检索结果-南通市图书馆

Effects of moisture and carbonate additions on CO_2 emission from calcareous soil during closed–jar incubation

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2014年第1期6卷 37-43页

作者： YanJie DONG Miao CAI jianbin zhou College of Natural Resources and Environment Northwest A&F University Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China Ministry of Agriculture

Calcareous soil contains organic and inorganic carbon(C) pools,which both contribute to CO2 emission during closed-jar incubation. The mineralization of organic C and dissolution of inorganic C are both related to soil moisture,but the exact effect of water content on CO2 emission from calcareous soil is unclear. The objective of this experiment was to determine the effect of soil water content(air-dried,30%,70%,and 100% water-holding capacity(WHC)),carbonate type(CaCO3 or MgCO3),and carbonate amount(0.0,1.0%,and 2.0%) on CO2 emission from calcareous soil during closed-jar incubation. Soil CO2 emission increased significantly as the water content increased to 70% WHC,regardless of whether or not the soil was amended with carbonates. Soil CO2 emission remained the same or increased slowly as the soil water content increased from 70% WHC to 100% WHC. When the water content was ≤30% WHC,soil CO2 emission from soil amended with 1.0% inorganic C was greater than that from unamended soil. When the soil water content was 70% or 100% WHC,CO2 emission from CaCO3 amended soil was greater than that from the control. Furthermore,CO2 emission from soil amended with 2.0% CaCO3 was greater than that from soil amended with 1.0% CaCO3. Soil CO2 emission was higher in the MgCO3 amended soil than from the unamended soil. Soil CO2 emission decreased as the MgCO3 content increased. Cumulative CO2 emission was 3-6 times higher from MgCO3 amended soil than from CaCO3 amended soil. There was significant interaction effect between soil moisture and carbonates on CO2 emission. Soil moisture plays an important role in CO2 emission from calcareous soil because it affects both biotic and abiotic processes during the closed-jar incubation.

关键词： calcareous soil soil moisture organic carbon CO2 emission

Effect of microstructure and surface chemistry in liquid-phase adsorptive nicotine by almond-shell-based activated carbon

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2013年第30期58卷 3715-3720页

作者： YANG JiLiang FANG Fang zhou jianbin College of Chemical Engineering Nanjing Forestry University

The effect of microstructure and surface chemistry on nicotine adsorption capacity of almond-shell-based activated carbon was ***-shell-based activated carbon was reactivated or modified with steam,ZnCl2and *** surface area and pore structure parameters of activated carbon were determined from the adsorption-desorption isotherm of nitrogen at *** titration and FTIR were explored to determine the surface oxygen *** results revealed that nicotine adsorption from solution on carbons depend on the micropores and phenolic groups.A strong correlation between the amounts of adsorbed nicotine and the phenolic groups was observed,whereas the higher amounts of carboxylic groups decrease the nicotine adsorption capacity on activated carbons.

关键词：液相吸附表面化学微观结构尼古丁活性炭杏仁表面含氧官能团羧酸基团

Analytic fitting and simulation methods for characteristic X-ray peaks from Si-PIN detector

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2013年第6期24卷 43-49页

作者： LI Zhe TUO Xianguo SHI Rui zhou jianbin Provincial Key Laboratory of Applied Nuclear Techniques in Geosciences Chengdu University of Technology State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Southwest University of Science and Technology

A semi-empirical detector response function(DRF)model is established to fit characteristic X-ray peaks recorded in Si-PIN spectra,which is mainly composed of four components:a truncated step function,a Gaussian-shaped full-energy peak,a Gaussian-shaped Si escape peak and an exponential tail.A simple but useful statistical distribution-based analytic method(SDA)is proposed to achieve accurate values of standard deviation for characteristic X-ray *** the values of the model parameters except for the standard deviation are obtained by weighted least-squares fitting of the pulse-height spectra from a number of pure-element samples.A Monte Carlo model is also established to simulate the X-ray measurement *** simulated flux spectrum can be transformed by Si-PIN detector response function to real pulse height spectrum as studied in this ***,the fitting result for a copper alloy sample was compared with experimental spectra,and the validity of the present method was demonstrated.

