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91.
利用回收非织造布环保购物袋生产纺粘法非织造布是降低成本的有效举措 总被引:1,自引:0,他引:1
“限塑令”的出台,大力促进了非织造布企业的发展,随着一些生产塑料袋的企业也已经成功转型生产非织造布环保袋,加速了纺粘法非织造布的应用发展^[1],同时也暴露出一些日趋严重的问题.特别是非织造布环保购物袋的回收及处理。本文着重介绍了纺粘法非织造布环保购物袋的回收及处理,并指出回收再利用环保购物袋是纺粘企业降低成本的有效举措。 相似文献
92.
Regulation of GRP1-catalyzed ADP ribosylation factor guanine nucleotide exchange by phosphatidylinositol 3,4,5-trisphosphate 总被引:1,自引:0,他引:1
JK Klarlund LE Rameh LC Cantley JM Buxton JJ Holik C Sakelis V Patki S Corvera MP Czech 《Canadian Metallurgical Quarterly》1998,273(4):1859-1862
Cellular levels of phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) are rapidly elevated in response to activation of growth factor receptor tyrosine kinases. This polyphosphoinositide binds the pleckstrin homology (PH) domain of GRP1, a protein that also contains 200 residues with high sequence similarity to a segment of the yeast Sec7 protein that functions as an ADP ribosylation exchange factor (ARF) (Klarlund, J., Guilherme, A., Holik, J. J., Virbasius, J. V., Chawla, A., and Czech, M. P. (1997) Science 275, 1927-1930). Here we show that dioctanoyl PtdIns(3,4,5)P3 binds the PH domain of GRP1 with a Kd = 0.5 microM, an affinity 2 orders of magnitude greater than dioctanoyl-PtdIns(4,5)P2. Further, the Sec7 domain of GRP1 is found to catalyze guanine nucleotide exchange of ARF1 and -5 but not ARF6. Importantly, PtdIns(3,4,5)P3, but not PtdIns(4,5)P2, markedly enhances the ARF exchange activity of GRP1 in a reaction mixture containing dimyristoylphosphatidylcholine micelles, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid, and a low concentration of sodium cholate. PtdIns(3,4,5)P3-mediated ARF nucleotide exchange through GRP1 is selectively blocked by 100 microM inositol 1,3,4,5-tetrakisphosphate, which also binds the PH domain of GRP1. Taken together, these data are consistent with the hypothesis that selective recruitment of GRP1 to PtdIns(3,4,5)P3 in membranes activates ARF1 and -5, known regulators of intracellular membrane trafficking. 相似文献
93.
94.
Adipose tissue mass is determined by both the number and volume of adipose cells. Adipose cell number reflects the balance of cell acquisition and cell loss, whereas adipose cell volume represents the balance of lipolysis and lipogenesis. It is well recognized that insulin resistance, NIDDM, and other metabolic disorders are associated more strongly with increased omental adiposity than with subcutaneous adiposity. Depot-related differences exist in adipocyte responses to lipolytic and lipogenic stimuli, in adipocyte apoptosis, and in the potential for preadipocyte replication and differentiation. In the present study, we address the question of whether there might also be a site-specific difference in the susceptibility of human preadipocytes to apoptosis. Paired samples of human omental and subcutaneous preadipocytes from 12 individuals were cultured, and apoptosis was induced by serum deprivation or treatment with tumor necrosis factor (TNF)-alpha for 4 h. Cells were then stained with acridine orange, and apoptotic indices were calculated as the fraction of cells showing nuclear condensation. Under both conditions, in 9 of 11 subjects, apoptotic indices were substantially greater in preadipocytes from the omental depot than in those from the subcutaneous depot, and mean apoptotic indices were more than twofold higher in omental cells (serum-free medium: P < 0.05; TNF-alpha: P < 0.02; paired t test). Omental preadipocytes are therefore more susceptible to two different apoptotic stimuli than subcutaneous preadipocytes, demonstrating another intrinsic site-specific difference between human adipose cells of the two depots. These results suggest that the regulation of adipose tissue distribution in humans could involve depot-specific differences in rates of preadipocyte apoptosis. 相似文献
95.
