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Now showing items 81 - 96 of 100

  • Characteristics and Evaluation of Heavy metal Pollution in Soil and Near-surface Atmospheric Dust of Typical Mining Cities in Southwest China——A case study from Panzhihua city

    LIU Rui;HUANG Yi;School of Earth Sciences, Chengdu University of Technology;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Environment, Chengdu University of Technology;  

    Taking Panzhihua City as the research area, the enrichment factor method, the potential ecological hazard coefficient method and the single factor index-Nemero comprehensive pollution index method were used to specifically target As, Cd, Cr, V, Zn and Ni and Cu in soil and near-surface atmospheric dust, and the pollution status of these seven heavy metals,, was comprehensively evaluated. The results show that the average content of Cd, Cr, Cu, As, V, Zn and Ni in studying area is higher than the background values in Sichuan Province, because is located around the Panzhihua Smelter. It has been affected by steel smelting for a long time, and the amount of motorized diesel vehicles is large, and the demand for coal combustion is also large. Various pollution sources have had a negative impact on the local environment. The average content of Cd, Cr, Cu, Zn, Ni and V in Baoding coal mine area and Iron and Steel Smelting is higher than that of Sichuan Province. The heavy metals in the near-surface atmospheric dust also exceed the soil background value of Sichuan Province. The solid waste and the steel smelting are the main sources of heavy metals in the environment. The Enrichment Factors Index of heavy metals around Iron and Steel Smelting areamainlyreach up to heavy pollution. The heavy metals in the near-surface atmospheric dust are also seriously affected by human activities, which may be related to the exhaust gas emission and steel smelting of diesel vehicles near the smelting area. The potential ecological hazard coefficient analysis indicates that the soil is in a strong to very strong ecological hazard. As far as the elements concerned, most of the elements are in minor ecological hazards, and the ecological hazard coefficient of Cd is the largest. The high RI worthy points are mainly concentrated in the vicinity of smelters and slag dump. Single factor index-Nemero comprehensive pollution index analysis, Cd, Cr and Ni pollution in Baoding coal mine area is serious, the main source of these heavy metals may be from the coal mine waste or coal gangue. The pollution of Cd, Cu, V, Cr and Ni is more serious, indicating that iron and steel smelting has a serious impact on soil heavy metals.
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  • Research on the application of a combined model in carbon emission prediction

    Nowadays, the prediction accuracy of carbon emissions is required to be improved, a combination model for prediction is proposed. First, calculate the carbon emissions according to the carbon emission conversion formula of petrochemical energy consumption, then use the trend moving average method to pre-process the calculated carbon emissions, and finally combine the pre-processed data with the grey linear regression model to realize the prediction of future carbon emissions. The experimental results show that the prediction accuracy of using traditional linear regression model and GM(1,1) is low, while using the grey linear regression model is good, but it is still lower than using the combined model proposed.
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  • A novel hydrolytic product from flesh of Mactra veneriformis and its bioactivities in calcium supplement

    Wang Lingchong   Chen Shiyong   Liu Rui  

    To prepare calcium-binding peptides, the flesh residue of Mactra Veneriformis was subjected to enzymatic hydrolysis. By comparing the capability of combining calcium of the hydrolyzates, pepsin was confirmed to be the most suitable enzyme for hydrolyzing the flesh residue to release calcium-binding peptides among the seven tested proteases. The pepsin hydrolyzate (PHM) was divided into three fractions according to the molecule weight of its composition, which ranged from 0.5 to 15 kDa. The low-molecule-weight fraction named PHM-3 had the highest capability in combining calcium. The peptides existing in the PHM-3 fraction consisted of higher contents of Glu, Ala and Leu, and could produce one type of calcium-peptide complex by powerfully chelating calcium ions. PHM-3 products could effectively increase calcium absorption and retention while they decreased the calcium excretion in animal tests. Additionally, symptoms caused by low calcium bioavailability in ovariectomized rats, such as bone mineral density reduction and mechanical strength loss could be significantly ameliorated by the hydrolytic products addition in diet.
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  • Total glucosides of paeony attenuates animal psoriasis induced inflammatory response through inhibiting STAT1 and STAT3 phosphorylation

    LI Bin-bin   HE Shu-cheng   LIU Rui   HUANG Liang-liang   LIU Ge   WANG Rui-xuan   YANG Zhuo-yue   LIU Xin-yi   LENG Ye   LIU Dan   YE Cheng-yu   LI Yun-man   CHEN Yong-jian   IN Hong   FANG Wei-rong  

