Mechanical and Experimental Study of Sprinkling Water Cooling System on Roof of Shanghai Expo Theme Pavilion

Based on the similarity theory,a scale effect model of the spraying water cooling system of Shanghai expo Theme Pavilion's roof was set up.According to the typical weather conditions in Shanghai city,different models were analyzed on solar radiation,and different heat transfer amount was obtained.And the following conclusions could be made:At the sunny day of summer in Shanghai,the temperature of inner roof with sprinkling system descended about 3 ℃,and the air conditioning load of the whole Theme Pavilion descend more than 320 kW.

Comparative Revenue, Obstacle Factors and Promoting Strategy of Sprinkling Irrigation in Wheat Field: A Case Study from Yanzhou, Shandong Province in China

This paper takes 30 hm2 wheat sprinkling irrigation land of Yunguo Family Farm in Yanzhou, Shandong Province, China as a sample, and draws a conclusion by comparing it with other households (including individual and large households). The conclusions are as follows: wheat sprinkling irrigation has a remarkable water-saving effect and comparative revenue. Water saving efficiency can reach 61.54% and a comprehensive income-increase rate can reach 38.67%. The main factors of increasing income and incentives of saving irrigation by sprinkling irrigation ranks as the following: saving land consolidation and water monitoring labors (accounts for 62.50%), saving land area of wheat bed to increase production and income (accounts for 23.44%), saving water bills (accounts for 14.06%). The incentive effect of water saving is not obvious mainly because the water price is low. The main obstacles to the promotion of sprinkling irrigation by individual household are the uneconomical scale and the barriers of coordination of proxy irrigation. Other large household’s (family farm) obstacles are mainly the instability of land tenure and mixed management. Suggestions on promoting sprinkling irrigation in wheat field: Accelerate land circulation and promote agricultural scale management to create basic scale conditions for spreading sprinkling irrigation;stabilizing farmland management rights as stabilizing farmland contractual rights, thus giving long-term business interests to all kinds of large household owners;guide the development of “scale + specialization” modern family farms;appropriate water saving subsidies should be given according to the positive externality of household water saving;confirm agricultural water rights to household and allow compensated transfer of “surplus water rights”.

Molecular insight into the GaP(110)-water interface using machine learning accelerated molecular dynamics

GaP has been shown to be a promising photoelectrocatalyst for selective CO_(2)reduction to methanol.Due to the relevance of the interface structure to important processes such as electron/proton transfer,a detailed understanding of the GaP(110)-water interfacial structure is of great importance.Ab initio molecular dynamics(AIMD)can be used for obtaining the microscopic information of the interfacial structure.However,the GaP(110)-water interface cannot converge to an equilibrated structure at the time scale of the AIMD simulation.In this work,we perform the machine learning accelerated molecular dynamics(MLMD)to overcome the difficulty of insufficient sampling by AIMD.With the help of MLMD,we unravel the microscopic information of the structure of the GaP(110)-water interface,and obtain a deeper understanding of the mechanisms of proton transfer at the GaP(110)-water interface,which will pave the way for gaining valuable insights into photoelectrocatalytic mechanisms and improving the performance of photoelectrochemical cells.

农业自动卷管机设计与试验

为了解决农业喷灌作业过程中通过人工收放水管存在效率低下、劳动强度大的问题,设计了一种由导向机构、收放管机构、排管机构及控制系统组成的自走式农业自动卷管机,提出了基于步进电机的精密排管系统以及基于增量式PID的恒张力收放管控制方法,开发了自动卷管机实物样机。样机试验结果表明:自动卷管机的排管效果良好,能够适应多种管径的水管且水管排列整齐紧密;卷管机的恒张力控制性能良好,在4.0km/h小时车速工况下,水管张力的最大相对误差为7.7%;在(0~4.0)km/h速度阶变工况下水管张力的最大相对误差为15.3%,收放管的速度能够自适应车速变化,水管的张力始终处于合理范围内。

微喷带激光打孔质量评价及对喷孔流量的影响

喷孔参数和流量是研究微喷带水力性能的基础.为探究微喷带喷孔结构与喷洒特性,选取了国内外2种激光打孔的加强压边型微喷带,每组组孔包含12个喷孔,利用图像处理进行了喷孔参数测量与加工质量评价,并进行了喷孔流量试验.结果表明,2种微喷带从喷孔内侧和外侧测得的面积误差均小于10%;进口微喷带和国产微喷带喷孔的平均圆度分别为0.82~0.88和0.82~0.91,进口微喷带不同组孔内相同位置喷孔的圆度偏差系数低于0.040、流量偏差系数小于0.120,而国产微喷带喷孔的圆度偏差系数和流量偏差系数的波动较大,其值分别为0.009~0.069和0.057~0.475.因此以喷孔面积和圆度为指标,可对不同激光打孔的微喷带喷孔进行评价,当喷孔面积的波动范围和圆度偏差系数较小时,微喷带不同组孔内相同位置的喷孔流量差异性较小.

