Water-saving Potential in aeolian sand soil under straight tube and surface drip irrigation in Taklimakan Desert in Northwest China

Evaporation loss from the saturated soil beneath drip irrigation emitters highly influences the irrigation efficiency of drip krigation （D1]. Subsurface drip irrigation （SDI） is one good approach to curb this inefficiency, but in a new irrigation method, straight tube irrigation （STI）, the irrigation tubes do not need to be buried and thus STI is recommended to increase the irrigation efficiency under normal surface-applied DI. STI consists of only connectors and water-transference tubes that can directly transfer irrigation water from the lateral emitters in the drip line to the root zone of plants. Five-month field experiments were carried out in aeolian sand soil in the forest-belts of the Taklimakan Desert, which have poor water storage capacity, to compare the potential water saving between STI and DI. The preliminary results showed that, compared with DI, STI （1） improved the soil water content in soil depths from 40 to 100 cm under the soil surface; （2） achieved the same irrigation effects in relatively shorter irrigation durations; （3） had very little water loss due to deep seepage; and （4） formed a layer of dry sand about 10 to 30 cm thick immediately below the soil surface, which lessened evaporation loss of soil water beneath the emitters on the soil surface. This demonstrates that STI can maximize the water-saving potential of DI through the reduction of wetted soil perimeters on the soil surface. This is valuable information for water-saving engineering applications and projects with STI in arid and semiarid regions.

Development Potentials and Benefit Analysis of Efficient Water-saving Irrigation in Lixin County

On the basis of analyzing water resources,crop planning structure,and irrigation mode in Lixin County,potentials and benefits of developing efficient water-saving irrigation in the county were explored to provide references for its future water-saving irrigation.

Minimization of Air Consumption and Potential Savings of Textile Denim Fabric Manufacturing Process

One of the most important aspects of Bangladesh’s textile industry is denim. Bangladesh now has a new opportunity thanks to the global demand for denim among fashion industry professionals. Entrepreneurs from Bangladesh provide denim products to well-known international merchants all over the world. The worldwide denim market is predicted to expand by roughly 8% through the year 2020. We must raise the standard of denim if we are to keep up with the expanding industry. In contrast to projectile and rapier systems, air-jet weaving machines nowadays can weave practically all types of yarns without any issues and at higher rates. Due to this, air-jet looms are an excellent substitute for other weft insertion techniques. This kind of device still has one significant flaw, though, and that is the enormous power consumption brought on by the creation of compressed air. Researchers and manufacturers of air-jet looms have therefore worked very hard to find a solution to this issue and achieve a huge reduction in air consumption without compromising loom performance or fabric quality. Therefore, the purpose of this project is to look into ways to decrease air consumption and reduce auxiliary selvedge waste without any decrease in loom performance and fabric quality on existing air-jet weaving looms which reduce the manufacturing costs with process improvement. Just updating the air pressure allowed a weaving mill to reduce air usage by 11 cfm. So, with just almost no cost, a company with 100 looms could save $0.15 M each year, on compressed air. Two new methods for decreasing process costs on air jet looms have also been developed by this project work.

A fast multipole boundary element method for three-dimensional potential flow problems

A fast multipole methodology (FMM) is developed as a numerical approach to reduce the computational cost andmemory requirements in solving large-scale problems. It is applied to the boundary element method (BEM) for three-dimensional potential flow problems. The algorithm based on mixed multipole expansion and numerical integration isimplemented in combination with an iterative solver. Numerical examinations, on Dirichlet and Neumann problems,are carried out to demonstrate the capability and accuracy of the present method. It has been shown that the methodhas evident advantages in saving memory and computing time when used to solve huge-scale problems which may beprohibitive for the traditional BEM implementation.

The spin-one Duffin Kemmer Petiau equation in the presence of pseudo-harmonic oscillatory ring-shaped potential

The Duffin-Kemmer-Petiau equation （DKP） is studied in the presence of a pseudo-harmonic oscillatory ring-shaped potential in （1 ＋ 3）-dimensional space-time for spin-one particles. The exact energy eigenvalues and the eigenfunctions are obtained using the Nikiforov-Uvarov method.

Research on Potential Energy Recovery System of 16T Wheeled Hybrid Excavator

The system translates the arm/boom/buck's potential energy into electrical energy and then the electrical energy is stored in a storage device.This study develops a set of energy management strategy to make the recoverable energy recycling efficiently.This energy of traditional excavator is lost in the form of heat energy,which is wasteful,and makes the component's temperature higher and higher to reduce the machine's life.Research on this system not only conforms to the current topic of energy crisis,but also mates with the actual engineering,so it is significant to research that.

