Discussion on the Soil and Water Conservation Model in Mountain Photovoltaic Power Generation Project

In the context of rising global energy demand and increasing awareness of environmental protection,photovoltaic power generation,as a clean and renewable form of energy,has become increasingly important and has received widespread attention and application worldwide.However,during the construction and operation of mountain photovoltaic power generation projects,water and soil erosion has become a major challenge,which not only restricts the sustainable development process of the project,but also has a significant negative impact on the local ecological environment.This article deeply analyzes the multiple causes,extensive impacts and effective prevention and control strategies of water and soil erosion in mountain photovoltaic power generation projects.The results show that rainfall intensity,terrain slope,soil type and vegetation coverage are the four key factors leading to soil erosion.Soil erosion not only causes a sharp decline in soil fertility,but also aggravates the problem of sediment deposition in rivers and reservoirs,and poses a direct threat to the stability and operating efficiency of photovoltaic equipment.In order to deal with the above problems,this paper innovatively puts forward a series of soil and water conservation technologies,covering multiple dimensions such as engineering measures,plant measures,farming measures and temporary measures,and deeply discusses the application models and management strategies of these measures in key stages such as planning and design,construction,operation and maintenance.Through specific case analysis,the successful practical experience of soil and water conservation is refined and summarized,and the key role of community cooperation,technical support and modern monitoring technology in preventing and controlling soil and water erosion is further emphasized.This article aims to achieve a win-win situation of ecological environment protection and energy development and utilization through scientific planning and effective governance,and contribute to the construction of a green,low-carbon,and sustainable energy system.

Influence of soil resistivity on stray current in power supply system of urban rail transit

In order to explore the influence of soil resistivity on stray current in power supply system of urban rail transit,we establish an equivalent circuit model of the rail-to-ground structure based on resistance network method first.After measuring the soil resistivity of a real subway system,a simulation model is established in Matlab to obtain the stray currents at different soil resistivities.Then the influence of soil resistivity on stray current is analyzed.Afterwards,to verify the rationality and reliability of the simulation model,we design a test circuit to measure the stray current and rail-to-ground voltage in a real subway system,and a comparison of the experimentally measured results and simulation results is presented.The results show that the stray current is the maximum when the soil resistivity is 211.57Ω·m;when the soil resistivity is 768.47Ω·m,the stray current is the minimum,that is,the smaller the soil resistivity,the greater the stray current.Therefore,the resistivity should be increased as much as possible when ramming the track foundation in urban rail transit system.

Optimization of Specific Draft Requirement and Hitch Length for an Animal Drawn Sub-Soiler: A Case of Sandy Clay Loam Soils

This study aimed at optimizing tillage depth and hitching length for optimal draft requirement in sandy clay loam soils for animal drawn subsoiler. Field experiments were conducted to collect draft datasets using the MSI 7300 digital dynamometer communicating remotely with MSI-8000 RF data logger connected to a laptop through the serial port. To determine the numeric values of soil parameters pertinent to subsoiling, field experiments, laboratory tests and numerical analysis techniques were employed. For a specified speed, a combination of three hitch lengths of 2.5 m, 3.0 m and 3.5 m and three depths from 0 cm to 30 cm with a range of 10 cm interval was used. Soil bulk density was found to vary between 1.52 to 1.37 g/cm3 and 1.44 to 1.67 g/cm3 for Machakos and Kitui experimental plots respectively. Soil moisture content increased with an increase in depth ranging from 3.53% to 9.94% for Machakos site and from 4.15% to 9.61% for Kitui site. Soil shear strength parameters ranged between 21.71 and 29.6 kPa between depths of 0 - 20 cm and decreased to 28.07 kPa for depths beyond 20 cm at Machakos experimental plot;while for Kitui experimental plot, it ranged between 30.02 and 39.29 kPa between depths of 0 - 30 cm. A second-order quadratic expression of the form y = ax2 + bx + c was obtained for the relationship between specific draft and depth at given hitching length as well as specific draft against hitching length at a given depth. The optimal hitching length and tillage depth for Machakos experimental plot were obtained as 2.9 m (~3 m) and 16.5 cm respectively. In Kitui experimental site, the optimal hitching length was obtained as 2.9 m (~3 m) and the optimal tillage depth was 15.4 cm.

