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For centuries, the continuous development of science and technology has greatly promoted the process of mankind's understanding and utilization of nature, and at the same time strongly enhanced exchanges and cooperation between various nationalities and different civilizations. In the modern era, science and technology are developing vigorously and changing with each passing day. Strengthening international scientific cooperation is invaluable in helping  相似文献   

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Direct absorption of light by glycosides dissolved in water has been discovered to produce changes in optical activities and formation of material which reduces the Shaffer, Hartmann, Somogyi reagent. Comparison of these measurements indicates in many cases the same products as are formed by hydrolysis in acid. The β glucosides and α fructoside, however, apparently give optically inactive photolytic products.Absorption spectra were obtained for α benzylfructofuranoside and β benzylfructopyranoside, and were found to be the same in the near ultraviolet as those previously obtained for benzyl glucosides and benzyl alcohol.The absorption spectrum for freshly purified fructose gives a deeper minimum about λ240 mμ than the previously reported values. The latter, however, were approached when the dry crystals had stood in air for several months although no change occurred in their sp.rot., m.p. or general apperance.All the glycosides studied were white crystalline compounds. Less than five per cent. of the ultraviolet light of λ254 mμ they absorb produces reaction; nevertheless, the apparatus and procedures available were adequate to study the reaction conveniently in monochromatic light of this wave-length.The absorption spectra, the products of photolysis, and the quantum yields, the latter based on the reducing material formed, lead to the hypothesis that the photochemical reaction is produced by an intramolecular transfer of absorbed energy from the aglycone to the hemiacetal oxygen bridge which is the reactive center. The efficiency of this transfer is, as expected, greater for benzyl than for phenylethyl glucosides but phenyl glucosides, contrariwise, are the least efficient.The structure and energy possessed by the glycoside outside the aglycone have no measurable effect on the efficiency of the photochemical reaction when followed by measuring the reducing material produced although they change up to one hundred thousand fold the rates of the thermal hydrolyses in acid.  相似文献   

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This is the case in which the court in Shanghai has es- tablished the very first well-kown mark since the amended Trademark Law entered into force in 2001.On 31 December 2005,the Shanghai No.2 Intermediate People's Court ren- dered the ruling of first instance,establishing that the"STARBUCKS"and"星巴克"(the Chinese translation of"STARBUCKS"pronounced as"xingbake") trademarks as well-known marks and deciding that the defendant's act con- stituted trademark infringement and unfair competition.Dis- satisfied with the ruling the defendants appealed to the Shanghai Higher People's Court,which made the ruling to have upheld the former ruling.In this article an in-depth study is presented of the establishment of the well-known marks in suit and the decision on the trademark infringement and unfair competition and on the amount of damages.  相似文献   

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At all times and in all countries of the world, people have been fascinated by obtaining deeper insights into life and have eagerly absorbed new knowledge from around the globe. Thus in addition to trade, the sciences early on became one of the most fruitful areas of worldwide exchange and international communication. Today, it is still often the sciences that bridge national and cultural differences between countries. The Chinese Academy of Sciences and the Max Planck Society can proudly look back on  相似文献   

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The Max Planck Society and the Chinese Academy of Sciences have been cooperating very successfully for 30 years. With their innovative collaboration, they have contributed considerably to intensifying bilateral relations and to the progress of science in both countries. An essential aspect of such efficient cooperation is creativity. In this context creativity means now and then following paths which deviate from the norm, departing from established patterns. Individual scientists who achieve creative results fulfil these essential criteria: They command a profound knowledge of their own discipline as well as possessing enormous curiosity.  相似文献   

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BackgroundXylanases and β-d-xylosidases are the most important enzymes responsible for the degradation of xylan, the second main constituent of plant cell walls.ResultsIn this study, the main extracellular xylanase (XYL I) and β-xylosidase (BXYL I) from the fungus Penicillium janczewskii were purified, characterized and applied for the hydrolysis of different substrates. Their molecular weights under denaturing and non-denaturing conditions were, respectively, 30.4 and 23.6 kDa for XYL I, and 100 and 200 kDa for BXYL I, indicating that the latter is homodimeric. XYL I is highly glycosylated (78%) with optimal activity in pH 6.0 at 65°C, while BXYL I presented lower sugar content (10.5%) and optimal activity in pH 5.0 at 75°C. The half-lives of XYL I at 55, 60 and 65°C were 125, 16 and 6 min, respectively. At 60°C, BXYL I retained almost 100% of the activity after 6 h. NH4+, Na+, DTT and β-mercaptoethanol stimulated XYL I, while activation of BXYL I was not observed. Interestingly, XYL I was only partially inhibited by Hg2 +, while BXYL I was completely inhibited. Xylobiose, xylotriose and larger xylooligosaccharides were the main products from xylan hydrolysis by XYL I. BXYL I hydrolyzed xylobiose and larger xylooligosaccharides with no activity against xylans.ConclusionThe enzymes act synergistically in the degradation of xylans, and present industrial characteristics especially in relation to optimal activity at high temperatures, prolonged stability of BXYL I at 60°C, and stability of XYL I in wide pH range.  相似文献   

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I.TheTragediesofShakespeare1.1.AnAnalysisoftherolesinShakespeare’stragediesTake“Hamlet”asexamples:Hamletisaboutanemotionallyscarredyoungmantryingtoavengethemurderofhisfather,theking.TheghostofHamlet'sfatherappearstoHamlet,tellinghimthathewasmurderedbyhisbrother,Claudius,whohasnowbecometheking.ClaudiushasalsomarriedGertrude,theoldking'swidowandHamlet'smother.Hamletisappalledbyhismother'sactionsandbywhattheghosttellshimaboutClaudius'scold-bloodedmurderofhisownbrother.Tobuytimetoplothisr…  相似文献   