水性聚氨酯压敏胶的合成及其性能表征 总被引:1,自引:0,他引:1
以异佛尔酮二异氰酸酯(IPDI)、聚醚多元醇(N220、N210)、二羟甲基丙酸(DMPA)和三羟甲基丙烷(TMP)为主要原料制得了环保交联型水性聚氨酯(WPU)压敏胶,讨论了n(-NCO)/n(-OH)比值、交联剂用量以及聚醚相对分子质量大小对该压敏胶性能的影响。研究结果表明,由N220合成的WPU压敏胶的初粘力优于由N210合成的WPU压敏胶;随着n(-NCO)/n(聚醚中-OH)比值的减小,压敏胶的初粘力提高,持粘力呈先降后增再降的趋势;适度的交联可以提高压敏胶的粘接强度;当n(-NCO)∶n(聚醚中-OH)为2.5∶1、n(TMP中-OH)∶n(聚醚中-OH)为1∶3.0时,压敏胶的综合性能优异,初粘力达到13号钢球,持粘力达到23.1h,180°剥离强度达到20.14N/(20mm)。 相似文献
96.
PR Foulis PM Wallach HM Adelman BH Sanford J McCain D Reed CM Schlede CU Kokseng CD Taylor 《Canadian Metallurgical Quarterly》1995,103(1):98-102
There is a need to monitor anticoagulation accurately, inexpensively, and rapidly. The accuracy and precision of a simple fingerstick method was studied in a large outpatient anticoagulation clinic using the Coumatrak method. The Coumatrak apparatus has been studied in the home setting, and three recent reports suggest that it is practical, accurate, and possibly superior to the standard method. These results differ from recently published studies. This technique was found to be less than acceptable in precision and accuracy. This method requires further study before it can be recommended for wide-spread use in making decisions for patient care. 相似文献
97.
M Roselli F Guadagni O Buonomo A Belardi V Vittorini R Mariani-Costantini JW Greiner CU Casciani J Schlom 《Canadian Metallurgical Quarterly》1996,14(7):2031-2042
PURPOSE: The ability of interferons (IFNs) to enhance tumor-associated antigen expression may be an important approach to enhance the efficacy of some monoclonal antibody (MAb)-based protocols for tumor diagnosis and/or therapy. The present study was designed to determine whether systemic IFN alpha-2a administration (via the intramuscular [IM] route) could upregulate the expression of tumor-associated glycoprotein-72 (TAG-72) and/or carcinoembryonic antigen (CEA) at histologically confirmed sites of carcinoma. PATIENTS AND METHODS: Eighteen patients diagnosed with gastrointestinal (GI) carcinoma received systemic IFN alpha-2a according to four dose schedules. In cohorts I and II, patients received two injections of 3 or 6 x 10(6) U IFN alpha-2a per injection, respectively. Patients in cohorts III and IV received the same doses of IFN alpha-2a, 3 and 6 x 10(6) U, respectively, but three injections were given. Tumor and normal colonic mucosa biopsies were obtained from each patient by endoscopy before IFN alpha-2a and after IFN alpha-2a at surgery. The levels of TAG-72 and CEA expression were measured by (1) immunohistochemistry and reported as percent antigen-positive tumor cells, as well as the relative staining intensity, and (2) a quantitative radioimmunoassay. RESULTS: TAG-72 and CEA levels were consistently increased in tumor biopsies taken from patients in cohorts III and IV. For example, of 10 patients treated in cohorts III and IV, eight had enhanced TAG-72 expression when measured either as percentage TAG-72-positive tumor cells or as an increased MAb staining intensity following IFN alpha-2a. CEA expression in tumor biopsies from seven of 10 patients in cohorts III and IV was also elevated following IFN alpha-2a treatment. Quantitative analysis of TAG-72 and CEA levels in tumor biopsies confirmed higher tumor antigen levels following IFN alpha-2a administration. No such increases in TAG-72 or CEA levels were observed in tumor samples taken from patients in cohorts I and II. CEA or TAG-72 expression in samples of histologically confirmed normal colonic mucosa showed little or no change after IFN alpha-2a treatment. CONCLUSION: Systemic IFN alpha-2a administration can upregulate TAG-72 and CEA expression at distal tumor sites, which may play an important role in immunodiagnosis and therapy. 相似文献
98.
