Modeling Soil Organic Matter Dynamics Under Intensive Cropping Systems on the Huang-Huai-Hai Plain of China

A modified CQESTR model, a simple yet useful model frequently used for estimating carbon sequestration in agricultural soils, was developed and applied to evaluate the effects of intensive cropping on soil organic matter (SOM) dynamics and mineralization as well as to estimate carbon dioxide emission from agricultural soils at seven sites on the Huang-Huai-Hai Plain of China. The model was modified using site-specific parameters from short- and mid-term buried organic material experiments at four stages of biomass decomposition. The predicted SOM results were validated using independent data from seven long-term (10-to 20-year) soil fertility experiments in this region. Regression analysis on 1151 pairs of predicted and measured SOM data had an r2 of 0.91 (P (?) 0.01). Therefore, the modified model was able to predict the mineralization of crop residues, organic amendments, and native SOM. Linear regression also showed that SOM mineralization rate (MR) in the plow layer increased by 0.22% when annual crop yield increased by 1 t ha-1 (P (?) 0.01), suggesting an improvement in SOM quality. Apparently, not only did the annual soil respiration efflux merely reflect the intensity of soil organism and plant metabolism, but also the SOM MR in the plow layer. These results suggested that the modified model was simple yet valuable in predicting SOM trends at a single agricultural field and could be a powerful tool for estimating C-storage potential and reconstructing C storage on the Huang-Huai-Hai Plain of China.

基于OBE理念的专业教育和思政教育协同育人实施路径研究

创新教育理念,持续深化教育改革,对标新修订的《中华人民共和国职业教育法》中“大国工匠”的培育要求,将思政教育和专业教育有机融合,是实现德技并修高素质技能型人才的重要路径。本文从城市轨道交通变配电行业需求、变配电检修员和低压配电检修员岗位要求出发,对基于OBE理念的专业教育和思政教育协同育人的实施路径进行研究,为职业院校深化新时代职业教育教学体系改革提供借鉴和参考。

铁矿废弃地复垦土壤重金属来源解析研究

为探明铁矿废弃地复垦土壤重金属含量特征及其主要来源,以铁矿废弃地复垦土壤为研究对象,采用多元统计分析和地统计学方法,对复垦土壤重金属(As、Cd、Cr、Cu、Hg、Zn)的主要来源、各来源的贡献量及其贡献量的空间分布特征进行研究。结果表明:研究区6种重金属变异系数在31%～67%,均属中等程度变异。对比当地背景值,除Cr外,其他5种元素均呈现富集现象,且以As、Cu累积明显。由相关性分析、主成分分析及聚类分析结果推测复垦土壤重金属主要有3个来源,PC1(As、Hg、Cu)为矿业活动源,PC2(Cd、Zn)为交通和农业活动源,PC3(Cr)为成土母质自然源。由主成分分析/绝对主成分分数(PCA/APCS受体模型)和地统计分析可知,几种元素受3种源共同作用,其中源1对As、Hg、Cu的贡献率分别为67.10%、46.30%、89.82%,源2对Cd、Zn的贡献率为86.05%、62.26%,而源3对Cr的贡献率为90.56%。Cu、Cd、Cr元素空间分布规律和其最大源贡献量空间分布格局较为一致。

FTIR,XPS和SEM研究含多胺基锚固基团分散剂在丙炔噁草酮颗粒表面的吸附性能

可分散油悬浮剂作为一种环境友好农药剂型,近年来得到快速发展。但由于稳定机理研究相对薄弱以及精准、量化、微观的表征手段相对缺乏,使得可分散油悬浮剂产品在生产和贮存的过程中容易出现析油分层、絮凝、膏化、结块等现象。X射线光电子能谱作为一种重要的表面分析技术,具有灵敏度高、制样简单、样品破坏性小等特点,常用于固体表面元素定性定量分析及原子价态分析,适用于分散剂吸附性能及稳定机理研究。本研究采用X射线光电子能谱、傅里叶变换红外光谱和扫描电子显微镜相结合的方式,在油性介质中,从微观角度研究含多胺基锚固基团油相分散剂在丙炔噁草酮颗粒表面的吸附性能,为该分散剂在农药可分散油悬浮剂中的应用提供理论依据。研究结果表明:丙炔噁草酮吸附多胺基锚固基团油相分散剂后,丙炔噁草酮界面的Cl,N和O电子峰强度减弱,C电子峰强度增强,说明该分散剂在丙炔噁草酮表面形成了良好的吸附。以Cl元素为特征元素计算出该分散剂在丙炔噁草酮表面的吸附层厚度为6.746 nm。分散剂吸附后,红外光谱图中没有出现新的吸收峰,分散剂与丙炔噁草酮之间的吸附是以范德华力为主要结合作用力的物理吸附。吸附前后样品微观形貌研究表明,未吸附分散剂的丙炔噁草酮原药颗粒表面较为粗糙,有晶面的层状结构,吸附分散剂后,原药颗粒表面变得较为光滑,晶面层状结构消失,说明分散剂在丙炔噁草酮表面形成了包覆,并通过非极性溶剂化链提供空间位阻,提高丙炔噁草酮可分散油悬浮剂体系的物理稳定性。

