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161.
能源话题主导了2005年的新闻,紧跟着这些热点新闻报道之后而来的,是猛增的风险投资。分析风险投资进入的力度以及领域可以把握未来清洁能源领域发展的趋势。[编按]  相似文献   
162.
The forthcoming introduction of lower standards for arsenic in drinking water requires new technologies for arsenic removal. We report the development of an electrochemical unit for remediating domestic water supplies for homes without municipally treated water. Electrolysis in a two‐anode system provides oxidants to convert As(III) to As(V) in situ, and a sacrificial anode to deliver iron into solution. Conditioning tanks after each electrolysis step ensure completion of the chemical reactions. At the pH of domestic water, As(V) co‐precipitates with Fe(OH)3; subsequent filtration leaves <10 ppb of inorganic arsenic in solution.  相似文献   
163.
A sustained delivery system for interleukin-1 receptor antagonist (IL-1Ra) may have great therapeutic and industrial potential due to the cytokine activity as an IL-1 inhibitor. Here, we investigated the capability of biodegradable polymeric microspheres to sustain the release and prolong the therapeutic efficacy of IL-1Ra. IL-1Ra was encapsulated within rapidly degrading poly(lactic/glycolic acid) PLGA RG502H microspheres, which showed a desirable release profile of IL-1Ra in vitro. Pharmacokinetic study in mice revealed elevated serum levels of the recombinant IL-1Ra (rIL-1Ra) for up to 8 days following subcutaneous injection of IL-1Ra microspheres. In comparison, the serum levels of rIL-1Ra following subcutaneous or intravenous bolus injection of the soluble cytokine decreased very rapidly; within 48 h no recombinant cytokine was detected in mice sera. The sustained delivery of rIL-1Ra for over two weeks was efficient in inhibiting IL-1ß-stimulated induction of serum IL-6. These results suggest that the present therapeutic protocol of daily bolus injections of the IL-1Ra may be replaced by a weekly injection of IL-1Ra within PLGA RG502H microspheres.  相似文献   
164.
A new Data Link Layer protocol, named the Twin-Bus-Controller (TBC) protocol, is proposed for a fibre optic network with unidirectional bus topology. The TBC protocol operates on a contention-based, time-division multiplexing scheme, and is managed by two centralized bus controllers. These controllers, which also function as network managers cooperate with each other to control and coordinate the activities on the twin bus. The IBC protocol has the capability to perform at a very high network utilization, and uses simple hardware at all stations except the two bus controllers. This arrangement provides a relatively inexpensive means to accommodate a large number of stations. Heterogeneous data consisting of real-time sensor and control signals, voice and video data, and non-real-time data such as those due to accounting and administration, can be simultaneously handled by the TBC protocol. The TBC protocol maintains global queues for all different types of data, and each class of data has a bounded delay. Furthermore, any new type of data can be added easily to the network without shutting it down or affecting those stations that are unrelated to the new data. A finite-state-machine model has been used to describe the TBC protocol. Performance of the TBC protocol has been evaluated by statistical analysis as well as via simulation for multiple classes of data traffic. Performance of the TBC protocol has been compared with that of Buzznet and Fasnet. The TBC protocol can be directly applied to diverse computer communication systems, e.g. office, manufacturing, and banking environments.  相似文献   
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回旋加速器制备放射性氯化亚铊(~(201)Tl)注射液   总被引:1,自引:0,他引:1  
本文叙述制备放射性氯化亚铊(~(201)Tl)注射液的方法。靶子为高纯金属铊片,装于具有水冷、气冷腔的2π靶室内,利用扇形聚焦回旋加速器所产生的30MeV质子进行辐照。靶片溶解后,联合使用液-液萃取和阴离子交换法进行化学处理,可同时获得无载体~(203)Pb。产品~(201)Tl核纯度大于99%(~(200)Tl~0.76%,~(202)Tl~0.04%),放化纯度大于98%,含铊量小于0.27×10~(-7)μg/Bq(1.0μg/mCi)~(201)Tl。化学杂质Fe、Al等均小于1ppm,~(201)Tl厚靶产额约为18.8MBq/μAh。产品经临床前药理试验、药检试验和临床试用,质量良好。  相似文献   
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BACKGROUND: The traditional guava variety cultivated in Israel, ‘Ben Dov’, emits a very strong odour, whereas some newly bred varieties have a mild odour. In this study the aroma profile composition of the high‐aromatic ‘Ben Dov’ variety was compared with those of four new low‐aromatic varieties. RESULTS: Overall, using gas chromatography/mass spectrometry, a total of 30 aroma volatiles were detected in fresh ripe guava fruit: 15 of them were specifically detected only in the high‐aromatic ‘Ben Dov’ variety, 13 were detected in both the high‐ and low‐aromatic varieties and two were detected only in the new low‐aromatic varieties. Interestingly, 11 out of the 15 volatiles specifically detected in ‘Ben Dov’ were esters that contribute sweet, tropical and fruity notes. In contrast, ten out of 13 detected terpenes and two detected aldehydes, contributing green, spicy, herbal and woody notes, were common to both the high‐ and low‐aromatic varieties. CONCLUSION: Based on these findings, it is concluded that accumulation of esters is the main reason why the traditional ‘Ben Dov’ guava variety emits such a strong tropical fruity odour. In contrast, the newly bred low‐aromatic guava varieties did not synthesise esters at all and thus lacked fruity aromatic notes. Overall, the results of this study point out the important role of esters in forming tropical fruity guava odours. Copyright © 2011 Society of Chemical Industry  相似文献   
170.
The effect of different mechanical and chemical pre-treatments on the adhesion strength of hydroxyapatite (HAp) coating on a commercially pure titanium (CP-Ti) substrate was studied by means of a standard tensile test followed by microscopic and chemical analysis to determine the locus of fracture. In addition, the effects of either these pre-treatments or post-treatment by low-energy electron irradiation, which allowed tuning the wettability of the surface, on both osteoblast progenitor attachment and S. aureus bacteria attachment were investigated. A dedicated program was developed for unambiguous identification and count of stained cells. A single-phase HAp coating was formed by electrodeposition. A series of surface pre-treatments consisted of grinding down to P1000, etching in HNO3/HF solution, grit blast, soaking in NaOH and subsequent heat treatment provided the highest adhesion strength to the HAp coating. Osteoblast progenitors derived from rats may be attached preferentially to a hydrophilic surface (post-treatment to θ = 30°), while the bacteria seemed to be less attached to hydrophobic surfaces (post-treatment to θ = 105°). However, the results were not statistically different. The bacteria seemed to be less attached to the smoother, uncoated surfaces.  相似文献   
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