关键词：硅PIN探测器最小二乘拟合特征X射线模拟方法 Si-PIN探测器蒙特卡罗模型响应函数标准偏差

Use of ^(15)N stable isotope to quantify nitrogen transfer between mycorrhizal plants

在线全文

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2009年第3期2卷 107-118页

作者： Xinhua He Minggang Xu Guo Yu Qiu jianbin zhou School of Life Sciences Yunnan Normal UniversityKunmingYunnan 650092China School of Plant Biology(M084) University of Western AustraliaCrawleyWestern Australia 6009Australia Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural SciencesBeijing 100081China Key Laboratory for Environmental and Urban Sciences Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China College of Resource and Environmental Sciences Northwest A&F UniversityYanglingShaanxi 712100China

Aims Mycorrhizas(fungal roots)play vital roles in plant nutrient acquisition,performance and productivity in terrestrial *** mycorrhizas(AM)and ectomycorrhizas(EM)are mostly important since soil nutrients,including NH+4,NO3 and phosphorus,are translocated from mycorrhizal fungi to *** species,genera and even families of plants could be interconnected by mycorrhizal mycelia to form common mycorrhizal networks(CMNs).The function of CMNs is to provide pathways for movement or transfer of nutrients from one plant to *** the past four decades,both ^(15)N external labeling or enrichment(usually expressed as atom%)and ^(15)N naturally occurring abundance(d^(15)N,&)techniques have been employed to trace the direction and magnitude of N transfer between plants,with their own advantages and *** Findings The heavier stable isotope ^(15)N is discriminated against 14N during biochemical,biogeochemical and physiological processes,due to a greater atomic *** general,non-N2-fixing plants had greater d^(15)N values than N2-fixing(;0&)*** d^(15)N often varied by 5 to 10&in the order:non-mycorrhizas/AMs>EMs>ericoid *** in d^(15)N(&)or ^(15)N(atom%)values could thus provide N transfer information between plants.A range of between 0 to 80%of one-way N transfer had been observed from N2-fixing mycorrhizal to non-N2-fixing mycorrhizal plants,but generally less than or around 10%in the reverse ***-to-plant N transfer may provide practical implications for plant performance in N-limited *** that N translocation or cycling is crucial,and the potential benefits of N transfer are great in both agricultural and natural ecosystems,more research is warranted on either oneway or two-way N transfers mediated by CMNs with different species and under field conditions.

关键词： ^(15)N enrichment ^(15)N natural abundance(^(15)N) ^(15)N stable isotope common mycorrhizal networks(CMNs) nitrogen transfer

Study of time-domain digital pulse shaping algorithms for nuclear signals

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2012年第3期23卷 150-155页

作者： zhou jianbin zhou Wei LEI Jiarong TUO Xianguo ZHU Xing LIU Yi College of Nuclear Chengdu University of Technology Chengdu 610059 China State Key Laboratory of Coal Resources & Mine Safety College of Mining Engineering China University of Mining & Technology Xuzhou 221116 China Institute of Physics and Chemical China Academy of Engineering Physics Mianyang 621900 China

With the development on high-speed integrated circuit,fast high resolution sampling ADC and digital signal processors are replacing analog shaping amplifier *** paper firstly presents the numerical analysis and simulation on R-C shaping circuit model and C-R shaping circuit *** models are established based on 1st order digital differential method and Kirchhoff Current Law in time domain,and a simulation and error evaluation experiment on an ideal digital signal are carried out with Excel VBA.A digital shaping test for a semiconductor X-ray detector in real time is also *** a numerical analysis for Sallen-Key(S-K) low-pass filter circuit model is implemented based on the analysis of digital R-C and digital C-R shaping *** applying the 2nd order non-homogeneous differential equation,the authors implement a digital Gaussian filter model for a standard exponential-decaying signal and a nuclear pulse ***,computer simulations and experimental tests are carried out and the results show the possibility of the digital pulse processing algorithms.