Seasonal Distribution of Manganese in the Soil-Water-Plant in the Zone of Burshtyn Thermal Power Station

This study deals with the impact of Burshtyn thermal power station on the amount of manganese in soil, water and celandine tissue. The research of manganese amount and form in the system： water-plant is of great importance due to active influence of thermal power station on the chemical structure of the polluted area. The changes in the amount and form of manganese in soil, water and plant are interrelated and depend on the season, the distance from the polluter and morph-functional plant structure, the cleaning system possibilities of the industrial enterprise and some meteorological factors.

Effect of SHAKTI and KUBOTA power tillers on physical properties of soil and rice yield under Sawah production system in Nigeria

The use of the power tillers （walking tractors） are increasingly popular in Nigeria among farmers adopting Sawah rice production technology. This study compares the effects of two types of power tillers on physical properties of soil and rice yield. because soil properties determine to a large extents rice yield. Data on soil properties and rice yield were collected and subjected to t-test statistics. The results show that, significant differences exit for all the physical properties of soils rice yields from fields where the two power tiller were used with yields from rice field where SHAKTI was used was higher than KUBOTA. It is important that farmers using these models of power tillers for rice production should not only focus on the purchase cost of these power tillers but their overall efficiency in order to achieve the desired high level of yield.

Effects of dust,soiling,aging,and weather conditions on photovoltaic system performances in a Saharan environment—Case study in Algeria

Solar photovoltaic(PV)power represents one of the most promising future sources of energy in the world.Considered the cleanest form of energy,extensive research is being undertaken to widen its use.Notably,mega projects are being considered for installation in the Middle East and North Africa(MENA)region because of its high solar potential,with hopes of eventually feeding Europe from the PV electricity generated in this region and transported through high voltage direct current(DC)lines.However,current implementation of PV systems has shown that their reliability and efficiency depend upon surrounding environmental factors,such as the ambient temperature,wind,and rainfall,as well as soiling,pollution,and aging.The aim of this study was to investigate,through experimental tests,the effects of such factors on the power output of a grid connected PV station.The results showed that the output power and efficiency are deeply affected by various environmental factors,which are weather dependent.These findings may help us develop appropriate solutions to overcome these drawbacks.

Model Estimates of Nutrient Uptake by Red Spruce Respond to Soil Temperature

A better understanding of the mechanisms that control nutrient acquisition in the context of plant and ecosystem responses to climate change is needed. Mechanistic nutrient uptake models provide a means to investigate some of the impacts of temperature change on soil nutrient supply and root uptake kinetics through the simulation of key soil and plant processes. The NST 3.0 model, in combination with literature values on plant and soil parameters from a red spruce (Picea rubens L.) site in the southern Appalachians, was used to conduct a series of model simulations focused on the combined effects of changes to the maximal rate of nutrient influx at high concentrations (Imax), root growth rate (k), concentration of nutrient occurring in the soil solution (Cli), and the ability of the soil solid phase to buffer changes to the soil solution nutrient concentration (b). Previous research has indicated that these four parameters are responsive to changes in root zone temperature. Simulated uptake of NH4 increased by a factor of up to 2.6 in response to increases in soil temperature of 1°C to 5°C. The model also projected an increase in P uptake coupled with up to an 80% reduction in solution P concentration in response to a 1°C -5°C increase over a 147-d simulation period. These hypothetical changes, if validated, have interesting implications for plant growth and competition and point to a need for additional studies to better define the impacts of soil temperature on soil nutrient supply and root uptake.