Optimization of Finishing Process and Energy Savings in Denim Textile Facility

Denim is widely accepted among exported textile products due to its aesthetics, appearance, and fashion. Practitioners employed several physical or chemical treatments to improve denim qualities in denim finishing operations. So, several treatment processes, including enzymatic, bleaching, singeing, heat set, and ozone finish, are used, which made this processing more energy consumption and time-consuming. Therefore, it is significant to investigate how changing the chemicals and raw ingredients could improve the finishing process, which is environmentally and economically beneficial for sustainable production practices in the denim finishing process. This study’s research design comprises an experimental investigation in a denim plant in Bangladesh. Two different fabrics were chosen to analyze, determining the potential savings of finishing on the denim fabrics’ performance characteristics. By deducting singeing and heat-set processes, the researchers ran an experimental process by maintaining the same length of fabric. Then, the impacts of finishing process optimization on the mechanical, thermal, and comfort parameters of drape, stiffness, and tear strength were examined. The study’s findings demonstrated that this experiment increased productivity and reduced the finishing unit’s energy consumption without compromising the denim fabrics’ quality. This study significantly impacts environmental sustainability by preserving limited energy resources and manufacturing denim finishing processes.

Problems and Development Countermeasures of Agricultural Water-Saving Irrigation

Agriculture is the biggest water user in China,and the development of agricultural water-saving has great significance to the national economy and social development. In this paper,the present situation of water used in agriculture irrigation and water-saving potential were analyzed,and the ＂ bottleneck＂ and main problems existing in water-saving irrigation in China were discussed. From the aspects of engineering investment channels,agricultural water-saving policies and management system,reform of agricultural water price and water right transfer,improvement of farmers＇ water-saving consciousness,and promotion of rural land transfer,suggestions were proposed for the development of China＇s agricultural water-saving in future,which will provide a technical support for the sustainable use of agricultural water resources in China.

江苏高效节水灌溉发展现状及对策研究

发展高效节水灌溉是江苏现代农业发展的必由之路。总结了江苏高效节水灌溉现状,分析发展高效节水灌溉的潜力和需求,从自然条件、技术装备、投入保障、管护水平等角度剖析发展的制约因素,提出选择适宜发展模式、强化科技支撑、加强典型示范引领、注重宣传发动等对策措施。

中国居民家庭生活用水十点规律与认识

居民家庭生活用水刚性强、标准高,是水资源消费最主要的终端单元,也是近年来我国经济社会用水需求增长最快的用户,其发展规律和未来趋势深刻影响对总体用水格局的分析。通过系统监测、试验、调查和模拟研究,阐释了家庭生活用水行为占比、不同人群生活用水差异、节水器具、节水宣传、水价等对生活用水的影响规律,对比分析了国外和我国生活用水变化规律,提出家庭生活用水增长规律,构建了基于人口特征的需水变化曲线,预测了未来我国居民生活用水变化趋势,以期为我国生活节水管理和总体用水发展趋势研判提供参考。

基于C-D生产函数的灌区节水贡献率研究

为挖掘灌区节水目标实现路径,提高灌区用水效率,研究分析了大中型灌区水利工程建设管护对节水战略目标的贡献程度。以江苏省为例,选取6个典型灌区,收集了2015-2022年统计数据,分别计算渠系工程、田间工程和非工程措施的节水潜力,并据此计算灌区总节水潜力。以水利工程投入、劳动力投入、土地投入、技术进步作为自变量,灌区总节水潜力作为因变量,利用改进C-D生产函数来构建“双对数模型”。利用SPSS软件对数据进行多元线性回归,运用步进法剔除无关变量后建立最优方程,通过弹性系数测算不同变量对节水目标的贡献率大小。结果表明,在灌区总节水潜力组成中,渠系工程节水占比最大,田间工程节水占比最小;水利工程投入、土地投入、技术进步对节水目标的平均贡献率分别为45.5%、30.4%、5.2%,但技术进步贡献率呈现逐年增长的趋势,水利工程收入贡献率先减小后增大。大型灌区水利工程对灌区节水的贡献率高于中型灌区。该研究将C-D生产函数模型运用到节水评价当中,结果较为合理可靠,可为大中型灌区节水发展提供技术参考。

寒冷地区既有高校宿舍被动式节能潜力分析——以南开大学八里台为例

文章以南开大学八里台校区宿舍为例,探索在低碳背景下寒冷地区既有高校宿舍建筑被动节能改造的潜力,通过实地调研,建立基准模拟,并利用Grasshopper软件搭建参数化平台对基准模型外围护结构热工性能的被动式节能因素进行模拟分析,设计正交试验,模拟不同试验的建筑能耗,通过SPSS分析影响能耗的参数与能耗间的关系,从而确定每个参数对建筑能耗的影响程度,得出不同因素对于建筑能耗的敏感性。结果表明:外墙、屋顶、外窗等部位传热系数与采暖、制冷能耗均呈线性关系;节能优先级依次为:外墙、外窗、屋顶;仅通过改变外围护结构热工性能,最大节能潜力为61.9%,若想实现零能耗,需要使用高能效的主动式设备和最大化利用可再生能源。