关键词：数字信号处理器脉冲整形算法时域基尔霍夫电流定律计算机模拟非齐次微分方程电路模型

Effects of long-term cultivation practices and nitrogen fertilization rates on carbon stock in a calcareous soil on the Chinese Loess Plateau

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2018年第1期10卷 129-139页

作者： CAI Miao CHEN Zhujun zhou jianbin HAN Jichang SHI Qianyun College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China Shaanxi Provincial Land Engineering Construction Group Xi'an 710075China

Soil organic carbon （SOC） and soil inorganic carbon （SIC） are important C pools in the Loess Plateau of Northwest China, however, variations of SOC and SIC stocks under different cultivation practices and nitrogen （N） fertilization rates are not clear in this area. A long-term field experiment started in June 2003 was conducted to investigate the SOC and SIC stocks in a calcareous soil of the Chinese Loess Plateau under four cultivation practices, i.e., fallow （FA）, conventional cultivation （CC）, straw mulch （SM）, and plastic film-mulched ridge and straw-mulched furrow （RF）, in combination with three N fertilization rates, i.e., 0 （NO）, 120 （N120）, and 240 （N240） kg N/hm2. Results indicate that the crop straw addition treatments （SM and RF） increased the contents of soil microbial biomass C （SMBC） and SOC, and the SOC stock increased by 10.1%-13.3% at the upper 20 cm soil depth in comparison to the 8-year fallow （FA） treatment. Meanwhile, SIC stock significantly increased by 19% at the entire tested soil depth range （0-100 cm） under all crop cultivation practices in comparison to that of soil exposed to the long-term fallow treatment, particularly at the upper 60 cm soil depth. Furthermore, moderate N fertilizer application （120 kg N/hm2） increased SOC stock at the upper 40 cm soil depth, whereas SIC stock decreased as the N fertilization rate increased. We conclude that the combined application of crop organic residues and moderate N fertilization rate could facilitate the sequestrations of SOC and SIC in the calcareous soil.

关键词： calcareous soil cultivation practices N appfication rate soil C stock Loess Plateau

A novel method of determining the optimal polyhedral orientation for discrete global grid systems applicable to regionalscale areas of interest

在线全文

学校读者我要写书评

暂无评论

International Journal of Digital Earth 2020年第12期13卷 1553-1569页

作者： jianbin zhou Jin Ben Rui Wang Mingyang Zheng Xiaochuang Yao Lingyu Du PLA Strategic Support Force Information Engineering University ZhengzhouPeople’s Republic of China College of Land Science and Technology China Agricultural UniversityBeijingPeople’s Republic of China Troops of 31617 FuzhouPeople’s Republic of China

The polyhedral discrete global grid system(DGGS)is a multi-resolution discrete earth reference model supporting the fusion and processing of multi-source geospatial *** orientation of the polyhedron relative to the earth is one of its key design choices,used when constructing the grid system,as the efficiency of indexing will decrease if local areas of interest extend over multiple faces of the spherical *** date,most research has focused on global-scale applications while almost no rigorous mathematical models have been established for determining orientation *** this paper,we propose a method for determining the optimal polyhedral orientation of DGGSs for areas of interest on a regional *** proposed method avoids splitting local or regional target areas across multiple polyhedral *** the same time,it effectively handles geospatial data at a global scale because of the inherent characteristics of *** show that the orientation determined by this method successfully guarantees that target areas are located at the center of a single polyhedral *** orientation process determined by this novel method reduces distortions and is more adaptable to different geographical areas,scales,and base polyhedrons than those employed by existing procedures.

