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| 1 | Element segregation behavior of aluminum-copper alloy ZL205A显示文摘In aluminum-copper alloy, the segregation has a severe bad effect on the alloying degree, strength and corrosion resistance. A deeper understanding of element segregation behavior will have a great signif icance on the prevention of segregation. In the study, the element segregation behavior of ZL205 A aluminum-copper alloy was investigated by examining isothermally solidifi ed samples using scanning electron microscopy and energy dispersive spectroscopy. The calculated results of segregation coeffi cients show that Cu and Mn are negative segregation elements; while Ti, V and Zr are positive segregation elements. The sequence of element segregation degree from the greatest to the least in ZL205 A alloy is Cu, Mn, V, Ti, Zr and Al. The density of residual liquid is expected to increase with a decrease in the quenching temperature ranging from 630 ℃ to 550 ℃. The calculated results conf irm that the quenching temperature has an insignif icant effect on the liquid density; and the variation of density is mainly due to element segregation. Consequently, segregations of Al, Cu and Mn lead to an increase in density, but Ti, V and Zr present the opposite effect. The contribution of each element to the variation of the liquid density was analyzed. The sequence of contributions of alloying elements to the variation of total liquid density is Cu>Al>Mn>V>Ti>Zr. | Fan Li Hao Qitang Xian Fuchao | 2014 | China Foundry2014，11，6： | 7 |
| 2 | Dissolution of different zinc salts and Zn uptake by Sedum alfredii and maize in mono-and co-cropping under hydroponic culture显示文摘Previous soil pot and field experiments demonstrated that co-cropping the hyperaccumulator Sedum alfredii with maize increased Zn phytoextraction by S. alfredii and decreased Zn uptake by maize shoots. This hydroponic experiment was conducted to investigate whether the facilitation of Zn phytoextraction by S. alfredii resulted from improved dissolution in this co-cropping system and its relation to root exudates. S. alfredii and maize were mono-and co-cropped (without a root barrier) in nutrient solution spiked with four Zn compounds, ZnS, ZnO, Zn3(PO4)2 and 5ZnO·2CO3·4H2O (represented as ZnCO3 ) at 1000 mg/L Zn for 15 days without renewal of nutrient solution after pre-culture. The root exudates were collected under incomplete sterilization and analyzed. The results indicated that the difference in Zn salts had a greater influence on the Zn concentration in maize than for S. alfredii, varying from 210-2603 mg/kg for maize shoots and 6445-12476 mg/kg for S. alfredii in the same order: ZnCO3 > ZnO >Zn3(PO4)2 > ZnS. For the four kinds of Zn sources in this experiment, co-cropping with maize did not improve Zn phytoextraction by S. alfredii. In most cases, compared to co-cropped and mono-cropped maize, mono-cropped S. alfredii resulted in the highest Zn2+ concentration in the remaining nutrient solution, and also had a higher total concentration of low molecular weight organic acids (LMWOA) and lower pH of root exudation. Root exudates did partly influence Zn hyperaccumulation in S. alfredii. | Cheng'ai Jiang Qitang Wu Shucai Zeng Xian Chen Zebin Wei Xinxian Long | 2013 | Journal of Environmental Sciences2013，25，9： | 3 |
| 3 | Effect of environmental C/N ratio on activities of lignin-degrading enzymes produced by Phanerochaete chrysosporium显示文摘Lignin-degrading enzymes secreted by white rot fungi play an important role in the degradation of lignin and persistent organic pollutants(POPs).In this study,effect of environmental C/N ratio on the activities of lignin-degrading enzymes,lignin peroxide(Li P)and manganese peroxidase(Mn P),produced by Phanerochaete chrysosporium,a white rot fungus,was investigated.Glucose was used as C source,and ammonium tartrate of different concentrations was used as N source to provide different C/N ratios.Relationships between Li P and Mn P activities and environmental C/N ratio were explored.The results showed that the higher the N source concentration,the faster the mycelium pellets aged.The faster the mycelium dry weight increased,the higher the Li P and Mn P activities.A high C/N ratio was a necessary condition for the secretion of Li P or Mn P.In addition,mycelium dry weight essentially affected enzyme activities.In the 122 C/N ratio and 50 C/N ratio treatments,mycelium dry weight essentially affected Mn P activity and both Li P and Mn P activities,respectively. | Saihua HUANG Deyin HUANG Qitang WU Meifang HOU Xiaoyan TANG Jian ZHOU | 2020 | Pedosphere2020，30，2： | 3 |
