共查询到20条相似文献，搜索用时 55 毫秒
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利用单因素试验筛选培养基碳氮源及氮源分别为玉米粉及豆柏粉,正交试验确定最佳培养时间为2天时,最佳液体发酵条件转速200r/min,温度30℃,装液量为50ml∕250ml,起始p H5.0。 相似文献
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本实验采用高速逆流色谱法对何首乌活性成分二苯乙烯苷进行分离。色谱条件为：正已烷-乙酸乙酯-乙醇-水（1：48：1：48）流速2.0ml/min,检测波长280nm。该方法简便、快捷适合分离何首乌中的二苯乙烯苷。 相似文献
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以无水乙醇和无水乙醛为原料,以无水氯化氢为催化剂制备乙醛缩二乙醇.利用正交试验的方法找出优化方案.通过单因素实验和正交实验确定出最佳反应条件为:无水乙醇与无水乙醛摩比为2.4:1.0,温度:30C～50C.硅胶用量为34g,反应时间 55min,通入新蒸的氯化氢13min,产率可以到90%以上. 相似文献
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采用单因素和正交实验设计,优化花生壳中白藜芦醇的超声波辅助浸提工艺,最佳工艺条件为:料液比为1∶25、乙醇浓度为50%、超声时间为35min、超声温度为30℃,为花生壳的利用提供了新途径。 相似文献
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目的：建立灵敏度高、操作简单的高效液相色谱法测定熟肉制品中柠檬黄、日落黄、胭脂红、诱惑红等合成色素。方法样品经涡旋离心等提取,得出最佳色谱条件,注入高效液相色谱仪进行分离。结果在选定的分离条件下4种色素在0．0－60．0ug/ml范围内线性关系良好,相关系数均≥0．9995。准确度试验,回收率在89．0％－109．5％。结论方法简单易操作,应用于实际样品的测定,结果满意。 相似文献
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连翘提取物制备工艺以连翘酯苷收率为指标,进行L9（3^4）正交试验对乙醇浓度、乙醇用量、提取时间和提取次数进行了优选,确定了最佳的回流提取条件。此外所建HPLC含量测定方法操作简便、重复性好、精密度高、回收率稳定、结果准确可靠,可用于连翘提取物的质量控制。 相似文献
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《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
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《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
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Prof. SUN Changpu from the CAS Institute of Theoretical Physics coworkers from University of Basel in Switzerland have worked out a way - at least in theory - to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams is similar to the famous Stern-Gerlach effect whereby a beam of atoms passing through a magnetic field is split in two according to the atoms' spin states 《中国科学院院刊(英文版)》2008,22(1):23-23
Prof. SUN Changpu from the CAS Institute of Theoretical Physics and coworkers from University of Basel in Switzerland have worked out a way --at least in theory --to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams and is similar to the famous Stern-Gerlach effect, whereby a beam of atoms passing through a magnetic field is split in two according to the atoms＇ spin states （Phys. Rev. Lett. 99 130403）. 相似文献
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《中国科学院院刊(英文版)》2014,(3):212-213
<正>In February 2014,the 30th Chinese Antarctic inland expedition team reported that they have successfully conducted the seeing measurement at the Antarctic Taishan Station using a Differential Image Motion Monitor(DIMM)developed by the Nanjing Institute of Astronomical Optic and Technology(NIAOT),Chinese Academy of Sciences.In astronomy,seeing is a physical parameter that describes the irregular movement and blur of the star 相似文献
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XIN Ling 《中国科学院院刊(英文版)》2014,(4):270-271
Amassive overhaul is coming to the Chinese Academy of Sciences （CAS）. To straighten its ＂fragmented, inefficient research＂, the academy has decided to restructure its 104 institutes for better teamwork. 相似文献
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SONG Jianlan 《中国科学院院刊(英文版)》2014,(4)
<正>DNA demethylation in mammalian zygotes,a biochemical process through which the parental genomes let go the epigenetic marks from their"past lives"to obtain totipotency,has long fascinated biologists:how does it happen?A joint team at the CAS Shanghai Institutes for Biological Sciences tells a surprising story. 相似文献
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China is one of the fastest growing economies worldwide. Are science and research also in the fast lane? We talked with LUO Yuan, scientist at the Institute of Coal Chemistry in Shanxi, and Axel Mosig, Professor at Ruhr University in Bochum, who has first-hand experience working and living in China. 相似文献
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INS 《中国科学院院刊(英文版)》2014,(4):311-311
Neonatal heart:Largely,postnatal coronary vessels might not have expanded from preexisting embryonic vasculature as formerly believed–see what CAS biologists revealed in page 311. 相似文献
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《中国科学院院刊(英文版)》2014,(4):312-312
<正>Recently a group of researchers at the unit of molecular virology,Institut Pasteur of Shanghai,Chinese Academy of Sciences revealed a new mechanism to regulate the survival of influenza A virus and reported their discoveries in the Journal of Virology on July 相似文献
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《中国科学院院刊(英文版)》2014,(4):319-320
<正>Amber-bearing deposits are among the most important Konservat-Lagersttten providing unique windows into past ecosystems.Fushun amber has been known for over a century and was traditionally regarded as an important source of medicine as well as organic gemstones.The inclusions,however,were not the subject of any comprehensive investigation 相似文献