关键词： Discrete global grid systems single polyhedral face convex polygons rotate and translate cost function

Influence of deep magma-induced thermal effects on the regional gas outburst risk of coal seams

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2021年第6期8卷 1411-1422页

作者： Jianshe Linghu Wei Zhao jianbin zhou Zhiming Yan Kai Wang Chao Xu Chuanwen Sun Huayang New Material Technology Group Co. LTD.Yangquan Shanxi 045000China Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources China University of Mining and Technology(Beijing)Beijing 100083China State Key Laboratory of Coal and Coalbed Methane Co-Mining Jincheng Shanxi 048012China Risk Management and Safety Engineering School China University of Mining and Technology(Beijing)Beijing 100083China

The thermal effect caused by deep magma intrusion can not only accelerate the metamorphism of coal body,but also bring additional thermal field that changes the mechanical environment of coal seams,thereby affecting the permeability of coal *** from shallow coal resources,deep coal resources are in a mechanical environment characterized by limited stress and ***,the thermal effect has a more significant influence on the distribution and permeability characteristics of deep coal *** this study,the evolution history of highly metamorphic coal seams in Yangquan mining area was analyzed,and the main effect of magmatic activity on coal seams was *** on the determined vitrinite reflectance data of typical mines in Yangquan mining area,the maximum paleotemperature was calculated by adopting the Barker’s ***,the paleotemperature distribution in Yangquan mining area was summarized,and its relationship with the metamorphic degree was ***,a new permeability model considering the thermal strain was proposed to analyze the permeability evolution in deep coal seams at different ground ***,through a combination of the results of gas pressure and outburst number in Sijiazhuang Mine,Yangquan No.5 Mine and Xinjing Mine,the influence of ground temperature on the gas outburst risk in Yangquan mining area was *** following conclusions were drawn:The maximum paleotemperature in Yangquan area can be 303*** addition,the paleotemperature in the south is higher than that in the north of Yangquan mining *** various temperatures at different depths bring about different degrees of thermal stress to different coal seams,leading to different *** the fixed displacement boundary conditions in the deep,the coal seam folds and bends to varying ***,the difference in the ground temperature raises the a value of coal seams and lowers the permeability,which promotes the formation of gas-r

关键词： Gas outburst Metamorphic degree Geological structure Thermal evolution Yangquan mining area

NITROGEN USE AND MANAGEMENT IN ORCHARDS AND VEGETABLE FIELDS IN CHINA: CHALLENGES AND SOLUTIONS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Agricultural Science and Engineering 2022年第3期9卷 386-395页

作者： Xueqiang ZHU Peng zhou Peng MIAO Haoying WANG Xinlu BAI Zhujun CHEN jianbin zhou College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China Ministry of Agriculture and Rural Affairs of ChinaYangling 712100China.

China is the largest producer and consumer of fruits and vegetables in the *** the annual planting areas of orchards and vegetable fields(OVF)account for 20%of total croplands,they consume more than 30%of the mineral nitrogen fertilizers in China and have become hotspots of reactive N *** N fertilization has not only reduced the N use efficiency(NUE)and quality of grown fruits and vegetables but has also led to soil acidification,biodiversity loss and climate *** using 15N labeling analysis showed that the recovery rate of N fertilizer in OVFs was only 16.6%,and a high proportion of fertilizer N resided in soils(48.3%)or was lost to the environment(35.1%).Nitrate accumulation in the soil of OVFs is the main fate of N fertilizer in northern China,which threatens groundwater quality,while leaching and denitrification are the important N fates of N fertilizer in southern ***,taking different measures to reduce N loss and increase NUE based on the main pathways of N loss in the various regions is urgent,including rational N fertilization,substituting mineral N fertilizers with organic fertilizers,fertigation,and adding mineral N fertilizers with urease inhibitors and nitrification inhibitors.

关键词： nitrogen fate nitrogen fertilizer orchards vegetable fields