基于无线组网技术的花园智能生态管理系统的研究

传统的花园养护主要是以人工为主,但花园管理相对复杂,涉及温度、湿度、pH值、生长习性、病虫害防护等方面,管理效果与管理人员经验密切相关,总体工作量较大、成本较高、效率偏低,防虫效果差且经常受到自然天气的影响。为此,设计一种基于无线组网技术的花园智能生态管理系统,通过准确地捕捉各种信息,为优化花园管理提供科学依据。实验结果表明:所设计系统运行性能良好,可为植物生长提供优良的成长环境,且具有性能稳定、成本低、效率高等优点,具有良好的实用和推广价值。

不同灌溉模式对小麦冬前幼苗生长及生理特性和产量的影响

为探明不同灌溉模式对淮北地区小麦冬前幼苗生长及生理特性和产量的影响,以‘烟农19’为供试材料,设置不灌溉(W0)、播后灌溉60 mm(W1)、播种后和分蘖期每次微喷30 mm(W2)共3种灌溉模式,研究不同处理对苗期土壤水分含量变化、幼苗农艺性状、叶片生理特性、籽粒产量及产量构成的影响。结果表明,与W0和W1相比,W2维持了小麦三叶期、六叶期和越冬期土壤0~20 cm适宜的水分含量。W1和W2较W0处理促进三叶期和六叶期幼苗的生长;越冬期幼苗的分蘖数、株高、叶龄、初生根和次生根数目均表现为W2显著高于W1,二者显著高于W0。不同时期幼苗的茎+鞘、叶干质量为W2>W1>W0。W2不同生育时期群体叶面积指数显著高于W1,W0最低;六叶期W1与W2的叶片叶绿素含量无显著差异,二者显著高于W0,越冬期为W2>W1>W0。W0不同时期叶片超氧化物歧化酶、过氧化氢酶、过氧化物酶活性和丙二醛含量显著高于W1,除六叶期W1与W2的过氧化氢酶活性无显著差异外,各时期的超氧化物歧化酶和过氧化物酶活性均为W2最低。成熟期小麦籽粒产量和产量构成要素均表现为W2>W1>W0。综上,播后和分蘖期利用微喷灌可以维持苗期适宜的土壤水分含量,促进幼苗生长发育,提高幼苗抗逆能力,进而有利于形成壮苗并增加产量。

首钢长钢窑炉物料溜槽的转运抛洒问题分析与治理

探讨皮带受料部位的漏料治理,不深入研究其运行机理,着重于经验技术的应用,不涉及大的改造工程,结合现场条件进行局部改善。分析物料起拱原理和物料流程,探析各因素的影响机理,通过变口塑形束控落入皮带的物料流形态,以最小代价进行案例实践。实践表明,收口并非越小越好,对中调整并非是越正越好,必要时可用偏心对中。通过多措并举实施抛洒问题治理,使得槽口塑形得到显著改善。

可双向钻土自升降式喷灌装置技术工程示范应用研究

水资源短缺问题日趋严重,开展农田节水灌溉设施研究及应用日益重要。本研究将一种可双向钻土自升降式喷灌装置应用于农业蔬菜种植示范区。通过分析其喷头流量、喷洒半径、喷洒均匀性等性能参数随试验压力的变化规律,得出该装置的最佳运行压力为0.3 MPa;在此压力条件下,该装置实现了研究区域内土壤墒情由轻旱向适墒的转变,灌溉用水定额从3200 m^(3)/hm^(2)下降到2800 m 3/hm^(2),水资源利用率提高了10%以上,具有良好的节水效果;同时通过引进可双向钻土自升降式喷灌装置,对整个研究区域开展节水灌溉,将区域土壤有效控制在适墒范围,使得研究区域内年作物总产量增加了43.4 t,估算经济产值增量高达34.73万元/年,取得了显著的经济效益。

