Compound Heat Transfer Enhancement of a Converging-Diverging Tube with Evenly Spaced Twisted-tapes

压力落下和一个收敛分叉试管与的复合的热转移特征均匀地， spaced 扭曲磁带(CD-T 试管) 试验性地被调查了。打漩被产生由均匀地，变化在的 spaced 扭曲磁带元素扭动比率和旋转角度。空间比率也在特征上有重要效果。为比较，在一个光滑的圆形的试管的实验和收敛分叉(CD ) ，没有扭曲磁带的试管被执行。在四之中的最好的表演扭曲磁带打的有扭曲比率 y=4.72 和 180 °有的旋转角度θ = 的扭曲磁带在这篇论文介绍了的结果表演。在，从 3400 ～ 20000 的雷纳兹数字空格比率 s=48.6，热转移效率索引，当雷纳兹数字增加，增加，是 0.85 1.21 和 1.07 1.15 分别地与没有扭曲磁带的一个光滑的圆形的试管和一个 CD 试管的相比插入。

A Comparison of Five Adhesive Tapes for Securing Endotracheal Tube in a Manikin

Background: Adhesive tape is the common method for endotracheal tube (ETT) secured to prevent tube displacement and unplanned extubation in an anesthesia setting. However, it is unclear which tape is superior for ETT fixation among the various tapes used in clinical practice. This study examines the force required to move 2 cm ETT and extubate ETT from an intubation manikin with five different adhesive tapes. Methods: We orally intubated an adult intubation manikin with an inner-diameter 7.5 mm ETT, inflated the cuff to 20 cm H2O. Then we secured ETT with five different adhesive tapes (Transpore tapeTM, Urgosyval tape®, TransporeTM White tape, Multipore tape, DuraporeTM tape) in a conventional fixation method. A digital force gauge was connected to the ETT and pulled in a direction erected to the oral cavity. We measured the force required to move 2 cm ETT and extubate ETT (defined as 5 cm ETT displacement) from the manikin. Data were analyzed with one-way analysis of variance, with P < 0.05. Results: DuraporeTM tape had the largest average force of 2 cm displacement (58.9 ± 5.7N) (P < 0.05). The extubation force of DuraporeTM tape (59.7 ± 4.9N) was larger than Urgosyval® tape (40.4 ± 2.9N) (P < 0.05), TransporeTM tape (48.7 ± 5.1N) (P < 0.05), Transpore WhiteTM tape (48.7 ± 5.1N) (P < 0.05). Conclusion: DuraporeTM tape was superior to the other four tapes (TransporeTM tape, Urgosyval® tape, TransporeTM white tape, Multipore tape) in holding the ETT in place in the manikin.

Effects of Irrigation Water Quality and Drip Tape Arrangement on Soil Salinity,Soil Moisture Distribution,and Cotton Yield (Gossypium hirsutum L.) Under Mulched Drip Irrigation in Xinjiang,China

More and more attention is being focused on saline water utilization in irrigation due to the shortage of fresh water to agriculture in many regions. For purpose of reducing the risks of using of saline water for irrigation, the mechanism of soil moisture and salinity distribution and transport should be well understood for developing optimum management strategies. In this paper, field experiments were carried out at Junggar Basin, China, to study the effects of drip irrigation water quality and drip tape arrangement on distribution of soil salinity and soil moisture. Six treatments were designed, including two drip tape arrangement modes and three irrigation water concentration levels （0.24, 4.68, and 7.42 dS m^-l）. Results showed that, soil moisture content （SMC） directly beneath the drip tape in all treatments kept a relatively high value about 18% before boll opening stage; the SMC in the narrow strip in single tape arrangement （Ms） plot was obviously lower than that in the double tapes arrangement （Md） plot, indicating that less sufficient water was supplied under the same condition of irrigation depth, but there was no significant reduction in yield. Mulching had not significant influence on salt accumulation but the drip tape arrangement, under the same condition of irrigation water depth and quality, compared with Md, Ms reduced salt accumulation in root zone and brought about relatively high cotton yield.

