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61.
Wire sweep is a main concern in the semiconductor packaging industry. The wire bonding technology, providing versatile and reliable chip-connection method, is usually adopted for MCM and 3-D package. However, there is no (standard) approach found to determine the ability of sweep resistance for a certain bond profile in the literature. In a parallel study, the concept of sweep stiffness is defined from the slope of the load–transverse displacement curves to express sweep resistance of wire bond. In this paper, two frequently used bond profiles, the Q Auto-Loop and Square-Loop bonds, were investigated experimentally to assess the effect of bond span and height on sweep resistance. Results show that the Q Auto-Loop bond has a higher sweep resistance than the Square-Loop bond, for all wire diameters. Moreover, numerical results and proposed model predictions were performed to compare with sweep stiffness experiments. Underestimated predictions indicate the importance of bond profile characteristics to sweep stiffness values, which must be included in numerical analysis. 相似文献
62.
63.
GW Daneker SA Lund SW Caughman RA Swerlick AH Fischer CA Staley EW Ades 《Canadian Metallurgical Quarterly》1998,34(5):370-377
BACKGROUND: Epidemiologic data concerning skin diseases in many rural areas in sub-Saharan Africa are not available. Little is known about the effect of regular treatment schedules by paramedical staff (especially community health workers) in the primary healthcare system on the severity and prevalence of dermatoses. METHODS: 5780 school and pre-school children from 13 primary schools in four sublocations in rural western Kenya (Kisumu District) were examined for dermatoses by the author, together with community health workers in 1993. On-the-spot training and weekend seminars about important and common dermatoses were also given. In 1994 a dermatology program was started within the primary healthcare system. Twelve trained community health workers carried out regular school visits once a week and diagnosed and treated pupils with dermatoses. Treatment was performed with gentian violet 1% solution for bacterial skin infections, Whitfield's ointment for dermatophytoses, benzylbenzoate emulsion 25% for scabies, and hydrocortisone acetate 1% cream for eczemas. All schools were visited again in 1995 to evaluate the long-term effects of the program. RESULTS: In 1993, the prevalence rate for dermatoses was 32.4%. Most of the skin diseases found were of infective origin (27.1% were caused by bacteria, 21.6% by fungi, and 17.6% by arthropods, mainly scabies mites). Dermatitis accounted for 3.5%. In 1995, the prevalence of dermatoses declined to 29.6% (p<0.05), and this reduction was most strongly observed for tropical ulcers and tinea capitis. Additionally, there was an improvement in the extent and severity of skin diseases. CONCLUSIONS: This study defines, for the first time, the number and extent of skin diseases in children in rural Kisumu District; most dermatoses were of infective origin. The study demonstrates that community health workers in the primary healthcare system are capable of dealing successfully with the most common dermatoses in children following a short training period. 相似文献
64.
OBJECTIVE: To examine the changes in neutrophil deformability, aggregation, and adherence in response to stimulation with proinflammatory cytokines and bacterial toxins. DESIGN: Prospective, randomized trial. SETTING: Research laboratory. SUBJECTS: Neutrophils isolated from healthy volunteers. INTERVENTIONS: Neutrophils were exposed to tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-8, their combination, endotoxin (LPS), lipoteichoic acid (LTA), and staphyloccocal enterotoxin B (SEB). Neutrophil deformability was measured as percent neutrophils filtered through 5-microm diameter filters. Aggregation was measured using a platelet aggregometer. Adherence was determined by examining the binding of neutrophils to albumin-coated latex beads. MEASUREMENTS AND MAIN RESULTS: Exposure to TNF-alpha and IL-1beta led to significant decreases in neutrophil filterability, which was attenuated by cytochalasin D pretreatment. LPS and LTA also decreased deformability, suggesting that these toxins directly stimulated neutrophils independent of cytokines. IL-8 and SEB did not significantly affect neutrophil deformability. TNF-alpha and LPS were associated with significant neutrophil aggregation, which was inhibited by pretreatment with anti-CD18 antibodies. Neutrophil aggregation was not affected by IL-1beta, LTA, or SEB. TNF-alpha, IL-8, and LPS increased neutrophil adherence, which also was attenuated by pretreatment with anti-CD18 antibodies. IL-1beta, LTA, and SEB did not significantly affect neutrophil adherence. CONCLUSIONS: Cytokines and bacterial toxins differ in their effects on neutrophil deformability, aggregation, and adherence. Of the cytokines examined, TNF-alpha appears to have the greatest direct effects on neutrophil rheology. Similarly, endotoxin appears to have greater direct effects on neutrophil rheology than the Gram-positive bacterial toxins, LTA, and staphylococcal enterotoxins. 相似文献
65.
