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Use of Several Plant Materials and Chemicals to inhibit Soil Urease Activity and Increase Nitrogen Recovery Rate of Urea by Plant

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Pedosphere 2002年第3期12卷 275-282页

作者： XU WEIHONG, WANG ZHENGYIN, JIA ZHONGYUAN, HUANG YUN, YUAN LUJIANG and WANG JUANMEIcollege of resources and environmental Science,{3., chongqing 400716 (China) college of resources and environmental Science Southwest Agricultural University Chongqing 400716China

Effects of residues of 9 plants, lemon eucalyptus (Eucalyptus citriodoraHook., P_1), robust eucalyptus (E. robusta Smith, P_2), Nepal camphortree (Cinnamomum glanduliferum(Wall.) Nees, P_3., tea (Camellia sinensis (Linn.) O. Ktze. f., P_4), oleander (Nerium indicum Mill,P_5), rape (Brassica campestris L., P_g), Chinese tallow tree (Sapium sebiferum L., P_7), tung(Vernicia fordii (Hemsl.), P_8), and croton (Croton tiglium L., P_9), 7 chemicals, boric acid (C_1),borax (C_2), oxalic acid (C_3., sodium oxalite (C_4), sodium dihydrogen phosphate (C_6), sodiumsilicate (C_7) and sodium citrate (C_8), and a natural organic substance, humic acid (C_5), onurease activity of a neutral purple soil and recovery of urea nitrogen by maize were studied throughincubation and pot experiments. Hydroquinone (HQ) was applied as the reference inhibitor. Afterincubation at 3.℃ for 24 h, 7 inhibitors with higher ability to inhibit urease activity wereselected and then incubated for 14 days at 25℃. Results of the incubation experiments showed thatsoil urease activity was greatly inhibited by them, and the inhibition effect followed an order ofP_2>P_4>C_3.C_2>P_3.C_1>HQ>P_1. The 7 selected materials reduced the accumulative amounts of Nreleased from urea and the maximum urease activity by 11.7%～28.4% and 26.7%～3..7%, respectively,and postponed the N release peak by 2～4 days in the incubation period of 14 days under constanttemperature, as compared to the control (no inhibitor). In the pot experiment with the 7 materialsat two levels of addition, low (L) and high (H), the C_1 (H), C_3.(H), C_1 (L), P_4 (L) and C_2 (L)treatments could significantly increase the dry weights of the aboveground parts and the totalbiomass of the maize plants and the apparent recovery rate of urea-N was increased by 6.3.～3..4% ascompared to the control (no hibitor).

关键词： chemicals plant materials recovery rate of fertilizer nitrogen ureaseactivity

A study of interaction between surface water and groundwater using environmental isotope in Huaisha River basin

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Science China Earth Sciences 2006年第12期49卷 1299-1310页

作者： SONG Xianfang1, LIU Xiangchao1, 2, XIA Jun1, YU Jingjie1 & TANG Changyuan1, 3.1. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographical Sciences and Natural Re- sources Research, Chinese Academy of Sciences, Beijing 100101, China 2. college of River and Ocean, chongqing Jiaotong university, chongqing 400074, China 3. Chiba university, Chiba 263.8522, Japan 1. Key Laboratory of Water Cycle and Related Land Surface Processes Institut of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China 2. college of River and Ocean Chongqing Jiaotong University Chongqing 400074 China 3. Chiba university Chiba 263-8522 Japan