Topical nitrate drip infusion using cystic duct tube for retained bile duct stone:A six patients case series

A retained bile duct stone after operation for cholelithiasis still occurs and causes symptoms such as biliary colic and obstructive jaundice.An endoscopic retrograde cholangiopancreatography with endoscopic sphincterotomy(EST),followed by stone extraction,are usually an effective treatment for this condition.However,these procedures are associated with severe complications including pancreatitis,bleeding,and duodenal perforation.Nitrates such as glyceryl trinitrate(GTN) and isosorbide dinitrate(ISDN) are known to relax the sphincter of Oddi.In 6 cases in which a retained stone was detected following cholecystectomy,topical nitrate drip infusion via cystic duct tube(C-tube) was carried out.Retained stones of 2-3 mm diameter and no dilated common bile duct in 3 patients were removed by drip infusion of 50 mg GTN or 10 mg ISDN,which was the regular dose of intravenous injection.Three other cases failed,and EST in 2 cases and endoscopic biliary balloon dilatation in 1 case were performed.One patient developed an adverse event of nausea.Severe complications were not observed.We consider the topical nitrate drip infusion via C-tube to be old but safe,easy,and inexpensive procedure for retained bile duct stone following cholecystectomy,inasmuch as removal rate was about 50% in our cases.

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.

不同铺设坡度及顺逆坡管长对滴灌管出水量及滴灌均匀度的影响研究

为探究坡度及顺、逆坡管长对滴灌管出水量和滴灌均匀度的影响,选取内镶贴片式滴灌管为试验对象,以坡度和顺、逆坡管长为试验因素,比较了上述3个因素在不同水平下的滴灌管出水量和滴灌均匀度。结果表明在滴灌管入水口处出水量最大;随着距入水口越远出水量呈下降趋势;顺坡管长布置越长会导致滴灌均匀度越低;通过建立函数模型进行寻优结合大田应用在3种不同坡度下所能获得的最大滴灌均匀度分别为:0.9812、0.8966和0.9006。在坡地双向布置滴灌管时,为了获得较高的滴灌均匀度,选择合适的顺、逆坡管长组合尤其重要,应在上述函数模型获得最大均匀度时顺、逆坡管长相差较小的范围内选取,以保证滴灌均匀度满足要求。

长沙某院儿童静脉输液时输液管与针头分离的原因分析

目的:分析长沙某院儿童静脉输液时输液管与针头分离的原因,探讨相应的对策,保障儿童输液安全。方法:回顾性选取2020年11月-2021年10月于长沙妇幼保健院门诊输液过程中发生输液管针头脱出输液瓶塞的400例患儿作为研究对象,收集患儿临床资料,分析输液管针头脱出输液瓶塞的原因。结果:400例患儿男236例(59.00%),女164例(41.00%);≤3岁311例(77.75%),4~7岁89例(22.25%);留置针输液122例(30.50%),非留置针输液278例(69.50%);输液部位在头部186例(46.50%),输液部位在手部195例(48.75%),输液部位在脚部19例(4.75%);发生于春季78例(19.50%),发生于夏季106例(26.50%),发生于秋季106例(26.50%),发生于冬季脱落110例(27.50%);输液第1天脱落170例(42.50%),输液第2天脱落162例(40.50%),输液第3、4天脱落68例(17.00%);输液时长0~30 min 177例(44.25%),输液时长31~60 min 145例(36.25%),输液时长>60 min 78例(19.50%)。400例患儿发生输液管与穿刺针头分离的主要原因为患儿玩耍拉扯、患儿哭吵躁动。不同性别、有无留置针患儿发生玩耍拉扯、哭吵躁动率比较,差异无统计学意义(P>0.05);≤3岁患儿发生玩耍拉扯、哭吵躁动率高于>3岁患儿,输液部位在手部时,患儿发生玩耍拉扯、哭吵躁动率高于输液部位在头部与脚部,输液季节在冬季时,患儿发生玩耍拉扯、哭吵躁动率高于其他季节,输液第1天,患儿发生玩耍拉扯、哭吵躁动率最高,输液时长31~60 min时,患儿最易发生玩耍拉扯、哭吵躁动,差异有统计学意义(P<0.05)。结论:长沙某院儿童静脉输液时输液管针头脱出输液瓶塞的主要原因为患儿玩耍拉扯、患儿哭吵躁动,此外还与患儿年龄、输液部位、输液季节、输液天次、输液时长有关,建议加强对患儿及家属的个性化健康教育,提供舒适的输液环境,以提高输液安全意识,保障儿童健康。

How to secure the connection between thoracostomy tube and drainage system?

