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Experimental study of surface texture and resonance mechanism of booming sand

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Science china Earth sciences 2007年第9期50卷 1351-1358页

作者： QU JianJun1, ZHANG KeCun1, SUN Bo2, JIANG ShengXiang3, DONG GuangRong1, ZU RuiPing1 & FANG HaiYan 1 Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research institute, chinese academy of sciences, lanzhou 730000, china 2 Shanghai institute of Polar Regions, Shanghai 210000, china 3 lanzhou institute of chemical physics, chinese academy of sciences, lanzhou 730000, china Key Laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Shanghai institute of Polar Regions Shanghai 210000 China lanzhou institute of chemical physics Chinese Academy of Sciences Lanzhou 730000 China

The sound-producing mechanism of booming sand has long been a pending problem in the blown sand physics. Based on the earlier researches, the authors collected some silent sand samples from Teng- ger Desert, Australian Desert, Kuwait Desert, beaches of Hainan Island and Japanese coast as well as the soundless booming sand samples from the Mingsha Mountain in Dunhuang to make washing ex- periments. In the meantime the chemical corrosion experiment of glass micro-spheres, surface coating experiment and SEM examination were also conducted. The experimental results show that the sound production of booming sand seems to have nothing to do with the presence of SiO2 gel on the surface of sand grains and unrelated to the surface chemical composition of sand grains but is related to the resonance cavities formed by porous (pit-like) physical structure resulting from a number of factors such as wind erosion, water erosion, chemical corrosion and SiO2 gel deposition, etc. Its resonance mechanism is similar to that of Hemholz resonance cavity. Under the action of external forces, nu- merous spherical and sand grains with smooth surface and porous surface are set in motion and rub with each other to produce extremely weak vibration sound and then become audible sound by human ears through the magnification of surface cavity resonance. However the booming sands may lose their resonance mechanism and become silent sand due to the damping action caused by the invasion of finer particles such as dust and clay into surface holes of sand grains. Therefore, clearing away fine pollutants on the quartz grain surface is an effective way to make silent sand emit audible sound.

关键词： booming sand, surface texture, quartz grain, sound-producing mechanism, Hemholz resonance cavity

Study on the Reaction of Proteins with 5-Nitrosalicylfluorone-molybdenum(Ⅵ) Complex by Spectrophotometry in PVA 124 Microemulsion

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chinese Journal of Chemistry 2004年第7期22卷 714-718,615页

作者：魏琴吴丹杜斌张慧欧庆瑜lanzhou institute of chemical physics chinese academy of sciences lanzhou Gansu 730000 china School of Chemistry & chemical Engineering Jinan University Jinan Shandong 250022 China Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou Gansu 730000 China School of Chemistry & chemical Engineering Jinan University Jinan Shandong 250022 China

The application of 5'-nitrosalicylfluorone (5'-NSF)-molybdenum(VI) complex as a spectroscopic probe was studied. In the buffer medium of HOAc-NaOAc at 3.45 and in the presence of PVA 124 microemulsion, 5'-NSF-Mo(VI) complex combines protein rapidly to form a stable compound, leading to an absorbance decrease at 525 nm of 5'-NSF-Mo(VI) complex. According to this change, microdetermination of protein has been described. Bovine serum albumin (BSA) could be determined in the linear range of 0—16 g昺L-1 with the detection limit of 11 ngmL-1. Many amino acid and metal ions studied do not interfere with the assay. The method possesses high sensitivity as well as high selectivity. It can be used to determine protein in human urine and milk powder successfully. The relative standard deviations are in all instances less than 4.7%, and the recoveries are between 97.6% and 106.0%. Moreover, the binding number of BSA with the complex, which is determined by using molar ratio, Rosenthanl graphic and slope ratio methods, is in good agreement with each other.

