首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   92篇
  免费   0篇
化学工业   23篇
建筑科学   5篇
矿业工程   1篇
能源动力   4篇
轻工业   26篇
无线电   3篇
一般工业技术   4篇
冶金工业   7篇
自动化技术   19篇
  2024年   1篇
  2022年   2篇
  2021年   3篇
  2020年   5篇
  2019年   4篇
  2018年   4篇
  2016年   1篇
  2015年   1篇
  2014年   1篇
  2013年   1篇
  2012年   2篇
  2011年   5篇
  2010年   6篇
  2009年   3篇
  2008年   6篇
  2007年   6篇
  2006年   6篇
  2005年   3篇
  2004年   2篇
  2003年   2篇
  2002年   1篇
  2000年   2篇
  1998年   4篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1992年   2篇
  1991年   1篇
  1987年   1篇
  1983年   3篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1973年   2篇
  1971年   1篇
排序方式: 共有92条查询结果,搜索用时 15 毫秒
1.
This paper presents a workplace study of triage work practices within an emergency department (ED). We examine the practices, procedures, and organization in which ED staff uses tools and technologies when coordinating the essential activity of assessing and sorting patients arriving at the ED. The paper provides in-depth empirical observations describing the situated work practices of triage work, and the complex collaborative nature of the triage process. We identify and conceptualize triage work practices as comprising patient trajectories, triage nurse activities, coordinative artefacts and exception handling; we also articulate how these four features of triage practices constitute and connect workflows, organize and re-organize time and space during the triage process. Finally we conceptualize these connections as an assessing and sorting mechanism in collaborative work. We argue that the complexities involved in this mechanism are a necessary asset of triage work, which calls for a reassessment of the concept of triage drift.  相似文献   
2.
Open Design is an emerging area of research that seeks to connect and extend the culture of making, social innovation, open-source software, and open-source hardware. A cornerstone for Open Design is to broaden participation in technology innovation by allowing people to use and contribute to publicly shared resources. Makerspaces are important access points to share and contribute to these resources. However, prior to entering the physical door of a makerspace, makerspaces’ social media presence serve as the ‘front door’ for Open Design activities. In this paper, we examine different ‘front doors’ of Open Design, asking: What are the characteristics that produce makerspaces’ social media presences, and how do these representations shape potential access to Open Design activities? We manually collected and qualitatively analyzed 500 public posts on the Facebook sites of five makerspaces in Copenhagen, Denmark. By choosing the same geographical area, we were able to explore the characteristics of makerspaces’ social media presences for the same potential population of Open Design participants. Our analysis identifies three main characteristics of makerspaces’ social media presence, which together shape access to Open Design activities, namely reach, transparency, and discourse. The display of these characteristics produce openness and availability in unique ways, and is constitutive for how Open Design activities are produced online. In this paper, we do not argue for or against specific social media representations. Instead, we argue that the specificities and differences between makerspaces’ social media presences in the same geographical region have the strength of producing different identities across spaces, allowing for a broader definition and potential participation in Open Design.  相似文献   
3.
Detecting the molecular targets of xenobiotic substances in vivo poses a considerable analytical challenge. Here, we describe the use of an NMR‐based tracer methodology for the instantaneous in vivo observation of sulfur(IV) action on cellular metabolism. Specifically, we find that glycolytic flux is directed towards sulfite adducts of dihydroxyacetone phosphate and pyruvate as off‐pathway intermediates that obstruct glycolytic flux. In particular, the pyruvate–sulfite association hinders the formation of downstream metabolites. The apparent in vivo association constant of pyruvate and sulfite agrees with the apparent inhibition constant of CO2 formation, thus supporting the importance of pyruvate interception in disturbing central metabolism and inhibiting NAD regeneration.  相似文献   
4.
De novo design and chemical synthesis of proteins and their mimics are central approaches for understanding protein folding and accessing proteins with novel functions. We have previously described carbohydrates as templates for the assembly of artificial proteins, so-called carboproteins. Here, we describe the preparation and structural studies of three alpha-helical bundle carboproteins, which were assembled from three different carbohydrate templates and one amphiphilic hexadecapeptide sequence. This heptad repeat peptide sequence has been reported to lead to 4-alpha-helix formation. The low resolution solution structures of the three carboproteins were analyzed by means of small-angle X-ray scattering (SAXS) and synchrotron radiation circular dichroism (SRCD). The ab initio SAXS data analysis revealed that all three carboproteins adopted an unexpected 3+1-helix folding topology in solution, while the free peptide formed a 3-helix bundle. This finding is consistent with the calculated alpha-helicities based on the SRCD data, which are 72 and 68 % for two of the carboproteins. The choice of template did not affect the overall folding topology (that is for the 3+1 helix bundle) the template did have a noticeable impact on the solution structure. This was particularly evident when comparing 4-helix carboprotein monomers with the 2x2-helix carboprotein dimer as the latter adopted a more compact conformation. Furthermore, the clear conformational differences observed between the two 4-helix (3+1) carboproteins based on D-altropyranoside and D-galactopyranoside support the notion that folding is affected by the template, and subtle variations in template distance-geometry design may be exploited to control the solution fold. In addition, the SRCD data show that template assembly significantly increases thermostability.  相似文献   
5.