Research on the attribution evaluating methods of dynamic effects of various parameter uncertainties on the in-structure floor response spectra of nuclear power plant

： Consideration of the dynamic effects of the site and structural parameter uncertainty is required by the standards for nuclear power plants （NPPs） in most countries. The anti-seismic standards provide two basic methods to analyze parameter uncertainty. Directly manually dealing with the calculated floor response spectra （FRS） values of deterministic approaches is the first method. The second method is to perform probability statistical analysis of the FRS results on the basis of the Monte Carlo method. The two methods can only reflect the overall effects of the uncertain parameters, and the results cannot be screened for a certain parameter＇s influence and contribution. In this study, based on the dynamic analyses of the floor response spectra of NPPs, a comprehensive index of the assessed impact for various uncertain parameters is presented and recommended, including the correlation coefficient, the regression slope coefficient and Tornado swing. To compensate for the lack of guidance in the NPP seismic standards, the proposed method can effectively be used to evaluate the contributions of various parameters from the aspects ＆sensitivity, acuity and statistical swing correlations. Finally, examples are provided to verify the set of indicators from systematic and intuitive perspectives, such as the uncertainty of the impact of the structure parameters and the contribution to the FRS of NPPs. The index is sensitive to different types of parameters, which provides a new technique for evaluating the anti-seismic parameters required for NPPs.

双向振动下高聚物胶凝戈壁土的动力特性试验研究

地震灾害是我国岩土工程中经常遇到的问题之一,为研究戈壁土受地震作用时的动力特性变化规律,采用大型动静三轴试验系模拟土体在受到地震纵横波共同作用时的激振应力,研究掺入一定量的高聚物胶凝材料后的高聚物戈壁土受双向振动作用下各因素对戈壁土动剪切模量、阻尼比及残余变形的影响。研究结果表明:双向振动下,动剪切模量随动剪切应变的增长逐渐减小,随径向动应力比增加,动剪切模量呈现出先增后减的趋势;围压和固结比与动剪切模量呈现出正相关;相位在0°~180°内增长时,双向振动作用下的试样动剪应力增大,动剪切模量随之增加,而阻尼比受各因素的影响较小。高聚物胶凝戈壁土的残余变形随高聚物质量比的增大而迅速减小;在相位差为180°时的动残余体应变和残余剪应变均增大。研究结果初步探明了高聚物胶凝戈壁土在双向振动下的动力变形特性,可为高聚物胶凝戈壁土的应用及工程抗震设计提供参考。

基于HSS模型海上风电桶形基础水平循环承载特性对比研究

采用土体本构模型对黏土中的桶形基础进行了有限元模拟,以研究桶形基础的水平循环承载特性。利用有限元方法模拟了在不同单调组合荷载作用下黏土中的桶形基础离心机试验,与试验结果对比验证了使用小应变硬化土(HSS)本构模型的适用性。在此基础上,基于HSS模型和硬化土(HS)模型对比研究了不同循环荷载和小应变模量对桶形基础累积转角、旋转中心和桶-土相对刚度的影响。结果表明,黏土中桶形基础的累积转角随着循环次数和水平荷载的增加而增加,然而每个循环中累积转角的增加逐渐减小。另外,提出了Tb和ζb之间的拟合关系式预测黏土中桶形基础的累积旋转。无论处于疲劳极限状态(ζb=0.3)还是正常使用极限状态(ζb=0.5),旋转中心类型都是从深中心变为浅中心。桶-土相对刚度随循环次数的增加而减小,并且循环荷载越大刚度衰减越大。另外,小应变模量对基础累积转角和桶-土相对刚度有较大影响而对旋转中心无显著影响。与已有的研究结果对比发现,HSS模型更加适用于精细化设计。

