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21.
Sludge disintegration treatment by using simultaneously ultrasonic irradiation and electrolysis was investigated experimentally. A lab-scale diaphragm cell irradiated with ultrasound at a constant oscillating frequency of 20 kHz was used as a reactor. The batch experiments were carried out under different conditions of electric outputs of the ultrasonic generator, electric current for the electrolysis and different initial SS concentrations. A simultaneous treatment in the cathodic compartment without any chemical doses considerably facilitated the sludge solubilization, compared to the sonication alone. An increase in the electric current up to 400 mA under a constant ultrasonic density decreased the specific energy by 55% within the experimental range. The specific energy consumption was also reduced when the initial SS concentration increased. In addition, before carrying out the simultaneous treatment, a brief electrolysis was effective for further reduction of the specific energy and the acceleration of soluble COD generation. 相似文献
22.
The effectiveness of extracranial-intracranial arterial bypass (EC-IC bypass) surgery for patients with hemodynamic compromise still remains controversial. In the present study, we evaluated the correlation between the pre- and post-surgical cerebral hemodynamics and long-term prognosis. 28 patients and a subsequent 21 patients (41 men, eight women: mean age 59.9 [S.D. 8.6] years) with reduced cerebrovascular reserve due to steno-occlusive disease of the cerebral major arteries formed the study groups 1 and 2, respectively. Measurement of the mean hemispheric cerebral blood flow (mCBF) and the cerebral vasoreactivity (%mCVR) with an intravenous acetazolamide injection were performed by a 133Xe inhalation method and SPECT. Patients were treated with EC-IC bypass surgery and measurement of mCBF and %mCVR were made again about one month after surgery. The patients were observed for a long period (mean 44.3 months). During the follow-up period, 6 patients experienced recurrent ischemic strokes. The annual incidence of recurrent ischemic stroke was 4.4%. The patients with significantly reduced pre- and post-surgical resting mCBF of the affected hemisphere were at significantly higher risk of recurrent ischemic stroke than the patients with normal mCBF (p < 0.01). The %mCVR of the affected hemisphere rose after surgery. 相似文献
23.
This paper describes the development of a conceptual model of an interaction system for future human-computer interaction. It is suggested that an integrated system is the most promising solution for diverse users and tasks. A ' hybrid interaction system' is considered, which tries to efficiently direct manipulation, menu selection, and natural language. The mechanism of the natural language interface module is described in more detail. Finally, the allocation of functionalities for generalized tasks on the conceptual model is considered from the taxonomic approach. 相似文献
24.
Land mobile radio systems such as car telephones and handy personal terminals used outdoors have enjoyed a remarkable evolution. To design reliable mobile radio systems, however, it is vital to have a good understanding of the impact of wave propagation characteristics on digital transmission quality in a wide variety of mobile radio environments. A very simple but general scheme for calculating irreducible bit error rate (BER) (namely, BER floor) due to intersymbol interference in frequency-selective Nakagami-Rice fading environments has been developed. The scheme, which we call the equivalent transmission-path model, plays a role in connecting wave propagation with digital transmission characteristics in a general manner. Through computer simulations assuming various types of delay profiles, we first identify key parameters of Nakagami-Rice fading dominating principally the occurrence of irreducible errors and we develop a simple method for the calculation of irreducible BER utilizing the nature or the key parameters. Then we examine the accuracy of the scheme for various types of phase-shift keying (PSK) transmission systems. Finally, based on the scheme, we show calculation examples of BER floor characteristics in line-of-sight fading environments 相似文献
25.
In this article, a new control scheme named repetitive control is proposed for a class of nonlinear systems described by x(t) = Ax(t) + Bu(t) + n(x(t)) and y(t) = Cx(t), in which the controlled variables follow periodic reference commands. The stability condition is derived by applying the passivity theorem. We show how to apply the repetitive control scheme to the trajectory control of a manipulator. A simple repetitive control scheme is developed for the trajectory control of a manipulator by using nonlinear compensation and feedbacks of position and velocity signals. Experimental results for a three link manipulator verify that the proposed repetitive control reduces the tracking error to a very low level. 相似文献
26.