石油天然气项目土壤污染特征与复垦防控对策

基于文献和自然资源部矿山地质环境保护与土地复垦方案评审材料的归纳总结,阐述了我国石油天然气项目土壤污染现状与危害,并根据石油天然气生产工艺,明确不同环节的污染源和类型。在此基础上,从完善立法,明确责任界线,强化企业污染防控意识;优化技术模式,预防优先;开展调查,差别化选择修复方式等三个方面提出了我国石油天然气项目的复垦防控对策。

FBMC/OQAM水声通信系统的适应性成型脉冲设计

水声信道是一个时变的双扩散信道,不仅会引起传输信号的时频扩展,而且会造成严重的信息损失。由于滤波器组多载波/交错正交幅度调制(Filter Bank Based Multicarrier/Offset Quadrature Amplitude Modulation, FBMC/OQAM)系统可通过改变发送信号的成型脉冲来减小时频扩展带来的符号干扰和子载波干扰,因此更适合快速时变的水下声信道。为了降低现有成型脉冲设计算法的优化难度,提出了一种快速且易于实现的成型脉冲设计方法,该方法根据信道时频统计特性对扩展高斯函数(Extend Gaussian Function, EGF)进行了优化,实现了期望信号能量最大化,并在时域符号间加入适当的保护间隔,进一步增强了抗多途干扰的能力。仿真结果表明,无论在高频散信道还是在低频信道下,相比于其它成型脉冲算法,该算法在降低计算量的同时,改进了的FBMC/OQAM系统的传输性能,误码率降低了2～3 dB。

基于图模一体化技术的配电网可靠性评估

数字电网发展对配电网规划提出了更高的要求,一种基于图模一体化技术的配电网可靠性评估方法,可在提高电网规划人员工作效率的同时,增强配网可靠性评估的可视化和提高精准化水平。该方法依托图模一体化技术,以可缩放矢量图形(Scalable Vector Graphics,SVG)作为可视化交互对象,将待规划馈线SVG模拟的规划内容映射至公共信息模型(Common Information Model,CIM)中,再进行解析,并构建配网拓扑数据模型。基于拓扑模型采用故障扩散遍历算法对规划态配电网的馈线和负荷点的可靠性指标进行求解。最后,通过模拟某地区的配网馈线规划改造,得出待规划馈线规划前后可靠性指标的变化,证明方法的有效性与实用性。该方法能有效提高规划人员对各类配网规划工程可靠性评估的效率,为配电网分析、配电网规划方案评估、配电自愈工程建设的效益评价等工作提供重要的支持。

纳米炭混悬注射液用于乳腺癌光热治疗的研究

纳米炭混悬液(CNSI)是一种商业化生产的临床用肿瘤引流淋巴结成像剂.CNSI中的sp2结构具有较大的近红外光吸收和光热转换能力,因此有望用于肿瘤的光热治疗,而无需担心生产工艺和生物安全性问题.评估了CNSI在乳腺癌肿瘤光热治疗中的效果,测定了CNSI在808 nm激光照射下MDA-MB-231乳腺癌细胞的细胞活力、肿瘤体积和荷瘤鼠生存期,并对肿瘤及其皮肤的组织病理学进行观察.结果显示,CNSI为直径29 nm左右的碳颗粒,对近红外光有明显吸收,并能将其转化为热量,溶液升温速率与照射功率和CNSI浓度正相关.激光照射下,CNSI转化产生的热量能有效杀死MDA-MB-231乳腺癌细胞,而单独的激光照射不影响细胞活力.动物实验中,激光照射引起肿瘤区域轻微的温度升高,而注射了CNSI的肿瘤温度升高迅速,可达61.4°C.注射CNSI后进行三次激光照射的光热治疗组肿瘤消失,生存期从28天延长至58天,60天内的生存率从0%增加至50%.CNSI瘤内注射后分布在细胞间隙,激光照射后严重破坏细胞结构.因此,CNSI可以用于乳腺癌的光热治疗,具有良好的效果.

