合肥市绿地土壤水分入渗性能研究

为探明影响城市绿地土壤水分入渗性能的限制因子,提高城市绿地在雨水径流调蓄中的作用,采用双环入渗法研究了合肥居民区、公园、道路绿化带（市政绿地）和文教区（校园）等不同类型绿地的土壤水分入渗特征及其与质地、容重和空隙度等土壤物理性质之间的关系。结果表明：合肥市不同功能区绿地土壤入渗速率在0~40 min内下降较快,90~100 min后趋于平缓。土壤水分平均入渗速率呈现：公园绿地(2.42×10-5 m/s)>市政绿地(2.10×10-5 m/s)>小区绿地(0.62×10-5 m/s)>校园绿地(0.56×10-5 m/s)的规律。土壤稳定入渗率属于快和较快级别的占21.1%,中等及较慢等级的占78.9%。合肥市绿地土壤黏粒平均含量在37.6%~44.7%之间;土壤容重在1.22~1.68 g/cm3之间,均值均大于1.40 g/cm3;绿地土壤通气孔隙度在9.21%~17.6%之间,其中小区绿地(14.1%)＞市政绿地(13.9%)＞公园绿地(13.7%)＞校园绿地(11.3%)。研究结果为合肥市城区绿地土壤消减城市面源污染设计提供科学依据。     

早实核桃采穗圃适宜定植密度和修剪强度研究

为重庆地区早实核桃采穗圃营建及高效管理提供参考,以早实核桃‘渝城1号’为研究对象,采用裂区试验设计,研究了4种定植密度(1 m×2 m、2 m×2 m、2 m×3 m、3 m×4 m)和4种修剪强度（长放、轻短截、中短截、重短截）对核桃枝条生长和穗芽产量的影响。结果表明：定植密度和修剪强度对有效枝数、枝粗、枝长和有效芽数有显著影响,且修剪强度的影响大于定植密度,两者交互作用对枝长影响显著,对其他指标则无显著影响。从定植密度上看,有效枝数、枝粗、枝长和有效芽数随密度降低而增加,在2 m×3 m和3 m×4 m密度下的有效枝数及有效芽数显著优于其他处理。从修剪强度上看,随着修剪强度增加有效枝数显著减少,而枝粗、枝长和有效芽数显著增加,其中重短截的枝条质量显著优于其他处理。综合来看,在16个处理中,2 m×3 m结合重短截处理的枝粗、枝长和有效芽数显著高于其他处理,且单产有效芽数较高,是兼顾了枝条质量和穗芽产量的最佳处理。定植密度和修剪强度对于重庆地区早实核桃‘渝城1号’采穗母树枝条的生长发育有显著影响,营建采穗圃的适宜定植密度为株行距2 m×3 m,适宜的修剪强度为休眠期重短截。     

基于表型性状和SSR分子标记构建甘薯核心种质

为更好地保存、研究和利用甘薯种质资源,本研究以国家甘薯种质资源圃(广州)保存的1091份甘薯种质为材料,分别采用欧氏距离和Nei’s距离进行NJ聚类分组,组内随机取样,构建核心种质。利用均值、方差、香农多样性指数、变异系数等指标对核心种质的表型性状数据进行代表性评价,以及利用有效等位基因、Nei’s遗传多样性指数、Shannon’s多样性指数等指标对核心种质的SSR分子标记数据进行代表性评价;并利用主成分分析对核心种质进行确认。结果表明,构建的甘薯核心种质包含289份材料,占全部种质的26.49%;在P<0.05概率下,核心种质中表型性状以及SSR分子标记的相关指标与全部种质无显著差异,且二者的表型频率分布基本一致;主成分分析表明核心种质具有与全部种质相似的遗传多样性和群体结构。建立的甘薯核心种质很好地代表了全部种质的遗传变异和群体结构,可为甘薯的品种改良、优良基因挖掘以及种质创新奠定良好基础。     