T Kuroda M Saeki K Tanaka M Komura T Honna M Nakano M Sugiyama S Nakagawa K Miyasaka 《Canadian Metallurgical Quarterly》1998,33(11):1641-1644
BACKGROUND/PURPOSE: To develop practical and less invasive techniques for fetal endoscopic surgery, new methods of lifting the uterine wall to allow fetal surgery without maternal laparotomy were developed and assessed. METHODS: Fetal endoscopic surgical procedures, including tracheostomy and umbilical vascular cannulation, were performed using one of the three methods to enter the uterus without maternal laparotomy in pregnant goats (n = 6; 105 to 115 days' gestation): (1) direct uterine lifting with an air-cushion device; (2) indirect uterine lifting, in which the uterine wall was fixed to the maternal abdominal wall using balloon tip ports inserted percutaneously by Seldinger's method, then the maternal abdomen was lifted mechanically; and (3) combined method, in which low pressure CO2 (5 mm Hg for initial inflation and 2 mm Hg for maintenance) was insufflated into the uterus in addition to the indirect uterine lifting cited above. RESULTS: The direct uterine lifting caused massive injury of myometrium and uterine membranes. The creation of intrauterine space and the protection of the membranes were not accomplished effectively by the indirect uterine lifting only. The combined method provided the adequate intrauterine space and excellent endoscopic visibility for completion of the endoscopic procedures with minimal uterine injury. CONCLUSION: The fetal endoscopic surgery may be accomplished simply and safely by the combined method, a novel technique of uterine lifting to allow fetal surgery without maternal laparotomy. 相似文献
27.
To examine the development of pancreatic fibrosis in alcoholics, the fibrosis types grouped according to Martin's classification were examined by immunohistochemistry using an antibody against alpha-smooth muscle actin (alpha-SMA). The initial stage of periacinar collagenization was also investigated by electron microscopy. The total incidence of pancreatic fibrosis at autopsy of the 29 alcoholics was significantly higher than that of the 40 non-alcoholics. Intralobular sclerosis was observed to be the most frequent type of fibrosis regardless of alcohol intake. No differences in the enhancement of alpha-SMA expression in each type of fibrosis were found between the alcoholics and non-alcoholics. Electron microscopically, myofibroblasts were found around acini in the early stage of periacinar collagenization, and were accompanied by numerous fine filaments (8-15 nm in diameter). The various changes in zymogen granules (ZG), lysosomes and lipid droplets were augmented in the acinar cells of alcoholics. Medium-density materials were also found in dilated rough endoplasmic reticulum (RER). The contents of ZG and RER occasionally leaked out. In conclusion, pancreatic fibrosis was increased in alcoholics; myofibroblasts may play an important role in the initial stage of periacinar collagenization; and the intracellular transport blockage of protein as represented by abnormalities of ZG, ER and lysosomes may contribute to the development of periacinar collagenization. 相似文献
28.
A computer aided monitor-data processing system (CAMP-System) was developed in order to get a consistent and comprehensive database which can very precisely reflect intra-operative haemodynamic courses. The goal of the present study was to introduce a new method to scan and to gauge haemodynamic courses and to demonstrate its superiority over the traditional way of data processing based on a handwritten anaesthesia protocol. METHODS: The computerized system was applied to a study which was designed to investigate the influence of ketanserin (K) vs. urapidil (U) on haemodynamic stability during cardiac operations. Twenty male patients scheduled for myocardial revascularization received either 20 mg K or 30 mg U. Heart rate, central venous, arterial and pulmonary artery pressures were measured and on-line recorded every 20 seconds by the computer record system. In the handwritten protocol these variables were registered at eight pre-defined time points. Computerized data processing (including artifact depletion and data condensation) was compared to the results evaluated from the handwritten protocol. RESULTS: While the only significant differences in the handwritten protocol were slightly higher values of pulmonary artery pressures in group K, the computer analysis revealed a number of further differences. Higher maximum and a less stable time course of HR in group K in the pre-bypass phase and lower mean and standard deviation of MAP during cardiopulmonary bypass. CONCLUSION: Computerized data processing including automatic artifact suppression and data condensation was able to reveal differences in the course of haemodynamic variables that cannot be detected in a conventional handwritten protocol. 相似文献
29.
