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Cells employ proteins to perform metabolic functions and maintain active physiological state through charge transfer and energy conversion. These processes are carried out in a narrow space precisely and rapidly, which, no doubt, bring great difficulty for their detection and dissection. Fortunately, in recent years, the development and expansion of single-molecule technique in protein research make monitoring the dynamical changes of protein at single-molecule level a reality, which also provides a powerful tool for the further exploration of new phenomena and new mechanisms of life activities. This paper aims to summarize the working principle and essential achievements of single-molecule technique in protein research in recent five years. We focus on not only dissecting the difference of nanopores, atomic force microscope, scanning tunneling microscope, and optical tweezers technique, but also discussing the great significance of these single-molecule techniques in investigating intramolecular and intermolecular interactions, electron transport, and conformational changes. Finally, the opportunities and challenges of the single-molecule technique in protein research are discussed, which provide a new door for single-molecule protein research.  相似文献   
3.
Genetic science, animal exploitation, and the challenge for democracy   总被引:1,自引:0,他引:1  
As the debates over cloning and stem cell research indicate, issues raised by biotechnology combine research into the genetic sciences, perspectives and contexts articulated by the social sciences, and the ethical and anthropological concerns of philosophy. Consequently, I argue that intervening in the debates over biotechnology requires supra-disciplinary critical philosophy and social theory to illuminate the problems and their stakes. In addition, debates over cloning and stem cell research raise exceptionally important challenges to bioethics and a democratic politics of communication.
Steven BestEmail:
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4.
Plants have been among the most important objects for civilized cultures. Soon plants will be not only nutrients but will form the basis for the production and supply of many objects needed in daily life. The processing of plants requires further developed skills in order to satisfy the growing demands. The use of separated plant components, mainly of fractions with selected constituents led to a further development of the knowledge of extraction. Advanced understanding of the materials sciences and mechanization allowed establish extraction processes which warrant continuous production of products of high quality. This period of time marks the beginning of the phytotechnology as an independent scientific and technical discipline of plant extraction.  相似文献   
5.
In the recent past, society has become increasingly aware of the environmental impact of political and corporate action. Hence, several industrial sectors are currently undergoing a transition to more sustainable products and processes. Sustainable production processes for C2-C4 alcohols can help to decrease the environmental impacts of large downstream markets such as fuels and polymers. However, a reliable and consistent framework is needed for companies to further develop and commercialize these processes. Furthermore, standardized procedures for determining the sustainability of a process are essential in evaluating the environmental benefits.  相似文献   
6.
The biggest material flows induced by industry are realized in energy production. Coal, oil and gas as raw material streams are moved from their deposits to their further converting. From there product streams are branched out. However, the biggest material flow of this industry is waste CO2 mobilized by chemical conversion from fossil deposits and released into the atmosphere. A waste management is urgently needed to reduce the amount of this flow, to neutralize its effects on environment and to establish applications yielding a return. Natural backflow of CO2 from the atmosphere to the biosphere waits for completion by industrial methods in order to shift it to a dimension equalizing the finally unavoidable amount of waste CO2 flow into the atmosphere.  相似文献   
7.
A protocol for the analysis of the positional distribution of fatty acids (FA) in solid triacylglycerols (TAG) was developed using sn-1(3) selective alcoholysis catalyzed by immobilized Candida antarctica lipase B (CALB). One part by weight of solid fat and ten parts by weight of ethanol (99.5 %) were warmed to liquefy the fat. After adding 0.44 parts by weight of CALB, the mixture was shaken at 50 °C for 10 min then at 30 °C for 2.8 h. The recovery of 2-MAG after the 3-h transesterification reaction was ca. 85 % of the maximum theoretical yield (33 mol%), with the loss of 15 % attributable to the acyl migration from sn-2 to sn-1(3). The recovery was similar to that of the solvent-free alcoholysis of structured lipids, 1,3-dipalmitoyl, 2-oleoyl glycerol and 1,3-dioleoyl, 2-palmitoyl glycerol, conducted at 30 °C for 3 h. In contrast, the acyl migration from sn-1(3) to sn-2 was hardly observed. Because the detected acyl migration was only in the direction of sn-2 to sn-1(3), and not vice versa, it is proposed to determine the FA composition of the sn-2 position of TAG by the gas chromatographic analysis of 2-MAG fraction recovered from the enzymatic reaction mixture, and the FA composition of sn-1(3) position by a mass balance using the FA composition of TAG and of the sn-2 position as inputs. The procedure was successfully applied to palm oil and shea butter, and docosahexaenoic acid (DHA)-rich single cell oil from Aurantiochytrium sp. KH105 for the first time.  相似文献   
8.
Acetyl‐triacylglycerols (acetyl‐TAG) possess an sn‐3 acetate group, which confers useful chemical and physical properties to these unusual triacylglycerols (TAG). Current methods for quantification of acetyl‐TAG are time consuming and do not provide any information on the molecular species profile. Electrospray ionization mass spectrometry (ESI–MS)‐based methods can overcome these drawbacks. However, the ESI–MS signal intensity for TAG depends on the aliphatic chain length and unsaturation index of the molecule. Therefore response factors for different molecular species need to be determined before any quantification. The effects of the chain length and the number of double‐bonds of the sn‐1/2 acyl groups on the signal intensity for the neutral loss of short chain length sn‐3 groups were quantified using a series of synthesized sn‐3 specific structured TAG. The signal intensity for the neutral loss of the sn‐3 acyl group was found to negatively correlated with the aliphatic chain length and unsaturation index of the sn‐1/2 acyl groups. The signal intensity of the neutral loss of the sn‐3 acyl group was also negatively correlated with the size of that chain. Further, the position of the group undergoing neutral loss was also important, with the signal from an sn‐2 acyl group much lower than that from one located at sn‐3. Response factors obtained from these analyses were used to develop a method for the absolute quantification of acetyl‐TAG. The increased sensitivity of this ESI–MS‐based approach allowed successful quantification of acetyl‐TAG in various biological settings, including the products of in vitro enzyme activity assays.  相似文献   
9.
The development of new products has become increasingly critical for the competitiveness of companies, due to increased diversity and variety of products, the reduction of product life cycles, and, primarily, globalization of markets. Thus, the identification and prioritization of critical success factors for developing new products is important, particularly for the high degree of risk and uncertainty involved. The main objective of this article is the identification and prioritization of critical success factors in new product development projects in biotechnology companies in the state of Minas Gerais, Brazil. The research method used was a survey questionnaire, which was sent to a sample of 31 biotechnology companies in Minas Gerais state. The principal findings of this research are that interpersonal skills/relationships of the project leader and technical skills are the most critical factors for successful new product development in this industry. The implications for the biotechnology industry in general, as well as for those responsible for managing new product development, are discussed.  相似文献   
10.
A stepwise process design approach is proposed to model membrane unit operations generally in combination with experimental model parameter determination in laboratory scale, in order to predict the purification performance a priori by simulations for multicomponent mixtures. The development of a rigorous model for an ultrafiltration membrane is described. In conceptual process design, the degree of comprehension of all unit operations integrated have to be almost identical to be able of any consistent process proposal taking equipment‐related fluid‐dynamical and kinetic nonidealities besides thermodynamical feasibility into account. Therefore, a process model, combining the most limiting factors within one mathematical model, is established and various filtrations are carried out with a binary solution for validation. Additionally, a standard laboratory equipment is instituted for logging time‐dependent concentration profiles. The practicability of the proposed procedure is proven in order to design and integrate ultrafiltration membranes into total purification processes.  相似文献   
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