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1.
Hebei Xinji Chemical Group Co.,Ltd.,one of the 6 major production basesof China Haohua Corporation,has suc-cessfully constructed barium carbon-ate and strontium carbonate bases inGuizhou Tianzhu and ChongqingTongliang in 2004. Barium carbonate and strontium  相似文献   

2.
Concentrations of calcium, iron, potassium, magnesium, phosphorus, zinc, copper, selenium and nickel were determined in the muscle tissue of seven species of fish (Plagioscion squamosissimus, Geophagus surinamensis, Prochilodus lacustres, Curimata sp., Schizodon dissimilis, Ageneiosus ucayalensis and Hypostomus plecostomus) collected from the lower course of the Itapecuru River in the state of Maranhão, Brazil. The samples were digested in a nitricperchloric solution and analyzed using an inductively coupled plasma atomic emission spectrometer, with the construction of specific calibration curves for each element. The highest concentrations of constituent minerals were found for phosphorus, potassium, nickel and magnesium (399.83, 144.60, 90.20 and 29.49 mg 100 g?1, respectively) in G. surinamensi, P. lacustres and Curimata sp. The lowest concentrations were found for copper, zinc, iron and selenium (0.12, 0.51, 1.05 and 8.31 mg 100 g?1, respectively) in Curimata sp., S. dissimilis, A. ucayalensis and P. squamosissimus. The concentrations of all minerals can be considered low and are below the maximum limit established by Brazilian legislation for the human ingestion of fish meat. A comparison of the seven species of fish investigated revealed no statistically significant differences regarding the concentrations of minerals, suggesting that size and different dietary habits do not exert an influence on absorption. The low concentrations of metals, such as Fe, Cu, Zn and Ni, may be related to the environmental conditions of the mouth of the river, which receives ocean inputs that produce particular tide cycles with a strong dispersion capacity, thereby diminishing residence time in the water column and reducing the availability of these metals to species of fish.  相似文献   

3.
taking the distortional angle as an unknown, the governing differential equation for distortion in the trapezoidal box section girder with single-cell and varyi  相似文献   

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The Mont Valérien plant supplies water to the western suburbs of Paris. Raw water comes from the River Seine downstream from the city. The old plant comprised two treatment lines: a slow sand filtration line built 80 years ago and a rapid settling and filtration line built in 1960. The process for the upgraded plant was determined after an in-depth study including industrial-scale experiments and laboratory tests.

The new treatment line includes the following: preozonation, oagulationflocculation and settling in a sludge-blanket type settling tank (PULSATOR), rapid gravity sand filtration, ozonation, and granular activated carbon filtration.

Results from laboratory tests used for the design are presented: ozonation rate, advantages for the quality of the treated water, expected reagejit savings, etc.  相似文献   


7.
Ethylene is a basic raw material forthe petrochemical industry.Around75% of petrochemical products arederived from ethylene.They includevarious important organic chemicalproducts such as polypropylene,poly-vinyl chloride,ethylene oxide/monoethylene glycol,dichloroethane,styrene,ethanol and vinyl acetate.Naphtha is the most importantethylene cracking raw material in theworld.The output of ethylene usingnaphtha as cracking raw material ac-counts for around 50% of the world  相似文献   

8.
Outlook on Refractories Development in China in the New Century   总被引:3,自引:0,他引:3  
《中国耐火材料》2001,10(4):3-9
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9.
Glycosphingolipids and sphingomyelin (SM) are important components of the apical brush border and the Golgi and endocytic vesicles of the gut epithelium. In particular, glucosylceramide is abundant in the microvilli. Synthesis and degradation of mucosal sphingolipids and targeting of sphingolipids to distinct cell compartments during cell differentiation are thus important features of intestinal lipid metabolism. Sphingolipids are also present in the ordinary Western diet, and sphingolipid‐rich formulations of dairy, plant or yeast origin are now available for studies of their biological effects in animals and humans. Since sphingolipids account for a large part of the polar lipids in milk, their digestion and effects in the suckling infant is of particular interest. Dietary sphingolipids are slowly digested and the exposure of the whole gut to sphingolipids and their metabolites can be increased by dietary supply. Metabolites from dietary sphingolipids may have anti‐inflammatory and anticarcinogenic effects and undigested sphingolipids may be protective. Dietary sphingolipids inhibit cholesterol absorption and may have beneficial metabolic effects. Some mucosal sphingolipids have blood group A, B and H reactivity and some act as receptors for bacterial toxins and virus. Sphingolipid signaling triggered by mucosal‐bacterial interaction may be important in both the gut and the bronchi.  相似文献   

