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81.
82.
Monika Haros Nils-Gunnar Carlsson Annette Almgren Marie Larsson-Alminger Ann-Sofie Sandberg Thomas Andlid 《International journal of food microbiology》2009,135(1):7-14
The growing awareness of the relationship between diet and health has led to an increasing demand for food products that support health above and beyond providing basic nutrition. Probiotics are live organisms present in foods, which yield health benefits related to their interactions with the gastrointestinal tract. Phytases are a subgroup of phosphatases that catalyse the desphosphorylation of phytate, which reduces its negative impact on mineral bioavailability, and generates lower inositol phosphates. The aims of this investigation were to (i) study the ability of the probiotic candidate Bifidobacterium pseudocatenulatum to degrade phytate in synthetic medium, to (ii) identify the lower inositol phosphates generated, to (iii) study its survival under conditions mimicking gastrointestinal passage and finally to (iv) assess adhesion of the bacteria to Caco-2 cells. The first steps of InsP6 degradation by B. pseudocatenulatum phytate-degrading enzyme/s were preferentially initiated at the DL-6-position and 5-position of the myo-inositol ring. It suggests that the main InsP6 degradation pathway by B. pseudocatenulatum by sequential removal of phosphate groups was D/L-Ins(1,2,3,4,5)P5 or D/L-Ins(1,2,3,4,6)P5; D/L-Ins(1,2,3,4)P4; to finally Ins(1,2,3)P3 and D/L-Ins(1,2,4)P3/D/L-Ins(1,3,4)P3. This human strain also showed a notable tolerance to bile as well as a selective adhesion capacity (adhesion to control surfaces was zero), to human intestinal Caco-2 cells comparable to the commercial probiotic B. lactis. The phytate-degrading activity constitutes a novel metabolic trait which could contribute to the improvement of mineral absorption in the intestine as a nutritional probiotic feature with potential trophic effect in human gut. 相似文献
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84.
We estimate firms’ probability of technological adoption based on a firm level panel data set from four major sectors in Sweden between 2000 and 2003. Technological adoption is measured by environmental protection investments (EPI), and we focus particularly on differences between the decisions to adopt end of pipe solutions and clean technologies. We find that there seem to be different drivers for investments in end of pipe solutions and clean technologies, in particular we show that the probability of a firm investing in clean technologies to reduce emissions to air increases if the firm has expenditures for R&D related to environmental protection (green R&D), while price on energy is important for the investment in end of pipe solutions. Furthermore, our results indicate complementarity between the two types of technologies. 相似文献
85.
Henrik C.J. Linderoth 《Automation in Construction》2010,19(1):66-72
There has been a considerable time lag between the emergence of visionary expectations of BIM's (Building Information Models) transformative potential in the architecture, engineering and construction industry, and the deployment of the technology in the industry's daily practice. By viewing adoption and use of BIM as the inter-linkage of actors forming a building and construction project, the aim of the paper is to uncover mechanisms facilitating and constraining the creation of actor networks in which BIM is adopted and used. The aim is pursued by a case study in a major Swedish construction company. It is concluded that the possibility of incremental implementation of BIM applications is well aligned with the character of the industrial context. But the context can also constrain the use of applications requiring more long term thinking. However, because of the disruptive nature of building and construction projects, the challenge is to maintain and re-establish the network in which BIM is used in consecutive projects. When clients and regulating bodies recognize benefits from BIM usage, the main obstacle created by these characteristics of the industry will diminish. 相似文献
86.
Cord Henrik Surberg Paul Stratton Klaus Lingenhöle 《BHM Berg- und Hüttenm?nnische Monatshefte》2010,155(9):425-429
For a tool steel AISI D2 (1.2379) and a case hardening steel (1.7131) the opportunity of reduction processing time and improvements of final properties and dimensional stability using deep cold treatments were investigated. Hardened blocks were subjected to various combinations of single and multiple tempering steps (520 °C and 540 °C for 1.2379 and 180 °C for 1.7131 respectively) and short- as well as long-time deep cold treatments (-90 °C, -120 °C and -150 °C). The greatest dimensional stability was achieved by deep cold treatments at the lowest temperature (-150 °C) and was independent of the deep cold treatment time. 相似文献
87.
Henrik Kragh Sørensen 《Centaurus; international magazine of the history of science and medicine》2010,52(1):38-72
During the first half of the nineteenth century, mathematical analysis underwent a transition from a predominantly formula-centred practice to a more concept-centred one. Central to this development was the reorientation of analysis originating in A ugustin- L ouis C auchy's (1789–1857) treatment of infinite series in his Cours d'analyse . In this work, C auchy set out to rigorize analysis, thereby critically examining and reproving central analytical results. One of C auchy's first and most ardent followers was the Norwegian N iels H enrik A bel (1802–1829) who vowed to shed some light on the vast darkness in analysis.