BACKGROUND: Thoracostomy tube insertion is one of the common bedside procedures in emergency medicine and many acute specialties. Dislodgement of thoracostomy tube from the connection tube of chest drainage system is an important problem with potential complications such as contamination, infection and pneumothorax. Besides, mere loosening can also lead to malfunction. It is a common practice to tape the connection of the system. This study aimed to evaluate the materials and methods of connection of chest drain system to minimize drainage dislodgement. METHODS: We conducted an experimental study to assess the tightness of the connection with various taping materials and methods. We selected three commonly used adhesive materials(3M^(tm) Transpore^(tm) Medical tape, 3M^(tm) Micropore^(tm) Medical tape, 3M^(tm) Soft Cloth Tape on Liner) and three different methods(cross method, straight method, nylon band) to secure the junction between the thoracostomy tube and the bi-conical adaptor in the drainage system. The measured outcome was the weight causing visible loosening of the junction between thoracotomy tube and the adaptor.RESULTS: For each taping material and taping method, 10 trials were performed. The median weight required to disconnect the junction is 26.22 lb for Transpore^(tm), 31.29 lb for Micropore^(tm) and 32.44 lb for Soft Cloth Tape on Liner. A smaller force was required to disconnect if Transpore^(tm) is used(P<0.001). There was no statistical signifi cant difference between Micropore^(tm) and Soft Cloth Tape on Liner(P=0.98). The median disconnecting force is 32.44 lb for straight taping method, 40.55 lb for cross taping method and 21.15 lb for plastic band. The cross-taping method was the more secure method(P<0.0001 when compared with plastic band)(P=0.033 when compared with straight method).CONCLUSION: Cross-taping is the most secure method among the tested varieties in connecting the thoracostomy tube to the chest drainage system. Transpore^(tm) is not a recommended material for thoracostomy tube taping.

错位滴头的3条毛管高频灌溉对棉田盐分的影响及节水效果

【目的】针对新疆降水稀少、蒸发量大,干旱缺水,土壤盐碱化蔓延,改良盐碱地用水量大等问题,通过室内外试验进行对比研究,提出节水改良盐碱地的新技术。【方法】以滴灌条件下盐分积累在湿润体边缘的规律为依据,将现有的滴灌改为错位滴头的3条毛管,确定3条毛管的间距、滴水规则、灌水定额及洗盐定额等参数,研究湿润体盐分的运移过程。【结果】在土壤性质及水质不变的条件下,对错位滴头的3条毛管采用滞后滴水的方法,灌水6次之后湿润体内取土检测盐分,探究棉花根区盐分的变化过程。湿润体水平距为40 cm处的垂线盐分从105.21 g/kg降到49.015 g/kg,该方法可扩大根区湿润体的脱盐范围,与滴灌相比可永久性节约每年3次的压盐水量。【结论】棉花根区的脱盐范围随灌水次数的增多而逐步扩大,脱盐范围的大小与土壤体积质量、灌水方法、次数、滴水规律、土壤盐分、水源的盐分及灌水周期有关。

基于耗散理论的电子模块管内传热数值研究

基于耗散理论,研究分析了在新型强化传热结构下管内传热的特性。以流动传热过程中的温度、压力和对流换热系数的为分析对象,使用数值计算的方法,对光管和内插螺旋片两种管道结构下的传热系统进行了研究。通过对网格独立解的研究,得到了适合于本文案例的分析参数,保证了数值计算结果的一致性。研究结果表明,内插螺旋片液冷管结构下的热源温度明显低于光管结构下的热源温度,具有显著的强化传热效果;且其强化效果随着流量增加而逐渐减弱,其驱动代价随着流量增加而显著提高,更加适合于应用在中小流量区域。

非复用型单翼迷宫式滴灌带人工紫外老化和热老化性能研究

分别对滴灌带进行人工加速紫外老化和50℃热老化试验,研究了两种老化后氧化诱导时间(OIT)、熔融温度(T_(m))、拉伸强度(σ_(m))、拉伸断裂应变(ε_(m))、熔体质量流动速率(MFR)和炭黑含量(c)指标的变化,以及50℃热老化后流量均匀性、爆破压力、耐水压、耐拉拔和抗泥沙堵塞水力学使用性能变化或符合国标情况。结果表明,滴灌带人工加速紫外老化后的性能指标变化幅度明显大于50℃热老化的,尤其是OIT;在老化624 h后,人工加速紫外老化的OIT下降速率是50℃热老化的4.25倍。人工加速紫外老化的σ_(m)、ε_(m)、c、T_(m)和MFR下降速率分别是50℃热老化的1.24、1.17、1.11、1.02和1.01倍;滴灌带在人工加速紫外老化后,OIT、σ_(m)、ε_(m)和c的指标保持率变化相对较大;在50℃热老化后OIT保持率变化相对较大,水力学使用性能受50℃热老化影响较小,且在老化过程及624 h后均符合国标要求;对国标OIT不小于5_(m)in的要求而言,当保持率为21%时,σ_(m)保持率达到失效程度;因此,使用过程中滴灌带的OIT应不小于1.05_(m)in,否则可能失效。