10.
Experimental results of measurements of the bubble and slug lengths in Taylor (slug) flow are presented. The experiments were carried out using 3 different straight microchannels (microreactor with square cross-section made of polydimethyloxosilane (PDMS); microreactor with circular cross-section made of glass; microreactor with rectangular cross-section made of polyethylene terephthalate modified by glycol (PETg)) and 4 different liquids (water, ethanol propanol and heptane). The results have been compared with the available literature correlations. It is concluded, that the values obtained from the correlation proposed by Laborie et al. [Laborie, S., Cabassud, C., Durant-Bourlier, L., Laine, J.M., 1999. Characterization of gas–liquid two-phase flow inside capillaries. Chem Eng Sci 54, 5723–5735] do not agree with the results of measurements, while the agreement of these results with the predictions obtained using the correlation proposed by Qian and Lawal [Qian, D., Lawal, A., 2006. Numerical study on gas and liquid slugs for Taylor flow in a T-junction microchannel. Chem Eng Sci 61, 7609–7625] is good. New, corrected values of the pre-exponential constant and the exponents in the Qian and Lawal [Qian, D., Lawal, A., 2006. Numerical study on gas and liquid slugs for Taylor flow in a T-junction microchannel. Chem Eng Sci 61, 7609–7625] correlation are proposed.  相似文献   

11.
Novartis announced on February thestrategic acquisition of two leadinggeneric drug companies that will be in-tegrated into its Sandoz division,creat-ing the world leader in the generic drugindustry. Definitive agreements have been  相似文献   

12.
The rapid developmentof the textile industry promotesthe polyester productionThe export of textiles and clothes inChina has made a robust growth inrecent years.The export valuereached US$111.9 billion in 2004 andthe share in the global export mar-ket reached 22.0%.The rapid devel-  相似文献   

13.
This paper presents the results of the structure and phase formation in the Ti/Nb/2Al, Ti/Nb/2.5Al and Ti/Nb/3Al systems in the thermal explosion mode of self-propagating hightemperature synthesis. The morphology, phase composition, microstructure, and physical properties have been studied. It has been found that compounds with the highest content of aluminum have the most homogeneous composition and the lowest porosity. The main phase of the synthesis product is a phase based a solid solution of Nb in γ-TiAl.  相似文献   

14.
6 p.m.of Jan.24 was the deadlinestipulated in the decree made bySingapore Court on Dec.10,2004.Itwas on that day that China Aviation  相似文献   

15.
《Journal of Catalysis》1999,181(2):244-255
Various Pt/NaCsβ catalysts with decreasing Na/Cs ratios and a Pt/KL sample taken as a reference catalyst for aromatization ofn-hexane, have been prepared by exchange of NaCsβ and KL zeolites in a Pt tetraammine solution then calcination and reduction. The increase of the Cs content in the NaCsβ zeolitic support results in a decrease of the cyclohexane adsorption and Pt exchange capacities. The Pt/Csβ and Pt/KL samples show similar behaviors which strongly differ from those of the Na-containing Pt/NaCsβ samples in terms of (i) reducibility of the Pt ions after calcination, (ii) shape of the FTIR spectra of CO adsorbed on the Pt clusters after reduction, and (iii) catalytic activity of these clusters in the conversion ofn-hexane. In particular, the selectivity to aromatization is much higher on the Pt/Csβ and Pt/KL catalysts than on the Na-containing Pt/NaCsβ ones. The reasons for the specific behaviors of the Pt/Csβ and Pt/KL samples are discussed.  相似文献   