机械制图课程思政“N+5+4”教学模式探究

以“机械制图与CAD”课程为载体,探索基于“MOOC+SPOC”课程思政的“N+5+4”混合式教学模式改革,以MOOC中的N个知识点为基础,将爱国主义、工匠精神、理想信念、社会主义核心价值观等与课程内容进行深度融合,从对象识别、场域定制、多元评估的精准化定制路线设计5次专题式教学,深度融合思政元素开展4次课内实践,助力培养具有“家国情怀、专业知识、理想信念”的专业技术人才,为建设科技强国提供支持,同时也为课程思政的教学提供一定的参考。

Spatial Interpolation of Soil Texture Using Compositional Kriging and Regression Kriging with Consideration of the Characteristics of Compositional Data and Environment Variables

The spatial interpolation for soil texture does not necessarily satisfy the constant sum and nonnegativity constraints. Meanwhile, although numeric and categorical variables have been used as auxiliary variables to improve prediction accuracy of soil attributes such as soil organic matter, they （especially the categorical variables） are rarely used in spatial prediction of soil texture. The objective of our study was to comparing the performance of the methods for spatial prediction of soil texture with consideration of the characteristics of compositional data and auxiliary variables. These methods include the ordinary kriging with the symmetry logratio transform, regression kriging with the symmetry logratio transform, and compositional kriging （CK） approaches. The root mean squared error （RMSE）, the relative improvement value of RMSE and Aitchison＇s distance （DA） were all utilized to assess the accuracy of prediction and the mean squared deviation ratio was used to evaluate the goodness of fit of the theoretical estimate of error. The results showed that the prediction methods utilized in this paper could enable interpolation results of soil texture to satisfy the constant sum and nonnegativity constraints. Prediction accuracy and model fitting effect of the CK approach were better, suggesting that the CK method was more appropriate for predicting soil texture. The CK method is directly interpolated on soil texture, which ensures that it is optimal unbiased estimator. If the environment variables are appropriately selected as auxiliary variables, spatial variability of soil texture can be predicted reasonably and accordingly the predicted results will be satisfied.

Spatial variability of organochlorine pesticides (DDTs and HCHs) in surface soils from the alluvial region of Beijing,China

The spatial variability in the concentrations of 1,2,3,4,5,6-hexachlorocyclohexane （HCH） and 1,1,1-trichloro-2,2-bis-（p-chloro- phenyl） ethane （DDT） in surface soils was studied on the basis of the analysis of 131 soil samples collected from the surface layer （0-20 cm depth） of the alluvial region of Beijing, China. The concentrations of total HCHs （including α-,β-, γ-, and δ-isomers） and total DDTs （including p,p＇-DDT, p,p＇-DDD, p,p＇-DDE, and o,p＇-DDT） in the surface soils tested were in the range from nondetectable to 31.72 μg/kg dry soil, with a mean value of 0.91, and from nondetectable to 5910.83 μg/kg dry soil, with a mean value of 32.13, respectively. It was observed that concentrations of HCHs in all soil samples and concentrations of DDTs in 112 soil samples were much lower than the first grade （50 μg/kg） permitted in ＂Environment quality standard for soils in China （GB 15618-1995）＂. This suggests that the pollution due to organochlorine pesticides was generally not significant in the farmland soils in the Beijing alluvial region. In this study, the spatial distribution and trend of HCHs and DDTs were analyzed using Geostatistical Analyst and GS＋（513）. Spatial distribution indicated how these pesticides had been applied in the past. Trend analysis showed that the concentrations of HCHs, DDTs, and their related metabolites followed an obvious distribution trend in the surface soils from the alluvial region of Beijing.

Effects of land use change on the spatiotemporal variability of soil organic carbon in an urban-rural ecotone of Beijing,China

Understanding the effects of land use changes on the spatiotemporal variation of soil organic carbon （SOC） can provide guidance for low carbon and sustainable agriculture. In this paper, based on the large-scale datasets of soil surveys in 1982 and 2009 for Pinggu District -- an urban-rural ecotone of Beijing, China, the effects of land use and land use changes on both temporal variation and spatial variation of SOC were analyzed. Results showed that from 1982 to 2009 in Pinggu District, the following land use change mainly occurred： Grain cropland converted to orchard or vegetable land, and grassland converted to forestland. The SOC content decreased in region where the land use type changed to grain cropland （e.g., vegetable land to grain cropland decreased by 0.7 g kg-1; orchard to grain cropland decreased by 0.2 g kg-l）. In contrast, the SOC content increased in region where the land use type changed to either orchard （excluding forestland） or forestland （e.g., grain cropland to orchard and forestland increased by 2.7 and 2.4 g kg-1, respectively; grassland to orchard and forestland increased by 4.8 and 4.9 g kg-1, respectively）. The organic carbon accumulation capacity per unit mass of the soil increased in the following order： grain cropland soil〈vegetable land/grassland soil〈orchard soil〈forestland soil. Therefore, to both secure supply of agricultural products and develop low carbon agriculture in a modern city, orchard has proven to be a good choice for land using.

