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Soil Microbial Biomass Nitrogen and Its Relationship to Uptake of Nitrogen by Plants

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Pedosphere 2002年第3期12卷 251-256页

作者： ZHOUJIANBIN LISHENGXIU 等 CollegeofResourcesandEnvironmentalSciences NorthwestSci－TechUniversityofAgricultureandForestryYanglingShaanxi712100（China） CollegeofResourcesandEnvironmentalSciences NorthwestSci－TechUniversityofAgr

The contents of the soil microbial biomass nitrogen (SMBN) in the soils sampled from the Loess Plateau of China were determined using chloroform fumigation aerobic incubation method (CFAIM), chloroform fumigation anaerobic incubation method (CFANIM) and chloroform fumigation-extraction method (CFEM).The N taken up by ryegrass on the soils was determined after a glasshouse pot experiment. The flushes of nitrogen (FN) of the soils obtained by the CFAIM and CFANIM were higher than that by the CFEM, and there were significantly positive correlations between the FN obtained by the 3 methods. The N extracted from the fumigated soils by the CFAIM, CFANIM and CFEM were significantly positively correlated with the N uptake by ryegrass. The FN obtained by the 3 methods was also closely positively correlated with the plant N uptake. The contributions of the SMBN and mineral N and mineralized N during the incubation period to plant N uptake were evaluated with the multiple regression method. The results showed that the N contained in the soil microbial biomass might play a noticeable role in the N supply of the soils to the plant.

关键词： mineral N N uptake soil microbial biomass N

Nitrate Accumulation in Soil Profile of Dry Land Farming in Northwest China

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Pedosphere 2003年第4期13卷 367-374页

作者： FAN Jun, HAO Ming-De and SHAO Ming-AnState Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, the Chinese Academy of Sciences, yangling 712.00 (China). State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation the Chinese Academy of Sciences Yangling 712100 China

A long-term fertilizer experiment on dry land of the Loess Plateau, northwestChina, has been conducted since 1984 to study the distribution and accumulation of NO_3-N down to adepth of 400 cm in the profile of a coarse-textured dark loessial soilafter continuous winter wheatcropping. Thirteen fertilizer treatments consisted of four levels of N and P applied alone or incombination. Annual N and P (P_2O_5) rates were 0, 45, 90, 135 and 180 kg ha^(-1). After 15successive cropping cycles, the soil samples were taken from each treatment for analysis of NO_3-Nconcentration. The results showed that NO_3-N distribution in the soil profile was quite differentamong the treatments. The application of fertilizer N alone resulted in higher NO_3-N concentrationin the soil profile than the combined application of N and P, showing that application of P couldgreatly reduce the NO_3-N accumulation. With an annual application of 180 kg N ha^(-1) alone, a peakin NO_3-N accumulation occurred at 140 cm soildepth, and the maximum NO_3-N concentration in thesoils was 67.92 mg kg^(-1). The amount of NO_3-N accumulated in the soil profile decreased as thecumulative N uptake by the winter wheat increased. Application of a large amount of N resulted inlowerN recoveries in winter wheat and greater NO_3-N accumulation in soil profile. KO_3-N did notenter underground water in the study region; therefore, there is no danger of underground waterpollution. Amount of NO_3-N accumulation can be predicted by an equation according to annual N and Prates based on the results of this experiment.

关键词： dry land long-term fertilizer experiment NO_3-N accumulation wheat

Mechanisms for the Movement of Fe，Mn，Cn and Zn to Plant Roots in Loessal So il and Lon Soil

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Pedosphere 1994年第3期4卷 245-254页

作者： XU MINGGANG, ZHANG YIPING, SUN BENHUA(Department of Soil Science and Agrochemistry, Northwestern Agricultural University, yangling, Shaanxi712.00(China))(

The pot experiments were conducted in the artificial climate laboratories to determine the relativeimportance of mass flow and diffusion in supplying Fe, Mn, Cu and Zn to wheat, soybean and maize plantsgrowing in loessal soil and lou soil. It was found that the calculated relative contribution of mass flow ofiron, manganese, copper and zinc to plant uptake varied from 5% to more than 100%,depending on the cropspecies and soil types as well as plant growth stage, soil moisture, atmosphere humidity, etc. The results alsoshowed that the major transportation mechanisms of these micronutrients in soil-root system varied with thecrop and its growth, climate and soil, significantly. In general, mass flow was more important for Cu andZn and diffusion was more significant for Fe and Mn at the seedling stage.