基于径流侵蚀功率的长江典型流域能沙关系模型及改进

基于径流侵蚀功率概念建立流域能沙关系模型,可为长江流域泥沙变化精准模拟与水土保持规划提供技术支撑。该研究以长江典型流域及其典型小流域为研究对象,通过收集1965—2018年金沙江流域、嘉陵江流域和湘江流域3个典型流域逐日水沙数据以及万安和李子口2个典型小流域2014—2020年场次降水径流泥沙数据,采用径流侵蚀功率、径流量和降雨侵蚀力对比分析不同时空尺度水沙(径流量和输沙量)、雨沙(降雨侵蚀力和输沙量)和能沙(径流侵蚀功率和输沙量)关系的优劣性,解析能沙关系优越性,并识别能沙关系非一致性变化,从而改进能沙关系模型提高流域输沙量模拟精度。结果表明:1)长江流域3个典型流域及2个典型小流域,在绝大部分情况下能沙关系的表现总是优于水沙关系和雨沙关系,在场次、月和年尺度修正的决定系数最大值分别可达到0.94、0.87和0.54。2)对于不同时间尺度,其流量序列中任意2个流量乘积与输沙量的相关性较高时,第一个流量Q_(1)分位点总是接近1且第二个流量Q_(2)分位点在0.5附近或者高于0.5。基于径流侵蚀功率可以较为准确地计算不同时空尺度流域输沙量,具有明显适用性。3)随着时间升尺度,水沙、雨沙和能沙关系逐渐变差,3个典型流域径流侵蚀功率和输沙量在一些月份上均存在显著变化趋势和显著突变点(P<0.05)。特别是在年尺度上,输沙量均为显著减少趋势(P<0.05),其能沙关系均表现出非一致性变化。4)水库建设和植被增加是导致流域能沙关系变差的重要原因,其均与输沙量呈现极显著负相关(P<0.001)。通过考虑水库指数和NDVI改进能沙关系模型的年决定系数(R^(2))可提高27.28%~97.62%。研究成果可支撑开发新的流域泥沙预报模型,服务长江流域生态保护与高质量发展。

基于有限元分析的动力驱动耙的设计与试验

鉴于花生种植的土壤必须具备耕层深、土壤疏松、地面平整等特点,而旋耕机将土壤粉碎后不利于土壤保墒且耕深仅为8~15cm,为使翻耕后的土壤适合花生栽培,设计了1BQ-3动力驱动耙。为提高耙地工作稳定性,动力耙传动采用框架式齿轮箱多齿轮啮合传动方式,主要工作部件包括驱动耙碎土机构、传动机构、镇压机构和机架。对动力耙耙刀进行了运动学和动力学分析,探究了影响耙刀碎土切削阻力的主要因素,确定耙刀的滑切角为30°,并对动力耙耙刀等关键部件进行了重点设计。通过有限元分析,得出动力耙耙刀的最大应力、位移量、平均变形量。在青岛农业大学胶州试验基地进行田间试验,结果表明:在前进速度为2m/s、耙刀转速为300r/min时,耙刀碎土率为91.78%,耕深均值为26.3cm,可满足花生整地深度25cm以上的农艺要求及国家标准与花生栽植要求。

光伏阵列对松嫩草地土壤细菌群落组成与多样性的影响

为阐明光伏电站对松嫩草地土壤细菌组成与多样性的影响,调查并测定了吉林西部一座光伏电站的光伏板行间、光伏板下和光伏阵列周边(对照)的植物群落特征和土壤特征,采用Illumina HiSeq 2500基因测序仪进行了土壤细菌16S rDNA测序.结果表明:光伏阵列呈现提高土壤细菌Ace,Chao1和Simpson多样性指数的趋势,并显著增加拟杆菌纲、梭菌纲、酸杆菌纲、放线菌纲和γ-变形菌纲的相对丰度.影响土壤细菌群落的主要因素是土壤pH和全碳、全氮和总有机碳含量,以及植物群落地上生物量和盖度.光伏阵列对松嫩草地土壤细菌群落组成和优势纲丰度均有一定的影响,并对土壤细菌多样性的恢复发挥了积极作用.

Effects of coal-fired power plants on soil microbial diversity and community structures