关键词： protein spectrophotometry 5'-NSF-Mo(VI) complex microemulsion

Characterization and Tribological Behavior of Octadecene,Dodecene and Undecenoic Acid Films on Si Substrate

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Journal of Materials Science & Technology 2005年第5期21卷 671-674页

作者： Jinfang ZHOU+ and Shengrong YANGState Key Laboratory of Solid Lubrication, lanzhou institute of chemical physics, chinese academy of sciences, lanzhou730000, china State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

The films of octadecene, dodecene, and undecenoic acid were prepared on H-terminated Si surface in the presence of ultraviolet irradiation. The resulted films were characterized with water-contact angle measurement and infrared spectroscopy. The friction-reducing behavior of the prepared films was examined on a static-dynamic friction coefficient measurement apparatus and on an atomic force microscope. It was found that all the reacted films on the Si substrate showed good friction-reducing ability; especially, the film of the octadecene exhibited the best friction-reducing ability. This was attributed to the transfer of the reacted films onto the counter face with formation of a transfer film on the counterpart surface, which led to the transformation of the sliding between the reacted films and the hard ceramic to fiat between the reacted films and its transfer film on the counterpart surface. The macroscopic and microscopic friction behaviors of the prepared films were dependent on their molecular chain lengths. Thus the octadecene reacted film with the highest degree of ordering arrangement showed the best friction-reducing and antiwear abilities in sliding against Si3N4.

关键词： Alkese Reaction film Hydrogen-terminated silicon Tribological behavior

Rem-meter correction factor for measuring high energyneutrons outside concrete shielding

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Nuclear Science and Techniques 1998年第2期9卷 109-112页

作者： Li Gui-Sheng (institute of Modern physics, the chinese academy of sciences, lanzhou 730000) Inititute of Modern physics Chinese Academy of Sciences Lanzhou 730000 China

Correction factors of both Rem-meters, the 10 inch diameter single-sphere Remmeter and the standard A-B Rem-meter, were estimated for measuring high energy neutron dose equivalent outside a concrete shielding wall and the effects that the emitted neutron spectra become remarkably "harder" penetrated through a concrete shielding wall, and the energy response of the Rem-meter were taken in account. The estimated results could be applied in the measurement of neutron dose equivalent for the intermediate energy heavy ion reactions to avoid the difficulty induced by the energy response of the Rem-meters.

关键词：高能中子混凝土屏蔽雷姆米修正因子

C_(19)-DITERPENOID ALKALOIDS OF DELPHINIUM MOLLIPILUM

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chinese chemical Letters 1995年第2期6卷 101-102页

作者： Suo Ming ZHANG Qing Yu Ou(lanzhou institute of chemical physics, chinese academy of sciences, lanzhou 730000) chinese Acad Sci Lanzhou Inst Chem Phys Lanzhou 730000 Peoples R China

Five C19-diterpenoid alkaloids were isolated from the aerial parts of Delphinium mollipilum ***. Four proved to be the known talitine B,talitine A, browniine and delcosine, while the fifth was a new C19-diterpenoid al...

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Reaction Chemistry of W-Mn/SiO2 Catalyst for the Oxidative Coupling of Methane

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Journal of Natural Gas Chemistry 2003年第1期12卷 1-9页

作者： Shuben LiState Key Laboratory for Oxo Synthesis and Selective Oxidation, lanzhou institute of chemical physics, chinese academy of sciences, lanzhou 730000, china State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

Reaction chemistry of the OCM reaction on W-Mn/SiO_2 catalyst has beenreviewed in this account. Initial activity and selectivity, stability in a long-term reaction,reaction at elevated pressures and a modelling test in a stainless-steel fluidized-bed reactor showthat W-Mn/SiO_2 has promising performance for the development of an OCM process that directlyproduces ethylene from natural gas. A study on surface catalytic reaction kinetics and used catalyststructure characterization revealed a possible reason why C_2 and CO_x selectivity changed duringthe long-term reaction. Further improvement of the catalyst composition and preparation methodshould be a future direction of study on OCM reaction over W-Mn/SiO_2 catalyst.