| 4 | Effect of centrifugal counter-gravity casting on solidification microstructure and mechanical properties of A357 aluminum alloy显示文摘To investigate the influence of Centrifugal Counter-gravity Casting(C3) process on the solidification microstructure and mechanical properties of the casting, A357 aluminum alloy samples were produced by different process conditions under C3. The results show that C3 has better feeding capacity compared with the vacuum suction casting; and that the mechanical vibration and the convection of melts formed at the centrifugal rotation stage suppress the growth of dendrites, subsequently resulting in the refinement of grains and the improvement of mechanical properties, density and hardness. A finer grain and higher strength can be obtained in the A357 alloy by increasing centrifugal radius and rotational speed. However, casting defects will appear near the rotational axis and the mechanical properties will decrease once the rotational speed exceeds 150 r·min-1. | Li Xinlei Hao Qitang Miao Xiaochuan Fan Li | 2014 | China Foundry2014，11，1： | 3 |
| 5 | Pressurization control system for low pressure crucible casting显示文摘A new compact pressurization control system of the low pressure casting machine for crucible pressure casting has been developed. It is especially designed for the production of high-quality aluminum or magnesium alloy parts with low input cost. This machine with such a system has the virtue of economical and compact, and combines the Fuzzy-PID technology and achieves accuracies of ±2.5 mbar. At present, this machine has been adopted by several users in China for the production of aluminum alloy castings with high property requirements. Furthermore, for magnesium alloy castings, this machine can be used with the gas protect unit. | Li Qiang Hao Qitang Jie Wanqi | 2011 | China Foundry2011，8，4： | 2 |
| 6 | Occurrence of organic contaminants in sewage sludges from eleven wastewater treatment plants, China 显示文摘 | CAI Quanying MO Cehui WU Qitang | 2007 | Chemosphere2007，68，9： | 1 |
| 7 | Characterization of cadmium desorption in soils and its relationship to plant uptake and cadmium leaching显示文摘 | WU Qitang XU Zhaoli MENG Qingqiang | 2004 | Plant and Soil2004，258，： | 1 |
| 8 | A new isopentenyl diphosphate isomerase gene from sweet potato: cloning, characterization and color complementation显示文摘 | Zhihua Liao Min Chen Yijian Yang Chunxian Yang Yufan Fu Qitang Zhang Qiang Wang | | 0，2008，： | 1 |
| 9 | Bioremediation of polycyclic aromatic hydrocarbons ( PAHs )-contaminated sewage sludge by different composting processes 显示文摘 | CAI Quanying MO Cehui WU Qitang | 2007 | J Hazard Mater2007，142，12： | 1 |
| 10 | Characterization of cadmium desorption in soils and its relationship to plant uptake and cadmium leaching显示文摘 | WU QITANG ZHAOLIi XU QINGQIANG MENG | 2004 | Plant and Soil2004，，： | 1 |
| 11 | Plant-biofilm oxidation ditch for in situ treatment of polluted waters 显示文摘 | Wu Qitang Gao Ting Zeng Shucai | 2006 | Ecological Engineering2006，28，2： | 1 |
| 12 | The status of soil contamination by semivolatile organic chemicals (SVOCs) in China: a review 显示文摘 | CAI Quanying MO Cehui WU Qitang | 2008 | Sci Total Environ2008，389，23： | 1 |
| 13 | Phytoextrac- tion of Zn and Cu from sewage sludge and impact on agro- nomic characteristics 显示文摘 | LIU Xiaomei WU Qitang BANKS M K | 2005 | Journal of Environmental Science and Health2005，40，4： | 1 |
| 14 | Co-cropping for phyto-separation of zinc and potassium from sewage sludge 显示文摘 | WU Qitang HEI Liang WONG J W C | 2007 | Chemosphere2007，68，10： | 1 |
| 15 | Effect of C/N on composting of pig manure with sawdust显示文摘 | Huang Guofeng Wong J W C Wu Qitang | 2004 | Waste Management2004，24，8： | 1 |
| 16 | The Status of Soil Contamination by Semivolatile Organic Chemicals (SVO Cs)in Chi- na,A review 显示文摘 | Cai Quanying Mo Cehui Wu Qitang | 2008 | Sci Total Environ science of the total environment2008，389，： | 1 |
| 17 | Concentration and speciation of heavy metals in six different sewage sludge-composts 显示文摘 | CAI Quanying MO Cehui WU Qitang | 2007 | J Hazard Mater2007，147，3： | 1 |