基于物联网技术的一体式自动灌溉系统设计与实现

在现代生活中,居家绿植的自动灌溉需求不断增加,传统灌溉系统常因缺乏自动控制功能而难以满足需求。为解决这一问题,文章设计并实现了一种基于物联网技术的自动灌溉系统。该系统以STC89C52单片机为核心,通过无线设备监测土壤湿度、环境温湿度和光照强度等参数。系统采用模块化设计,包含温湿度传感器、光照传感器、土壤湿度传感器、AD/DA模数转换模块、OLED显示模块及蓝牙通信模块。通过仿真实验和实际测试,验证了系统的稳定性和有效性。结果表明,该系统能在无人值守的情况下,实现对绿植的精准灌溉,减少人工操作,提高灌溉效率,并有效节约水资源。系统具有较强的适应性,能够根据环境变化自动调整灌溉策略,满足不同绿植的需求,展现出良好的应用前景。

高站杆远射程森林防火灭火喷灌工程应用分析

日照市山海天旅游胜地卧龙山植被区森林防火喷淋工程项目在教科书中无现成设计理论可供参考。针对项目的特殊性,依据管网水力学计算原理,结合该地区实际情况,采用高站杆远射程旋转式喷头,对项目区森林植被防火灭火喷灌工程进行了规划设计,并于2018年完成了工程的施工技术指导。经过多年实践,工程运行情况良好,达到了预期目的。

Experimental and CFD Heat Transfer Studies of Al2Oa-Water Nanofluid in a Coiled Agitated Vessel Equipped with Propeller

This paper presents the heat transfer characteristics of A1203-water nanofluid in a coiled agitated vessel with propeller agitator. The experimental study was conducted using 0.10%, 0.20% and 0.30% volume concentra tion of A1203-water nanofluids. The results showed considerable enhancement of convective heat transfer using the nanofluids. The empirical correlations developed for Nusselt number in terms of Reynolds number, Prandtl number, viscosity ratio and volume concentration fit with the experimental data within ±10%. The heat transfer characteris tics were also simulated using computational fluid dynamics using FLUENT software with the standard ke model and multiple reference frame were adopted. The computational fluid dynamics （CFD） predicted Nusselt number agrees well with the experimental value and the discrepancy is found to be less than ＋8%.

Natural convection of an alumina-water nanofluid inside an inclined wavy-walled cavity with a non-uniform heating using Tiwari and Das' nanofluid model

The present study is devoted to numerical analysis of natural convective heat transfer and fluid flow of alumina-water nanofluid in an inclined wavy-walled cavity under the effect of non-uniform heating. A single-phase nanofluid model with experimental correlations for the nanofluid viscosity and thermal conductivity has been included in the mathematical model. The considered governing equations formulated in dimensionless stream function, vorticity, and temperature have been solved by the finite difference method. The cavity inclination angle and irregular walls(wavy and undulation numbers)are very good control parameters for the heat transfer and fluid flow. Nowadays, optimal parameters are necessary for the heat transfer enhancement in different practical applications. The effects of the involved parameters on the streamlines and isotherms as well as on the average Nusselt number and nanofluid flow rate have been analyzed. It has been found that the heat transfer rate and fluid flow rate are non-monotonic functions of the cavity inclination angle and undulation number.

Sprinkles:一种防治婴幼儿贫血的新型方法

Sprinkles是一种新型的铁剂及其他微量营养素的添加方式 ,可以有效地防治婴幼儿的缺铁性贫血。本文综述了Sprinkles产生的背景和它对贫血婴幼儿的防治效果、婴幼儿及其母亲对这种补铁方式的接受程度 ,另外还对Sprinkles的优点和缺点进行了概述。

Sprinkle formulations——A review of commercially available products

Currently, sixty-five original sprinkle drug products are available in various dosage forms including tablets, powders, granules, immediate-release capsules, extended-release capsules, delayed-release capsules, and multiparticulate drug delivery systems. By sprinkling on soft food vehicles, these products provide dosing flexibility and convenience of administration, which potentially improve the compliance of patients with dysphagia.Due to these advantages, the growth of sprinkle products picked up since the 1990s, and several regulatory issues regarding this dosage form have been raised and documented.In this article, the types of sprinkle formulations were discussed by dividing them into seven categories, and the commercial products were summarized in terms of the drug substance, pharmaceutical excipients, storage conditions and administration methods. In addition, several US Food and Drug Administration guidelines related to the regulatory issues of sprinkle formulations were reviewed, which led to the conclusion that the future development of this promising dosage form demands integrated guidance for industry rather than scattered information in various documents.