基于节能潜力的办公建筑外窗设计优化策略——以郑州市主城区为例

通过分析建筑设计环节与节能之间的关系,提出了基于节能潜力的办公建筑外窗设计优化策略。基于Grasshopper参数化平台,以郑州市主城区多层办公建筑为例构建典型模型,对外窗设计尺度参数、外窗设计性能参数、遮阳设计参数等3个层级和11个影响建筑能耗的设计参量进行能耗模拟和量化分析。结果表明:在3个层级中,外窗设计尺度参数的全年单位面积总能耗节能潜力最大;在11个设计参量中,窗墙比的全年单位面积总能耗和制冷能耗节能潜力最大,玻璃传热系数的全年单位面积采暖能耗节能潜力最大。因此,在设计郑州市主城区办公建筑的外窗时,建议优先考虑窗墙比,其次是窗口中心线和玻璃材质。

南水北调中线受水区全要素水资源绿色效率及节水减排潜力

采用非径向、非角度SBM-DEA模型测算2015—2021年南水北调中线受水区20个城市全要素水资源绿色效率,探究其时空演变规律,并分析各市节水减排潜力。结果表明:受水区全要素水资源绿色效率总体呈现以京津冀、郑州两大都市圈为核心向外围逐渐递减的“核心-外围”空间结构模式以及全要素水资源绿色效率由高到低依次为京津、河南、河北的空间分异规律;2015—2021年受水区全要素水资源绿色效率总体呈波动上升趋势,但仍处于较低水平,仅实现了最优效率的70%~85%;不同城市节水减排潜力差异显著,空间上呈现“南高北低、西高东低”的分布格局。

基于室内非均匀环境营造的新型通风模式下人员热舒适性及系统节能潜力

为解决现有通风空调系统无法根据占用区域实现按需供冷造成的热不舒适及能源浪费问题,本研究根据人员占用区域需求实时切换气流模式组合及冷量供给,提出了一种新型通风模式,旨在利用多种气流模式的最优组合控制特定需求场景。采用数值模拟的方法探究了不同占用区域情况下新型通风模式的人员热舒适性和系统的节能潜力,并与混合通风模式和层式通风模式进行了对比。结果表明:新型通风模式在气流组织上具有明显优势;新型通风模式较混合通风模式和层式通风模式具有更高的热舒适性,空气分布特性指数最大;新型通风模式局部冷量利用系数最小,冷量有效利用率最高,所需供冷量最小,因此新型通风模式的节能潜力最大。

基于AquaCrop模型的塔额盆地夏玉米节水潜力分析

以AquaCrop模型为基础,结合2021—2022年塔额盆地夏玉米实测数据,对模型部分保守参数和产量模块的标准水分生产力(WP*)和参考收获指数(HI 0)进行校准与验证,通过设置起始灌水时间、灌溉定额和灌水周期三因素交叉试验,对夏玉米进行产量模拟,分析其产量与作物水分利用效率受灌溉定额和起始灌水时间的影响程度,在产量和作物水分利用效率均为较高值的前提下选择最优灌溉方案。以实际夏玉米播种面积为参考值,模拟并预测2022年及未来4年在不同灌溉方案下的夏玉米产量和节水总量,并依此分析塔额盆地夏玉米节水潜力。结果表明:(1)对AquaCrop模型作物生长模块主要参数、土壤水分胁迫参数和产量模块参数WP*和HI 0进行参数率定,最终产量模块参数选择WP*=35 g·m^(-2)、HI 0=43%,2021年和2022年产量模拟相对误差值分别为1.26%和1.07%。(2)结合模型模拟得出最优灌溉方案如下:起始灌水时间5月20日,灌溉定额470 mm,灌水周期7 d,灌水11次,作物水分利用效率2.005 kg·m^(-3),产量9.423 t·hm^(-2)。(3)以2022年为现状水平年,最优灌溉方案下,现状水平年和未来水平年(2022—2025年)可分别实现节水量2.1338×10^(5)、2.1826×10^(5)、2.1992×10^(5) m^(3)和2.2306×10^(5) m^(3)。

