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71.
ST Murphy DD Lewis JT Shiroma LA Neuwirth RB Parker PS Kubilis 《Canadian Metallurgical Quarterly》1998,59(11):1351-1357
OBJECTIVE: To ascertain effects of x-ray beam centering and limb position on apparent congruity of a normal cubital joint (elbow). ANIMALS: 6 skeletally mature male Treeing Walker Coonhounds without physical, radiographic, or gross evidence of elbow abnormalities. PROCEDURE: Relative movement among humerus, radius, and ulna and measured joint space width on mediolateral and craniocaudal radiographic views was compared, using various x-ray beam centering and limb positions. RESULTS: Highest agreement and greatest certainty on subjective determination of congruity was for the flexed 90 degrees mediolateral radiographic view with the x-ray beam centered on the elbow. Distortion artifact of the proximal ulnar measurements was significant when the x-ray beam was centered on the midpoint of the radius. On the mediolateral view, the humeroradial joint space became significantly wide when the elbow was flexed. On the craniocaudal view, maximal humeroradial joint space width was obtained when the x-ray beam bisected the angle of the joint or was angled +30 degrees toward the humerus. CONCLUSIONS: Artifact distortion of joint width affected objective and subjective assessment of elbow congruity when the limb was placed in extreme flexion or extension or when the x-ray beam was not centered over the area of interest. Optimal visualization of the humeroradial joint space on the craniocaudal view was achieved when the x-ray beam bisected the angle of the elbow or was slightly angled toward the humerus. CLINICAL RELEVANCE: Elbow congruity was best assessed on the flexed 90 degrees lateral radiographic view with the x-ray beam centered on the joint. 相似文献
72.
D Knaack ME Goad M Aiolova C Rey A Tofighi P Chakravarthy DD Lee 《Canadian Metallurgical Quarterly》1998,43(4):399-409
Bacteroides fragilis strains isolated from different sources, i.e. 1 strain (AA1) from an aquatic environment, 1 strain from normal flora (118310) and the type strain (ATCC 25285) originally isolated from clinical material, were analysed for both cell envelope proteins composition and surviving under oxidative stress starvation. All strains examined showed a similar survival response when cultured in drinking water with a ten-fold decrease in viable counts per day during the 7 days of analysis. The outer membrane protein (OMP) profiles of all strains were quite similar during the stress period as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). However, the periplasmic proteins of the strain 118310 showed two protein bands at 48 and 58 kDa, respectively, that were absent in the strains AA1 and ATCC 25285 during the incubation period in potable water. Whole cells and periplasmic 35S-labelled proteins from bacteria cultured in drinking water showed a significant increase in proteins at 16, 18, 24, 26, 35, 48, and 58 kDa and 18, 22, 24, 48, 58, and 70 kDa, respectively, in all strains when compared to cells grown in BHI-PRAS media as detected by autoradiography following SDS-PAGE. These data suggest that B. fragilis may have a synthesis mechanism that allows them to adapt to adverse environments. 相似文献
73.
Prognostic risk stratification to identify perioperative and long-term cardiac risk in selected patients undergoing noncardiac surgery is part of good clinical practice. Exercise variables associated with significant increased risk include poor functional capacity (eg, <4 metabolic equivalents), marked exercise-induced ST segment shift or angina at low workloads, and inability to increase or actually decrease systolic blood pressure with progressive exercise. Approximately 40% of patients tested before peripheral vascular surgery will have an abnormal exercise electrocardiogram (ECG). The predictive value for a perioperative event, ie, death or myocardial infarction, ranges from 5% to 25% for a positive test and 90% to 95% for a negative test. Whereas exercise cardiac imaging is the modality of choice in patients with a noninterpretable exercise ECG, pharmacological stress imaging should be used in the 30% to 50% of patients who require perioperative noninvasive risk stratification and are unable to perform an adequate level of exercise to test cardiac reserve. Myocardial perfusion variables predictive of increased cardiac events include severity of the perfusion defect, number of reversible defects, extent of fixed and reversible defects, increased lung uptake of thallium-201, and marked ST segment changes associated with angina during the test. The reported sensitivity and specificity of dobutamine-induced echocardiographic wall motion abnormalities in patients with peripheral vascular disease is similar to myocardial perfusion scintigraphy, but the confidence limits are wider due to the smaller sample size in these more recent studies. In conclusion, noninvasive cardiac testing should be used selectively in patients undergoing noncardiac surgery; the results provide useful estimates of short- and long-term risk of cardiac events, and the magnitude of abnormal response on noninvasive testing should be used to formulate decisions regarding the need for coronary angiography and subsequent revascularization. 相似文献
74.
