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991.
Igor Czar Pereira Pedro Ivo Vianello Denis Boing Gilmar Guimares Marcio Bacci da Silva 《The International Journal of Advanced Manufacturing Technology》2020,106(11):4891-4901
During internal threading, small alterations in cutting parameters, tool geometry, or process characteristics produce considerable effects on torque and te 相似文献
992.
Daniele de Almeida Paula Eduardo Basílio de Oliveira Alvaro Vianna Novaes de Carvalho Teixeira Ariana de Souza Soares Afonso Mota Ramos 《International Journal of Food Science & Technology》2018,53(2):475-483
This study addressed the correlation between physical characteristics of double emulsions and sensory perception, as the microstructure of these systems may provide the mechanism to understanding the initial cause of the altered salty taste. Thus, double emulsions (W/O/W) were prepared using different volumes of the internal aqueous phase while maintaining the same fat and sodium contents in the evaluated systems. Polyglycerol polyricinoleate (PGPR) and tween 80 were used as hydrophobic and hydrophilic emulsifiers, respectively. After preparation, the samples were stored at 25 °C for 4 days and submitted to analysis of optical microscopy, distribution and polydispersity of the oil droplets size, electrical conductivity, rheological behaviour and sensorial analysis. It was found that the use of different emulsifier concentrations (PGPR) did not influence the physical characteristics of the emulsions with the same formulation, but emulsions with different internal aqueous phase concentrations presented different results. These distinct characteristics may have influenced sensorial perception, as the emulsion with higher internal phase concentration was considered saltier. Thus, it can be concluded that structural differences of the double emulsions can be used to decrease the sodium contents without perceivable changes in salty taste. 相似文献
993.
Microbiological,physical and chemical characteristics of freshwater prawns (Macrobrachium rosenbergii) in modified‐atmosphere packaging 下载免费PDF全文
Julia S. Simoes Eliane T. Mársico César A. Lázaro Micheli da S. Ferreira Robson M. Franco Ana Paula A. A. S. Pereira Carlos A. Conte‐Junior 《International Journal of Food Science & Technology》2015,50(1):128-135
This study evaluated the influence of packaging atmosphere (air versus 50% N2/50% CO2) on microbiological (mesophiles, psychrotrophs), physical (gas measurement) and chemical (pH, total volatile basic nitrogen [TVB‐N], NH3, H2S and biogenic amines) parameters in freshwater prawns during storage at 0 ± 1 °C for 240 h. To select the most appropriate packaging, 21 batches of each treatment were analysed. Both the packaging permeability and the combination of gases affected the shelf life, but the modified‐atmosphere packaging (MAP) was more efficient than air packaging, increasing the shelf life by 40 h. The parameters of pH and TVB‐N showed no statistical difference between the two atmosphere conditions all along the storage period. The biogenic amine agmatine showed potential for use as a quality indicator due to the increased concentration during storage. In further studies, this amine can be applied as an indicator for public health issue. 相似文献
994.
Clara Lucía Contreras Barón Priscila Robertina dos Santos-Donado Patricia Maloso Ramos Carlos M. Donado-Pestana Eduardo Francisquine Delgado Carmen J. Contreras-Castillo 《International Journal of Food Science & Technology》2021,56(7):3333-3343
Ultimate pH (pHu) is an indicator that influences post-mortem meat quality. We studied physiological and biochemical changes of steaks obtained from Nellore bulls (Bos indicus) during post-mortem ageing. To this, Longissimus lumborum (LL) muscles were classified into three groups: Normal-pHu (≤5.79), Intermediate-pHu (5.80–6.29) and High-pHu (≥6.30) groups, portioned into steaks, vacuum packaged and matured at 2 °C for 0, 7, 14, 21 and 28 days. High-pHu steaks exhibited impaired colour stability and were darker compared to the other groups. High- and Normal-pHu steaks showed improved tenderness and myofibrillar fragmentation linked to proteolysis. Intermediate-pHu steaks were associated with a lower meat tenderness and decreased collagen solubility. High-pHu steaks retained a high pH during ageing and increased water-holding capacity. These findings provide evidence that highlight pHu as a strategy for the classification of pHu-dependent beef quality from Nellore bulls that can be adopted by the Brazilian meat industry. 相似文献
995.
996.
V.G. de Resende E. De Grave G.M. da Costa J. Janssens 《Journal of Alloys and Compounds》2007,440(1-2):236-247
Amorphous Fe–B alloys can be prepared at room temperature by reduction with borohydride of iron-oxide particles in suspension. By varying the borohydride concentration, amorphous Fe–B alloys with boron contents between 2 and 13 at.% have been produced by reduction of synthetic (nano-sized particles) and natural (micro-sized) hematite (α-Fe2O3) using sodium borohydride (NaBH4). The results presented in this paper were obtained from a systematic study of the effect of borohydride concentration on the resulting reaction products using a variety of experimental techniques, such as X-ray diffraction, wet chemical analyses, thermal analyses, scanning electron microscopy, transmission Mössbauer spectroscopy (TMS) and integral low-energy electron Mössbauer spectroscopy (ILEEMS). Three distinct NaBH4 concentrations have been applied. Beside unreacted hematite, amorphous Fe1−xBx alloys have been identified from the TMS spectra recorded at various temperatures between 15 K and room temperature. The amount of Fe1−xBx increases strongly with increasing NaBH4 concentration, and for a given concentration with increasing specific surface area (SSA). Thermal analyses have suggested that for any given reduction condition, the boron content x in the formed amorphous alloy has a bimodal distribution. This is found to be consistent with the finding that the contribution of the Fe1−xBx phase to the total Mössbauer spectra consists of a superposition of a broad sextet and doublet. ILEEMS has further revealed that especially the surface layers of the hematite grains are affected by the reduction processes. 相似文献
997.