OBJECTIVE: The purpose of this investigation was to study the correlation between diagnostic delay and the stage of the lung cancer at the time of operation. A second objective was to study differences in symptoms between the patients grouped according to stage. METHODS: A total of 172 patients consecutively admitted for surgery between 1 January 1994 and 1 June 1995 at the Department of Thoracic and Cardiovascular Surgery of Rigshospitalet National Hospital of Denmark were included in the retrospective study. Two groups of patients were compared, one group with good prognosis (patients in Stages I and II) and one group with poor prognosis (patients in Stages III and IV). The time-spans studied were: (1) interval from the patient's perception of the first symptom to operation; and (2) the time from first contact with the healthcare-system to operation. The median delay between the patient-groups was compared using the Mann-Whitney U-test. To compare the symptoms which brought the patients in contact with the healthcare-system, the chi2-test was used. RESULTS: In the time interval between appearance of the first symptom and operation, a significantly shorter median delay was found for patients with Stages I and II compared to Stages III and IV (P = 0.037). Concerning the interval from first contact with the healthcare system to operation a significantly shorter median delay was found for the group of patients in Stage I and II compared to the patients-group in Stage III and IV (P = 0.017). It was found that the cancer was an accidental finding, significantly more often in patients in Stages I or II compared to patients in Stages III or IV (P = 0.0002). CONCLUSIONS: A few months delay before final treatment of a non-small-cell lung cancer seems to have an impact on the perioperative stage of the cancer, and thereby on the patients prognosis. A screening of asymptomatic risk-group patients will result in recognition of early lung cancer. 相似文献
99.
CY Tai PA Escarpe RW Sidwell MA Williams W Lew H Wu CU Kim DB Mendel 《Canadian Metallurgical Quarterly》1998,42(12):3234-3241
An oral prodrug of GS 4071, a potent and selective inhibitor of influenza neuraminidases, is currently under clinical development for the treatment and prophylaxis of influenza virus infections in humans. To investigate the potential development of resistance during the clinical use of this compound, variants of the human influenza A/Victoria/3/75 (H3N2) virus with reduced susceptibility to the neuraminidase inhibitor GS 4071 were selected in vitro by passaging the virus in MDCK cells in the presence of inhibitor. After eight passages, variants containing two amino acid substitutions in the hemagglutinin (A28T in HA1 and R124M in HA2) but no changes in the neuraminidase were isolated. These variants exhibited a 10-fold reduction in susceptibility to GS 4071 and zanamivir (GG167) in an in vitro plaque reduction assay. After 12 passages, a second variant containing these hemagglutinin mutations and a Lys substitution for the conserved Arg292 of the neuraminidase was isolated. The mutant neuraminidase enzyme exhibited high-level (30,000-fold) resistance to GS 4071, but only moderate (30-fold) resistance to zanamivir and 4-amino-Neu5Ac2en, the amino analog of zanamivir. The mutant enzyme had weaker affinity for the fluorogenic substrate 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid and lower enzymatic activity compared to the wild-type enzyme. The viral variant containing the mutant neuraminidase did not replicate as well as the wild-type virus in culture and was 10,000-fold less infectious than the wild-type virus in a mouse model. These results suggest that although the R292K neuraminidase mutation confers high-level resistance to GS 4071 in vitro, its effect on viral virulence is likely to render this mutation of limited clinical significance. 相似文献
100.