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Economics-related ICT research has moved from the fringes of the discipline to penetrate all of its branches. It is, therefore, not a separate economics subdiscipline. It is also unlikely to become part of an “ICT or Internet research” proto-discipline. Instead, it should be seen as only one part of a bigger agenda toward a proper “information and knowledge economics” and possibly a future proto-discipline of a “unified theory of information and knowledge” or a meta-discipline of information sciences.  相似文献   

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On the occasion of the 30th anniversary of the establishment of cooperation between the Chinese Academy of Sciences and the Max Planck Society for the Advancement of Science, 1 hope that the scientific and technological cooperation between the two organizations can be continu-  相似文献   

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针对1988--2010年期间全球风能产业不同动态发展阶段及其演化动力进行分析。早期,丹麦和美国加州的风能产业发展主要依靠风力等自然资源禀赋;随着德国风能接入法等公共政策领域的创新,进一步推动了全球风能产业发展;以美国、西班牙、印度等为代表的新一轮全球风机产业发展越来越受到公共政策创新和产业技术能力双重动力的影响。对于中国风能产业发展的主要启示是:有利于风机整体产业发展的公共政策学习和创新、技术引进和不断增强的制造能力。针对国情的公共政策创新、良好的产业生态组织和培育自主创新能力是未来风能产业可持续发展的方向。  相似文献   

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A review is presented of the present status of the theory, the developed technology and the current applications of dielectrophoresis (DEP). Over the past 10 years around 2000 publications have addressed these three aspects, and current trends suggest that the theory and technology have matured sufficiently for most effort to now be directed towards applying DEP to unmet needs in such areas as biosensors, cell therapeutics, drug discovery, medical diagnostics, microfluidics, nanoassembly, and particle filtration. The dipole approximation to describe the DEP force acting on a particle subjected to a nonuniform electric field has evolved to include multipole contributions, the perturbing effects arising from interactions with other cells and boundary surfaces, and the influence of electrical double-layer polarizations that must be considered for nanoparticles. Theoretical modelling of the electric field gradients generated by different electrode designs has also reached an advanced state. Advances in the technology include the development of sophisticated electrode designs, along with the introduction of new materials (e.g., silicone polymers, dry film resist) and methods for fabricating the electrodes and microfluidics of DEP devices (photo and electron beam lithography, laser ablation, thin film techniques, CMOS technology). Around three-quarters of the 300 or so scientific publications now being published each year on DEP are directed towards practical applications, and this is matched with an increasing number of patent applications. A summary of the US patents granted since January 2005 is given, along with an outline of the small number of perceived industrial applications (e.g., mineral separation, micropolishing, manipulation and dispensing of fluid droplets, manipulation and assembly of micro components). The technology has also advanced sufficiently for DEP to be used as a tool to manipulate nanoparticles (e.g., carbon nanotubes, nano wires, gold and metal oxide nanoparticles) for the fabrication of devices and sensors. Most efforts are now being directed towards biomedical applications, such as the spatial manipulation and selective separation∕enrichment of target cells or bacteria, high-throughput molecular screening, biosensors, immunoassays, and the artificial engineering of three-dimensional cell constructs. DEP is able to manipulate and sort cells without the need for biochemical labels or other bioengineered tags, and without contact to any surfaces. This opens up potentially important applications of DEP as a tool to address an unmet need in stem cell research and therapy.  相似文献   

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This article asks whether the global process of digitization has led to noteworthy changes in the shares of the amount of text, images, audio, and video in worldwide technologically stored and communicated information content. We empirically quantify the amount of information that is globally broadcast, telecommunicated, and stored (1986–2007) and assess the evolution of the respective content shares. Somewhat unexpectedly, it turns out that the transfer from analog to digital has not led to toward increasing shares of media-rich audio and video content, despite vastly increased bandwidth. First, there is a certain inertia in the evolution of content, which seems to stick to stable proportions independent of its technological medium (be it analog vinyl and VHS tapes, or digital CDs and hard disks). Second, the relative share of text and still images actually captures a larger portion of the total amount than before the digital age. Text merely represented 0.3% of the (optimally compressed) bits that flowed through global information channels in 1986 but grew to almost 30% in 2007. On another level, we are seeing an increasing transition of text and images from one-way information diffusion networks (like newspapers) to digital storage and two-way telecommunications networks, where they are more socially embedded. Both tendencies are good news for big-data analysts who extract intelligence from easily analyzable text and image data.  相似文献   

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《Research Policy》2019,48(9):103798
This study adds to the product innovation literature by emphasizing the important yet understudied role of price distribution in shaping product demography (i.e. new product introductions and exits). While prior research has focused on market niches in the technological and geographic spaces in order to explain product demography, price space has received very limited attention despite the important role of price in the market. We posit that product dynamics are largely shaped by the existing price distribution. More specifically, we argue that local density in price space determines both the likelihood of existing products exiting the market and the rate of new products entering it. Analyzing product exit and entry in the U.S. workstation industry from 1980 to 1996, we find that while price density increases an existing product’s exit rate, new products are also more likely to enter the niches where the price density is high. We also draw attention to internal price density within multiproduct firms, analyzing a product’s price distance from the other products launched by the same firm. We find that this type of internal price density decreases both existing products’ exit rate and new products’ entry likelihood. Our emphasis on price space contributes to the literature on product innovation and demography.  相似文献   

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《Endeavour》1987,11(2):88-93
James Hutton's theory of the decay and renewal of continents and of the infinite time required for a cycle to be completed, met with a mixed reception two centuries ago. He was obliged to collect further evidence from rock outcrops and was able to demonstrate conclusively that the Earth is a machine fired by heat and that the cycle of decay and renewal is repeated.  相似文献   

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