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991.
ME Solov''eva VS Akatov VV Leshchenko AA Kudriavtsev 《Canadian Metallurgical Quarterly》1998,8(2):194-199
OBJECT: The goal of this study was to investigate the impact of mild or moderate degrees of degenerative or ischemic encephalopathy on predicting clinical outcome following unilateral posteroventral medial pallidotomy for treatment of advanced Parkinson's disease (PD). METHODS: Thirty-five patients with PD were studied prospectively. The presence and degree of cortical atrophy, ventriculomegaly, deep white matter lesions (DWML), periventricular lucencies (PVL), and the presence of lacunes and status cribriformis (multiple and bilateral enlarged Virchow-Robin spaces) were determined by magnetic resonance (MR) imaging before the patients underwent stereotactic pallidotomy performed according to a standard protocol. Clinical outcome was measured using a standard battery of tests including application of the Unified Parkinson's Disease Rating Scale (UPDRS). The preoperative MR imaging features were correlated with UPDRS subscores such as motor "off' score, the activities of daily living (ADL) off score, the off subscore for bradykinesia, the percentage of "on" time dyskinesias, and a global outcome rating. The MR findings were also correlated with the occurrence of side effects. Global outcome was rated as markedly improved in 22 patients (63%) and as moderately improved in 12 patients (34%) 6 months postoperatively. At the 1-year follow-up examination, global outcome in 31 patients was rated as markedly improved in 14 patients (45%), as moderately improved in another 14 (45%), as slightly improved in two (6%), and as worse in one patient (3%). The mean UPDRS motor off score changed from 58.7 preoperatively to 33.2 at 6 months and 33.4 at 1 year (p < 0.0001), the ADL off score from 31.8 to 18.2 at 6 months and 18.6 at 1 year (p < 0.0001), the off score from contralateral bradykinesia from 11.6 to 5.6 at 6 months and 4.1 at 1 year (p < 0.0001), and the percentage of awake time with dyskinesias from 37.4 to 17.4% at 6 months and 21.1% at 1 year (p < 0.0001). The presence of mild or moderate degrees of cortical atrophy, PVL, and DWML had no effect on clinical outcome. Patients with status cribriformis and those with lacunes tended to show comparatively less improvement in the UPDRS ADL off score (p = 0.014 and p = 0.016, respectively) at 6 months. This tendency was also present in patients with status cribriformis 1 year postoperatively (p = 0.046). Patients with both status cribriformis and lacunes had a higher incidence of transient altered mental status immediately postoperatively (p = 0.05). CONCLUSIONS: Mild-to-moderate degrees of cortical atrophy, ventriculomegaly, and ischemic encephalopathy do not predispose patients to less favorable outcomes following unilateral pallidotomy. Patients with both status cribriformis and lacunes have a higher risk of transient side effects; however, with regard to clinical outcome, these patients should not be denied surgical treatment. 相似文献
992.
K Schulze-Osthoff D Ferrari M Los S Wesselborg ME Peter 《Canadian Metallurgical Quarterly》1998,254(3):439-459
How do stimulus size and item number relate to the magnitude and direction of error on center estimation and line cancellation tests? How might this relationship inform theories concerning spatial neglect? These questions were addressed by testing twenty patients with right hemisphere lesions, eleven with left hemisphere lesions and eleven normal control subjects on multiple versions of center estimation and line cancellation tests. Patients who made large errors on these tests also demonstrated an optimal or pivotal stimulus value, i.e., a particular size center estimation test or number of lines on cancellation that either minimized error magnitude relative to other size stimuli (optimal) or marked the boundary between normal and abnormal performance (pivotal). Patients with right hemisphere lesions made increasingly greater errors on the center estimation test as stimuli were both larger and smaller than the optimal value, whereas those with left hemisphere lesions made greater errors as stimuli were smaller than a pivotal value. In normal subjects, the direction of errors on center estimation stimuli shifted from the right of true center to the left as stimuli decreased in size (i.e., the crossover effect). Right hemisphere lesions exaggerated this effect, whereas left hemisphere lesions diminished and possibly reversed the direction of crossover. Error direction did not change as a function of stimulus value on cancellation tests. The demonstration of optimal and pivotal stimulus values indicates that performances on center estimation and cancellation tests in neglect are only relative to the stimuli used. In light of other studies, our findings indicate that patients with spatial neglect grossly overestimate the size of small stimuli and underestimate the size of large stimuli, that crossover represents an "apparent" shift in error direction that actually results from normally occurring errors in size perception, and that the left hemisphere is specialized for one aspect of size estimation, whereas the right performs dual roles. 相似文献
993.