| 18 | Sewage sludge ditch for recovering heavy metals can improve crop yield and soil environmental quality显示文摘The treatment and disposal of municipal sewage sludge(MSS)is an urgent problem to be resolved in many countries.Safely using the nutrients within MSS to increase crop yield and enhance the fertility of poor soil could contribute to achieving sustainable development.An indirect use of MSS in ditches alongside Pennisetum hybridum plants was studied in field plots for 30 months and the contents of heavy metals and macronutrients were monitored in soil,sludge and plant samples.We found that the yield of P.hybridum was significantly increased by 2.39 to 2.80 times and the treated plants had higher N content compared with no sludge.In addition,the organic matter(OM)and N contents in the planted soil increased significantly compared with the initial soil.The OM content in the planted soil of the MSS treatment was 2.9 to 5.2 times higher than that with no sludge,and N increased by 2.0 to 3.8 times.However,MSS had no significant effect on the N,P and K contents in the soil at the bottom of the MSS ditch,and the content of heavy metals(Cd,Pb,Cu and Zn)were also within the safe range.Moreover,the moisture content and phytotoxicity of MSS after this indirect use were reduced and the heavy metal contents changed little,which is favorable to the further disposal of recovered MSS.Therefore,this indirect use of MSS is beneficial to agricultural production,soil quality and environmental sustainability. | Xianke Lin Xiaohong Chen Sichang Li Yangmei Chen Zebin Wei Qitang Wu | 2021 | Frontiers of Environmental Science & Engineering2021，15，2： | 0 |
| 19 | Chemical and Biological Evaluation of Maturity of Pig Manure Compost at Different C/N Ratios显示文摘Aerobic static pile composting (mechanical turning every 3 days) of pig manure was prepared at & m3 windrow heaps. Sawdust was used as the bulking agent to provide additional carbon and to increase the porosity of the substrate. Two treatments at initial C/N ratios of 30 and 15, respectively, were designed in the study. Dissolved organic carbon (DOC), soluble NH+4-N, C/N ratios in solid and aqueous phases, E4/E6 ratios, and seed germination index (GI) were determined to evaluate the maturity of the co-composts. Seed germination index, a biological parameter, was suggested as one of the most reliable maturity indicators for organic compost. The results showed that the treatment at the initial C/N ratio of 30 reached maturity after 49 days of composting; however, the treatment at the initial C/N ratio of 15 should require composting time of longer than 63 days to obtain maturation. Chemical multi-indicator evaluation was necessary, and the GI measurement was the recommended approach for maturity evaluation in the study. | HUANG GUOFENG WU QITANG LI FANGBAI and J. W. C. WONG College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642 (China) Department of Biology, Hong Kong Baptist University, Hong Kong (China) | 2001 | Pedosphere2001，11，3： | 0 |
| 20 | Root cell walls and phytochelatins in low-cadmium cultivar of Brassica parachinensis显示文摘‘Lvbao-701’ is a cultivar of Chinese flowering cabbage(Brassica parachinensis) that exhibits low cadmium(Cd) accumulation and high Cd tolerance.In this study, this cultivar was compared with a high-Cd accumulating cultivar, ‘Chixin-4’, to characterize the mechanisms influencing Cd accumulation in B. parachinensis. Root cell walls were isolated by dissolving the cytoplasm with an organic solvent, and root Cd and phytochelatin(PC) contents were analyzed. In addition, a PC synthase gene fragment was cloned and expressed under Cd stress conditions. The proportions of Cd bound to root cell walls were higher in the ‘Lvbao-701’ plants(68.32%–76.80%) than in the ‘Chixin-4’ plants(35.36%–54.18%) after exposure to Cd stress. The proportions of Cd bound to root cell walls measured using cell walls isolated with a non-destructive method were higher than those obtained using a conventional method that required grinding and centrifugation. Exposure to Cd stress induced the PC production and resulted in higher PC contents in the ‘Lvbao-701’ plants than in the ‘Chixin-4’ plants. Cloning and expression analysis of a B. parachinensis PC synthase cDNA fragment indicated that PC synthase gene expression was induced by Cd and occurred mainly in the roots of both ‘Lvbao-701’ and ‘Chixin-4’ plants. However, the PC synthase gene expression level was higher in the‘Lvbao-701’ roots than in the ‘Chixin-4’ roots. Therefore, a higher abundance of Cd in the root cell walls of ‘Lvbao-701’ and up-regulated PC production in the roots are probably the main reasons why ‘Lvbao-701’ exhibits lower Cd translocation to the shoots and higher tolerance to Cd than ‘Chixin-4’. | Yan SUN Hui YE Zebin WEI Xuhui KONG Qitang WU | 2020 | Pedosphere2020，30，3： | 0 |
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