Long-term deposition of atmospheric pollutants emitted from coal combustion and their effects on the eco-environment have been extensively studied around coal-fired power plants.However,the effects of coal-fired power plants on soil microbial communities have received little attention through atmospheric pollutant deposition and coal-stacking.Here,we collected the samples of power plant soils(PS),coal-stacking soils(CSS)and agricultural soils(AS)around three coal-fired power plants and background control soils(BG)in Huainan,a typical mineral resource-based city in East China,and investigated the microbial diversity and community structures through a high-throughput sequencing technique.Coal-stacking significantly increased(p<0.05)the contents of total carbon,total nitrogen,total sulfur and Mo in the soils,whereas the deposition of atmospheric pollutants enhanced the levels of V,Cu,Zn and Pb.Proteobacteria,Actinobacteria,Thaumarchaeota,Thermoplasmata,Ascomycota and Basidiomycota were the dominant taxa in all soils.The bacterial community showed significant differences(p<0.05)among PS,CSS,AS and BG,whereas archaeal and fungal communities showed significant differences(p<0.01)according to soil samples around three coal-fired power plants.The predominant environmental variables affecting soil bacterial,archaeal and fungal communities were Mo-TN-TS,Cu-V-Mo,and organic matter(OM)-Mo,respectively.Certain soil microbial genera were closely related to multiple key factors associated with stacking coal and heavy metal deposition from power plants.This study provided useful insight into better understanding of the relationships between soil microbial communities and long-term disturbances from coal-fired power plants.

不同植被恢复类型下土壤碳含量对光伏组件遮阴的响应

【目的】探究云南石漠化脆弱区光伏场区不同植被恢复类型下,土壤微生物量碳(MBC)、可浸提有机碳(EOC)及总碳(TC)含量对光伏组件遮阴的响应特征,以期为石漠化脆弱区光伏电站退化土地生态恢复中的植被选型优化提供科学依据。【方法】2021年10月,在云南省昆明市东川光伏电站内,选取黄金菊(Euryops pectinatu)和红花檵木(Loropetalum chinense var.rubrum)2种人工建植植被样地,分别在每个样地的光伏板间(IP)、前檐(FP)、后檐(RP)、板下(UP)设置4个平行采样带,并以未受电站建设干扰的场外草地(以黄茅(Heteropogon contortus)为优势物种群落)样地作为对照(CK),测定2种植被恢复类型下光伏场区不同位置的光照强度以及表层(0~20 cm)的土壤温度、土壤碳(TC、MBC、EOC)含量以及土壤理化性质(pH、电导率、含水量),并分析光照强度、土壤温度、土壤碳含量以及土壤理化性质间的相关性。【结果】光伏场区不同位置的光照强度在07:00-19:00差异明显,且光照强度由大到小表现为对照>板间>前檐>后檐>板下,其中对照、后檐及板下位置的光照强度日变化均呈单峰变化,而板间和前檐位置的日变化均呈双峰变化趋势。场外的土壤温度明显高于光伏场区内,光伏场区不同位置的土壤温度差异较小。植被类型和光伏场区不同位置的光照异质性对土壤碳含量均有显著影响。在黄金菊样地,场区不同位置的土壤微生物量碳含量均较对照显著升高,其中前檐位置的土壤微生物量碳含量最高;在红花檵木样地,除了板间位置的土壤微生物量碳含量较对照显著降低外,其他位置均显著升高。2种植被恢复类型下不同位置土壤pH与对照无显著差异,土壤含水量和电导率均显著高于对照。相关性分析结果表明,光照强度与土壤微生物量碳含量和土壤含水量呈显著负相关,与可浸提有机碳含量、电导率、土壤温度呈显著正相关;土壤含水量与土壤可浸提有机碳和总碳含量均呈显著负相关(P<0.05)。【结论】在石漠化脆弱区的光伏场区,光伏组件遮阴与植被恢复均有利于提高土壤微生物量碳含量,但对可浸提有机碳和总碳含量的影响有一定差异,其中黄金菊样地的土壤可浸提有机碳和总碳含量明显高于对照。若短期内想达到较好的恢复效果,应优先选用黄金菊进行植被恢复。

戈壁石土壤葡萄埋藤装置设计与试验

针对含戈壁石土壤机械化葡萄埋藤越冬作业难度大、能耗高、理论研究少等难题,考虑含戈壁石土壤的葡萄埋藤农艺要求,设计了一种可在戈壁石土壤中葡萄埋藤的铰臂式锯齿形刀结构和葡萄埋藤机装置,并根据葡萄埋藤农艺要求,对埋藤装备关键部件进行参数设计和计算。考虑土壤的挖掘、摩擦、移动和抛出等影响因素建立了功耗算法,特点是土壤容重越大所需功耗也越大。通过确定含戈壁石土壤埋藤机所匹配的履带式拖拉机总功率,在戈壁石含率分别为19.73%和32.24%的两种实验区进行了埋藤覆土试验。在这两个实验区,埋藤覆土平均厚度的最大值分别为0.19m和0.21m,最小值分别为0.1m和0.097m,埋藤覆土宽度均为1.2m,满足吐鲁番地区含戈壁石土壤的葡萄埋藤农艺要求,可有效降低葡萄种植成本、减轻劳动强度、提高综合经济效益。