Managerial Competences for ERP Journeys   总被引:2,自引:0,他引:2  
This paper investigates the managerial competences required for the complex interactions required to successfully integrate an Enterprise Resource Planning system into an organization—the ERP journey. A feature of the study (a five year longitudinal study of a Danish production company implementing SAP R/3) was the rise and fall of the ERP project managers. The study showed that different stages of the ERP journey required different competences from the managers. A manager with a certain competence mix might successfully oversee part of the ERP journey, but a different blend of competences was required to manage other parts. The paper concludes that a wide range of competences are required: personal, business and technical. The competence mix should be expected to vary through the journey, and is often too much to expect of one person.  相似文献   
6.
Current treatment of the remaining soil fines from soil wash is onerous and expensive, and therefore, in this work, we investigated the feasibility of electrodialytic remediation (EDR) as an alternative treatment. The study focuses on EDR efficiency as a function of current strength, liquid-to-solid-ratio (L/S), pH and time. We found out that during the experiments, Pb was easily dissolved by the acidification resulting from water splitting at the anion-exchange membrane. When higher currents and/or higher L/S ratios were applied, it was found that water splitting occurring at the cation-exchange membrane increased the pH, and this resulted in decreased remediation efficiency. It was shown that complete remediation of the soil-fines is possible, with the majority of the Pb being transported into the catholyte and precipitated at the cathode. Based on the results it is recommended that EDR is implemented using a number of reactors in series, where the initial reactor works at the highest possible removal rate, and the final reactor works at the target Pb-concentration.  相似文献   
7.
To enable a better characterization of pathophysiologic processes in colon and rectum, we have developed a perfusion technique for collection of soluble substances and cells from standardized intestinal segments. A tube with balloons attached to its outer wall was endoscopically introduced into the rectum and sigmoid colon, and its position ascertained fluoroscopically. The balloons delimited two segments, one in the sigmoid colon and one in the rectum. The segments were simultaneously perfused by a buffer at 37 degrees C. After a 30-min rinsing period, perfusate and cells were collected at 20-min intervals. Of 51 attempted perfusions, 45 were successfully completed. Recovered volumes equaled those infused. Leakage from the proximal intestine to the segments was negligible. In 18 healthy volunteers, the mean perfusate concentration from the rectal segment was 57.5 (27.5-120.2) mg/L for albumin, 1.3 (1.0-1.7) micrograms/L for eosinophil cationic protein, 5.1 (2.8-9.5) ng/L for prostaglandin E2, and 61.7 (41.7-89.1) micrograms/L for hyaluronan, and all values were lower in the sigmoid segment. Steady state conditions were achieved from the second perfusion period. The perfusate contained 4-80 x 10(4) cells, more than 95% of which were epithelial cells. The technique is safe, has a good subject compliance, and seems to be a valuable tool in investigations on quantitative release of soluble substances and cells in, e.g., colorectal inflammation.  相似文献   
8.
The role of lipid surfactants in toppings has been investigated. Based on low-resolution pNMR analysis it seems that part of the fat phase in toppings is present in a supercooled state induced by lipid-protein interactions. Upon reconstitution in cold water, protein is desorbed from the fat globule surface and dissolves into the water, thereby eliminating the protein-induced supercooling of the fat. Subsequently, spontaneous fat crystallization takes place which can be followed by pNMR measurements. These phenomena result in an increase in the viscosity of the reconstituted emulsion. The surfactants usually used in toppings (e.g. propylene glycol monostearate) act as destabilizing factors in the reconstituted topping emulsion, accelerating (i) protein desorption from the fat globule surface, and (ii) the crystallization rate of coalesced fat. The fat crystallization process seems to be important for the texture and foam stability of whipped toppings.  相似文献   
9.
Carrot homogenate contains a palmitoyl-CoA hydrolase. The enzyme was detected by spectrophotometric and radiochemical methods. The activation energy (Ea) for the reaction was determined to be 16700±2000 cal mol?1 with a Q10 of 1.8. The rate of reaction reaches its maximum at 45°C and ceases completely at 55°C. The inactivation energy was found to be 67000±11000 cal mol?1. A purification factor of 60 was obtained when polyvinylpyrolidone, polyethylene glycol, dithiothreitol and glycerol were used as stabilising agents, and the purification of palmitoyl-CoA hydrolase was carried out without delay. The method used successively, polyethylene glycol fractionation and DEAE-cellulose, hydroxylapatite and Ultrogel AcA 34 chromatography. Palmitoyl-CoA hydrolase has a molecular weight of 42000 daltons and a pI of 4.6. The role of this enzyme in the development of off-flavour in carrot has been discussed.  相似文献   
10.
Small diameter (<6 mm) vessel grafts still pose a challenge for scientists worldwide. Decellularised umbilical artery (dUA) remains promising as small diameter tissue engineered vascular graft (TEVG), yet their immunogenicity remains unknown. Herein, we evaluated the host immune responses, with a focus on the innate part, towards human dUA implantation in mice, and confirmed our findings in an ex vivo allogeneic human setup. Overall, we did not observe any differences in the number of circulating white blood cells nor the number of monocytes among three groups of mice (1) dUA patch; (2) Sham; and (3) Mock throughout the study (day −7 to 28). Likewise, we found no difference in systemic inflammatory and anti-inflammatory cytokine levels between groups. However, a massive local remodelling response with M2 macrophages were observed in the dUA at day 28, whereas M1 macrophages were less frequent. Moreover, human monocytes from allogeneic individuals were differentiated into macrophages and exposed to lyophilised dUA to maximize an eventual M1 response. Yet, dUA did not elicit any immediate M1 response as determined by the absence of CCR7 and CXCL10. Together this suggests that human dUA elicits a minimal pro-inflammatory response further supporting its use as a TEVG in an allogeneic setup.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号