云南烤烟多酚含量空间变异分析

利用GPS定位,在云南省主要烟区选取705个样点,2007年和2008年分别采集C3F等级烤烟样品,将各取样点两年的烤烟样品多酚含量平均值作为原始统计数据。对多酚含量的原始数据、对数转化和Box-Cox转化后的数据进行正态分布性检验。采用地统计学进行烤烟多酚含量的空间趋势和空间变异分析。结果表明,云南烤烟多酚含量经对数转化后服从正态分布。在进行普通Kriging插值时,趋势效应参数宜选择0阶,理论模型宜选择高斯模型(gaussian model)。云南烤烟多酚含量具有中等的空间相关性(C0/C0+C=35.71%),没有空间趋势效应(0阶)。大部分烟区烤烟多酚含量在3.50%～4.00%之间(为背景值);多酚含量大于4.00%的板块主要分布在滇西、滇中和滇东,大于4.50%的板块零星分布于4.00%～4.50%的板块中间,且多数板块多酚含量由中心向四周呈梯度状由高到低分布;多酚含量在5.50%～6.73%的板块位于南涧县、永平县北部、龙陵县西北部和武定县西部,且位于南涧县的板块面积最大。     

新疆中天山北坡断裂带不同海拔高度土壤温度分布特征

研究中天山断裂带从高山带到准噶尔盆地边缘整个过渡带的土壤温度分布特征有助于理解干旱区土壤环境特征,从而为土地利用、农业生产提供依据。本文选取新疆中天山断裂带海拔高度呈梯度分布的6个气象站2005年至2020年各层土壤温度的日观测数据,利用统计方法分析了不同地形、不同深度土壤温度随海拔高度的变化特征以及不同海拔高度土壤温度随深度的变化特征。分析表明：中天山北坡土壤温度变幅随海拔高度的降低而升高。不同地形的土壤最高温和最低温的年温差浅层大于深层,由浅至深年最高温度和年最低温度出现的时间逐渐推迟;年内中天山北坡不同海拔高度0～20 cm的土壤日平均温度曲线大致呈余弦函数曲线,320 cm深度的土壤温度基本呈正弦函数分布,较0～20 cm地温的最高和最低晚3个月左右。研究区土壤温度随海拔高度降低呈现先升高后降低的趋势。在海拔为3539～600 m高度范围,土壤温度随着海拔的升高而降低。在600～441 m高度范围,土壤温度随着海拔的下降而下降;0～20 cm为土壤温度变化的活跃层,40 cm深度的土壤温度可称之为过渡层,320 cm深度称为土壤温度的稳定层,80～160 cm称为土壤温度的次稳...     

香鳞毛蕨净光合速率的环境响应及模拟

为了探明香鳞毛蕨[Dryopteris fragrans (L.) Schott]净光合速率对环境因子的响应及其函数关系,采用LCi便携式光合仪对野生香鳞毛蕨的瞬时净光合速率（Pn）对环境因子（光合有效辐射PAR、温度Ta、饱和水汽压差VPD和大气CO2浓度Cs）进行了测定,借助于叶子飘提出的直角双曲线光合作用修正模型和Ball-Berry提出的气孔导度修正模型,建立了耦合模型,探讨模型的准确性、精度及Pn对环境因子的生理响应。结果表明：该模型模拟精度较高,能够很好地模拟香鳞毛蕨主要生长季节的Pn变化规律;香鳞毛蕨Pn对环境因子的响应规律：（1）Pn随PAR的变化出现了陡增,之后又有所下降的现象,当PAR达到1200μmol/(m2?s)左右时,Pn达到最大,为6.5μmol/(m2?s);（2）香鳞毛蕨Pn对Ta的响应呈单峰形变化,最适温度为25℃左右;（3）Pn随Cs的增加而逐渐升高,Cs浓度为300~450μmol/mol时,Pn增加速度较快,随着Cs超过450μmol/mol,Pn上升的较慢;（4）当VPD值达到4.0kPa左右时,Pn达到最高。因此,可以利用此模型结合环境因子模拟Pn,为香鳞毛蕨生产实践提供理论依据。     

延河流域耕层土壤养分空间变异及与地形因子的相关性研究

了解耕层土壤养分空间变异规律及其与地形因子的相关关系,以期为土壤养分有效利用和农业管理提供理论依据。以延河流域为研究对象,利用地统计学与GIS相关方法,研究土壤空间分布及变异规律,并基于DEM数据提取相关地形因子,分析流域尺度下地形因子对土壤养分空间分布的影响。研究区耕层全氮和有机质处于较低水平,速效钾和有效磷处于中等水平,pH呈弱碱性,空间变异大小依次为速效钾>有效磷>全氮>有机质>pH。构建的土壤养分指标半方差函数决定系数均大于0.6;土壤pH空间分布最为破碎;土壤速效钾和pH块金系数小于25%,主要为结构性因素影响;土壤全氮、有效磷、有机质具有中等水平的块金效应,受结构性因素和随机因素共同作用;其中有效磷块金系数最大,人类活动对其空间变异影响更大。全氮与有机质分布规律由西北向东南先递增后递减,速效钾呈现由西北向东南波浪形递减的分布格局,有效磷整体分布趋势表现为由中游向上下游降低,土壤pH沿某一方向变化的趋势不强。土壤养分空间变异情况与地形因子的相关关系相一致。在地势较低且平坦的区域内,更有利于农业生产,土壤养分较为充足;在高海拔、地形起伏较大区域养分含量相对较低。     

