Evaluating the soil evaporation loss rate in a gravel-sand mulching environment based on stable isotopes data

In order to cope with drought and water shortages,the working people in the arid areas of Northwest China have developed a drought-resistant planting method,namely,gravel-sand mulching,after long-term agricultural practices.To understand the effects of gravel-sand mulching on soil water evaporation,we selected Baifeng peach(Amygdalus persica L.)orchards in Northwest China as the experimental field in 2021.Based on continuously collected soil water stable isotopes data,we evaluated the soil evaporation loss rate in a gravel-sand mulching environment using the line-conditioned excess(lc-excess)coupled Rayleigh fractionation model and Craig-Gordon model.The results show that the average soil water content in the plots with gravel-sand mulching is 1.86%higher than that without gravel-sand mulching.The monthly variation of the soil water content is smaller in the plots with gravel-sand mulching than that without gravel-sand mulching.Moreover,the average lc-excess value in the plots without gravel-sand mulching is smaller.In addition,the soil evaporation loss rate in the plots with gravel-sand mulching is lower than that in the plots without gravel-sand mulching.The lc-excess value was negative for both the plots with and without gravel-sand mulching,and it has good correlation with relative humidity,average temperature,input water content,and soil water content.The effect of gravel-sand mulching on soil evaporation is most prominent in August.Compared with the evaporation data of similar environments in the literature,the lc-excess coupled Rayleigh fractionation model is better.Stable isotopes evidence shows that gravel-sand mulching can effectively reduce soil water evaporation,which provides a theoretical basis for agricultural water management and optimization of water-saving methods in arid areas.

Optimization of Maturation of Radio-Cephalic Arteriovenous Fistula Using a Model Relating Energy Loss Rate and Vascular Geometric Parameters

The main reason for the early failure of radio-cephalic arteriovenous fistula (RCAVF) is non-maturity, which means that the blood flow rate in the fistula cannot increase to the expected value for dialysis. From a mechanical perspective, the vascular resistance at the artificially designed anastomosis causes an energy loss that affects blood flow rate growth and leads to early failure. This research studied how to maximize the RCAVF maturity and primary patency by controlling the energy loss rate. We theoretically analyzed and derived a model that evaluates the energy loss rate Eavf in RCAVF as a function of its blood vessel geometric parameters (GPs) for given flow rates. There was an aggregate of five controllable GPs in RCAVF: radial artery diameter (Dra), cephalic vein diameter (Dcv), blood vessel distance between artery and vein (h), anastomotic diameter (Da), and anastomotic angle (θ). Through this analysis, it was found that Eavf was inversely proportional to Dra, Dcv, Da, and θ, whereas proportional to h. Therefore, we recommended surgeons choose the vessels with large diameters, close distance, and increase the diameter and angle of the anastomosis to decrease the early failure of RCAVF. Simultaneously, we could explain the results of many clinical empiricisms with our formula. We found that increasing Dcv and θ was more significant in reducing Eavf than increasing Dra and Da. Based on our model, we could define two critical energy loss rates (CELa, CELb) to help surgeons evaluate the blood vessels and choose the ideal range of θ, and help them design the preoperative RCAVF plan for each patient to increase the maturity and the primary patency of RCAVF.

THE ANALYSIS OF CELL LOSS RATES IN AN ATM MUX WITH LOSS PRIORITIES

The analysis of cell loss rates in an ATM Mux with loss priorities is an important problem in the-study of traffic control in ATM networks. In this paper, the loss rates of the cells with different priorities in an ATM Mux are analyzed by approximating the actual input process with two-state MMDP and fluid flow technique, and the analytical expressions of the relation between the loss rates and the buffer size are obtained. Simulation shows that the approach is sulliciently accurate for applications.

Improvement of Water Use Efficiency in Winter Wheat byBreeding Lines with Low Rate of Water Loss of Excised-Leaves

A study was conducted with the objective of improvement of water use efficiency (WUE) and yield of winter wheat for Lowland Dryland Farming systems through a breeding approach. Various genotypes were screened in 1988 for rate of water loss of excised leaves (RWL) , followed by inter-crossing of diverse parents in 1993. Analysis of the relationship between RWL and yield components and plant traits demonstrated significant differences in RWL among genotypes. Under most circumstances, RWL was correlated negatively with yield and grain weight, and positively with plant height. The results demonstrated a basis for simultaneous selection for high yield and low RWL. It was found that genotypic rank varied with the duration of water loss. Correlation between RWL and yield was reduced by extended water loss duration. Analysis of the genetic variation and segregation of RWL of progenies and the effect of simultaneous screening for RWL and agronomic traits showed that good lines with improved yield and water use performance could be obtained.

Metabolic rate and evaporative water loss in the silky starling （Sturnus sericeus）

To better understand the physiological characteristics of the silky starling(Sturnus sericeus), its body temperature(Tb), basal metabolic rate(BMR), evaporative water loss(EWL) and thermal conductance(C) elicited by different ambient temperatures(Ta)(5-30 °C) were determined in the present study. Our results showed that they have a high Tb(41.6±0.1 °C), a wide thermal neutral zone(TNZ)(20-27.5 °C) and a relatively low BMR within the TNZ(3.37±0.17 mL O2/g·h). The EWL was nearly stable below the TNZ(0.91±0.07 mg H2O/g·h) but increased remarkably within and above the TNZ. The C was constant below the TNZ, with a minimum value of 0.14±0.01 mL O2/g·h·°C. These findings indicate that the BMR, Tb and EWL of the silky starling were all affected by Ta, especially when Ta was below 20 °C and the EWL plays an important role in thermal regulation.