One current higher education paradigm shift is the movement from traditional classroom settings and interactive television satellite transmission to course and program delivery via the World Wide Web (WWW). The authors describe the experiences of faculty in reconceptualizing and redesigning course and program delivery via the Internet. An electronic "template" has been collaboratively developed by multidisciplinary university partners to facilitate this work. The template incorporates an advanced nursing practice conceptual framework based on American Association of Colleges of Nursing (AACN) core educational essentials for advanced practice combined with a continuum of electronic course tools. Strategies, tools, and applications are discussed. 相似文献
994.
M Ito D Grujic ED Abel A Vidal-Puig VS Susulic J Lawitts ME Harper J Himms-Hagen AD Strosberg BB Lowell 《Canadian Metallurgical Quarterly》1998,47(9):1464-1471
Beta-adrenergic receptors (ARs) are expressed predominantly in adipose tissue, and beta3-selective agonists are effective anti-obesity drugs in rodents. Rodent and human beta3-ARs differ with respect to expression in white versus brown adipocytes as well as their ability to be stimulated by beta3-AR-selective agonists. Humans express beta3-AR mRNA abundantly in brown but not white adipocytes, while rodents express beta3-AR mRNA abundantly in both sites. To determine the basis for this difference, we have transgenically introduced 74 kilobases (kb) of human beta3-AR genomic sequence into gene knockout mice lacking beta3-ARs. Importantly, human beta3-AR mRNA was expressed only in brown adipose tissue (BAT) of transgenic mice, with little or no expression being detected in white adipose tissue (WAT), liver, stomach, small intestine, skeletal muscle, and heart. This pattern of expression differed from that observed in mice bearing a murine beta3-AR genomic transgene in which beta3-AR mRNA was expressed in both WAT and BAT, but not in other sites. Furthermore, we have transgenically introduced smaller human constructs containing -14.5 and -0.6 kb of upstream sequence into beta3-AR gene knockout mice. Both -14.5 and -0.6 kb constructs were expressed in BAT but not WAT. Thus, human but not murine cis-regulatory elements direct beta3-AR gene expression preferentially to brown adipocytes. Identification of responsible cis-regulatory element(s) and relevant trans-acting factor(s) should provide insight into mechanisms controlling human beta3-AR gene expression. In addition, the beta3-AR agonist, CGP-12177, stimulated oxygen consumption in mice expressing human but not murine beta3-ARs by 91% compared with only 49% in control beta3-AR gene knockout mice, demonstrating that the human beta3-AR can functionally couple with energy expenditure. These "humanized" mice should assist us in the development of drugs that may become effective anti-obesity agents in humans. 相似文献
995.
CS Fox J Esparza M Nicolson PH Bennett LO Schulz ME Valencia E Ravussin 《Canadian Metallurgical Quarterly》1998,68(5):1053-1057
BACKGROUND: The high prevalence of obesity and type 2 diabetes in some populations is believed to be the expression of a "thrifty genotype," which conferred survival advantages during periods of harsh environmental conditions, but has become a liability in industrialized environments of abundance. Low plasma leptin concentrations and a low metabolic rate may be the phenotypic expression of this genotype. OBJECTIVE: We hypothesized that plasma leptin concentrations and resting metabolic rate would be lower in Mexican Pima Indians not yet exposed to an affluent lifestyle than in non-Pima Mexicans living in the same environment. DESIGN: We studied 208 nondiabetic Pima Indians (105 women and 103 men) living a traditional lifestyle in a remote, mountainous area of northwest Mexico and 183 nondiabetic non-Pima Mexicans (90 women and 93 men) living in the same environment. A subset of 40 (17 women and 23 men) Pima Indians and 40 (19 women and 21 men) non-Pima Mexicans was selected for studies of energy metabolism with a ventilated-hood system. RESULTS: Leptin concentrations were strongly correlated with percentage body fat in both groups (r = 0.83, P < 0.0001). There was no significant difference in plasma leptin concentration between groups in absolute value (P = 0.90) or after adjustment for percentage body fat, waist circumference, age, and sex (P = 0.40). Similarly, there was no significant difference in resting metabolic rate between groups in absolute value (P = 0.27) or after adjustment for fat-free mass (P = 0.32). CONCLUSIONS: These results do not support the hypothesis that hypoleptinemia, a relatively low resting metabolic rate, or both are expressions of the thrifty genotype. 相似文献
996.