豫东砂壤土区强筋小麦施钾增产保优效应研究

为了在强筋小麦次适宜种植区实现高产优质目标,采用田间试验及统计分析方法,对易缺钾的砂壤土类型区栽培强筋小麦进行施用钾肥增产保优效应研究。结果表明,在豫东砂壤土区耕层土壤速效钾(K₂O)含量为90 kg/hm²左右的条件下,在施用氮磷肥的基础上,增施钾肥(K₂O) 60~300 kg/hm²,强筋小麦增产18.7%~41.4%,平均增产30.6%。砂壤土强筋小麦产量与施钾量之间呈二次曲线函数关系,即y= 5296.35+22.20x-0.059x2,F=55.76**。增施钾肥小麦籽粒蛋白质含量平均为15.32%,平均提高1.72个百分点,相对提高12.6%。钾肥增进了小麦面粉的加工品质,湿面筋含量达到35.2%~38.0%,平均37.1%,超过一等强筋小麦≥35%的国家标准。施钾小麦面粉沉降值为45.1~47.3 mL,较对照增大3.2~5.4 mL,同时较全面地改善了面团流变学性能,如形成时间增加0.6~1.8 min,平均增加1.3 min;稳定时间延长1.9~ 4.4 min,平均延长约3.4 min;弱化度(FU)则下降2.8~9.3,平均下降6.3。钾肥提高产量、改善品质的主要生理生化基础是促进了开花至灌浆期旗叶光合速率,提高了挑旗至灌浆期旗叶磷酸蔗糖合成酶(SPS)活性。在本试验条件下,豫东砂壤土强筋小麦增产保优最佳的施钾(K₂O)量为180 kg/hm²。适宜的氮磷钾肥施肥配比(N:P₂O₅:K₂O)为1:0.78:1.30。     

Effects of Spherical Joint Stiffness on Seismic Response of Single-Layer Cylindrical Reticulated Shell Changing with Peak Ground Acceleration

The previous studies find that the hollow spherical joint stiffness has a certain influence on seismic response of single-layer cylindrical reticulated shell. In order to analyze the rule of this influence with PGA (peak ground acceleration) changing, two types of finite element models are built. The two types of models have the same size except the spherical joint. The first type is a fine model built by shell element and its spherical joints and tubes are built by considering the real size; the other type is the common model which is built by beam element, and the spherical joints are neglected. Comparing with the seismic response of the two types of models when PGA changes, the results show the difference between the two types of model in node displacement-time curves is increased as PGA increases; when the PGA is larger than the collapse acceleration of structure, the influence of increasing joint wall thickness on improving the structural capacity of anti-stability is decreased as PGA increases.     

上覆分数阶粘弹性饱和场地土位移地震放大系数

考虑土体液相和固相的耦合作用,将基岩上覆场地土视为两相饱和多孔介质。为了考虑饱和场地土的粘弹性特性,其固相土骨架的应力应变关系利用分数阶Kelvin粘弹性模型来描述,建立了上覆分数阶粘弹性饱和场地土在简谐地震波作用下的运动控制方程。运用分数导数的性质并考虑上覆场地土的边界条件和透水性条件求解了上覆分数阶粘弹性场地土在简谐地震波作用下的振动问题,得到了饱和场地土的位移地震放大系数。采用数值算例分析讨论了分数导数的阶数、液固耦合系数、土体模型参数、基岩土体剪切模量比等参数对位移地震放大系数的影响。研究结果表明,分数导数的阶数、液固耦合系数、土体模型参数、基岩土体剪切模量比对饱和场地土的地震响应有较大的影响,通过压实场地土,可以达到增大液固耦合系数减小地震响应的作用,通过增大饱和场地土的粘性和剪切模量也可以减小地震反应。     