关键词： diffusion iron manganese mass flow soil-root system

考虑环保约束的矿产资源型供应链收益及分配研究

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考虑环保约束的矿产资源型供应链收益及分配研究

作者：杨玲成都理工大学

学位级别：硕士

资源不仅是物质基础,还关系到国家经济复苏,具有重要的战略作用。而正是依托丰富资源建立起来的资源型企业想要在经济全球化的市场上占领一席之地,以供应链的形式进行竞争是企业的必经之途。但供应链带来高利益、高效率与高市场占有率... 详细信息

资源不仅是物质基础,还关系到国家经济复苏,具有重要的战略作用。而正是依托丰富资源建立起来的资源型企业想要在经济全球化的市场上占领一席之地,以供应链的形式进行竞争是企业的必经之途。但供应链带来高利益、高效率与高市场占有率的同时,其失败率也高居不下,内部冲突便是主要原因之一,而收益问题恰是最易引起内部冲突的因素之一。因此分析收益问题,在一定程度上不仅可以化解供应链节点企业间的对立与冲突,还可以保证供应链的稳定运行。而随着中国经济的高速发展,正确处理经济发展和生态环境保护的关系也变得尤其重要,因而在环保约束的条件下,探讨资源型供应链的收益及其分配问题具有极强的现实意义。基于此,本文考虑一个由资源开发商与资源加工商组成的两级资源型供应链在环保约束下进行供应链的收益分析并探索集中决策下的收益分配问题。首先,对资源型供应链的内涵、环保约束以及对收益分配的影响因素等进行定性地分析。其次,在定性分析的基础上,提炼出低碳减排因子和生态修复因子两个重要的环保因素、市场波动因素以及消费者的“环保偏好”等因素,并进行量化,建立供应链收益模型。再根据资源型供应链收益模型的定量分析,结合资源型供应链的定性分析,综合考虑风险因子、生态因子、努力程度三个影响因素,将传统的Shapley值法进行了改进和完善,进行集中决策下的资源型供应链的收益分配,并辅以算例验证模型的有效性。与现有研究相比,论文在两个方面进行了创新:一、首次结合环保形势分析资源型供应链,并首次提出生态修复因素并将市场波动考虑进资源型供应链收益模型的构建和具体分析中;二、首次提炼出适合集中决策下的资源型供应链系统收益的分配模型。并通过模型的分析可以得到以下主要结论:(1)市场需求波动增大,资源型供应链的期望收益会减少。(2)减排水平与资源开发商的价格正相关,与资源加工商的价格关系取决于顾客对环保重要性的认知程度和产品需求的价格弹性系数,客户的环保认知程度越高,需求的价格弹性越低,资源加工商的价格与减排水平呈现正相关关系,反之,负相关。(3)生态修复水平与资源加工品以及资源品的价格都呈现正相关关系。(4)在下游主导型的这种市场结构下,随着生态修复水平γ(减排水平ξ)的增加,资源开发商的收益E(πr(D))(资源加工商的期望利润E(πm(D))会先升高后降低。(5)当资源型供应链各企业集中决策时,供应链系统利润比分散决策时高。(6)在环保约束的情况下,合作决策时资源型供应链实现的最优减排水平最高,其次是下游主导型结构,然后是上下游均衡型供应链,最后是上游主导下的供应链。(7)在考虑环保因素以及顾客有限“环保偏好”的情况下,合作决策时资源型供应链实现的最优生态修复水平最高,其次是上游主导型资源供应链,然后是上下游均衡型供应链,最后是下游主导下的供应链。(8)在环保约束下,考虑风险因子、生态因子、努力水平3个影响因素,引入综合修正因子对Shapley值法进行改进,并将其用于合作决策下的收益分配,对比发现改进后的模型较传统Shapley值法更加科学合理。

关键词：矿产资源型供应链低碳约束生态修复收益分配博弈

颈项透明层增厚胎儿的绒毛染色体及微阵列结果分析

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分子诊断与治疗杂志 2024年第3期16卷 553-556页