Spatial distribution prediction and benefits assessment of green manure in the Pinggu District,Beijing,based on the CLUE-S model

Green manure use in China has declined rapidly since the 1980 s with the extensive use of chemical fertilizers.The deterioration of field environments and the demand for green agricultural products have resulted in more attention to green manure.Human intervention and policy-oriented behaviors likely have large impacts on promoting green manure planting.However,little information is available regarding on where,at what rates,and in which ways（i.e.,intercropping green manure in orchards or rotating green manure in cropland） to develop green manure and what benefits could be gained by incorporating green manure in fields at the county scale.This paper presents the conversion of land use and its effects at small region extent（CLUE-S） model,which is specifically developed for the simulation of land use changes originally,to predict spatial distribution of green manure in cropland and orchards in 2020 in Pinggu District located in Beijing,China.Four types of land use for planting or not planting green manure were classified and the future land use dynamics（mainly croplands and orchards） were considered in the prediction.Two scenarios were used to predict the spatial distribution of green manure based on data from 2011：The promotion of green manure planting in orchards（scenario 1） and the promotion of simultaneous green manure planting in orchards and croplands（scenario 2）.The predictions were generally accurate based on the receiver operating characteristic（ROC） and Kappa indices,which validated the effectiveness of the CLUE-S model in the prediction.In addition,the spatial distribution of the green manure was acquired,which indicated that green manure mainly located in the orchards of the middle and southern regions of Dahuashan,the western and southern regions of Wangxinzhuang,the middle region of Shandongzhuang,the eastern region of Pinggu and the middle region of Xiagezhuang under scenario 1.Green manure planting under scenario 2 occurred in orchards in the middle region of Wangxinzhuang,and croplands in most regions of Daxingzhuang,southern Pinggu,northern Xiagezhuang and most of Mafang.The spatially explicit results allowed for the assessment of the benefits of these changes based on different economic and ecological indicators.The economic and ecological gains of scenarios 1 and 2 were 175691 900 and143000 300 CNY,respectively,which indicated that the first scenario was more beneficial for promoting the same area of green manure.These results can facilitate policies of promoting green manure and guide the extensive use of green manure in local agricultural production in suitable ways.

Water and salt movement in different soil textures under various negative irrigating pressures

supported by the National High-Tech R＆D Program of China （2013AA102901）

东北旱作区粮食产量冷热点格局及耕层特征差异

基于2005~2015年东北旱作区85县市的粮食单产数据和土壤属性数据,探讨了东北旱作区粮食单产冷热点时空格局演变特征,并分析了不同冷热点区耕层特征的差异。结果表明:(1)2005,2010和2015年东北旱作区粮食单产全局Moran's/值分别为0.57,0.41、0.65,呈现明显空间集聚特征。吉林省旱作区中部、黑龙江省旱作区南部县市是稳定的粮食单产热点区;而各级冷点区在吉林省旱作区西部和黑龙江省旱作区北部、西南部集中连片分布。(2)粮食单产一、二级热点区土壤容重在10~20 cm土层最高,分别为1.51 gcm=1.53 gcm3呈现亚表层较高的特点。粮食单产一级冷点区各土层深度有机质含量均大于其他类型区;而二级热点区各土层深度有机质含量均小于其他类型区。(3)东北旱作区56.00%的样点耕层厚度在15~25 cm之间,53.03%的样点压实层厚度在5~10 cm之间。一级热点区耕层厚度在15-25 cm和压实层厚度在5~10 cm的样点各占该类型区样点数的81.82%和68.18%,呈现“耕层较厚、压实层厚度适中、穿透阻力相对较小”的特点。

QuEChERS-HPLC法测定土壤中麦角甾醇含量

结合QuEChERS法与高效液相色谱(HPLC)技术,建立了一种土壤中麦角甾醇的快速检测方法。以甲醇为提取溶剂,N-丙基-乙二胺(PSA)为吸附剂,实现了样品的快速提取净化;利用Agilent HC-C18色谱柱(250 mm×4. 6 mm,5μm)进行HPLC分离,以甲醇为流动相,紫外检测器于280 nm波长处检测,基质匹配标准溶液外标法定量。结果表明,麦角甾醇在0. 01～10. 00 mg/L浓度范围内具有良好的线性关系(R^2> 0. 999);在添加浓度为0. 5,1. 0和5. 0 mg/kg的添加回收试验中,平均回收率为87. 6%～92. 8%,相对标准偏差(RSD)为0. 82%～3. 0%,方法的定量限为0. 5 mg/kg。该方法可以直接用于土壤样品中麦角甾醇的含量检测,并已成功分析了山西省安太堡露天煤矿的28个土样。