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81.
Effects of premilking preparation on complete lactation performance were measured with two groups of multiparous Holstein cows; 1) 17 cows received full stimulation, a 60-s routine, and 2) 16 cows received minimum stimulation, a 15-s routine, before machine attachment. Actual unadjusted average lactation milk yield for cows receiving full stimulation was 5.4% less than that for cows receiving minimum stimulation. When postpeak persistencies were compared by linear regression of either 1) daily milk weights or 2) 3.5% FCM from DHI records of milk yield and milk fat percent and fitted to lactation curves using an incomplete gamma function, cows receiving full stimulation produced 1) 2.8 or 2) 2.5% more milk per lactation than did cows receiving minimal stimulation. However, none of the treatment differences in mean milk yield was significant statistically. Milk flow rates, strip yields, and machine on-times were measured at 8-wk intervals throughout lactation. Cows receiving full stimulation had significantly higher average milk flow rates and shorter machine on-times starting at wk 32. There were no significant differences in strip yields or percent residual milk between cows receiving full and minimum stimulation.  相似文献   
82.
Ogran  Ariel  Wasserstrom  Haggai  Barzilai  Michal  Faraj  Tomer  Dai  Nir  Carmi  Nir  Barazani  Oz 《Journal of chemical ecology》2021,47(8-9):768-776

In natural and agricultural ecosystems, plants are often simultaneously or sequentially exposed to combinations of stressors. Here we tested whether limited water availability (LWA) affects plant response to insect herbivory using two populations of Eruca sativa from desert and Mediterranean habitats that differ in their induced defenses. Considering that such differences evolved as responses to biotic and possibly abiotic stress factors, the two populations offered an opportunity to study ecological aspects in plant response to combined stresses. Analysis of chemical defense mechanisms showed that LWA significantly induced total glucosinolate concentrations in the Mediterranean plants, but their concentrations were reduced in the desert plants. However, LWA, with and without subsequent jasmonate elicitation, significantly induced the expression of proteinase inhibitor in the desert plants. Results of a no-choice feeding experiment showed that LWA significantly increased desert plant resistance to Spodoptera littoralis larvae, whereas it did not affect the relatively strong basal resistance of the Mediterranean plants. LWA and subsequent jasmonate elicitation increased resistance against the generalist insect in Mediterranean plants, possibly due to both increased proteinase inhibitor expression and glucosinolate accumulation. The effect of LWA on the expression of genes involved in phytohormone signaling, abscisic acid (ABA-1) and jasmonic acid (AOC1), and the jasmonate responsive PDF1.2, suggested the involvement of abscisic acid in the regulation of defense mechanisms in the two populations. Our results indicate that specific genotypic responses should be considered when estimating general patterns in plant response to herbivory under water deficiency conditions.

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83.
A method of manufacturing free‐standing, micrometer‐scale honeycomb polyetherimide films is reported for the first time. Films are manufactured with a dip‐coating technique under water‐assisted self‐assembly. It is shown that the addition of poly(organosilane/siloxane)s and poly(ethylene glycol) allows the formation of regular honeycomb patterns. The films demonstrated the high thermal stability inherent for polyetherimide. The wetting properties of films are reported. The presence of nanopores was revealed with SEM imaging of the films. The makeup of the films allows their use as asymmetric membranes for reverse osmosis and ultrafiltration.