    OBJECTIVE Psoriasis is an immune system meditated disease, especially T cells. It disturbed many people around the world and hard to therapy. Paeonia lactiflora Pall has been used as a medicine in china for thousands of years. Recent studies has found that the main component of Paeonia lactiflora Pall can alleviates the immune response in many diseases. In this study, we researched the effects and possible mechanisms of total glucosides of paeony(TGP) on animal psoriasis in order to study the therapeutic effects and mechanisms of TGP in 5 % propranolol creaminduced psoriasis in guinea pigs and Imiquimod(IMQ) cream-induced psoriasis in mice. METHODS The effect of TGP was evaluated using a psoriasis-like model of guinea pigs and mice. Ear thickness was accessed, and pathology injury was observed by HE staining. The levels of serum IL~(-1)β, IL-6, IL~(-1)2, IL~(-1)7, IL-23, TNF-α, and IFN-γ, skin IL~(-1)7 A, IL-22 and orphan nuclear receptor(RORγt) mR NA expression, proliferating cell nuclear antigen(PCNA), total or phosphorylated signal transducers and activators of transcription(STAT1 and STAT3) were determined by ELISA, real time PCR, immunohistochemical staining, and Western blotting, respectively. RESULTS Compared with model group, TGP treatment decreased the ear thickness, improved pathology of psoriasis, alleviated IMQ-induced keratinocyte proliferation, reduced the inflammatory cytokine, and downregulated IL~(-1)7 A, IL-22, and RORγt mRNA in mice. Further study indicated that TGP inhibited STAT1 and STAT3 phosphorylation in lesion skins of psoriasis-like mice. CONCLUSION TGP alleviates the symptoms of psoriasis-like guinea pigs and mice, and the possible mechanism may relate to inhibit T helper 17(TH17) cell differentiation and keratinocytes proliferation by inhibiting STAT1 and STAT3 phosphorylation.
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  • Using Elitist Particle Swarm Optimization to Facilitate Real Estate Portfolio Based on Information Entropy

    Liu Rui   Wang Xiaoya  

    The real estate industry has been the pillar industry Of national economic. And the high returns and high risks would coexist in this industry. First, this paper established the real estate portfolio model based on information entropy, with the smallest risk as the greatest benefits. In addition, this paper developed a new algorithm to find the optimal real estate portfolio to achieve the smallest risk as the greatest benefits. And the proposed algorithm modified a population based search procedure, particle swarm optimization, by adopting an elite archiving scheme to store nondominated solutions and by aptly using members of the archive to direct further search. Moreover, the termination of the proposed algorithm was set to that no new members have entered into the elite archive. In addition, through a practical case, the proposed algorithm is shown effective and efficient in real estate portfolio.
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  • Simultaneous determination of seven major triterpenoids in Pyrola decorata H. Andres by LC-MS method.

    Zhang YuanYuan   Zhang Chao   Ren Rui   Liu Rui  

    A liquid chromatography-mass spectrometry method was developed and validated for the quantitative determination of seven triterpenoids, 3-beta-O-alpha-L-arabinopyranosylsiaresinolic acid-28-O-beta-D-glucopyranosyl ester, ziyuglycoside I, pomolic acid, maslinic acid, colosic acid, oleanolic acid and ursolic acid in Pyrola decorata H. Andres. Chromatographic separation was achieved on a Hypersil C 18 column using isocratic elution followed by a linear gradient elution of methanol and water as mobile phase. The analytes were ionized by atmospheric pressure chemical ionization source and determined on selected ion monitoring mode. All analytes showed good linearity ( r2≥0.9984) within the test ranges and the recovery rates were 94.5%-103.3%. Satisfactory precision and reproducibility were obtained with relative standard deviation less than 5%. The method was simple, accurate and performed well in application to the determination of twenty commercial samples of P. decorata collected from different regions of China. It could be used for the quality control of both plant materials and preparations of P. decorata.
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  • Effect of silica particles on electrical treeing initiation in silicone rubber

    Zhou Yuan-xiang   Liu Rui   Hou Fei   Xue Wen-bin   Zhang Xu  

    Silicone rubber (SIR) widely used in the insulation of the prefabricated power cable accessories is actually a kind of polymer composite which is usually composited by neat SIR and several weight percentages of silica (SiO 2) particles. The aim of dispersing SiO 2 powders into the SIR is mainly to enhance the mechanic properties of the polymer. Some research indicates that the particles may also affect the electrical treeing progress of the polymer composite. Electrical treeing is one of the main causes of degradation and breakdown of solid insulating material such as SIR. In this article, a serial of SIR samples with different weight percentages of SiO 2 particles were made, a classic needle-plate electrode system was used to test their electrical treeing initiation performance and an optical microscope system was founded to observe the electrical treeing progress. In the experiment, the AC voltage applied on the electrodes was raised at a certain rate and when the electrical trees initiated in the SIR samples, the voltages and the photos of the trees were recorded. By comparing the results of experiment, it was found that when the weight percentages were under a threshold value, the SiO 2 particles hindered the electrical tree growth in the polymer composites. This work afforded experimental evidence to the research on the electrical treeing in polymers.
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  • Microstructure and Mechanical Properties of Nano-Size Zirconium Carbide Dispersion Strengthened Tungsten Alloys Fabricated by Spark Plasma Sintering Method

