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1.
Flora-bearing mice with targeted disruption of T cell receptor (TCR)-alpha or -beta genes spontaneously develop intestinal inflammation with features similar to ulcerative colitis in humans. TCR-alpha-deficient mice maintained germfree or colonized with a limited number of intestinal bacteria failed to develop inflammatory bowel disease (IBD)-like lesions. Evidently, inflammation in these mice does not develop spontaneously or result from a generalized antigenic stimulation, but rather requires induction by a heretofore unidentified specific stimulus. We describe the development of IBD-like lesions in germfree TCR-alpha-deficient mice monoassociated with the protozoan Cryptosporidium parvum. Lesions were seen in distal ileum, cecum, and colon and were most severe in the cecum. A prominent leukocytic infiltrate within the lamina propria was a common characteristic of the lesions observed in the C. parvum-infected germfree TCR-alpha-deficient mice. The leukocytic infiltrate was composed of aggregates of B220+ cells, the majority of which expressed surface IgD (ie, conventional B lymphocytes). It has been proposed that antigenic stimulation by a microorganism(s) is needed to initiate intestinal inflammation in TCR-alpha-deficient mice. Our results indicate that a single microbial species, C. parvum, is capable of triggering the development of IBD-like lesions in germfree TCR-alpha-deficient mice.  相似文献   
2.
In vitro effects of killed Staphylococcus aureus cells on bovine blood mononuclear leukocytes from uninfected cows or cows with chronic staphylococcal mastitis were assessed using a lymphocyte proliferation assay and a [51Cr] release cytotoxicity assay. Killed S. aureus cells cultured with mononuclear leukocytes caused a concentration-dependent decrease in lymphocyte proliferation that was associated with a concomitant decrease in mononuclear leukocyte viability. Responses of mononuclear leukocytes from uninfected and infected cows to killed S. aureus were similar, indicating effects were independent of the infection status of the animal. Addition of blood polymorphonuclear leukocytes to blood mononuclear leukocyte cultures without S. aureus cells did not alter mononuclear leukocyte viability but suppressed lymphocyte proliferation at the highest polymorphonuclear leukocyte:mononuclear leukocyte ratios (4:1 and 8:1) tested. When S. aureus cells and polymorphonuclear leukocytes were cultured with mononuclear leukocytes, both blood and milk polymorphonuclear leukocytes protected against the loss of viability compared with leukocytes cultured with S. aureus cells alone but did not consistently restore proliferative responses of the lymphocytes. These observations demonstrate that lymphocyte proliferation and mononuclear leukocyte viability are detrimentally affected by S. aureus cells, an effect that can be modulated by blood or milk polymorphonuclear leukocytes.  相似文献   
3.
Leick L  Harpøth A  Svalgaard M 《Applied optics》2002,41(21):4325-4330
We present an empirical model for the waveguiding properties of directly UV-written planar waveguides in silica-on-silicon. The waveguides are described by a rectangular core step-index profile, in which model parameters are found by comparison of the measured waveguide width and effective index with modal field calculations. The model is used as input for beam propagation method calculations to design UV-written optical components. Subsequent fabrication of such components showed a good agreement with the model predictions. Using the model will reduce the number of iterations and thereby the development time of new optical devices.  相似文献   
4.
A consensual qualitative research strategy was used to examine data from 127 interviews conducted with 8 psychologists immediately following their sessions of brief therapy with 8 clients. Analyses revealed 3 domains relevant to countertransference: origins (including categories of family issues, needs and values, therapy specific issues, and cultural issues), triggers (including categories of content of client material, therapist comparing client with others, change in therapy structure or procedures, therapist assessing progress of therapy, therapist perception of client, and emotions), and manifestations (including categories of approach, avoidance, negative feelings, and treatment planning). The frequency of categories within and across cases was classified, and relationships among categories from the 3 domains were detected, generating hypotheses for future empirical research. Implications for practice, training, and continued research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
5.
Although much of executive decision making is based on soft information—opinions, predictions, news, and even rumors—executive information systems (EISs) have only recently begun to augment factual data with such information. A study of current use of soft information in EISs yields 15 propositions designed to help EIS developers determine what kinds of soft information are most valuable and how best to capture and deliver this information.  相似文献   
6.
A new method of input linearising a c.c.d. is described. Improvements of 5 to 15dB in linearity over conventional `potential-equilibrium? methods have been obtained.  相似文献   
7.
