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1.
We first report discovery of the spinel-garnet-orthopyroxene granulite with pure CO2 fluid inclusions from the Fuyun region of the late Paleozoic Altay orogenic belt in Central Asia, NW China. The rock is characterized by an assemblage of garnet, orthopyroxene, spinel, cordierite, biotite, plagioclase and quartz. Symplectites of orthopyroxene and spinel,and orthopyroxene and cordierite indicate decompression under UHT conditions. Mineral chemistry shows that the orthopyroxenes have high XMg and Al2O3 contents (up to 9.23 wt%). Biotites are enriched in TiO2 and XMg and are stable under granulite facies conditions. The garnet and quartz from the rock carry monophase fluid inclusions which show peak melting temperatures of around -56.7 ℃, indicating a pure CO2 species being presented during the ultrahigh-T metamorphism in the Altay orogenic belt. The inclusions homogenize into a liquid phase at temperatures around 15.3-23.8℃ translating into CO2densities of the order of 0.86-0.88 g/cm3. Based on preliminary mineral paragenesis, reaction textures and petrogenetic grid considerations, we infer that the rock was subjected to UHT conditions. The CO2-rich fluids were trapped during exhumation along a clockwise P-T path following isothermal decompression under UHT conditions.  相似文献   

2.
α-diketones and β-diketones react with Grignard reagents in the presence of a catalytic amount of Cp2TiCl2 to yield α-ketols and corresponding ketones respectively. Sulfoxides can be deoxygenated by Cp2TiCl2/Al system. The possible mechanisms are also discussed. Project (No. 20072033) supported by the National Natural Science Foundation of China and the Specialized Research Fund for the Doctoral Program of Higher Education Ministry, China  相似文献   

3.
A skutterudite-related antimonide, CoFe3Sb12, was prepared with vacuum melting. XRD analysis showed the material contained Sb, FeSb2, CoSb2 and CoSb3 phases. The electrochemical properties of the ball-milled CoFe3Sb12−10 wt% graphite composite were studied using pure lithium as the reference electrode. A maximal lithium inserting capacity of about 860 mAh/g was obtained in the first cycle. The reversible capacity of the material was about 560 mAh/g in the first cycle and decreased toca. 320 mAh/g and 250 mAh/g after 10 and 20 cycles respectively.Ex-situ XRD analyses showed that the antimonides in the pristine material were decomposed after the first discharge and that antimony was the active element for lithium to insert into the host material. Project supported by the National Natural Foundation of China (No. 59771032) and the RFDP of the Education Ministry of China (No. 20010335045)  相似文献   

4.
The basic granulite of the Altay orogenic belt occurs as tectonic lens in the Devonian medium- to lower-grade metamorphic beds through fault contact. The Altay granulite (AG) is an amphibole plagioclase two-pyroxene granulite and is mainly composed of two pyroxenes, plagioclase, amphibole and biotite. Its melano-minerals are rich in Mg/(Mg Fe2 ),and its amphibole and biotite are rich in TiO2. The AG is rich in Mg/(Mg Fe2 ), Al2O3 and depletion of U, Th and Rb contents. The AG has moderate ∑REE and LREE-enriched with weak positive Eu anomaly. The AG shows island-arc pattern with negative Nb, P and Ti anomalies, reflecting that formation of the AG -05 be associated with subduction. Geochemical and mineral composition data reflect that the protolith of the AG is calc-alkaline basalt and formed by granulite facies metamorphism having peak P-T conditions of 750 ℃-780 ℃ and 0.6-0.7 Gpa. The AG formation underwent two stages was suggested. In the early stage of oceanic crustal subduction, calc-alkaline basalt with island-arc environment underwent granulite facies metamorphism to form the AG in deep crust, and in the late stage, the AG was thrust into the upper crust.  相似文献   

5.
This paper proposes a new approach for multi-objective robust control. The approach extends the standard generalizedl 2 (Gl 2) and generalizedH 2 (GH 2) conditions to a set of new linear matrix inequality (LMI) constraints based on a new stability condition. A technique for variable parameterization is introduced to the multi-objective control problem to preserve the linearity of the synthesis variables. Consequently, the multi-channel multi-objective mixed Gl 2/GH 2 control problem can be solved less conservatively using computationally tractable algorithms developed in the paper. Project supported by the National Natural Science Foundation of China (No. 60374028), and the Scientific Research Foundation for Returned Overseas Chinese Scholars, Ministry of Education (No. [2004]176)  相似文献   

