-FnLRFa) leads to increased efficacy and potency. Moreover, elimination of the C-terminal Phe (daYWnLRa, daYFLRa,) leads to a loss of biological activity. However, substitution with L-1,2,3,4 tetrahydroisoquinoline-3-carboxylic acid, a rigid analog of the C-terminal Phe (daYFnLR[TIC]a), leads to decreased efficacy but not loss of potency. The data suggest that immobilization or modification of the C-terminal Phe may produce highly selective and potent FMRFamide antagonists. These results agree with published receptor radioligand studies and indicate that the [35S]GTP-gamma-S assay may be useful in classifying novel FMRFamide-selective ligands.  相似文献   
73.
74.
Some bacteria form intracellular nanometer-scale crystals of greigite (Fe3S4) that cause the bacteria to be oriented in magnetic fields. Transmission electron microscope observations showed that ferrimagnetic greigite in these bacteria forms from nonmagnetic mackinawite (tetragonal FeS) and possibly from cubic FeS. These precursors apparently transform into greigite by rearrangement of iron atoms over a period of days to weeks. Neither pyrrhotite nor pyrite was found. These results have implications for the interpretation of the presence of pyrrhotite and greigite in the martian meteorite ALH84001.  相似文献   
75.
76.
A study was carried out to determine the possibility of a more-closed farming system for (Dutch) dairy farms. The objective of the study was to provide effective and economically profitable management advice for improving the animal-health status of farms. Management measures will only be successfully applied if supported by farmers and their advisors (such as veterinarians). Therefore, the perception of farmers and advisors of the importance of various risk factors for the introduction of diseases to a farm was determined by using bovine herpes virus type 1 (BHV1) as an example. As part of the study, an evening-long workshop was organized and run thrice. In total, 49 farmers, veterinarians and AI technicians participated in these workshops. The computerized questionnaire technique was based on adaptive conjoint analysis (ACA). ACA has the advantage that participants can work with a large number of risk factors in a relatively short period of time. Another advantage of ACA (compared with standard questionnaires) is that the answers from each participant can be checked with regard to consistency with respect to the importance assigned to them. Data from participants with inconsistent responses can be excluded from further analyses. The results of the ACA interview were compared with the risk factors reported in the literature as being associated with BHV1 status (e.g. purchase of cattle, participation in cattle shows) and with farmers' actual management to prevent the introduction of diseases. The workshop participants were all operating in the dairy sector and they seemed well aware of the risk of direct animal contacts for the introduction of BHV1. Farmers thought visitors to be more risky than did AI technicians and (especially) veterinarians. Farmers who purchased cattle or participated in cattle shows were of the opinion that the risks of direct animal contacts were more important than did farmers who were not involved in those practices. Farmers whose farms were BHV1-positive (and participated in cattle shows more often) thought the risk of participation smaller than did farmers with BHV1-negative farms.  相似文献   
77.
We recently described two eye guanylyl cyclases (GC-E and GC-F) that contain an apparent extracellular domain potentially capable of binding ligands (Yang, R.-B., Foster, D. C., Garbers, D. L., and Fülle, H.-J. (1995) Proc. Natl. Acad. Sci. U. S. A. 92, 602-606). Here, Northern and Western analyses showed that both cyclases are expressed in the retina and enriched in photoreceptor outer segments. By the use of specific GC-E and GC-F antibodies coupled to different sized gold particles both cyclases were colocalized within the same photoreceptor cells raising the possibility of homomeric and/or heteromeric interactions. A point mutant of GC-E (D878A) was constructed and expressed; it contained no detectable cyclase activity but acted in a dominant negative fashion to abolish the activity of native GC-E and GC-F in coexpression studies. These results suggested that GC-E and GC-F could form either homomers or heteromers, at least when overexpressed in COS-7 cells. Immunoprecipitation with GC-E and GC-F antibody followed by Western analysis confirmed that both homomers and heteromers could be formed. However, similar experiments using retina or outer segments revealed that a vast majority of GC-E and GC-F were precipitated as homomers in the eye. Therefore, like other members of the membrane guanylyl cyclase subfamily, GC-E and GC-F appear to preferentially form homomers.  相似文献   
78.
During metamorphosis, the larval thoracic legs of the hawk moth Manduca sexta are replaced by a new set of adult legs. The larval leg motoneurons persist to innervate new adult muscles, and the motor terminals remain within the developing adult legs. Here we describe the fate of the larval leg muscles and the origin of new muscles within the adult legs. During the larval instars, large and small nuclei proliferate within leg muscle fibers. Near the end of the larval stage a subset of the small nuclei undergo a wave of proliferation, as indicated by the incorporation of 5-bromodeoxyuridine, whereas other nuclei die. However, none of the larval leg muscles fibers persist to serve as templates for adult muscle formation, and there was no evidence for persistence of larval myonuclei. Migrating myoblasts that are born within aggregate to form adult muscle anlagen at specific production sites within the developing imaginal legs. Intense nuclear proliferation occurs within the anlagen during the early pupal stage, followed by muscle fiber formation and striation. We conclude that adult leg muscles form mainly, if not exclusively, from migrating myoblasts that without the involvement of larval elements.  相似文献   
79.
This research has been made in infectious-parasitary disease sector of a public university hospital in Rio de Janeiro on the first semester of 1995. The logbook research has been introduced to 5 adult clients, from both sexes, who had been interned in the construction of two categories, which are: a) Category I: Feelings and expectations of the client and; b) Category II: Communication and relationship between client and nurse. The results found in the first category were: 1) Lack of affection; 2) Affection, fear and anxiety; 3) Loneliness and depression; 4) Reflection; 5) Insecurity; 6) Worry about the equipment, to be cut, to be impersonally treated, lose self-control and physical dependence. The results found in the second category were: 1) Doubts and interests in information about their disease, its evolution and how long they will stay in hospital: 2) Opportunity to express feelings and ideas; 3) Comprehension of the message given by the nurse. We emphasize the increase of interchange of information, ideas, beliefs, feelings and acts in nurse-client interaction to develop the therapeutic relationship aiming at helping the client to fulfill his basic needs.  相似文献   
80.
We have determined that three type-specific and conformationally dependent monoclonal antibodies, H16.E70, H16.U4, and H16.V5, neutralize pseudotype human papillomavirus type 16 (HPV16) virions in vitro. H16.U4 and H16.V5 neutralized pseudotype virions derived from the German HPV16 variant 114K and the Zairian variant Z-1194 with equal efficiency. In contrast, neutralization of Z-1194 pseudotype virions by H16.E70 was two orders of magnitude weaker than neutralization of 114K pseudotype virions. This difference correlated with enzyme-linked immunosorbent assay reactivity of H16.E70 to L1 virus-like particles of the two variants. A substitution at residue 282 of L1 was responsible for this differential reactivity, suggesting that this residue constitutes part of the H16.E70 epitope.  相似文献   
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