种植模式协同秸秆管理对稻田温室气体排放的影响

在浙江省嘉善县选取1.3 hm^(2)稻田,设置节水旱管+秸秆还田/不还田与普通淹灌+秸秆还田/不还田2种种植模式4个处理组(以下简称节水还田、节水不还田、普通还田、普通不还田),采用静态箱-气相色谱法获取28批次336个稻田甲烷(CH_(4))和氧化亚氮(N_(2)O)排放数据,同时结合土壤颗粒有机碳(POC)等6个环境因子12个样品分析结果,探究种植模式协同秸秆管理对稻田温室气体排放特征的影响。结果显示:1)CH_(4)累计排放量依次为普通还田>普通不还田>节水还田>节水不还田,N_(2)O累计排放量为普通还田>节水不还田>节水还田>普通不还田。全球增温潜势(GWP)与温室气体排放强度(GHGI),普通还田最高,分别为7696.03 kg/hm^(2)(以CO_(2)计,全文同)、0.97 kg/kg;节水不还田最低,分别为2110.12 kg/hm^(2)、0.21 kg/kg。2)最小显著差异法分析结果表明,各处理组之间CH_(4)累计排放量存在显著差异。据Pearson相关性分析结果,CH_(4)累计排放量与POC含量呈极显著正相关(P<0.01),与微生物碳含量呈显著正相关(P<0.05);N_(2)O累计排放量则与硝态氮(NO_(3)^(-)-N)含量呈显著正相关(P<0.05),GWP、GHGI与POC含量呈极显著正相关(P<0.01)。3)种植模式与秸秆管理均对CH_(4)累计排放量有极显著影响(P<0.01),二者交互作用对CH_(4)累计排放量、N_(2)O累计排放量有显著影响(P<0.05)。研究表明,水稻节水旱管种植协同秸秆还田措施是一种气候友好型的高产经济种植模式,既可保证粮食安全,降低秸秆离田成本,对于减缓全球温室效应也具有积极作用。

面向动臂势能再生的主动式储能元件控制策略

主动式储能元件是一种针对现有液压蓄能器不足而提出的新型气-电混合型储能元件,但其存在着液压能、压缩气体能和电能间的能量耦合问题,导致其工作时抗干扰能力较差,降低了工作液压系统的节能效率。为了解决其存在抗干扰能力差的问题,针对液压挖掘机动臂液压回路的工作特点,提出了利用主动式储能元件实现动臂势能再生的系统架构,并设计了一种自抗扰控制策略及其参数优化方法,通过设计扩张状态观测器来解决干扰和参数不确定性等问题。为验证控制策略的可行性,首先介绍了主动式储能元件的结构;其次,设计了以主动式储能元件为控制对象的自抗扰控制器。建立了基于主动式储能元件的动臂势能再生系统仿真模型,并进行了试验验证。研究结果表明,蓄能器模式、普通控制模式及自抗扰控制模式的回收效率分别为42.81%、56.76%和58.60%;再利用效率分别为96.01%、97.06%和95.81%;再生效率分别为41.1%、55.1%和56.1%。仿真试验验证结果也表明,以主动式储能元件为对象提出的自抗扰控制策略有效地改善了控制性能,增强了系统压力稳定性。

面向绿洲安全和干旱区可持续发展的农业节水潜力研究

为确保用水总量控制下绿洲安全及干旱区可持续发展目标的实现,以新疆开孔河流域为例,提出基于用水总量控制指标、地下水安全等约束条件的干旱区灌溉节水潜力计算新方法。结果表明:1)开孔河流域现状年(2020年)地下水开采量为12.97亿m^(3),灌溉用水总量为34.85亿m^(3);传统节水模式下,流域中期规划年(2030年)节水潜力为0.74亿m^(3),远期规划年(2050年)节水潜力为5.02亿m^(3)。2)在节水潜力新内涵下,开孔河流域中期规划年没有节水潜力,且需要休耕18667 hm^(2),远期规划年节水潜力为1.77亿m^(3)。3)为防止干旱区次生盐渍化,实现水资源短缺的干旱区可持续发展,在节水后应控制绿洲地下水位在3.5~4.0 m之间。对于水土不均衡的干旱区灌区而言,传统节水思路对绿洲安全的重视程度不够,对节水潜力评价过高。

超长电力电缆隧道冬季温度分布特征及通风节能潜力

为了解冬季通风时隧道内的换热情况和节能潜力,对冬季室外气温为4~12℃时超长通风区间特高压电力隧道内的温度分布特征进行数值模拟研究。采用ANSYS Fluent 19.2软件,通过用户自定义程序完成电力隧道全长的模拟。对冬季隧道的传热特征和通风节能潜力进行分析,定义并给出了冬季能实现最大节能效果的临界通风量。结果表明:具有超长通风区间的电力隧道存在通过降低通风量从而实现节能的潜力;冬季电力隧道前段土壤放热、后段土壤吸热,土壤放热量占比受室外气温影响,而土壤吸热量占比受室外空气温度和通风量影响;冬季室外气温越低,临界通风量越小,通风节能潜力越大,当冬季室外气温为4~12℃时,最大可能节能率为91%。