地下节水灌溉技术研究综述

地下节水灌溉技术作为一种新型灌溉方式备受关注,对缓解农业水资源不足,保证粮食安全及促进农业现代化具有重要意义。概述了地下节水灌溉技术的研究进展,探讨其在农业生产中的应用潜力和发展前景。通过对地下滴灌、地下渗灌、微润灌溉、直插式根灌、涌泉根灌与微孔陶瓷根灌6种地下节水灌溉技术要点、存在问题及研究现状进行详细总结与分析,指出地下节水灌溉技术面临的主要挑战以及未来发展方向,这不仅对于深化人们对该技术工作原理和应用方式的理解起到重要作用,而且对于该技术创新及科学高效灌溉方案的提出具有重要指导意义。

Heat transfer characteristics in micro-fin tube equipped with double twisted tapes: Effect of twisted tape and micro-fin tube arrangements

An experimental study was carried out to investigate the influence of double twisted-tape inserts （DTs） in micro-fin tubes （MFs） on heat transfer, friction factor and thermal performance factor characteristics of the compound devices in the following configurations： （1） twisted tapes acted in the same direction （for co-swirl） while MF and twisted tapes acted in the same （parallel） direction （MF-CoDTs：P）, （2） twisted tapes acted in the same direction （for co-swirl） while micro-fin tube and twisted tapes acted in opposite directions （MF-CoDTs：O） and （3） twisted tapes acted in opposite directions for counter swirl （MF-CDTs）. The MF alone and the MF equipped with a single twisted tape in parallel/opposite arrangement were also considered for comparison. The experiments were conducted for the flows with the Reynolds numbers between 5 650 and 17 000, under uniform heat flux condition. The experimental results indicate that MF-CDTs induce stronger swirl/turbulence flow, resulting in higher heat transfer rate, friction factor and thermal performance factor than other combined devices. The thermal performance factors associated with the use of MF-CDTs were found to be higher than those associated with the uses of MF-CoDTs：P, MF-CoDTs：O and MF alone up to 9.3%, 6.5% and 56.4%, respectively. The empirical correlations developed using the present experimental data for the Nusselt number, friction factor and thermal performance factor are also reported.

自制敷料按压带在经皮肾镜术后肾造瘘拔管后患者的应用

目的探讨肾造瘘拔管后自制敷料按压带在经皮肾镜术(PCNL)后患者的应用效果。方法该研究制作的经皮肾镜术后拔除肾造瘘管专用敷料按压带由敷料按压带及充气装置2个部分组成。选取在我院泌尿外科于2021年6月至2022年6月行单侧单通道经皮肾镜碎石术后患者80例为试验对象,采用随机数字表法分组为试验组40例和对照组40例。试验组在拔除肾造瘘管后,造瘘口贴上敷料后采用自制造瘘敷料按压带,取健侧卧位按压1h;对照组在拔除肾造瘘后,采用传统方法贴上敷料,取健侧卧位,患者家属或护理人员按压敷料1 h。比较两组患者拔除肾造瘘管后医护工作量(更换敷料次数、更换衣物次数、更换被褥次数、工作耗时),患者舒适度及漏尿率。结果试验组患者肾造瘘管拔除后更换敷料次数、更换衣物次数、更换被褥次数及工作耗时均少于对照组(P<0.05),试验组患者舒适度高于对照组(P<0.05),试验组患者漏尿率低于对照组(P<0.05)。结论肾造瘘拔管后自制敷料按压带既能防止患者漏尿、减轻患者痛苦,又能解放双手,减少人力物力,减轻医务人员的工作负荷,值得临床进行推广及应用。

自制可调节硅胶气管套管固定带在面颈部烧伤气管切开患者中的应用研究

目的探讨自制可调节硅胶气管套管固定带在面颈部烧伤气管切开患者中的应用效果。方法选取我科2019年10月-2023年2月收治的面颈部烧伤行气管切开的患者40例,按随机数字表法分为2组,每组各20例;对照组采用传统气管套管固定带,观察组采用自行设计的可调节硅胶气管套管固定带。(1)比较2组患者面颈部新增皮肤损伤情况。(2)比较2组患者更换气管套管固定带的操作时间,气管切开第1周更换气管套管带次数、更换纱布及敷料的次数。(3)比较2组患者刺激性呛咳时间、气管套管移位的情况。(4)比较2组患者气管套管固定舒适度。结果观察组患者颈部新增皮肤损伤低于对照组(P<0.001),更换气管套管固定带的操作时间、气管切开第1周更换气管套管带次数、气管切开第1周更换纱布及敷料的次数均少于对照组,差异有统计学意义(P<0.001)。观察组患者发生刺激性呛咳时间、气管套管移位例数均低于对照组,差异有统计学意义(P<0.001)。观察组患者气管套管固定舒适度高于对照组,差异有统计学意义(P<0.001)。结论本研究自制可调节硅胶气管套管固定带可保护面颈部烧伤气管切开患者皮肤免受损伤,减少固定带更换操作时间、更换次数,提升患者佩戴舒适度,可减轻医护人员的工作量,值得临床推广。