The surface water and groundwater are important components of water cycle, and the interaction between surface water and groundwater is the important part in water cycle research. As the effective tracers in water cycle research, environmental isotope and hydrochemistry can reveal the interrelationships between surface water and groundwater effectively. The study area is the Huaisha River basin, which is located in Huairou district, Beijing. The field surveying and sampling for spring, river and well water were finished in 2002 and 2003. The hydrogen and oxygen isotopes and water quality were measured at the laboratory. The spatial characteristics in isotope and evolution of water quality along river lines at the different area were analyzed. The altitude effect of oxygen isotope in springs was revealed, and then using this equation, theory foundation for deducing recharge source of spring was estimated. By applying the mass balance method, the annual mean groundwater recharge rate at the catchment was estimated. Based on the groundwater recharge analysis, combining the hydrogeological condition analysis, and comparing the rainfall-runoff coefficients from the 1960s to 1990s in the Huaisha River basin and those in the Chaobai River basin, part of the runoff in the Huaisha River basin is recharged outside of this basin, in other words, this basin is an un-enclosed basin. On the basis of synthetically analyses, combining the compositions of hydrogen and oxygen isotopes and hydrochemistry, geomorphology, geology, and watershed systems characteristics, the relative contributions between surface water and groundwater flow at the different areas at the catchments were evaluated, and the interaction between surface water and groundwater was re- vealed lastly.

关键词： environmental isotope,hydrochemistry,surface water,groundwater,interaction.

Tillage Effect on Organic Carbon in a Purple Paddy Soil

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Pedosphere 2006年第5期16卷 660-667页

作者： HUANG Xue-Xia GAO Ming WEI Chao-Fu XIE De-Ti PAN Gen-Xing college of resources and environment Southwest Agricultural University Chongqing 400716 （China） college of environmental Science and Technology Guangzhou University Guangzhou 510006 （China） college of resources and environment Nanjing Agricultural University Nanjing 210095 （China）

The distribution and storage of soil organic carbon (SOC) based on a long-term experiment with various tillage systems were studied in a paddy soil derived from purple soil in chongqing, China. Organic carbon storage in the 0-20 and 0-40 cm soil layers under different tillage systems were in an order: ridge tillage with rice-rape rotation (RT-rr) > conventional tillage with rice only (CT-r) > ridge tillage with rice only (RT-r) > conventional tillage with rice-rape rotation (CT-rr). The RT-rr system had significantly higher levels of soil organic carbon in the 0-40 cm topsoil, while the proportion of the total remaining organic carbon in the total soil organic carbon in the 0-10 cm layer was greatest in the RT-rr system. This was the reason why the RT-rr system enhanced soil organic carbon storage. These showed that tillage system type was crucial for carbon storage. Carbon levels in soil humus and crop-yield results showed that the RT-rr system enhanced soil fertility and crop productivity. Adoption of this tillage system would be beneficial both for environmental protection and economic development.

关键词： carbon sequestration organic carbon storage purple paddy soil tillage system

Effects of atmospheric mercury pollution on terrestrial ecosystem in chongqing, China

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Journal of environmental Sciences 2000年第S1期12卷 31-38页

作者： WANG Ding yong, LIU De shao, YAO Ai jun, PI Guang jie, MOU Shu sen, QING Chang le (college of resources and environment,{3., chongqing 400716, China)

The results from investigations indicated that mercury pollution in terrestrial ecosystem was serious due to the anthropogenic mercury emission growing in chongqing, China. The concentration of atmospheric mercury in chongqing was 3..4±2.7 ng/m\+3.with the range of 9.2—101.5. The accumulation of mercury in surface soil was increasing with time. The mercury content of some agricultural products have exceeded the food health standard value, especially near the mercury emission sources. The mercury accumulation in soil plant system was affected by atmospheric mercury and a positive correlation between them was found. Volatilization of mercury was the most important processes with which soil mercury joined the global mercury recycling.

关键词： accumulation agricultural product atmospheric mercury pollution plant soil terrestrial ecosystem

Characteristics and origins of primary fluids and noble gases in mantle-derived minerals from the Yishu area,Shandong Province,China

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Science China Earth Sciences 2006年第1期49卷 77-87页

作者： MA Jinlong1,2, TAO Mingxin2,3.& YE Xianren2 1. resources and environmental School, Lanzhou university, Lanzhou 73.000, China 2. Key Laboratory of Gas Geochemistry, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 73.000, China 3.{3. of resources Science & Technology, Beijing Normal university, Beijing 100875, China 1. resources and environmental School Lanzhou University Lanzhou 730000 China 2. Key Laboratory of Gas Geochemistry Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou 730000 China 3. college of resources Science & Technology Beijing Normal University Beijing 100875 China