海床加固对海上风电单桩基础的动力特性影响

建立海上风电单桩基础浅层土体三维数值有限元模型,分析不同范围、不同形状海床加固方式,以及作用不同幅值、不同方向循环荷载单桩基础的累积变形、振动特性动力响应影响,为加固体应用于单桩桩周土体加固工程提供优化建议。结果表明:不同加固条件下,风力机一阶自振频率改变较为显著;加固后单桩基础相较于未加固单桩基础,在循环荷载作用下,单桩桩身位移、转角和内力响应极值均有所减小,泥面位移极值最多可降低81%;桩周土体剪应力与剪应变亦减小,随着循环次数增加,剪应变增幅减少,土体塑性区域变小。

海上风电场吸力筒基础沉贯特性研究

吸力筒沉贯特性是影响其工程应用的重要因素。基于海上风电场吸力筒导管架基础筒体下沉过程的实测数据,研究真实海床地基条件下吸力筒沉贯阻力的CPT计算方法的可行性以及DNV规范推荐的土体沉贯阻力的经验系数的适用性,分析黏土层和砂土层中沉贯阻力的组成和负压下沉过程中的筒内土塞机制。研究结果表明:CPT计算方法能够较精确地计算吸力筒沉贯阻力,DNV规范推荐的经验系数高估了海床地基中淤泥质土、粉质黏土层的黏土经验系数k_(f)(z)以及砂砾、中砂、粗砂层等砂土经验系数k_(p)(z);负压下沉过程中,筒内土塞体积的发展规律与海床土层分布及土体物理力学性质密切相关。

地震作用下桩-土-核电结构相互作用的异步分析方法

为拓展核电厂的选址范围,有必要对非基岩场地桩基情形的核电结构进行地震安全性评估。在目前的桩-土-结构相互作用分析方法中,Winkler地基梁模型以及p-y法都将桩-土-结构相互作用问题进行了简化,难以反映复杂地基情形。整体有限元法可考虑复杂地基情形,但计算量较大,效率较低。本文基于高效的三维时域土-结构相互作用分区分析(Partitioned Analysis of Soil-Structure Interaction,PASSI)方法,实现桩基与土体分别采用不同时间步距的计算方法,避免土体采用桩基相对较小的时间步距而增加不必要的计算量。本文以AP1000核岛结构作为研究对象,建立了桩-土-核电结构相互作用的三维有限元模型并对其进行分析。通过输入脉冲波验证了该异步算法的有效性,并结合运动相互作用和惯性相互作用,分析了桩身最大剪力和最大弯矩的特点。分析了桩-土-核电结构在地震波输入下的响应。由于桩的自由度数相对于土体的自由度数可以忽略不计,采用桩-土异步算法时,桩附加的计算量可以忽略,这种高效方法有望用于大型核电结构的桩-土-结构动力相互作用分析中。

可调式分土装置的设计及试验

针对垄作大葱收获分土阻力大问题,确定了可调式分土装置的结构,降低了分土作业时消耗的功率。装置由分土圆盘、支架、调节座等组成,可将葱垄两侧的土壤进行切割、抛送。借助Design-Expert8.0.6软件,以分土盘的距离、偏角、转速为试验因素,功率为指标设计正交旋转组合试验,确定距离、偏角、转速对分土盘功率的影响顺序为偏角>转速>距离。利用响应曲面对试验结果进行优化,得到分土盘低功耗的最佳参数组合,即距离为100mm、偏角为20°、转速为30r/min。通过田间试验验证了最佳参数组合分土盘的分土效果较好,分土功率均值为145.8W。