This paper investigates some important aspects of A bel's contribution to the reorientation in analysis. In particular, it stresses the role for critical revision in the process of rigorization. By critically examining past practice, the new practice sought to explain the relative success of the previous—now outdated—approach. This is illustrated by discussing a number of issues related to A bel's new proof of the binomial theorem (1826) including his reactions to the exception that he encountered to one of the central theorems of C auchy's theory.
Following this discussion, the formation of new concepts as the result of critical revisions is illustrated by analysing the early history of the concept of absolute convergence. Thereby, it is shown how a new concept was distilled, investigated, put to use and eventually superseded. 相似文献
This paper investigates some important aspects of A bel's contribution to the reorientation in analysis. In particular, it stresses the role for critical revision in the process of rigorization. By critically examining past practice, the new practice sought to explain the relative success of the previous—now outdated—approach. This is illustrated by discussing a number of issues related to A bel's new proof of the binomial theorem (1826) including his reactions to the exception that he encountered to one of the central theorems of C auchy's theory.
Following this discussion, the formation of new concepts as the result of critical revisions is illustrated by analysing the early history of the concept of absolute convergence. Thereby, it is shown how a new concept was distilled, investigated, put to use and eventually superseded. 相似文献
88.
Population data and apparent prevalence data from the Salmonella surveillance and control program in pigs (NSSCP) from 1998 and 1999 were used in a simulation model to evaluate the efficacy of the program. The model consists of three parts: modelling of individual prevalence at the abattoir (abattoir part), modelling of the number of sampled herds of different sizes when carcasses are randomly sampled at the abattoir (sampling strategy part) and finally, modelling of the within herd prevalence (within herd part). A total of 136,550 sows and 2,866,550 finishing pigs slaughtered, 4446 herds and 11 herds positive for Salmonella in 1994/1995-2000 were included in the abattoir part, sampling strategy part and the within herd part of the model, respectively. The abattoir part showed an average estimated prevalence of Salmonella in sows and finishing pigs of (median) 0.4% (5-95 percentiles = 0.03-2%) and 0.1% (0.04-0.2%) respectively. The estimated number of infected sow carcasses that entered the market was 502 (37-2157) while the estimated number of finishing pig carcasses was 2919 (1218-5771). The probability of being sampled for the 10% smallest herds was (mean) 1.9% (1.6-2.2), to 25% (24.7-26.5%) for the 10% largest herds. The within herd prevalence was estimated to be from 1% to 4% for Norwegian pig herds. The conclusions drawn from this evaluation are that the NSSCP does not have any significant consumer protection effect, and that the documentation could be done more effectively using the herd rather than the individual animal as the unit of sampling. Sampling should focus on the larger herds supplying most of the meat on the market and on herds that produce breeding sows and piglets and thus can contribute to the spread of Salmonella among herds. 相似文献
89.
Determination of estrogens in sludge and sediments by liquid extraction and GC/MS/MS 总被引:11,自引:0,他引:11
Two methods have been developed that enable the determination of estrogens down to 2 ng/g in digested and activated sludge from domestic sewage treatment plants (STPs) and down to 0.2 ng/g in freshwater sediments. The method for sludge analysis consists of solvent extraction; a gel permeation chromatography (GPC) cleanup step, a 1 g silica gel column; and finally, detection by GC-ion trap MS/MS of the silylated estrogens with MSTFA. For sediments, the solvent extraction was successively followed by silica gel cleanup, solid phase enrichment (SPE), and a HPLC cleanup before derivatization and GC/MS/MS detection. Mean recoveries of the estrogens mainly exceeded 70% in sludge and 90% in sediments. In activated and digested sewage sludge, estrone and 17beta-estradiol were detected up to 37 ng/g and 49 ng/g, respectively, and 17alpha-ethinylestradiol up to 17 ng/g. The occurrence of estrogens in digested sludge indicates that estrogens can be persistent during sludge digestion. In river sediments, estrone and 17beta-estradiol were detected up to 2 ng/g (estrone), and the contraceptive 17alpha-ethinylestradiol was found with a maximum of 0.9 ng/g. Mestranol, a prodrug for 17alpha-ethinylestradiol, was not detected either in sludge or in sediments. 相似文献
90.
A realtime online learning system with capacity limits needs to gradually forget old information in order to avoid catastrophic forgetting. This can be achieved by allowing new information to overwrite old, as in a so-called palimpsest memory. This paper describes an incremental learning rule based on the Bayesian confidence propagation neural network that has palimpsest properties when employed in an attractor neural network. The network does not suffer from catastrophic forgetting, has a capacity dependent on the learning time constant and exhibits faster convergence for newer patterns. 相似文献