BACKGROUND: So far only a few cases of carcinoma in situ of the fallopian tube have been reported, but its detailed clinical and pathologic findings, including cytology, have not been fully described. CASE: A 70-year-old female was admitted to our hospital because of irregular genital bleeding. Endometrial smear revealed a small number of atypical cells with a clear background. Hysterectomy, bilateral salpingo-oophorectomy and omentectomy were performed. Grossly, a grayish white papillary tumor, measuring 1.5 x 1.0 cm, was observed within the lumen of the left fallopian tube. Microscopically, the diagnosis of papillary adenocarcinoma in situ of the left fallopian tube was made according to 1992 International Federation of Gynecologists and Obstetricians fallopian tube staging. CONCLUSION: Although endometrial brush cytology is not sensitive enough to detect a primary carcinoma of the fallopian tube, our case indicates that it may contribute useful information on extrauterine diseases and can detect a stage 0 cancer of the fallopian tube. Clinicians, as well as pathologists, should consider the possibility of fallopian tube cancer if cervical or endometrial cytology shows atypical cells with papillary patterns with a clear background but endometrial curettage cannot prove malignancy. 相似文献
75.
The catalytic characteristics and structure of the M1-1 isoenzyme of rat glutathione (GSH) transferase in which all four tryptophan residues in each monomer are replaced with 5-fluorotryptophan are described. The fluorine-for-hydrogen substitution does not change the interaction of the enzyme with GSH even though two tryptophan residues (Trp7 and Trp45) are involved in direct hydrogen-bonding interactions with the substrate. The rate constants for association and dissociation of the peptide, measured by stopped-flow spectrometry, remain unchanged by the unnatural amino acid. The 5-FTrp-substituted enzyme exhibits a kcat of 73 s-1 as compared to 18 s-1 for the native enzyme toward 1-chloro-2,4-dinitrobenzene. That the increase in the turnover number is due to an enhanced rate of product release in the mutant is confirmed by the kinetics of the approach to equilibrium for binding of the product. The crystal structure of the 5-FTrp-containing enzyme was solved at a resolution of 2.0 A by difference Fourier techniques. The structure reveals local conformational changes in the structural elements that define the approach to the active site which are attributed to steric interactions of the fluorine atoms associated with 5-FTrp146 and 5-FTrp214 in domain II. These changes appear to result in the enhanced rate of product release. This structure represents the first of a protein substituted with 5-fluorotryptophan. 相似文献
76.
William Serson Paul Armstrong Elizabeth Maghirang Ahmed AL-Bakri Timothy Phillips Maythem AL-Amery Kai Su David Hildebrand 《Journal of the American Oil Chemists' Society》2020,97(1):3-13
Chia (Salvia hispanica) is an ancient crop that has experienced an agricultural resurgence in recent decades owing to the high omega 3 fatty acid (ω-3) content of the seeds and good production potential. Analysis of 563 lots of chia grown in Kentucky and 10 lots from Arizona, Australia, Mexico, and Peru was performed. All of these lots were assessed for fatty acid, oil, and protein content, while a subset of 120 samples were assessed for amino acids, fiber, minerals, and trace elements. The mean oil content was 31.3%, ranging from 21.4% to 35.3%. The protein content averaged 22.8%, ranging from 18.2% to 28.2%, and the ω-3 FA α-linolenic acid (ALA) averaged 61.3%, ranging from 33.9% to 69.9%. Using these seed lots, nondestructive near-infrared spectroscopy (NIRS) calibrations were developed for whole and ground seed oil, protein, moisture, and the six major fatty acids. The R2 and SE of cross-validation (SECV) values for oil were 0.78 and 0.95, respectively, while those for protein were 0.75 and 1.05, respectively. The NIRS calibrations for fatty acid had R2 and SECV greater than 0.6 and less than 10% of actual values for all major fatty acids, respectively. An R2 of 0.99 was established for moisture content of whole seeds within the range of 3–10% moisture content. The precision and accuracy of these calibrations is adequate for use by breeders, growers, and food quality experts to quantitatively assess these major constituents without the need for costly and time-consuming chemical analysis. 相似文献
77.