Asako Yamamoto Lingli Yang Yasutaka Kuroda Jiao Guo Lanting Teng Daisuke Tsuruta Ichiro Katayama 《International journal of molecular sciences》2021,22(1)
As the outermost barrier of the body, skin is a major target of oxidative stress. In the brain, estrogen has been reported synthesized locally and protects neurons from oxidative stress. Here, we explored whether estrogen is also locally synthesized in the skin to protect from oxidative stress and whether aberrant local estrogen synthesis is involved in skin disorders. Enzymes and estrogen receptor expression in skin cells were examined first by quantitative real-time PCR and Western blot analyses. Interestingly, the estrogen synthesis enzyme was mainly localized in epidermal keratinocytes and estrogen receptors were mainly expressed in melanocytes among 13 kinds of cultured human skin cells. The most abundant estrogen synthesis enzyme expressed in the epidermis was 17β-hydroxysteroid dehydrogenase 1 (HSD17β1) localized in keratinocytes, and the most dominant estrogen receptor expressed in the epidermis was G protein-coupled estrogen receptor 1 (GPER1) in melanocytes. To investigate whether keratinocyte-derived estradiol could protect melanocytes from oxidative stress, cultured human primary epidermal melanocytes (HEMn-MPs) were treated with H2O2 in the presence or absence of 17β estradiol or co-cultured with HSD17β1 siRNA-transfected keratinocytes. Keratinocyte-derived estradiol exhibited protective effects against H2O2-induced cell death. Further, reduced expression of HSD17β1 in the epidermis of skin from vitiligo patients was observed compared to the skin from healthy donors or in the normal portions of the skin in vitiligo patients. Our results suggest a possible new target for interventions that may be used in combination with current therapies for patients with vitiligo. 相似文献
30.
Gaku Yamanaka Shinichiro Morichi Tomoko Takamatsu Yusuke Watanabe Shinji Suzuki Yu Ishida Shingo Oana Takashi Yamazaki Fuyuko Takata Hisashi Kawashima 《International journal of molecular sciences》2021,22(9)
Accumulating evidence has demonstrated that the pathogenesis of epilepsy is linked to neuroinflammation and cerebrovascular dysfunction. Peripheral immune cell invasion into the brain, along with these responses, is implicitly involved in epilepsy. This review explored the current literature on the association between the peripheral and central nervous systems in the pathogenesis of epilepsy, and highlights novel research directions for therapeutic interventions targeting these reactions. Previous experimental and human studies have demonstrated the activation of the innate and adaptive immune responses in the brain. The time required for monocytes (responsible for innate immunity) and T cells (involved in acquired immunity) to invade the central nervous system after a seizure varies. Moreover, the time between the leakage associated with blood–brain barrier (BBB) failure and the infiltration of these cells varies. This suggests that cell infiltration is not merely a secondary disruptive event associated with BBB failure, but also a non-disruptive event facilitated by various mediators produced by the neurovascular unit consisting of neurons, perivascular astrocytes, microglia, pericytes, and endothelial cells. Moreover, genetic manipulation has enabled the differentiation between peripheral monocytes and resident microglia, which was previously considered difficult. Thus, the evidence suggests that peripheral monocytes may contribute to the pathogenesis of seizures. 相似文献