16.
Henan Luohe Xrngmao Titanium IndustryCo.,Ltd.will make an investment ofRMB680 million to introduce advancedchlorination-process production equip-ment and technology from abroad,and  相似文献   

17.
SOM management in the tropics: Why feeding the soil macrofauna?   总被引:2,自引:0,他引:2  
This paper synthesises information on the food requirements of soil macroinvertebrates and some of their effects on soil organic matter dynamics. Some clues to techniques that would optimise their activities through organic matter management are suggested. Soil macroinvertebrates can consume almost any kind of organic residues in mutualistic association with soil microflora. Significant amounts estimated at several T per ha of predominantly easily assimilable C are used yearly in natural ecosystems as energy to sustain these activities. Sources of C used are highly variable depending on the feeding regime. The largest part of the energy assimilated (e.g., 50% by the tropical earthworm Millsonia anomala) is actually spent in burrowing and soil transport and mixing. Bioturbation often affects several thousand tons of soil per hectare per year and several tenth of m3 of voids are created in soil. A great diversity of biogenic structures accumulate and their nature and persistance over time largely controls hydraulic soil properties. The OM integrated into the compact biogenic structures (termite mounds, earthworm globular casts) is often protected from further decomposition. Most management practices have negative effects on the diversity and abundance of macroinvertebrate communities. Structures inherited from faunal activities may persist for some weeks to years and the relationship between their disappearance and soil degradation is rarely acknowledged. When SOM supply is maintained but diversity is not, the accumulation in excess of structures of one single category may have destructive effects on soil. It is therefore essential to design practices that provide the adequate organic sources to sustain the activity and diversity of invertebrates. Special attention should also be paid to the spatial array of plots and rotations in time. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

18.
《化学试剂》2012,18(5)
目的 了解厦门市老年人口死亡特征,评价老年人口主要死因的影响程度及变化趋势.方法 应用死亡率、标化死亡率、死因构成及死因顺位、老年保健效益指数(GEI)等统计指标,对2002-2009年厦门市60岁以上老年人口死因资料进行分析.结果 2002-2009年间老年人口死亡总数为42 435人,占全部死亡人数的72.43%,平均死亡率为31.11‰.死亡率男性高于女性,城乡差异无统计学意义.主要死因为恶性肿瘤、脑血管病、心脏病、呼吸系统疾病、损伤与中毒等,前五位死因占总死亡的84.68%,全死因中慢性非传染性疾病的死亡占总死亡的90.59%.主要疾病的GEI顺位为恶性肿瘤、意外伤害、传染病、呼吸系统疾病和心脑血管疾病,大多数死因的GEI高于0.5,女性普遍高于男性.与1987-1997年统计结果比较,死亡率呈下降趋势,各主要疾病的GEI也有所下降.结论 厦门市老年人口主要死因是恶性肿瘤、心脑血管疾病和呼吸系统疾病等慢性疾病,是影响老年人寿命的最主要原因,应当作为老年医疗卫生工作的重点,并引起全社会的关注.  相似文献   

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Careful preparation of the iron nano-particle catalyst for carbon nanotubes (CNTs) fabrication has crucial importance for initial growth of multi-wall carbon-nanotubes (MWCNTs). Thin iron layer was thermally deposited in a high vacuum onto the surface of the SiO2/Si wafer at about 300 K. The sample was heated up to 700℃ in a hydrogen atmosphere, and then the sample was heated once again at750℃ in ethylene atmosphere. After hydrogen treatment continuous Fe layer was changed into many well separated Fe nano-peaks. AFM, SEM and HR-TEM studies of deposited MWCNTs allow us to propose a growth mechanism for long, straight MWCNTs.  相似文献   

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