关键词： W-Mn/SiO_2 catalyst oxidative coupling of methane elevated pressure methane

Pentacyclic triterpenoid ketones in peat from Gannan Marsh,china

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chinese Science Bulletin 2001年第17期46卷 1433-1436页

作者： DUAN Yilanzhou institute of Geology, chinese academy of sciences, lanzhou 730000, china lanzhou institute of Geology Chinese Academy of Sciences Lanzhou China

Abundant terrigenous triterpenoid ketones and a series of hopanoid ketones were detected in a peat sample from the recent Gannan Marsh. The identifications of pen-tacyclic triterpenoid ketones are discussed in detail. Based on the compositional features of pentacyclic triterpenoid ketones in the sample, it is proposed that terrigenous triterpenoid kentones originate directly from organisms or are diagenetic oxidation products of their alcohols, and hopanoid ketones are formed from hopanoids (e.g. hopanoid alcohols and hopenes) by chemical and biochemical processes. These data provide evidence for the applied studies of pentacyclic triterpenoid ketones as biomarker compounds.

关键词： Gannan Marsh peat pentacyclic triterpenoid ketones identification biochemistry.

Enthalpy and entropy interaction parameters of sodium chloride with some monosaccharides in water

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Science china Chemistry 2004年第1期47卷 59-66页

作者： ZHUO Kelei, WANG Jianji, BAI Guangyue, YAN Haike & WANG HangingSchool of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453002, china institute of Chemistry, chinese academy of sciences, Beijing 100080, china lanzhou institute of chemical physics, chinese academy of sciences, lanzhou 730000, china School of Chemistry and Environmental Science Henan Normal University Xinxiang China institute of Chemistry Chinese Academy of Sciences Beijing China lanzhou institute of chemical physics Chinese Academy of Sciences Lanzhou China

Dilution enthalpies of sodium chloride and some monosaccharides (glucose, galactose, xylose, arabinose, and fructose) in water and mixing enthalpies of aqueous sodium chloride and these monosaccharide solutions were measured by using an improved precision semimicro-titration calorimeter. Transfer enthalpies of sodium chloride from water to aqueous saccharide solutions were evaluated as well as enthalpy interaction parameters of sodium chloride with these monosaccharides in water. Combined with Gibbs energy interaction parameters, entropy interaction parameters were also obtained. The results show that interactions of the saccharides with sodium chloride depend on the stereochemistry of saccharide molecules. These interaction parameters can identify stereochemical structure of saccharide molecules. Keywords sodium chloride - monosaccharide - enthalpy interaction parameter - entropy interaction parameter - calorimetry

关键词： sodium chloride, monosaccharide, enthalpy interaction parameter, entropy interaction parameter, calorimetry.

Three Novel Eremophilanolides from Ligularia virgaurea ***

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chinese chemical Letters 2004年第12期15卷 1441-1444页

作者： Quan Xiang WU Yan Ping SHI Li YANG State Key Laboratory of Applied Organic Chemistry, lanzhou University, lanzhou 730000 lanzhou institute of chemical physics chinese academy of sciences (CAS) lanzhou 730000 State Key Laboratory of Applied Organic Chemistry Lanzhou University lanzhou institute of chemical physics Chinese Academy of Sciences (CAS)

From the alcoholic extract of the whole plant of Ligularia virgaurea spp. oligocephala,three novel eremophilane sesquiterpene lactones, 6α, 10α-dihydroxy-1-oxoeremophila- 7(11),8(9)-dien-8, 12-olide, 6β, 10α-dihydroxy-1-oxoeremophila-7 (11), 8 (9)-dien-8, 12-olide and10α-diydroxy-1-oxoeremophila-7(11), 8 (9)-dien-8, 12 olide were isolated. Their structure s wereelucidated by various, spectroscopic methods including intensive 2D NMR techniques (COSY,HMQC, HMBC and ~1H-~1H NOESY) and HR-MS.

关键词： Ligularia virgaurea spp oligocephala Compositae sesquiterpene lactones eremophilanolides.