Doping effects of ZrC and ZrB_2 in the powder-in-tube processed MgB_2 tapes

We have investigated the effects of ZrC and ZrB2 doping on the superconducting properties of the powder-in-tube processed MgB2/Fe tapes. Sam- ples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM/EDX), transport and magnetic measurements. We confirmed the fol- lowing quite different roles of ZrC and ZrB2 in MgB2. ZrC doping was found to decrease the transport critical current density (Jc) at 4.2 K, while the critical temperature (Tc) kept constant. In contrast, the Jc values in magnetic fields were enhanced greatly by the ZrB2 addition, which resulted in a decrease in Tc by only 0.5 K. The reason for different effects of two dopants is also discussed.

内镶式滴灌带绕流流道水力性能研究

该文运用水力学公式、数值模拟和快速原型试验研究了绕流流道滴灌带的水力性能,并建立了设计流量与流道结构参数之间的计算模型。数值模拟得到的流场水力结构显示水流的水头损失主要集中在流道的拐角,分支和交汇处。在数值模拟的基础上,利用快速成形技术制造出16种结构形式的绕流流道,并进行压力与流量特性试验。试验结果表明:绕流流道的流态指数为0.5左右,且受流道的截面积和单元数的影响较小;而流量系数则随截面积的增加而增加,随单元数的增加而减小。144组试验数据的回归结果显示:流量随流道的截面积和工作压力的增加而增大,随单元数的增加而减小;其中,截面积影响最大,单元数次之,最后是工作压力。

温室大棚蔬菜生产中滴灌带灌溉应用效果分析

在温室大棚蔬菜生产中应用膜下软管滴灌技术，能为作物生长发育创造良好的水、肥、气、热等生态环境，使温室大棚内５～１５ｃｍ土壤层平均温度提高１．５～２℃，气温平均提高０．５℃，空气相对湿度降低１０％～１５％，改善土壤理化性状，减轻病害，省水、省肥、省农药，促进蔬菜早熟。

滴灌春小麦生长发育与水分利用效率的研究

试验于2009—2010在石河子大学试验站进行,设置了滴灌和漫灌两种灌溉方式,滴灌又设置了一管四行和一管六行两种滴灌带布置方式,目的在于分析不同灌溉方式及不同毛管布置方式对滴灌小麦生长发育及水分利用率等方面的影响。结果表明:滴灌与传统漫灌相比,株高、叶绿素含量、根系活力增加,叶绿素后期下降缓慢,滴灌可降低小麦干物质在营养器官中的分配率,促进干物质向籽粒中分配,防止后期叶片早衰;滴灌比漫灌相比灌水量降低了25%,产量平均增加14.4%,水分利用效率提高35.4%。滴灌小麦实行一管四行毛管布置与一管六行相比受水均匀,不同边行间植株生长差异小,产量及水分利用效率均比一管六行高。

滴灌模式对棉花根系分布和水分利用效率的影响

理解膜下滴灌参数对土壤盐分运移和作物生长的影响是制定科学滴灌制度、合理利用水资源的重要环节。毛管布置方式和滴灌水质是膜下滴灌的重要参数,为研究其对土壤盐分变化、棉花根系分布及水分利用效率的影响,设计了2种毛管布置方式(一管四行(Ms)和一管两行(Md))和3个滴灌水质水平(淡水0.24dS/m、微咸水4.68dS/m、咸水7.42dS/m)。结果表明,滴管布置方式对土壤盐分变化和根系分布有显著影响。在相同滴灌水质条件下,Ms处理有利于降低棉花根区土壤含盐量。所有处理根系主要分布于0～40cm土层内,矿质水滴灌时Md中根系受抑制程度明显高于Ms,但其主要影响根系密度δR>0.5kg/m3区域的分布范围,对δR>0.2kg/m3区域范围分布无明显影响。生育期内棉花总耗水量随滴灌水矿化度的上升而降低,与滴管布置无关。相对淡水滴灌而言,矿质水滴灌时Ms处理产量有所降低,但其水分利用效率随灌水矿化度上升而升高;而Md处理产量和水分利用效率均随灌水矿化度上升而下降。