Single-unit recordings were made in the intact anesthetized rat of the responses of dorsal horn neurons to C-, Adelta-, and Abeta-fiber stimulation. The postdischarge and windup responses of the same cells along with responses to innocuous stimuli, prod and brush, also were measured. The effects of (-)-bicuculline-methobromide (0.5, 5, 50, and 250 microg) were observed on these neuronal responses. The C- and Adelta-fiber-evoked responses were facilitated significantly in a dose-dependent manner. The input was facilitated, but as the final overall response was not increased by the same factor, windup appeared to be reduced. However, postdischarge, resulting from the increase in the excitability produced by windup, tended to be facilitated. After doses of >/=5 microg bicuculline, stimulation at suprathreshold Abeta-fiber-evoked activity caused enhanced firing, mainly at later latencies corresponding to Adelta-fiber-evoked activity in normal animals. Few cells responded consistently to brush and so no significant change was observed. Responses evoked by innocuous pressure (prod) always were observed in cells that concurrently responded to electrical stimulation with a C-fiber response. This tactile response was facilitated significantly by bicuculline. The effects of N6-cyclopentyladenosine (N6-CPA), an adenosine A1-receptor agonist, was observed after pretreatment with 50 microg bicuculline, as were the effects of morphine and 7-chlorokynurenate (7-CK). N6-CPA inhibited prod, C- and Adelta-fiber-evoked responses as well as the initial and overall final response to the train of C-fiber strength stimuli. Inhibitions were reversed with 8(p-sulphophenyl) theophylline. Morphine, the mu-receptor agonist, also inhibited the postbicuculline responses to prod, C-, and Adelta-fiber responses and initial and final responses to a train of stimuli. Inhibitory effects of morphine were reversed partly by naloxone. 7-CK, an antagonist at the glycine site on the N-methyl-D-aspartate-receptor complex, inhibited the responses to C- and Adelta-fiber-evoked activity as well as prod. The postdischarges were inhibited by this drug. Again both the initial and overall responses of the cell were inhibited. To conclude, bicuculline caused an increase in the responses of deep dorsal horn cells to prod, Adelta-fiber-evoked activity, increased C-fiber input onto these cells along with the appearance of responses at latencies normally associated with Adelta fibers, but evoked by suprathreshold Abeta-fiber stimulation. These alterations may be responsible for some aspects of the clinical phenomenon of allodynia and hyperalgesia. These altered and enhanced responses were modulated by the three separate classes of drugs, the order of effectiveness being 7-CK, N6-CPA, and then morphine. 相似文献
66.
OBJECTIVES: To determine whether oxytocin exists in the cerebrospinal fluid (CSF) of dogs and whether the amount of oxytocin in the CSF of dogs with neck or back pain caused by spinal cord compression is significantly different than that in the CSF of clinically normal dogs. STUDY DESIGN: Prospective controlled study. ANIMAL POPULATION: A total of 15 purpose-bred beagles and 17 client-owned dogs. METHODS: CSF was collected by needle puncture of the cerebellar medullary cistern after induction of general anesthesia. Oxytocin levels within the samples were determined through radioimmunoassay. RESULTS: Dogs with spinal cord compression had significantly more oxytocin in their CSF than the clinically normal dogs (13.76 +/- 2.0 pg/mL and 3.61 +/- 0.63 pg/mL, respectively; P < .0001). Dogs with chronic signs (>7 days) had significantly more oxytocin in their CSF than dogs with acute signs (<7 days) (21.60 +/- 0.86 pg/mL and 6.80 +/- 0.81 pg/mL, respectively; P < .0001). Both acutely and chronically affected dogs had significantly more oxytocin in their CSF than the controls (P < .005 and P < .0001 respectively). CONCLUSIONS: Dogs with neck and back pain caused by spinal cord compression have significantly more oxytocin in their CSF than clinically normal dogs. Dogs with chronic clinical signs have significantly more oxytocin in their CSF than dogs with acute clinical signs. CLINICAL RELEVANCE: In humans, intrathecal injection of oxytocin is effective in treating low back pain for up to 5 hours. Intrathecal oxytocin may be a logical choice for perioperative analgesia in dogs undergoing myelography because the intrathecal space is accessed for injection of contrast agent. 相似文献
67.