6.
Study of the SISO mixedH 2/l1 problem for discrete time systems showed that there exists a unique optimal solution which can be approximated within any prescribed missing error bound inl 2 norm with solvable suboptimal solutions and solvable superoptimal solutions. Project supported by the National Natural Science Foundation of China (No. 60174026) and the Scientific Research Foundation for Returned Overseas Chinese Scholars of Zhejiang Province (No. J20020546)  相似文献   

7.
Composite materials of Fe/Al2O3, which consist of small particles of iron supported by thermally stable alumina even at 500–700 °C, have been widely used in the water-gas shift reaction for natural gas reforming. Therefore, Fe/Al2O3 is one of the promising candidates for re-transformation of exhausted CO2 into fuels such as alcohols and hydrocarbons. The development of a CO2 reforming system using the composite materials of Fe/Al2O3 through CO2 reduction to CO, dissociation of water into hydrogen, and methanol synthesis has been investigated. It was found that dry and steam (i.e. wet) reforming of CO2 produced almost the same amount of CO. At a temperature above 500 °C, maximal and saturated yields of CO and H2 from CO2 and water were obtained. However, this CO2 reforming system requires higher-pressure conditions from several tens to hundreds standard atmospheric pressure in order to achieve high yield and selectivity for methanol production. In this study we developed the modified CO2 reforming system by the utilization of Ni and/or Cu instead of Fe in order to obtain other types of useful products such as CO, CH4, and carbon, more efficiently and selectively under atmospheric pressure. When Ni or Cu was used, conversion of CO2 was reduced to 76%, while 9% of methane was detected in the case of Ni. On the other hand, though the CO2 conversion reduced half of the Fe, the selectivity of CO from CO2 increased to 95% in the case of Cu.  相似文献   

8.
The structural characteristics and optical and electrical properties of molecular-beam-epitaxy (MBE) grown ZnS0.8Se0.2 thin films on indium-tin-oxide(ITO) glas substrates were investigated in this work. TheX-ray diffraction (XRD) results indicated that high quality polycrystalline ZnS0.8Se0.2 thin film grown at the optimized temperature had a prefered orientation along the (111) planes. The transmission electron microscopy (TEM) cross-sectional micrograph of the sample showed a well defined columnar structure with lateral crystal dimension in the order of a few hundred angstroms. Ultraviolet (UV) photoresponsivity as high as 0.01 A/W had been demonstrated and for wavelengths longer than 450 nm, the response was down from the peak response by more than 3 orders of magnitude. The thin ZnS0.8Se0.2 photosensor layer, with a wide energy gap and anisotropic electrical property, makes a transmission UV liquid crystal light valve (LCLV) with high resolution feasible. Project supported by the National Natural Science Foundation of China (No. 59910161981) and RGC grant from the Hong Kong Government Grant (No. NSFC/HKUST 35), China  相似文献   

9.
In this study, supported nonmetal （boron） doping TiO2 coating photocatalysts were prepared by chemical vapor deposition （CVD） to enhance the activity under visible light irradiation and avoid the recovering of TiO2. Boron atoms were successfully doped into the lattice of TiO2 through CVD, as evidenced from XPS analysis. B-doped TiO2 coating catalysts showed drastic and strong absorption in the visible light range with a red shift in the band gap transition. This novel B-TiO2 coating photocatalyst showed higher photocatalytic activity in methyl orange degradation under visible light irradiation than that of the pure TiO2 photocatalyst.  相似文献   

10.
A new concept of low-cost direct air capture technology integrated with a fertilization system is proposed, as an alternative to the application of air derived CO2. A moisture swing sorbent can elevate the CO2 concentration from 400 parts per million (ppm) to several thousand ppm, and this can be used to cultivate plants. Desorption isotherms were determined and are described well by a Langmuir model. The adsorption rate constant and the desorption rate constant were gained at 25 °C, 35 °C, and 45 °C under 1000 ppm concentration of CO2. In accelerated cultivation experiments, the effects of CO2 concentration, light intensity, and spectrum on the CO2 uptake rate of the plants were investigated. A multi-bed desorption system which is capable of providing a continuous and stable CO2 supply for a greenhouse is demonstrated based on the desorption characteristic and CO2 uptake feature of plants. An energy and cost assessment for the integrated system was performed and the results indicated that minimum energy requirements and cost estimate of CO2 are 35.67 kJ/mol and 34.68 USD/t, respectively. This makes direct air capture a competitive and sustainable carbon source for agriculture.  相似文献   