Fluids and noble gases of mantle-derived materials are important tracers forthe mantle information. Compositions of primary fluids and noble gases in mantle-derived mineralsfrom the Yishu area, Shandong Province, China, were tested by the methods of heat-bursting andheat-melting respectively. The fluids are mainly composed of CO_2, CO and H_2, which account forabout 90% of the total, and are similar to the mantle-derived rocks from other areas of easternChina; ratios of ~3.e/~4He in almost all samples range from 0.82 Ra to 2.74 Ra, whereas^(40)Ar/^(3.)Ar from 299.5 to 758.8. Both ranges are much lower than those of the typical oceanmantle-derived samples (such as MORB) and primarily reflect the influences of the atmosphericcomponents and the radiogenic isotopes. Ratios of C/~3.e range from 27.6 x 10~9 to 1050 x 10~9,N_2/Ar from 927 to 56612, and N_2/~3.e from 2.5 x 10~9 to 27 x 10~9, similar to those in westernUnited States and New Zealand which belong to the tectonic plate collision regions. The ratios fallin the intersect of mantle-crust-atmosphere in the comprehensive tracer-charts, reflecting theinfluences of the atmosphere and the crusts with organic components. Our results suggest that thecomposition of the primary fluids and the isotopic ratios of the noble gases may either reflect theevolution process of mantle-derived rocks connected with the rise and eruption of magma, or theinfluence of the ancient subduction-plate on the continental mantle of this region.

关键词： noble gases, primary fluids, mantle-derived minerals, Yishu area.

Thermal Conductivity and Heat Transfer Coefficient of Concrete

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Journal of Wuhan university of Technology(Materials Science) 2011年第4期26卷 791-796页

作者：郭利霞 North China university of Water resources and Electric Power

A very simple model for predicting thermal conductivity based on its definiensis was presented. The thermal conductivity obtained using the model provided a good coincidence to the investigations performed by other authors. The heat transfer coefficient was determined by inverse analysis using the temperature measurements. From experimental results, it is noted that heat transfer coefficient increases with the increase of wind velocity and relative humidity, a prediction equation on heat transfer coefficient about wind velocity and relative humidity is given.

关键词： thermal conductivity heat transfer coefficient relative humidity wind velocity

Air flow exploration of abrasive feed tube

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Acta Mechanica Sinica 2009年第6期25卷 761-768页

作者： Shijin Zhang Xiaohong Li Yilei Gu college of resources and environmental Science,{3. university, 400044 {3., China college of resources and environmental Science Chongqing University 400044 Chongqing China

An abrasive water-jet cutting process is one in which water pressure is raised to a very high pressure and forced through a very small orifice to form a very thin high speed jet beam. This thin jet beam is then directed through a chamber and then fed into a secondary nozzle, or mixing tube. During this process, a vacuum is generated in the cham- ber, and garnet abrasives and air are pulled into the chamber, through an abrasive feed tube, and mixes with this high speed stream of water. Because of the restrictions introduced by the abrasive feed tube geometry, a vacuum gradient is generated along the tube. Although this phenomenon has been recog- nized and utilized as a way to monitor nozzle condition and abrasive flowing conditions, yet, until now, conditions inside the abrasive feed line have not been completely understood. A possible reason is that conditions inside the abrasive feed line are complicated. Not only compressible flow but also multi- phase, multi-component flow has been involved in inside of abrasive feed tube. This paper explored various aspects of the vacuum creation process in both the mixing chamber and the abrasive feed tube. Based on an experimental exploration, an analytical framework is presented to allow theoretical calculations of vacuum conditions in the abrasive feed tube.