Natural convection of SiO_2-water nanofluid in square cavity with thermal square column

A square with a thermal square column is a simple but nontrivial research prototype for nanofluid research. However, until now, the effects of the temperature of the square column on the heat and mass transfer of nanofluids have not been revealed comprehensively, especially on entropy generation. To deepen insight into this important field, the natural convection of the SiO2-water nanofluid in a square cavity with a square thermal column is studied numerically in this study. The effects of the thermal column temperature （T = 0.0, 0.5, 1.0, 1.5）, the Rayleigh number （ranging from 103 to 106）, and the volume fraction of the nanoparticle （varying from 0.01 to 0.04） on the fluid flow, heat transfer, and entropy generation are investigated, respectively. It is found that, no matter at a low or high Rayleigh number, the volume fraction of the nanoparticle shows no considerable effects on the flow field and temperature field for all the temperatures of the thermal column. With an increase in the volume fraction, the mean Nusselt number increases slightly. At the same time, it is found that, with an increase in the temperature of the thermal column, the average Nusselt number gradually decreases at all values of the Rayleigh number. Meanwhile, it is found that, at a high Rayleigh number, the heat transfer mechanism is the main parameter affecting the increase in the total entropy generation rather than the volume fraction. In addition, no matter at a high or low Rayleigh number, when T = 0.5, the total entropy generation is the minimum.

微喷灌施肥对三七土壤氮素运移转化试验研究

为探明微喷灌施肥对三七土壤氮素运移转化影响,2017—2020年在泸西县大栗树村三七种植基地设置3个灌水水平0.4FC(W1),0.6FC(W2),0.8FC(W3),4个施肥水平3.20(F1),4.80(F2),6.20(F3)和120.00 kg/ha(F4),CK为对照,共13个处理.研究微喷灌施肥条件下不同灌水及施肥对三七土壤全氮、硝态氮和铵态氮运移转化影响.结果表明:不同灌水施肥全氮质量比随时间增加先增大后减小,硝态氮质量比随时间增加先减小后增大,铵态氮质量比随时间增加逐渐减小,8月W2F3全氮质量比最大,9月W2F4硝态氮质量比最大,6月W2F4铵态氮质量比最大.全氮和铵态氮质量比随土层深度增加逐渐减小,硝态氮质量比随土层深度增加先减小后增大,全氮、硝态氮和铵态氮聚集在土层0~10 cm, W2F3土壤全氮和硝态氮质量比最大,W2F4铵态氮质量比最大.灌水量与硝态氮和铵态氮相关性具有统计学意义(P<0.01),与全氮呈负相关且相关性具有统计学意义(P<0.05),施肥量与硝态氮呈正相关且相关性具有统计学意义(P<0.01),与铵态氮相关性具有统计学意义(P<0.05).该研究明确灌溉施肥可调控酸性红壤土三七氮素运移转化特性,改善农田微生态环境,提高水氮利用效率,为有效防治病虫害提供技术支持和理论依据.

Sweat Sprinkled in Rumaila

Anti-corrosion inspection engineers are responsible for 14 degassing stations, which complete anti-corrosion examinations of desalination and dehydration containers under maintenance, detecting potential corrosion, drawing up the diagram illustrations and inspection reports of Rumaila's oil field and gas system, guiding the completion of equipment sandblasting and anti-corrosion inspections, and ensuring the fulfillment of other relevant work reports. Anti-corrosion inspection engineers can be called the "health doctors" of oil and gas systems.

一种谷物均洒装置的设计与试验

为了加快谷物输送到储粮仓内的速度,使谷物在储粮仓内均匀抛洒,通过集料筒来抵消作用于谷物上的外力,从而使谷物呈自由落体状态,并通过出料筒的大小调节使谷物均匀地落入到抛洒盘内,实现均匀抛洒,以大幅度提高作业效果及抛洒均匀,降低劳动强度,提高生产效率。试验结果表明:装置作业性能稳定,抛洒均匀度、破损率、吨料电耗和生产率平均值分别为90.9%、0.14%、22855.7kg/h、0.040kW·h/t,适用于谷物运进粮仓的机械化作业。

北方农田节水灌溉技术探讨

农业灌溉用水方式直接影响我国粮食安全和经济安全。介绍我国农业用水及节水灌溉现状,分析节水灌溉技术研究方向,重点在自走式圆形喷灌及技术集成研究、自走式喷灌机田间规划软件开发、低能耗大田微灌系统系列化产品研发、智能化自走式喷灌机研发等领域发力,提升我国北方节水技术装备水平,实现农业灌溉用水高效利用。