11.
Well-cubic perovskite lanthanum aluminate (LaAlO3) film on (110) silicon substrate was fabricated by sol-gel method with corresponding inorganic salts. Lanthanum acetate and aluminum acetate glacial acetic acid solutions were prepared via ligand exchange starting from lanthanum nitrate hexahydrate and aluminum nitrate hexahydrate after being refluxed. (CH3CO)2O removed nitrates and the crystallized H2O completely, acetylacetone (AcAc) was partially bidentated with metallic ion of the metallic acetates and formed La(OAc)3−x (AcAc) x which were hydrolyzed into La(AcAc)3−x(OH) x by adding 10 ml 0.4% methyl cellulose (MCL) solution. The La(AcAc)3−x (OH) x , polymerizing and combining with MCL, formed the LaAlO3 sol precursor with heteropolymeric structure and formed film easily. The epitaxial LaAlO3 film on Si(110) substrate was crystallized after being annealed in thermal annealing furnace for 650–750 °C/30 min. The morphologies and microstructures were characterized. The refractive index of the LAO film was 1.942 to 2.007; the dielectric constant and the dissipation factors were estimated to be 23–26 and 2.1×10−4−2.4×10−4 respectively. Project (No. 2002CB613305) supported by the National Basic Research Program (973) of China  相似文献   

12.
Novel MgCl2-supported Ziegler-Natta (Z-N) catalysts prepared using a new one-pot ball milling method can effectively control the amounts of Ti-loading in the catalysts. Complex GPC data on polypropylene synthesized by these novel catalysts were analyzed using the method of fitting the molecular weight distribution (MWD) curves with a multiple Flory-Schulz function. It was found that multiple active centers exist in these novel catalysts. Detailed study of the effects of the Ti-loadings in the catalysts on the distribution of the active centers showed that the Ti-loadings in the novel MgCl2-supported Z-N catalysts might affect the proportion of each type of active centers; and might be the main factor responsible for the effect of the Ti-loadings on the microstructure, the molecular weight and molecular weight distribution width of the resultant polymer, the catalytic activity and polymerization kinetics. Project supported by the National Natural Science Foundation of China (No. 20172045), Science and Technology Plan Fund of Zhejiang Province (No. 001101116) and Foundation for Doctors of Ningbo City (No. 2003A62012), China  相似文献   

13.
This paper describes the preparation and properties of TiNx-SiO2 double-layered antireflective(AR) coatings that were applied with print process. The coating material was analyzed and TiNx was used instead of TiO2 as high refractive material. The influence of solution concentration on AR property was studied. The testing result shows that the coatings using print process are featured with excellent mechanical property and the AR property is comparable to American Southwall AR product. It is expected that the study would promote the industrialization progress in AR coatings.  相似文献   

14.
Methane (CH4) is an important greenhouse gas and a major environmental pollutant, second only to carbon dioxide (CO2) in its contribution to potential global warming. In many cases, methane emission from landfills otherwise emitted to the atmosphere can be removed and utilized, or significantly reduced in quantity by using cost-effective management methods. The gas can also be used as a residential, commercial, or industrial fuel. Therefore, emission reduction strategies have the potential to become low cost, or even profitable. The annual growth rate of Municipal Solid Waste (MSW) output in China is 6.24%, with the highest levels found in South China, Southwest China and East China. Cities and towns are developing quickly in these regions. MSW output was only 76.36 Mt in 1991 and increased to 109.82 Mt in 1997, registering an average increase of 43.8%. In China, methane emission from landfills also increased from 5.88 Mt in 1991 to 8.46 Mt in 1997; so the recovery of methane from landfills is a profitable project. Project supported by the Germany Technological Cooperation Co. (GTZ)  相似文献   

15.
Thermodynamic Optimization of DyCl3 -NaCl System   总被引：2，自引：0，他引：2  
In this paper, the phase diagram of the DyCl3 -NaCl system is optimized and calculated with CALPHAD ( calculation of phase diagram ) technology. A set of thermodynamic functions of compounds Na3 DyCl6, NaDyCl4, and NaDY2 Cl7 have been optimized and calculated based on an interactive computer-assisted analysis. The optimized thermodynamic parameters, calculated phase diagram and experimental phase diagram are thermodynamically serf-consistent.  相似文献   