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84.
Sea urchin embryos form their calcitic spicular skeletons via a transient precursor phase composed of amorphous calcium carbonate (ACC). Transition of ACC to calcite in whole larvae and isolated spicules during development has been monitored using X‐ray absorption spectroscopy (XAS). Remarkably, the changing nature of the mineral phase can clearly be monitored in the whole embryo samples. More detailed analyses of isolated spicules at different stages of development using both XAS and infrared spectroscopy demonstrate that the short‐range order of the transient ACC phase resembles calcite, even though infrared spectra show that the spicules are mostly composed of an amorphous mineral phase. The coordination sphere is at first distorted but soon adopts the octahedral symmetry typical of calcite. Long‐range lattice rearrangement follows to form the calcite single crystal of the mature spicule. These studies demonstrate the feasibility of real‐time monitoring of mineralized‐tissue development using XAS, including the structural characterization of transient amorphous phases at the atomic level.  相似文献   
85.
Nanoscale packed-capillary liquid chromatography (LC) columns have been coupled with mass spectrometry (MS) using a coaxial continuous-flow fast atom bombardment interface. The combined system has been applied to the analysis of mixtures of peptides, including synthetic mixtures of bioactive peptides and tryptic digests of proteins. Nanoscale packed-capillary columns offer two principal advantages for LC/MS analysis--high chromatographic separation efficiencies and low mobile-phase flow rates. The high separation efficiencies facilitate the separation of complex mixtures, and the low mobile-phase flow rates reduce problems with coupling the LC effluent with the high-vacuum, high-voltage environment of sector MS ion sources. The columns used in this work were 50- or 75-micron i.d., 1-2 m long, packed with 10-micron C18 particles, using mobile-phase flow rates of 50-350 nL/min.  相似文献   
86.
The pediatric emergency department (PED) is an important component of the medical services provided by a hospital. The purpose of the study was to describe the patterns of referrals, admissions, and discharges in a PED to determine to what extent the PED is used solely as an emergency unit, as opposed to being used as a part of a set of primary care facilities. Data were recorded from 1200 patient charts, out of 19,000 visits to a PED in Israel in 1988. Variables such as age, sex, ethnicity, and distance between residence and hospital were checked. About half of the patients arrived during the morning shift. There was an inverse relationship between the distance from the patient's home to the hospital and the rate of visits to the PED. Fifty-eight percent of the total were self-referred; this rate increased to 84% during the night shift. Only one quarter of all children had additional laboratory or x-ray tests. Most of the diagnoses did not require emergency services. Eighty-one percent of the patients were discharged from the PED to their community physician. The rate of admissions was low (11%). This study shows that a large part of the PED work is actually primary care. Some of the demographic, cultural, and ethnic reasons for these patterns are reviewed.  相似文献   
87.
It is well known that discrimination response variability increases with stimulus intensity, closely related to Weber's Law. It is also an axiom that sensation magnitude increases with stimulus intensity. Following earlier researchers such as Thurstone, Garner, and Durlach and Braida, we explored a new method of exploiting these relationships to estimate the power function exponent relating sound pressure level to loudness, using the accuracy with which listeners could identify the intensity of pure tones. The log standard deviation of the normally distributed identification errors increases linearly with stimulus range in decibels, and the slope, a, of the regression is proportional to the loudness exponent, n. Interestingly, in a demonstration experiment, the loudness exponent estimated in this way is greater for females than for males. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
88.
This article focuses on kibbutz care for infants and young children. It reviews (1) past and present practices of collective education within the context of its historical background and guiding principles and (2) the results of developmental research regarding the impact of multiple caregiving and group care on children's socioemotional development within the framework of attachment theory. The research results indicate that, from a psychological point of view, collective sleeping is a problematic aspect of kibbutz child rearing. However, group care and multiple caregiving of high quality do not necessarily interfere with the formation of close relationships between parents and children or with the development of social skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
89.
Experiments on the absolute identification of pure tones were conducted at a single frequency with 3 Ss (aged 18, 25, and 52 yrs) to explore several effects. The change in transmitted information as the stimulus range was varied was measured as well as the change in transmitted information as the number of categories within a fixed range was increased. In the former case, information increased with increasing range. In the latter case, information increased with increasing number of categories, but the increase was due to a purely mathematical effect. Transmitted information was estimated by means of computer simulation designed to overcome, in part, small sample bias. This simulator is of potential use to others by helping them calculate transmitted or mutual information accurately using a minimum number of experimental trials. The graph of calculated information against number of trials was found to assume a characteristic shape. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
90.
Effects of exogenous oxytocin on production and milking variables of cows   总被引:1,自引:0,他引:1  
Five doses of oxytocin (.5, 1.0, 1.5, 2.0, 3.0 IU) were injected through the subcutaneous abdominal vein (milk vein) of 15 Holstein Friesian cows 1 min before machine attachment. After teat cup removal, cows were given 10 IU of oxytocin via the milk vein for measurement of residual milk 1. An additional 10 IU of oxytocin was given 15 min later for estimating residual milk 2. Total milk yield was slightly higher for cows receiving 2.0 and 3.0 IU oxytocin. Milk fat yield was highest for cows receiving 2.0 and 3.0 IU oxytocin. Percent milk protein was less for cows receiving higher doses. Administration of 2.0 or 3.0 IU oxytocin significantly reduced total residual milk yield as compared with other doses. Fat percent in total residual milk was not affected by administration of oxytocin. Machine-on time, peak flow rate, and average milk flow rate did not differ with oxytocin treatment. A dose of either 2.0 or 3.0 IU oxytocin given via the milk vein will lead to slightly higher milk yields but will not affect milk flow dynamics as compared with lower doses. Moreover, milk fat yield is increased and total residual milk yield is decreased with either 2.0 or 3.0 IU oxytocin, suggesting that these doses result in more efficient extraction of milk. Administering more than 3.0 IU of oxytocin intravenously to promote milk ejection should be of no advantage.  相似文献   
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