Post-earthquake Residual Deformation Prediction of SDOF System

Accurately predicting the residual displacement of reinforced concrete (RC) structures after an earthquake is of great significance in post-earthquake structural performance evaluation and control. To study the residual deformation of the structure, seismic time-history responses of single degree-of-freedom (SDOF) systems with different parameters were analyzed. Based on the analytical results, simplified models for estimating the likely residual deformations of structures characterized by Takeda and Kinematic hysteretic models were proposed respectively, and the residual deformation was found to be sensitive to hysteretic characteristics, stiffness ratio of structures, peak ground acceleration (PGA), as well as maximum elasto-plastic deformation. A case study for RC single-column bridge pier was provided to illustrate the process of residual deformation calculation and post-earthquake performance evaluation by using the proposed methods. Calculation results indicate that the residual deformation of the single-column pier characterized by the Takeda model often is much larger than that of columns characterized by the Kinematic model.     

Inelastic Seismic Response of Ordinary Reinforced Concrete Regular Frames

With an inelastic dynamic analysis program developed by the authors, seismic response analysis of regular RC frames designed to Chinese codes in different earthquake fortification zones are carried out. The results indicate that the displacement responses of structures are improved due to the more rigorous limitation on the inter-story drift under frequent earthquakes in the revised codes. The frames in seismic-intensity-9 zone designed to the former codes and the revised codes form plastic energy-dissipated mechanisms mostly With beam hinges, which can satisfy the requirement of seismic performance expectably. The frame in seismic-intensity-8 zone designed to the former code forms a plastic energy- dissipated mechanisms mostly with column hinges and shows a risk of occurrence of story-sway mechanism, while the frame in seismic-intensity-8 zone designed to the revised codes exhibits a relatively improved seismic performance but still with excessive column hinges, which suggests a need to further increase the column moment amplification measures for this kind of frames. The frame in seismic-intensity-7 zone shows a somewhat improved seismic performance than the frames in seismic-intensity-8 zone, but the protection to columns by the seismic measures is sill insufficient, which indicates that the column moment amplification measures for this kind of frames should be enhanced further.     

Nonlinear Seismic Response Analysis of Long- span CFST Arch Bridge

The non-linear seismic response behavior of concrete filled in steel tube(CFST) arch bridge subjected to synchronous seismic excition and multi-support seismic excitation is studied in this paper.The non-linear seismic response of CFST arch bridge is calculated by time-history analysis method,and the effect of geometric nonlinear to long-span CFST arch bridge is studied.The influence of internal-force and deformence under dead-load,multi-support seismic excitation,etc to nonlinear seismic response behavior of CFST arch bridge is analysed.The result show that the effect of geometric nonlinear to long-span CFST arch bridge is obvious.     

Phenology and grape ripening characteristics of cv Tempranillo within the Ribera del Duero designation of origin (Spain): Influence of soil and plot characteristics

The aim of this research was to evaluate the variability of phenology and ripening characteristics of the Tempranillo variety within the Ribera del Duero Designation of Origin (Spain). This area covers approximately 115 km along the Duero River, where Tempranillo is the main variety cultivated. The analysis included the information recorded during the period 2004–2013 in 20 plots for phenology dates and 26 plots for grape characteristics. The variability in soil, phenology, grape quality and plot characteristics throughout the Ribera del Duero DO as well as their relationships were evaluated using multivariate analysis. Four different groups of plots were characterized as distinct from each other, with differences in elevation, distance to the Duero River and soil type. The differences in phenology among groups started during flowering and were observed through the end of the growth cycle. Despite the high phenological variability driven by year to year variations in climate characteristics, it was possible to define the soil and plot characteristics that favor advanced phenology within the Ribera del Duero DO. Regarding grape ripening characteristics, the highest acidity and anthocyanin concentrations were found in plots with soils with higher clay and organic matter content. The effect was greater in the wet and intermediate years, than in dry years. High variability in phenology and ripening characteristics is found within the Ribera del Duero related to site soil and landscape characteristics, and from year to year due to climatic conditions. Zones with common characteristics and similar response have been identified within the area. The results highlight the potential of establishing viticultural zones with differences in vineyard treatment and management and the elaboration of site specific wine styles from those zones.     