作者：刘建珍林铿许碧秋孟祥荣李熹翀鞠爱萍覃燕龄陈鸿桢广州市花都区妇幼保健院检验科广东广州510800

目的探讨核型分析及染色体微阵列分析(CMA)技术在颈项透明层(NT)增厚胎儿产前诊断中的应用价值,评价NT增厚在产前筛查中的作用。方法选取2018年1月至2020年12月孕11~13+6周在广州市花都区妇幼保健院筛查NT增厚(NT≥2.5 mm)胎儿137例,... 详细信息

目的探讨核型分析及染色体微阵列分析(CMA)技术在颈项透明层(NT)增厚胎儿产前诊断中的应用价值,评价NT增厚在产前筛查中的作用。方法选取2018年1月至2020年12月孕11~13+6周在广州市花都区妇幼保健院筛查NT增厚(NT≥2.5 mm)胎儿137例,经胎盘绒毛穿刺,行“核型分析+CMA”检测,按NT值和临床指征分组,分别分为2.5~2.9 mm、3.0~3.9 mm、4.0~4.9 mm、NT≥5.0 mm组和孤立性NT增厚组、非孤立性NT增厚组,分析各组核型分析和CMA结果。结果核型分析检出率为10.95%(15/137),CMA检出率为16.79%(23/137),CMA联合核型分析异常检出率为18.25%(25/137)。2.5~2.9 mm、3.0~3.9 mm、4.0~4.9 mm、NT≥5.0 mm组的检出率分别为7.89%(3/38)、8.20%(5/61)、33.33%(7/21)、52.94%(9/17),各组间差异有统计学意义(χ^(2)=22.54,P<0.05)。孤立性NT增厚组和非孤立性NT增厚组的检出率分别为12.24%(12/98)和26.67%(12/45),差异有统计学意义(χ^(2)=4.59,P<0.05)。结论染色体核型分析联合CMA技术能提高NT增厚胎儿异常检出率,染色体异常发生率随NT值增高及合并其他超声异常明显增高。

关键词：颈项透明层厚度核型分析染色体微阵列产前诊断

Effect of apple production base on regional water cycle in Weibei upland of the Loess Plateau

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Journal of Geographical Sciences 2001年第2期11卷 239-243页

作者： HUANG Ming-bin~1, HE Fu-hong~2, YANG Xin-min~1, LI Yu-shan~1 (1. Institute of Soil and Water Conservation, CAS, yangling 712.00, China 2. Northwest Sci-tech University of Agriculture and Forestry, yangling 712.00, China) Institute of Soil and Water Conservation CAS Northwest Sci-tech University of Agriculture and Forestry

Weibei upland, located in southern part of the Loess Plateau, is a commercial apple production base in China. The enlargement of apple-planting area has a great impact on the regional water cycle. The effects of different land use on hydrological parameters are compared and studied in this paper. The main results are as follows (1) The initial and steady infiltration rates in apple orchard are higher than those in other land use types such as grassland, idle land and farmland. Their initial rates of infiltration are 0.823 cm/min, 0.215 cm/min, 0.534 cm/min and 0.586 cm/min in apple orchard, grassland, idle land and farmland respectively. Their steady infiltration rates are 0.45 cm/min, 0.038 cm/min, 0.191 cm/min and 0.155 cm/min respectively. (2) There is no runoff generated in plot of apple orchard in all 8 storm events in observed natural rainfalls, while runoff is generated in winter wheat plot, corn plot and alfalfa plot with runoff coefficients of 2.39%, 1.58% and 0.31% respectively. (3) The transpiration of apple trees is strong and thus soil moisture is gradually depleted. The average soil water contents in 3–9 m soil profile in Changwu plots with apple trees of 14 and 32 years in age are 11.77% and 11.59% and in Luochuan plots with those of 15 and 28 years in age are 11.7% and 11.59% respectively, which are nearly 9.0% of wilting moisture of Changwu soil and 8.6% of wilting moisture of Luochuan soil. The pathway of rainfall percolating to groundwater is hindered by dry soil profile.