P Zielinsky MH da Costa LT Oliveira FP Bonow NI da Silva LL Hagemann 《Canadian Metallurgical Quarterly》1997,69(6):389-394
This work is devoted to the study of polarographic reduction of three antibiotic compounds including adriamycin, chloramphenicol and erythromycin and of a synthetic antibacterial chemotherapeutic compound--5-nitrofurantoin. The polarographic reduction was performed in the strictly anhydrous N,N-dimethylformamide with or without alpha-lipoic acid (LA) by the means of DC polarography. The values of half-wave potentials E1/2 and parameter of potential carcinogenicity were determined for the all compounds. Adriamycin was reduced during the five-step process, other compounds were reduced in two steps. The presence of LA in a polarographic solution resulted in a new polarographic one-electron wave in the range of -1.120 V to -1.790 V vs. SCE possessing a diffuse and reversible character. Its height is linearly dependent on the LA concentration in solution. The highest parameter of potential carcinogenicity tg alpha was determined for adriamycin (0.575) which belongs among compounds classified by WHO as "probably carcinogenic to humans". The lowest determined value of parameter tg alpha belonged to 5-nitrofurantoin (0.290) which has not yet been included into the IARC classification. 相似文献
998.
L Clemente Ramos FJ Burgos Revilla E Fernández Fernández M Jiménez Cidre N Cruz Guerra A Escudero Barrilero 《Canadian Metallurgical Quarterly》1997,50(7):773-780
Heat shock (HS) proteins (HSP) function as molecular chaperones and protect cells from thermal and oxidative injury. The signals leading to HSP synthesis, i.e. the "cellular thermometer(s)," are still a matter of debate. In the human premonocytic line U937, we investigated the effects of specific modification of membrane fatty acid (FA) composition by incubation with various saturated and unsaturated fatty acids (UFA) on the HS response and on hydrogen peroxide (H2O2)-induced cell death. FA readily incorporated into U937 cell membranes. UFA did not modulate the HS response but potentiated H2O2-mediated damage, while pre-exposure to HS protected the UFA-treated cells from this increased H2O2 toxicity. 相似文献
999.
OBJECTIVES AND DESIGN: A prospective study of 709 patients undergoing carotid surgery in the U.K. and Ireland was performed to evaluate the performance of vascular surgeons. MATERIALS AND METHODS: Fifty-nine surgeons (range 2-39 cases each) were sampled and all patients undergoing surgery over a 6-month period (1 March 1994-31 August 1994) were included in the study. Indications for surgery were TIA (35.9%), AF (23.3%), CVA (21.4%) and "others" (19.6%). RESULTS: Mean ipsilateral stenosis was 82% (30%-99%). Thirty-one percent of patients had preoperative neurological consults. Shunts were used in 67.6%, tacking sutures in 40.1%, drains in 71.9% and patches in 54.4% of cases. At 30 days there were nine (1.3%) deaths (four cardiac, three neurological). There were 15 ipsilateral postoperative CVAs (2.1%); 19% of patients had one or more complication, usually minor. Statistical analysis showed no independent risk factor for CVA other than seniority of the surgeon. CONCLUSIONS: A combined stroke/death rate of 3% for the series was obtained at 30 days for all cases. This large, validated study suggests that members of the Vascular Society of G.B. and Ireland currently have a very low morbidity/mortality rate for performing carotid surgery. Continued audit is required to ensure that this quality of service does not deteriorate. 相似文献
1000.
Nattane Luíza da Costa Laura Andrea García Llobodanin Inar Alves Castro Rommel Barbosa 《Expert Systems》2019,36(2)
The identity of the Carménère variety was lost in Chile and regarded as a Merlot grape. This grape disappeared in Bordeaux, France, the country of origin of the grape, because of the phylloxera plague. In the present paper, a study on the classification of Chilean Carménère and Merlot wine samples based on chemical parameters was carried out. A total of 64 samples were analysed, and 20 chemical parameters were determined. Forty‐five samples were labelled as “Carménère” and 19 samples as “Merlot” according to the wine label. The samples were preprocessed with sampling algorithms to double the number of Merlot samples to 38 and reduce the Carménère samples to 38. The dataset was analysed with the data mining techniques support vector machines and correlation‐based feature selection. The capability of classifying the samples with all 20 chemical parameters was 86.8% accurate, and when using only the variables a*, total anthocyanins, cyan‐3‐glu, malv‐3‐acetylglu, peon‐3‐acetylglu, and vitisin A, which were selected through correlation‐based feature selection, accuracy increased to 93.4%. Therefore, wine anthocyanins and the parameter a* of wine colour proved useful to discriminate the wines. 相似文献