We report two patients where the finding of isolated fetal hydrocephalus led to the detection of severe fetal thrombocytopenia, using fetal blood sampling. Serological investigation led to the diagnosis of fetomaternal alloimmune thrombocytopenia (FMAIT) due to anti-HPA-1a. Both women had had previous unsuccessful pregnancies probably due to FMAIT; one had had four miscarriages at 17-18 weeks' gestation. The other had had one previous pregnancy complicated by severe fetal anaemia, and eventually hydrocephalus developed and the fetus died without the diagnosis of FMAIT being considered. Subsequent pregnancies in the two women were also affected by FMAIT, but prenatal treatment, predominantly with serial fetal platelet transfusions, resulted in a successful outcome in both cases. These observations suggest that FMAIT should be suspected if there is isolated fetal hydrocephalus, unexplained fetal anaemia, or recurrent miscarriages. The accurate diagnosis of FMAIT is important because recent advances in prenatal management can improve the outcome of subsequently affected pregnancies. 相似文献
68.
Zhang Q. Brown D.A. Kung H. Townsend J.E. Chen M. Reinhart L.J. Morse T.F. 《Electronics letters》1995,31(6):480-482
The authors present a technique for detecting Bragg wavelength shifts using highly overcoupled couplers (HOCC). An HOCC of 60%/nm was fabricated with 626 cycles. With our HOCC, a 5 μW LED and a 95% reflective Bragg grating we were able to detect 10 μstrain (Δλ=0.01 nm) 相似文献
69.
JC Meltzer V Sanders PC Grimm N Chiasson HJ Hoeltke KL Garrett AH Greenberg DM Nance 《Canadian Metallurgical Quarterly》1998,19(8-9):1351-1355
The application of nonradioactive RNA probes for Northern blotting offers the advantage of a rapid turn-around time for results without the loss of sensitivity for target mRNA detection. However, a problem that has impeded the widespread use of nonradioactive RNA probes for use in Northern blotting is the difficulty in stripping these probes from nylon membranes after hybridization. In this report we describe two protocols for stripping digoxigenin (Dig)-labeled RNA probes from nylon membranes. One protocol utilizes a phosphate-buffered formamide stripping solution to remove nonchemically modified (regular) RNA probes while the other method utilizes strippable probes that were produced with a chemically modified nucleotide (CTP) and removed by a specific stripping solution. This latter method was developed by Ambion Inc. and is called Strip-EZ. We also describe a protocol for the detection of two separate rat mRNAs using both biotin and digoxigenin-labeled RNA probes that does not require stripping the membrane after hybridization. Finally, we describe the use of another new labeling technology, called Chem-Link, that quickly and conveniently labels RNA for use in Northern blotting. 相似文献
70.
AH Kolk LF Kox J van Leeuwen S Kuijper HM Jansen 《Canadian Metallurgical Quarterly》1998,11(6):1222-1226
This study examines the diagnostic utility of the polymerase chain reaction (PCR) in 156 patients (five human immunodeficiency virus (HIV) seropositive) suspected of extrapulmonary tuberculosis. The results of PCR in 226 samples from 11 different sites were compared with the results of microscopy and culture. Positive culture results were predicted in 86% of samples by PCR but in only 31% by microscopy. Specificity of PCR was 92%. In cases with culture-proven tuberculosis, PCR identified all 11 microscopy positive cases and 19 of 24 (79%) of the microscopy-negative cases. In four patients, PCR excluded the diagnosis of tuberculosis in microscopy-positive samples, which were later shown to contain mycobacteria other than Mycobacterium tuberculosis or laboratory contaminants. In 20 patients (microscopy, PCR and culture negative) a trial of antituberculous drugs was given, but patients showed no improvement and treatment was stopped. In 17 patients, all culture negative (in nine PCR was positive, three of whom also had positive microscopy) the diagnosis was probable tuberculosis based on clinical findings and response to treatment. This polymerase chain reaction has a much higher sensitivity than microscopy and can facilitate therapeutic decisions for those with suspected extrapulmonary tuberculosis. 相似文献