Genetic variability among sugarcane genotypes based on polymorphisms in sucrose metabolism and drought tolerance genes

Target region amplification polymorphism (TRAP) markers were used to estimate the genetic similarity (GS) among 53 sugarcane varieties and five species of the Saccharum complex. Seven fixed primers designed from candidate genes involved in sucrose metabolism and three from those involved in drought response metabolism were used in combination with three arbitrary primers. The clustering of the genotypes for sucrose metabolism and drought response were similar, but the GS based on Jaccard’s coefficient changed. The GS based on polymorphism in sucrose genes estimated in a set of 46 Brazilian varieties, all of which belong to the three Brazilian breeding programs, ranged from 0.52 to 0.9, and that based on drought data ranged from 0.44 to 0.95. The results suggest that genetic variability in the evaluated genes was lower in the sucrose metabolism genes than in the drought response metabolism ones.     

Characteristic ‘fingerprints’ of crop model responses to weather input data at different spatial resolutions

Crop growth simulation models are increasingly used for regionally assessing the effects of climate change and variability on crop yields. These models require spatially and temporally detailed, location-specific, environmental (weather and soil) and management data as inputs, which are often difficult to obtain consistently for larger regions. Aggregating the resolution of input data for crop model applications may increase the uncertainty of simulations to an extent that is not well understood. The present study aims to systematically analyse the effect of changes in the spatial resolution of weather input data on yields simulated by four crop models (LINTUL-SLIM, DSSAT-CSM, EPIC and WOFOST) which were utilized to test possible interactions between weather input data resolution and specific modelling approaches representing different degrees of complexity. The models were applied to simulate grain yield of spring barley in Finland for 12 years between 1994 and 2005 considering five spatial resolutions of daily weather data: weather station (point) and grid-based interpolated data at resolutions of 10 km × 10 km; 20 km × 20 km; 50 km × 50 km and 100 km × 100 km. Our results show that the differences between models were larger than the effect of the chosen spatial resolution of weather data for the considered years and region. When displaying model results graphically, each model exhibits a characteristic ‘fingerprint’ of simulated yield frequency distributions. These characteristic distributions in response to the inter-annual weather variability were independent of the spatial resolution of weather input data. Using one model (LINTUL-SLIM), we analysed how the aggregation strategy, i.e. aggregating model input versus model output data, influences the simulated yield frequency distribution. Results show that aggregating weather data has a smaller effect on the yield distribution than aggregating simulated yields which causes a deformation of the model fingerprint. We conclude that changes in the spatial resolution of weather input data introduce less uncertainty to the simulations than the use of different crop models but that more evaluation is required for other regions with a higher spatial heterogeneity in weather conditions, and for other input data related to soil and crop management to substantiate our findings. Our results provide further evidence to support other studies stressing the importance of using not just one, but different crop models in climate assessment studies.     

调优站网布局融合乡村振兴提升气象服务精细的思考

为减少门头沟区地形复杂、局地性强对流天气多发给当地人民群众生命财产安全造成的极大威胁,分析了门头沟区区域自动气象站调优前后不同地形的降水分布,结合实例分析调优后站网在乡村振兴和精细化气象服务中的实效,并提出相关建议。结果表明：2018—2019年新增气象站26个,平均距离约7 km;2006—2017年汛期平均降水量低海拔地区多于中、高海拔地区;站网调优后,2018年汛期降水量中、高海拔地区多于低海拔地区;部分气象站在实际强降雨过程中发挥实效;还可从加强现有气象站网管理、加密建设气象站网、加强多种气象方式融合应用、完善气象监测体系机制4个方面高效发挥站网监测精密能力,有利于基层气象部门将精细化气象服务融入当地乡村振兴战略之中,在全国气象部门中起到良好的示范作用。     

重庆地区雷电日雷暴日关系研究

为了更好地应用雷电定位系统的自动监测数据统计雷电日参数,在比较多年重庆地区雷暴日资料与近年来自动监测数据的基础上,重点研究该区域13个国家基准气候站的雷电日与雷暴日数据。结果表明：（1）平均雷暴日与平均雷电日的比值各站差异显著。总体来看,雷暴日数值小于雷电日并成正相关;其比例与观测区域面积、地形地貌环境关系密切;（2）不同雷电日观测半径差异显著,且均小于10 km,一方面说明雷电活动的不均匀性;另一方面,说明器测的灵敏度远高于人的听力和视觉,观测人员对雷声的听力范围不大于10 km;（3）主城区域雷电日观测半径最小,这是由于观测站周围的建筑物阻碍、环境噪声与空气中能见度变化共同作用的结果;（4）雷电日观测半径与地形地貌的关系明显,重庆市主城区雷电日观测半径较小,东北和东南部雷电日观测半径较大,总体来看地形地貌、城市化进程相似的区域,雷电日半径有可比性,器测数据是连续性的。