关键词： Loess Plateau Weibei upland water cycle

Dynamics of Nutrient Accumulation in Maize Plants Under Different Water and N Supply Conditions

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Agricultural Sciences in China 2002年第12期1卷 1350-1357页

作者： SONG Hai-xing and LI Sheng-xiu(Northwestern Science and Technology University of Agriculture and Forestry, yangling 712.00 , P. R. China) Northwestern Science and Technology University of Agriculture and Forestry Yangling 712100 P.R.China

The dynamics of accumulations of plant dry matter, nutrient uptake and N fertilizer recovery were studied with different water and N supply, using summer maize (Zea mays L. var. Shandan9) as an indicator crop. The total dry matter (including roots) and N, P, K uptake amounts were continuously increased with plant growth, and their accumulations with time during plant-growing period were shaped in S curves that could be described by exponential regression equations. Differentiating the regression equations fitting the curves over time for first derivatives, the momentary rate was obtained of the dry matter and nutrient uptake. Results show that the dry matter and the nutrient uptake were not in the same rate at all time, but changed from one time to another. Usually, the rate increased rapidly at early stages, and gradually decreased after reaching their peak. Of N, P and K, the uptake rate of N and K was higher, and their increase and decrease were both fast while P was reversed. The time of the maximum absorptive rate appeared earlier for K, followed by N, and then by P. In any case, the maximum nutrient uptake rate appeared earlier than did the dry matter. The momentary N recovery rate was similar in trend to those of dry matter and N uptake, and its maximum recovery rate occurred almost at the same time as its maximum uptake rate. Supplemental irrigation raised the cumulative and momentary rates of N. Although water and N supplies increased dry matter and nutrient uptake rates, they did not alter their changing trends during the plant-growing period.

关键词： Maize Dynamics of nutrient accumulation Rate of nutrient absorption N recovery rate

Quantitative Effect of Soil Texture Composition on Retardation Factor of K^+ Transport

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Pedosphere 2001年第4期11卷 377-382页

作者： WANGYU ZHANGYIPING DepartmentofNaturalResourecsandEnvironmentalSciences NorthwestScienceandTechnologyUniversityofAgicultureandForestryYanglingShaanxi712100（China） DepartmentofNaturalResourecsandEnvironmentalSciences N

With six packed columns composed of < 1 μm and 5 μm～0.25 mm fractions from an Eum-Orthic An- throsol (Columns 1～6) and one column of the Eum-Orthic Anthrosol (Column 7), K～(+) transport experiments under the condition of saturated steady water flow were conducted to qualify the effects of soil texture com- position on the retardation factor (R) of K～(+) transport. The results showed that the retardation factor of K～ (+) transport in the tested soil columns greatly increased with increasing clay contents. In an attempt to use pedo-transfer function (PTF) approach in the solute transport study, a preliminary PTF was established through the six packed columns (Columns 1～6) with soil basic data including soil bulk density, volumet- ric water content and clay content to predict the retardation factor, and proved valid by the satisfactory prediction of R in Column 7.

关键词： pedo-transfer function retardation factor soil basic properties soil solute transport

Expression of EGF and EGFR in Developing Skin of the Goat Fetus

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畜牧兽医学报 2010年第S1期41卷 102-107页

作者： QING Su-zhu,LIN Ji-mao,ZHANG Ling-zhi,WANG Lei-lei,LUO Shi-shuang (College of Veterinary Medicine,Northwest A & F University,yangling 712.00,China)

The histological characteristics,distribution and variability of epidermal growth factor(EGF) and epidermal growth factor receptor(EGFR) during development of skin in the goat fetus were studied with histological and immunohistochemical *** results showed that the epidermis formed at the 6th gestational week,the thickness increased gradually because of transition from simple epithelium to stratified epithelium,and then decreased after the 15th *** dermis was present at the 10th week,and the dermal derivatives appeared after the 11th *** structures of the skin matured gradually during prenatal *** expression of EGF and EGFR could be observed at the 6th week and increased *** the 11th week,EGF was mainly located in the cytoplasm of the basal layer of cells of epidermis,hair follicular epithelial cells and fibroblasts,and EGFR was mainly located on cell membranes of these *** the 11th to 16th week,the expression of EGF and EGFR extended from basal layer cells,prickle cells,hair follicular epithelial cells and fibroblasts to vascular endothelial cells,epithelial cells of sweat glands and arrector pili *** was mainly detected cytoplasmically,and EGFR was located on membranes of these *** the 17th week to birth,EGF was mainly located in cells of the basal layer and hair follicular epithelial cells as the skin thinned and staining intensity continued to *** expressed amount of EGF and EGFR tended to increase throughout the whole development stage encompassed by gestational weeks 6 to 21 and the two components of the EGF signaling system were highly *** results suggest that EGF and EGFR play important roles in the development of skin and its derivatives.

关键词： epidermal growth factor epidermal growth factor receptor skin development goat