997.
M Soncin A Busetti R Biolo G Jori G Kwag YS Li ME Kenney MA Rodgers 《Canadian Metallurgical Quarterly》1998,42(3):202-210
The incidence of risk factors for atherosclerosis was investigated in a group of 846 patients under 65 years of age, hospitalized with acute myocardial infarction (AIM) in coronary hospital units in 21 districts of the Czech Republic in 1996. The group of patients comprises 649 men and 197 women. The incidence of risk factors in patients was compared with the incidence of risk factors in the population of the Czech Republic: the mean values of the investigated indicators are in patients with AIM higher in both sexes (total serum cholesterol, triacylglycerols, BMI, WHR). As to anamnestic data, in the majority low or irregular physical activity predominates, a high percentage of patients reported that they "do not restrict" or "rather do not restrict" their total food intake nor the intake of animal fats. Among the patients 52.6% males and 42.1% females were smokers. The results indicate that patients with AIM have a higher incidence of risk factors for atherosclerosis, a higher percentage of patients have cumulated risks and a higher percentage of patients has a higher risk score than the general population. The incidence of AIM is markedly higher in subjects with lower education. 相似文献
998.
999.
Controversies abound in the literature about the safety and efficacy of tamoxifen and estrogen. We studied the effect of these 2 hormonal agents on factors involved in in vitro thrombogenesis: platelets and endothelial cells. Endothelial cells were derived from human umbilical veins and platelets were obtained from premenopausal and postmenopausal women, women on oral contraceptives, postmenopausal women on hormone replacement therapy, men, and patients with breast cancer who had been taking adjuvant tamoxifen for more than 1 year. The interaction of platelets with endothelial cell matrix was measured in 2 systems: 1) in a flow chamber at low shear rate and, 2) with 51Cr labeled platelets in a "static" culture system. In the static system, platelets from women on tamoxifen exhibited decreased platelet adherence to endothelial cell matrix whether they were grown in tamoxifen or control conditions, when compared to platelets from premenopausal women. When flow (25 sec-1) was added these differences were negated. Neither tamoxifen nor 17 beta estradiol had an effect on endothelial cell proliferation or platelet aggregation. Adhesion of platelets at low shear was not altered when platelet rich plasma was incubated with tamoxifen nor when endothelial cells were grown in tamoxifen. In contrast, incubation of platelets in 17 beta estradiol decreased platelet adhesion at low shear rate, however, there was no effect on platelet adhesion when endothelial cells were grown in 17 beta estradiol. We conclude that in early stages of thrombus formation as measured in vitro, tamoxifen may not have a detrimental effect and estrogen may be protective. 相似文献
1000.
The present study examines the similarity in the symptoms and binding properties between the depressant and excitatory insect-selective neurotoxins, derived from scorpion venom. A comparison of their primary structures and neuromuscular effects is presented. A new depressant toxin (LqhIT2) was purified from the venom of the scorpion Leiurus quinquestriatus hebraeus. The effects of this toxin on a prepupal housefly neuromuscular preparation mimic its effects on the intact insect, i.e, a brief period of repetitive bursts of regular junction potentials (JPs) is followed by reduced amplitude JPs ending with a block of the neuromuscular transmission. "Loose" patch clamp recordings indicate that the repetitive activity has a presynaptic origin (the motor nerve) and resembles the effect of the excitatory toxin AaIT. The final synaptic block is supposed to be the end result of neuronal membrane depolarization. Such an effect is not caused by an excitatory toxin, which induces long "trains" of repetitive firing. The amino acid sequences of three depressant toxins were determined by automatic Edman degradation indicating a high degree of sequence homology. This conservation differs from those of other groups of scorpion toxins. The opposing pharmacological effects of depressant toxins are discussed in light of the above neuromuscular effects and sequence analysis. A genetic approach in the study of the structure-function relationships of the depressant toxins was initiated by isolating cDNA clones encoding the LqhIT2 and BjIT2 toxins. Their sequence analysis revealed the precursor form of these toxins: A 21 amino acid residue signal peptide followed by a 61 amino acid region of the mature toxin, and three additional amino acids at the carboxy terminus. 相似文献