16.
Using SnxTi1-xO2 as carriers, CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 were examined using a microreactor-gas chromatography (GC) NO CO reaction system and the methods of BET (Brun- auer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H2-temperature programmed reduction (TPR). The results showed that NO conversions of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the γ peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (δ) of the catalysts meant that the SnxTi1-xO2 mixed oxides could be reductive.  相似文献   

17.
MBE growth of ZnSxSe1−x thin films on ITO coated glass substrates were carried out using ZnS and Se sources with the substrate temperature ranging from 270°C to 330°C. The XRD σ/2σ spectra resulted from these films indicated that the as-grown polycrystalline ZnSxSe1−x thin films had a preferred orientation along the (111) planes. The evaluated crystal sizes as deduced from the FWHM of the XRD layer peaks showed strong growth temperature dependence, with the optimized temperature being about 290 °C. Both AFM and TEM measurements of these thin films also indicated a similar growth temperature dependence. High quality ZnSxSe1−x thin film grown at the optimized temperature had the smoothest surface with lowest RMS value of 1.2 nm and TEM cross-sectional micrograph showing a well defined columnar structure. Project supported by the National Science Council of PRC (No. 59910161981) and RGC grant from the Hong Kong Government under Grant (No. NS-FC/HKUST 35)  相似文献   

18.
Nanostructures enhance phonon scattering and improve the figure of merit of thermoelectric materials. Nanosized CoSb3 skutterudite was synthesized by solvothermal methods using CoCl2 and SbCl3 as the precursors. A “two-step” model was suggested for the formation of CoSb3 based on the X-ray diffraction analysis. The first step is the formation of cobalt diantimonide in the earlier stage during the synthesis process. Diantimonide was then combined with antimony atoms to form the skutterudite structured triantimonide, CoSb3, in the later stage of the synthesis process as the second step. The synthesized CoSb3 powders consist of irregular particles with sizes of about 20 nm and sheets of about 80 nm. Project supported by the National Natural Science Foundation of China (No. 50171064) and the Hi-Tech Research and Development Program (863) of China (No. 2002AA302406)  相似文献   

19.
In this study on the mutagenic effects of different concentrations of chromium trioxide (CrO3) on Vicia faba root tip, micronucleus assay and chromosome aberration assay were used to determine the mitotic indexes, micronucleus rate and chromosome aberration rate of Vicia faba root tip cells. The results showed that the effects of CrO3 concentration on the mitotic indexes were complicated. CrO3 increases the micronucleus rate of Vicia faba root tip cells. It was found that within certain range of CrO3 concentration the micronucleus rate increased systematically with increased concentration of CrO3, but that the micronucleus rate decreased at higher level of CrO3 and that CrO3 also caused various types of chromosome aberration at a rate which increased systematically with increased concentration of CrO3. We concluded that CrO3 has significant mutagenic effect on Vicia faba root tip cells. Project supported by Wenzhou Technology Bureau (No. S2002A015) and Wenzhou “551” Talented People Fund of China  相似文献   

20.
This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam. and Lolium perenne L. exposed to two CO2 levels (360 and 1 000 μl/L) and three Cd levels (0, 4, and 16 mg/L) under hydroponic conditions. The results show that elevated levels of CO2 increased shoot biomass more, compared to root biomass, but decreased Cd concentrations in all plant tissues. Cd exposure caused toxicity to both Lolium species, as shown by the restrictions of the root morphological parameters including root length, surface area, volume, and tip numbers. These parameters were significantly higher under elevated levels of CO2 than under ambient CO2, especially for the number of fine roots. The increases in magnitudes of those parameters triggered by elevated levels of CO2 under Cd stress were more than those under non-Cd stress, suggesting an ameliorated Cd stress under elevated levels of CO2. The total Cd uptake per pot, calculated on the basis of biomass, was significantly greater under elevated levels of CO2 than under ambient CO2. Ameliorated Cd toxicity, decreased Cd concentration, and altered root morphological traits in both Lolium species under elevated levels of CO2 may have implications in food safety and phytoremediation.  相似文献   

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