Raw vegetables inoculated with selected pathogenic bacteria were treated with a strain of Lactobacillus delbrueckii subsp. lactis, which was selected for its ability to produce hydrogen peroxide at refrigerated temperatures. The vegetables inoculated included broccoli, cabbage, carrots, and lettuce. Each vegetable was rinsed, chopped, and stored under conditions similar to those used for ready-to-eat vegetables sold at retail. Portions of each vegetable were separately inoculated with one of two pathogenic bacteria, Escherichia coli O157:H7 or Listeria monocytogenes. Prior to packaging, one portion of each inoculated vegetable was treated with a cell suspension of the selected strain of L. delbrueckii subsp. lactis. The vegetables were stored at 7 degrees C for 6 days. The populations of pathogens and lactobacilli on each sample were enumerated on storage days 0, 3, and 6. Although populations of L. delbrueckii subsp. lactis remained at high levels during storage, there was no noticeable antagonistic action against the pathogens under conditions similar to those used for these products at the retail level. Each pathogen survived on all vegetables throughout storage. Further testing revealed that there was apparently sufficient catalase activity in the cut vegetables to destroy enough of the hydrogen peroxide to prevent antagonistic action against the pathogens.  相似文献   
8.
The US Department of Energy has embarked on a series of tests of TRISO coated particle reactor fuel intended for use in the Very High Temperature Reactor (VHTR) as part of the Advanced Gas Reactor (AGR) program. The AGR-1 TRISO fuel experiment, currently underway, is the first in a series of eight fuel tests planned for irradiation in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The AGR-1 experiment reached a peak compact averaged burnup of 9% FIMA with no known TRISO fuel particle failures in March 2008. The burnup goal for the majority of the fuel compacts is to have a compact averaged burnup greater than 18% FIMA and a minimum compact averaged burnup of 14% FIMA. At the INL the TRISO fuel in the AGR-1 experiment is closely monitored while it is being irradiated in the ATR. The effluent monitoring system used for the AGR-1 fuel is the Fission Product Monitoring System (FPMS). The FPMS is a valuable tool that provides near real-time data indicative of the AGR-1 test fuel performance and incorporates both high-purity germanium (HPGe) gamma-ray spectrometers and sodium iodide [NaI(Tl)] scintillation detector-based gross radiation monitors. To quantify the fuel performance, release-to-birth ratios (R/B's) of radioactive fission gases are computed. The gamma-ray spectra acquired by the AGR-1 FPMS are analyzed and used to determine the released activities of specific fission gases, while a dedicated detector provides near-real time count rate information. Isotopic build up and depletion calculations provide the associated isotopic birth rates. This paper highlights the features of the FPMS, encompassing the equipment, methods and measures that enable the calculation of the release-to-birth ratios. Some preliminary results from the AGR-1 experiment are also presented.  相似文献   
9.
We compared mitogenic responses of milk and peripheral blood lymphocytes from nonmastitic (control) cows and cows with experimentally induced staphylococcal mastitis in one gland. Milk lymphocytes from infected glands were essentially unresponsive to Concanavalin A, phytohemagglutinin-P, and pokeweed mitogen. Proliferative responses of milk lymphocytes from uninfected glands of infected cows were not as depressed as those from infected glands but were significantly less than those of milk lymphocytes from control cows. Proliferative responses of peripheral blood lymphocytes from control and infected cows to Concanavalin A and phytohemagglutinin-P were similar; however, peripheral blood lymphocytes from infected cows responded in reduced fashion to pokeweed mitogen compared with peripheral blood lymphocytes from control animals. These observations demonstrate that in vitro lymphocyte blastogenesis is markedly depressed during infection, suggesting that in vivo lymphocyte function is compromised, possibly contributing to the chronicity of staphylococcal mastitis.  相似文献   
10.
Between November 1994 and January 1997, 42 cases of cyanotic congenital cardiac defects underwent definitive surgery at Matsudo Municipal Hospital. We evaluated 30 cases, each weighing from 7 to 20 kg. The procedures were performed at the age of 9 months to 6 years (mean age-2.4 years). The body weights were 7.7 to 20 kg (mean weight-11.4 kg). The preoperative diagnoses were Tetralogy of Fallot (TOF) in 19 cases, Fontan candidates in 6 and the others in 5. We classified them into 3 groups; Group A--15 cases were completed with non-blood transfusion, Group B--8 cases used only plasma protein fraction and Group C--7 cases used blood transfusion. Cardiopulmonary bypass (CPB) system is a semi-closed circuit and priming volume is 400 to 600 ml. There is no difference among the 3 groups in operative age, body weight, operation time, CPB time, aortic cross clamp time, bleeding and postoperative state. The same results were obtained in minimum base excess and urine output during CPB and the changes of hematocrit and total protein. In Groups A and B, CPB blood was returned to the patient as soon as possible after CPB was weaned, but in Group C, blood transfusion was performed without the return of CPB blood. In all groups, hemodynamics were stable. Retrospectively, it is thought that blood transfusion was not necessary in Group C and the use of the plasma protein fraction was not needed in Group B. In conclusion, the open heart surgery can be performed safely without blood transfusion for cyanotic congenital cardiac defects.  相似文献   
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