    Xie Zhuoming   Liu Rui   Fang Qianfeng   Zhang Tao   Jiang Yan   Wang Xianping   Liu Changsong  

    W-(0.2, 0.5, 1.0)wt% ZrC alloys with a relative density above 97.5% were fabricated through the spark plasma sintering (SPS) method. The grain size of W-1.0wt% ZrC is about 2.7 mu m, smaller than that of pure W and W-(0.2, 0.5)wt% ZrC. The results indicated that the W-ZrC alloys exhibit higher hardness at room temperature, higher tensile strength at high temperature, and a lower ductile to brittle transition temperature (DBTT) than pure W. The tensile strength and total elongation of W-0.5wt% ZrC alloy at 700 degrees C is 535 MPa and 24.8%, which are respectively 59% and 114% higher than those of pure W (337 MPa, 11.6%). The DBTT of W-(0.2, 0.5, 1.0)wt% ZrC materials is in the range of 500 degrees C-600 degrees C, which is about 100 degrees C lower than that of pure W. Based on microstructure analysis, the improved mechanical properties of the W-ZrC alloys were suggested to originate from the enhanced grain boundary cohesion by ZrC capturing the impurity oxygen in tungsten and nano-size ZrC dispersion strengthening.
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  • Effect and intracellular uptake of pure magnetic Fe(3)O(4) nanoparticles in the cells and organs of lung and liver

    Liu Shi-yuan   Long Ling   Yuan Zheng   Yin Long-ping   Liu Rui  

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  • Caledonian reworking of Paleoproterozoic basement in the Cathaysia Block: Constraints from zircon U-Pb dating, Hf isotopes and trace elements

    Zeng Wen   Zhang Li   Zhou HanWen   Zhong ZengQiu   Xiang Hua   Liu Rui   Jin Song   Lue XinQian   Li ChunZhong  

    A combined study of zircon U-Pb dating, Hf isotopes and trace elements has been carried out for granodioritic neosomes of migmatites from the Tianjingping area in northwestern Fujian Province. Zircons are characterized by zoning, higher Th/U ratios (mostly >= 0.1), HREE enrichment, and positive Ce and negative Eu anomalies, and show features similar to magmatic or anatectic zircons. Apparent Pb-206/U-238 ages for the zircons are 447 +/- 2 Ma (95% conf., MSWD = 0.88), corresponding to a Caledonian event. epsilon(Hf)(t) values are -13.3 to -9.7, indicating a crustal source. Two-stage Hf model ages are 1.7 to 1.9 Ga, suggesting that protolith of the migmates was probably formed in the Paleoproterozoic. The granodioritic neosomes have the characteristics of peraluminous calc-alkaline granite, and their REE patterns and trace elements spidergrams show features of middle to upper crustal rocks. Together with previous studies, we conclude that the protolith of the Cathaysia basement in the Tianjingping area was likely formed in the middle-late Paleoproterozoic and experienced partial melting during the Caledonian period. The recognition of Caledonian reworking of the Paleoproterozoic basement in the Cathaysia Block provides a new insight into the tectonic evolution of the Cathaysia Block in the Caledonian period and the interaction between the Cathaysia Block and the Yangtze Block.
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  • Exploration of nano-surface chemistry for spectral analysis

    LI ChengHui   LIU Rui   Lü Yi   HOU XianDeng   WU Peng  

    The applications of nano-surface chemistry in the field of spectral analysis have attracted growing interest in recent years.In this article,we reviewed the applications of nanomaterials-based chemical reactions for spectral analysis,including the development in plasma-catalysis,surface-enhanced spectroscopy,separation and preconcentration,chemical vapor generation,labeling and signal amplification.Introduction of nano-surface chemistry to spectral analysis not only improves the sensitivity and selectivity,broadens the application range of spectral analysis,but also affords analytical community special characterization tools.
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  • Protective Effects of Luteolin against Amyloid beta(25-35)-induced Toxicity on Rat Cerebral Microvascular Endothelial Cells

