共查询到20条相似文献,搜索用时 93 毫秒
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采用控制环量方法设计了一单级涡轮。该方法打破了传统的设计规律,为验证该方法的可靠性进行了模型试验。在宽广的范围内测定了总特性;在设计点附近作了沿叶高效率分布及动叶进、出口速度三角形的测定。本文给出了主要试验结果并作了简要分析。结果表明基本上达到了设计要求,控制环量设计的主要特征得到了验证,该方法基本可行。 相似文献
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本文系统地讨论了大统一理论的来龙去脉。回顾了大统一理论的发展历史,讨论了其发展现状及存在问题,指出了进一步发展的方向。本文重点介绍了SU(5)和SO(10)两个模型,讨论了Higgs场、规范等级、渐近自由、重正化等问题。文章进而讨论了一些有趣问题,比如提供了对宇宙重子起源的解释、计算了质子衰变寿命、论述了B-L是否守恒以及讨论了中子和中微子可能有的振荡现象等。 相似文献
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本文系统地讨论了大统一理论的来龙去脉。回顾了大统一理论的发展历史,讨论了其发展现状及存在问题,指出了进一步发展的方向。本文重点介绍了SU(5)和SO(10)两个模型,讨论了Higgs场、规范等级、渐近自由、重正化等问题。文章进而讨论了一些有趣问题,比如提供了对宇宙重子起源的解释、计算了质子衰变寿命、论述了B-L是否守恒以及讨论了中子和中微子可能有的振荡现象等。 相似文献
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体内(in Vivo)NMR研究 总被引:1,自引:1,他引:0
本文综述了体内(in Vivo)核磁共振波谱技术的目前概况,简要介绍了这一技术的基本原理。对空间定位技术进行了重点评述,并给出了分类表。同时讨论了化学位移对空间定位精确的影响,介绍了提高定位精确度的实验方法。列举了空间定位波谱技术在生命科学研究中的应用,给出了大量的参考文献。 相似文献
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用ICP-AES技术研究了胆石粉的处理过程,选择了合适的实验条件,并做了精密及回收率实验。为21例结石粉及其难溶部分进行了元素测定。计算了残留元素百分比,为医学研究提供了有用数据。 相似文献
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A. B. Grachev L. V. Levshin A. N. Ponomarev V. I. Yuzhakov 《Journal of Applied Spectroscopy》1995,62(2):212-219
M. V. Lomonosov Moscow State University, Leninskie Gory, 119899, Moscow, Russia. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 62, No. 2, pp. 38–46, March–April, 1995. 相似文献
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Hong-Wen Gao 《Journal of Applied Spectroscopy》1995,62(6):1047-1051
Huaibei Environmental Monitoring Center, Huaibei, Anhui Province, 235000, P. R. China. Translated from Zhurnal Prikladnoi
Spektroskopii, Vol. 62, No. 6, pp. 76–80, November–December, 1995. 相似文献
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Hybrid dendrimers constitute a unique class of well-defined complex architecture featured with a central domain and bifurcated branches with two different dendritic sequences for their atomic configuration and functional groups at the periphery. This review article pioneers the field of new hybrid dendrimers using different generations by nanoconjugation with metals, carbohydrates, nucleotides, proteins/peptides, carbosilane, urea, silica, stem cells, guanidine, etc. The smart dendrimers contain desirable electrical, magnetic, optical, and biological attributes to increase surface area, monodisperse behavior, dose reduction, dissolution, permeability, long-term stability, and significant decrement in nanotoxicity studies. The higher encapsulation of lipid soluble and insoluble moieties explores an excellent platform for the delivery of drugs (ibuprofen, indomethacin, etc.), nucleic acids (oligonucleotide, siRNA, and aptamer), genetic materials , and chemical diagnostic agents (gadolinium chelates and superparamagnetic iron oxide particles) for imaging. Owing to their flexibility in structural adaptability, different health conditions like glaucoma, inflammation, microbial infection, neurodegenerative problems (Alzheimer's disease and Parkinsonism), and cancer are benefited using such long-lasting drug delivery. Advancements in molecular engineering techniques, 3D printing, artificial intelligence, robotic, green synthesis, and microwave-assisted methods aid in the development of economically reliable and personalized pharmaceutical hybrid dendritic systems resembling antibodies, globular proteins, stem cells, enzymes, and genetic materials. 相似文献
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ICP-AES测定微硅粉中Ca、Mg、Fe和Al的含量 总被引:1,自引:0,他引:1
微硅粉样品经氢氟酸、硝酸、高氯酸消解,电感耦合等离子体-原子发射光谱法(ICP-AES)测定Ca、Mg、Fe、Al杂质元素含量。方法的回收率为:Ca 95.2%—100.3%,Mg 96.2%—99.6%,Fe 95.8%—97.2%,Al 98.6%—104.6%,精密度在1.50%—2.59%之间。本方法线性范围宽、分析效率高、具有良好的准确性和精密度,能快速准确地测定微硅粉中Ca、Mg、Fe和Al杂质元素的含量。 相似文献
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Ehrlich H Koutsoukos PG Demadis KD Pokrovsky OS 《Micron (Oxford, England : 1993)》2008,39(8):1062-1091
In contrast to biomineralization phenomena, that are among the most widely studied topics in modern material and earth science and biomedicine, much less is systematized on modern view of demineralization. Biomineralized structures and tissues are composites, containing a biologically produced organic matrix and nano- or microscale amorphous or crystalline minerals. Demineralization is the process of removing the inorganic part, or the biominerals, that takes place in nature via either physiological or pathological pathways in organisms. In vitro demineralization processes, used to obtain mechanistic information, consist in the isolation of the mineral phase of the composite biomaterials from the organic matrix. Physiological and pathological demineralization include, for example, bone resorption mediated by osteoclasts. Bioerosion, a more general term for the process of deterioration of the composite biomaterials represents chemical deterioration of the organic and mineral phase followed by biological attack of the composite by microorganisms and enzymes. Bioerosional organisms are represented by endolithic cyanobacteria, fungi, algae, plants, sponges, phoronids and polychaetes, mollusks, fish and echinoids.In the history of demineralization studies, the driving force was based on problems of human health, mostly dental caries. In this paper we summarize and integrate a number of events, discoveries, milestone papers and books on different aspect of demineralization during the last 400 years. Overall, demineralization is a rapidly growing and challenging aspect of various scientific disciplines such as astrobiology, paleoclimatology, geomedicine, archaeology, geobiology, dentistry, histology, biotechnology, and others to mention just a few. 相似文献
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B. I. Stepanov Institute of Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 2, pp. 200–205, March–April, 1995. 相似文献
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AAS法对几种调味品中微量元素的测定 总被引:1,自引:0,他引:1
本文采用原子吸收法测定了六种调味品中Sr,Ba,Fe,AI,Cu,Cr,Zn,Mo,Ni,Co,Mn,Cd,Mg等十三种微量元素含量。结果表明,不同的调味品中各微量元素含量均有较大差别。本实验同时对姜粉中各元素进行了回收实验,回收率在90%-108%之间。 相似文献