关键词： Abrasive feed tube- Water jet cutting. Vacuum gradient

Constraints of authigenic carbonates on trace elements (Sr,Mg) of lacustrine ostracod shells in paleoenviron-ment reconstruction and its mechanism

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Science China Earth Sciences 2008年第5期51卷 654-664页

作者： HU Guang1,2, JIN ZhangDong1 & ZHANG Fei3.1 State Key Laboratory of Loess and Quaternary Geology, Institute of Earth environment, Chinese Academy of Sciences, Xi’an 710075, China 2 Graduate university of the Chinese Academy of Sciences, Beijing 100049, China 3.college of{3. and environmental Science, Nanjing agricultural university, Nanjing 210095, China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China Graduate university of the Chinese Academy of Sciences Beijing 100049 China college of resources and Env

Molar ratios of Mg/Ca and Sr/Ca were measured in two species of ostracod shells preserved in the upper core (15–55 m) of the Hequing Basin in Yunnan Province, southwest China. By correlating the molar ratios between Mg/Ca and Sr/Ca and comparing them with Sr concentrations of the sediments, we suggested that: (1) the molar Mg/Ca and Sr/Ca ratio variations in respective ostracod primo reflected the changes in its ambient water composition and ecology; (2) the molar Sr/Ca ratios responded better to the salinity change linearly than Mg/Ca without aragonite precipitation in the system, and otherwise there was no linear relation between them; and (3. the molar Sr/Ca ratios were mainly controlled by salinity and authigenic carbonate precipitation, whereas the molar Mg/Ca ratios were related to both salinity and temperature. In fact, the rate of ostracod growth owing to temperature controls the fluctuation of Mg/Ca in shells. Here, more attentions should be paid to the constraint of authigenic mineral precipitation processes on the trace elements in ostracod shells and to the correlation between these trace elements in biogenic carbonates and compositions of the sediments in systems and in future in vitro experiments.

关键词： ostracod shell molar Sr/Ca ratio molar Mg/Ca ratio environmental response Heqing Basin

Root Exudates, Rhizosphere Zn Fractions, and Zn Accumulation of Ryegrass at Different Soil Zn Levels

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Pedosphere 2007年第3期17卷 389-396页

作者： XU Wei-Hong LIU Huai MA Qi-Fu XIONG Zhi-Ting college of resources and environmental Sciences Southwest University Chongqing 400716 （China） college of Plant Protection Southwest University Chongqing 400716 （China） Soil Science and Plant Nutrition University of Western Australia Crawley WA 600Y （ Australia） college of resources and environmental Sciences Wuhan University Wuhan 430072 （China）

A glasshouse experiment was conducted using a root-bag technique to study the root exudates, rhizosphere Zn fractions, and Zn concentrations and accumulations of two ryegrass cultivars （Lolium perenne L. cvs. Airs and Tede） at different soil Zn levels （0, 2, 4, 8, and 16 mmol kg^-1 soil）. Results indicated that plant growth of the two cultivars was not advérsely affected at soil Zn level ≤ 8 mmol kg^-1. Plants accumulated more Zn as soil Zn levels increased, and Zn concentrations of shoots were about 540 μg g^-1 in Aris and 583.9 μg g^-1 in Tede in response to 16 mmol Zn kg^-1 soil. Zn ratios of shoots to roots across the soil Zn levels were higher in Tede than in Airs, corresponding with higher rhizosphere available Zn fractions （exchangeable, bound to manganese oxides, and bound to organic matter） in Airs than in Tede. Low-molecular-weight （LMW） organic acids （oxalic, tartaric, malic, and succinic acids） and amino acids （proline, threonine, glutamic acid, and aspartic acid, etc.） were detected in root exudates, and the concentrations of LMW organic acids and amino acids increased with addition of 4 mmol Zn kg^-1 soil compared with zero Zn addition. Higher rhizosphere concentrations of oxalic acid, glutamic acid, alanine, phenylalanine, leucine, and proline in Tede than in Airs likely resulted in increased Zn uptake from the soil by Tede than by Airs. The results suggested that genotypic differences in Zn accumulations were mainly because of different root exudates and rhizosphere Zn fractions.

关键词： plant Zn accumulation rhizosphere Zn fractions root exudates ryegrass soil Zn level