    Liu Rui   Lan Xi   Ying Jian  

    AIM: To evaluate the effects of luteolin against amyloid beta-peptide 25-35 (A beta(25-35)) on rat cerebral microvascular endothelial cells (CMECs). METHODS: CMECs were isolated from Wistar rats at 3-week-old, and randomly divided into 5 groups including control group, A beta(25-35) group, 0.1, 1.0, and 10.0 mu mol.L-1 luteolin groups. Cell viability was determined with MTS assay. Intracelluar ROS level and SOD activity were monitored by DCFH-DA and SOD inhibition assay, respectively. Transendothelial electrical resistance was measured using an EVOM resistance meter. gamma-Glutamyl transpeptidase and alkaline phosphatase activities were detected using activity assay kits. Levels of TXA(2) and PGI(2) in culture medium were measured as their stable metabolites, TXB2 and 6-keto-PGF(1 alpha), by ELISA. RESULTS: Luteolin attenuated A beta(25-35)-induced toxicity at 0.1, 1.0, and 10 mu mol.L-1, inhibited intracellular ROS generation, and increased SOD activity at 1.0 and 10 mu mol.L-1. Luteolin was also found to preserve CMECs barrier function, involving the alleviation of TEER reduction, the increase of characteristic enzymatic activity, and regulation of TXA(2) and PGI(2) secretion. CONCLUSION: Luteolin had the ability to protect rat CMECs against A beta(25-35)-induced toxicity.
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  • U-Pb zircon geochronology and Hf isotope study of metamorphosed basic-ultrabasic rocks from metamorphic basement in southwestern Zhejiang: The response of the Cathaysia Block to Indosinian orogenic event

    Xiang Hua   Zhang Li   Zhou HanWen   Zhong ZengQiu   Zeng Wen   Liu Rui   Jin Song  

    A combined study using LA-ICP-MS U-Pb dating, Hf isotopes, trace elements and the Ti-in-zircon geothermometer was carried out on zircons from the metamorphosed basic-ultrabasic rocks in the metamorphic basement of the Cathaysia Block, southwestern Zhejiang Province. The formation and metamorphic ages of the rocks from the metamorphic basement of the Cathaysia Block were determined based on zircon U-Pb geochronology. The age for the magmatic crystalline zircons from the protolith is about 1.85 Ga. The epsilon (Hf) (t) values of the older zircons were from -7 to -3, with two-stage model Hf ages (T(DM2)(LC)) of about 2.9 to 3.4 Ga, indicating that the source material was derived from anatexis and recycling of the Archean crust. The newly formed metamorphic zircons yielded U-Pb ages of 260-230 Ma. The metamorphic temperature calculated using the Ti-in-zircon geothermometer ranged from 610 to 720 degrees C, consistent with the results from petrographic observations, indicating that the Cathaysia Block experienced an amphibolite facies metamorphism during the Indosinian. Results from this study provided an important timeframe for the tectonic evolution in South China and the Southeast Asia during the Late Permian and Early Triassic times.
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  • Enhanced Efficiency of Dye-sensitized Solar Cells Using rGO@TiO2 Nanotube Hybrids

    Liu Rui   Qiao Yingjie   Song Yingjin   Song Kehan   Liu Chuan  

    We established a novel strategy for the synthesis of reduced graphene oxide(rGO)@TiO2 nanotube hybrids using an 18 W UV-assisted photo-catalytic reduction method for utilization as photo-anode of dye-sensitized solar cells(DSSCs). The photo-conversion efficiency of DSSCs was significantly enhanced after the addition of rGO, and in addition, the photo-anode showed decreased internal resistance. Analysis of rGO@TiO2 hybrids by transmissions scanning electron microscopy(TEM), X-ray diffraction(XRD), Raman spectra, N-2 adsorption and desorption, atomic force microscopy(AFM) and X-ray photoelectron spectroscopy(XPS) demonstrates that the rGO modified TiO2 nanotubes can increase the short-circuit current and the conversion efficiency of dye-sensitized solar cells. The efficiency is improved by almost two folds as much compared to those of the bare TiO2 nanotubes.
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  • An Algorithm for Estimating Fundamental Matrix Based on Removing the Exceptional Points

    Liu Rui   Wang Feng  

    In this paper, an algorithm for estimating fundamental matrix based on removing the exceptional points is proposed. It uses normalized 8-point algorithm to estimate the initial value of the fundamental matrix, and then refines it by eliminating the exceptional points. Furthermore, the Genetic Algorithm(GA) is used to optimize the initial fundamental matrix by minimizing the Sampson error. Experiment results show that our algorithm is quite correct and reasonable for estimating the fundamental matrix.
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  • Application of chemical vapor generation in ICP-MS:A review

    GAO Ying   LIU Rui   YANG Lu  

    Chemical vapor generation(CVG) is an important sample introduction technique,and is widely used for atomic spectrometry for its enhanced sensitivity and selectivity.In the past 30 years,inductively coupled plasma mass spectrometry(ICP-MS) has become a widely used and the most sensitive instrument for(ultra-)trace element determination and elemental speciation.A review of applications of this state-of-the-art coupling of CVG and ICP-MS is presented.Discussion is focused on its applications for both element determination and speciation,including hydride generation,cold vapor generation,photochemical vapor generation,alkylation,and electrochemical vapor generation.In addition,recent studies undertaken isotope dilution calibration in CVG-ICPMS for achieving improved accuracy and precision are summarized,and the future perspectives are discussed.
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