Michael W. Murphy Timothy R. Armstrong Peter A. Smith 《Journal of the American Ceramic Society》1997,80(1):165-170
The effects of process additives, ball milling, and solids loading were evaluated for tape casting suspensions of glycinenitrate-synthesized La0.7 Ca0.31 CrO3 powder. An optimized formulation was obtained based on rheological characterization, electrokinetic sonic amplitude measurements, qualitative examination of green tapes, and the sintered microstructure. The tape casting formulation incorporated 66:34 methyl ethyl ketone/ethyl alcohol solvent, an aliphatic phosphate ester dispersant, and 80 wt% (35 vol%) solids. The best binder/plasticizer system was 12 wt% (15 vol%) poly(isobutyl methacrylate) and 5 wt% (6.3 vol%) benzyl butyl phthalate plasticizer (binder:plasticizer = 2.3). Cast tapes were sintered at 1300°C for 2 h, producing a bulk density of 96.2% theoretical, with linear shrinkage of 22% and an approximate grain size of 1.3 μm. 相似文献
78.
Hotchkiss PJ Jones SC Paniagua SA Sharma A Kippelen B Armstrong NR Marder SR 《Accounts of chemical research》2012,45(3):337-346
Transparent metal oxides, in particular, indium tin oxide (ITO), are critical transparent contact materials for applications in next-generation organic electronics, including organic light emitting diodes (OLEDs) and organic photovoltaics (OPVs). Understanding and controlling the surface properties of ITO allows for the molecular engineering of the ITO-organic interface, resulting in fine control of the interfacial chemistries and electronics. In particular, both surface energy matching and work function compatibility at material interfaces can result in marked improvement in OLED and OPV performance. Although there are numerous ways to change the surface properties of ITO, one of the more successful surface modifications is the use of monolayers based on organic molecules with widely variable end functional groups. Phosphonic acids (PAs) are known to bind strongly to metal oxides and form robust monolayers on many different metal oxide materials. They also demonstrate several advantages over other functionalizing moieties such as silanes or carboxylic acids. Most notably, PAs can be stored in ambient conditions without degradation, and the surface modification procedures are typically robust and easy to employ. This Account focuses on our research studying PA binding to ITO, the tunable properties of the resulting surfaces, and subsequent effects on the performance of organic electronic devices. We have used surface characterization techniques such as X-ray photoelectron spectroscopy (XPS) and infrared reflection adsorption spectroscopy (IRRAS) to determine that PAs bind to ITO in a predominantly bidentate fashion (where two of three oxygen atoms from the PA are involved in surface binding). Modification of the functional R-groups on PAs allows us to control and tune the surface energy and work function of the ITO surface. In one study using fluorinated benzyl PAs, we can keep the surface energy of ITO relatively low and constant but tune the surface work function. PA modification of ITO has resulted in materials that are more stable and more compatible with subsequently deposited organic materials, an effective work function that can be tuned by over 1 eV, and energy barriers to hole injection (OLED) or hole-harvesting (OPV) that can be well matched to the frontier orbital energies of the organic active layers, leading to better overall device properties. 相似文献
79.
Joseph J. Armstrong Adilakshmi G. Robin C. R. Rene Vidhya S. Narukullapati Bharath Kumar Reddy M. Koti Kumar T. Ch. Anil 《SILICON》2023,15(1):127-131
Silicon - We designed a new model tunnel field-effect transistor (TFET) based on Triple Heterojunction Tunnel Field Effect Transistor (THJ-TFET) is investigated and designed in this paper. This... 相似文献
80.
Z. J. Yang E. Harkin‐Jones G. H. Menary C. G. Armstrong 《Polymer Engineering and Science》2004,44(7):1379-1390
A non‐isothermal finite element (FE) model for the injection stretch‐blow molding (ISBM) process of polyethylene terephthalate (PET) bottles is presented in this paper. The constitutive behavior of PET is modeled by the physically based Buckley glass‐rubber model in form of UMAT in ABAQUS. The heat transfer between the stretch rod, the preform, and the mold is modeled. Particular attention is paid to thermal and contact modeling, material model, and selection of proper element types. Extensive FE simulations are carried out to model ISBM of a 20 g‐330 ml bottle made in plant tests. Comparisons of numerical results with the measurements demonstrate that the model can satisfactorily predict the bottle thickness and material distributions. Significant nonlinear differentials are found in strain, temperature, and temperature reduction rate in both bottle thickness and length direction during the process. A volume approach is therefore necessary for accurate predictions of final bottle properties because they are governed by orientation and crystallinity, which are highly temperature and strain dependent. Parametric studies on contact modeling and heat transfer coefficient are also conducted and the results are discussed. Polym. Eng. Sci. 44:1379–1390, 2004. © 2004 Society of Plastics Engineers. 相似文献