Comparison of Success Rate and Radiological Bone Loss in Patients with Mini-Implant versus Conventional-Sized Implant Removable Prostheses: A Meta-Analysis

Background: The objective of this meta-analysis was to assess whether mini-implants have added benefit in terms of implants success rate and average bone loss over conventional-sized implants after one year of follow-up. Methods: An electronic search of randomized clinical trials was conducted in MEDLINE (via PubMed), Cochrane Central Register of Clinical Trials (CENTRAL) and Web of Science for studies including complete or partial edentulous patients requiring two or four mini-implants or conventional/ standard-sized implants in the maxilla or mandible for implant-supported removable prostheses who completed 12 months of follow-up. Results: The search provided 194 unique articles which were screened for title and abstract. Screening generated 12 articles which went through full-text analysis using eligibility criteria, and 4 articles were included for meta-analysis. Meta-analysis of these studies indicated a non-significant difference in the success rate between the two interventions (OR = 1.69 [0.74, 3.85;p = 0.21]). Bone loss estimates resulted in a significant bone reduction (Mean Difference = -0.74 [-0.95, -0.53;p < 0.05]) in favor of two mini-implants when compared with two conventional-sized implants, but when compared four mini- with two conventional-sized implants, the estimates were non-significant (Mean Difference = -0.24 [-0.69, 0.20;p = 0.29]). Conclusion: The current evidence does not provide solid evidence of the benefits of one intervention over the other. More studies with follow-up times of 10 and more years are needed as current studies have described the short-term outcomes.

Analysis of Gas Flow Rate and Pressure Loss of Medical Mask Differential Pressure Tester

The objective of this study is to find a suitable method to overcome the pressure loss problem in the gas pipe during the gas exchange detection of medical masks.Based on the European Standards EN 14683,the parameters of a medical mask differential pressure tester were selected,subsequently two schemes of gas pipe layouts were designed,including four kinds of pipe diameter which are 4,5,6.5,and 8mm respectively.Lastly,the models of each scheme were established and imported into Fluent,and the relevant parameters were set for simulation.After data analysis,the results showed that among the four different pipe diameters,the pressure loss of 8mm diameter of the pipe was lower in both the schemes,additionally the pressure loss of the second scheme(the gas pipe was short and smooth)was lower under the same pipe diameter.At the flow rate of v=8L/min,the pressure loss from the inlet to the measurement point is less than 200Pa,and the estimated measurement error is less than 1.5%.In conclusion,shortening the length of the pipe,and increasing the diameter of the pipe can reduce the gas pressure loss,subsequently improve the measurement accuracy of the medical mask differential pressure tester.

分离禽蛋壳膜粉碎装置刀片的设计与试验

为高效分离回收蛋壳膜,设计了一款采用剪切和碾压的粉碎方式专用于分离禽蛋壳膜的粉碎装置。采用干燥的蛋壳膜进行试验,通过理论分析和预试验确定刀片类型、刀片间隙、转子转速、筛网目数为主要影响因素,根据实际生产情况确定各因素的试验水平,以分离率和损耗率为评价指标进行四因素三水平响应面试验;利用Design-Expert 12.0对试验结果进行响应面分析,研究不同影响因素对评价指标的影响规律。验证试验结果表明:当调整转子转速为1374r/min、安装2目筛网、刀片间隙为1mm的50°剪切式刀片时,分离率为86.72%,损耗率为3.71%,大粒径蛋膜较多。试验装置有效提高了粉碎蛋壳膜后蛋膜的分离效果,降低了损耗率,具有极大的优越性。

基于PLC技术的联合收割机电气控制系统设计

以联合收割机电气控制系统为研究对象,利用可编程控制器(PLC)对联合收割机电气控制系统进行改进,以提高联合收割机运行效率和可靠性。通过对联合收割机的工作原理和液压作动系统进行分析,基于可编程控制器(PLC)进行联合收割机电气系统整体设计,并对电气系统的运行效果进行测试分析。试验结果表明:系统运行可靠,能够获得良好的收割效果,可将收割损失率控制在2%以内,验证了系统运行过程稳定性。

原油裂解气资源评价的理论技术创新与评价应用——以四川盆地震旦系—寒武系为例

四川盆地震旦系—寒武系天然气资源丰富。近年来,在四川盆地川中古隆起和北部斜坡区先后获得了两个万亿级大气区的重大发现。为了明确该领域天然气的资源规模以及未来的勘探方向和创建一套切实可行的原油裂解气资源量的评估方法,本次研究基于该区天然气为古油藏原油裂解的基本认识,按照干酪根生油,再到古油藏裂解生气的技术路线对原油裂解气的资源量进行计算。应用成因法,采用PetroMod 3D盆地模拟软件,输入地层等厚图、岩相古地理图、烃源岩综合评价图、剥蚀量展布图以及生油动力学参数图版,建立整个盆地的三维地质模型,并切分为5个区块分别计算生油量,然后探讨了石油运聚系数、石油裂解率、天然气散失率以及寒武系石油运移的分配系数,并创建了天然气散失系数计算公式。在以上基础上,恢复了盆地及5个构造单元的生油史,并明确了古油藏形成的关键时刻,最终得到全盆地震旦系—寒武系常规天然气资源量为13.43×10^(12)m^(3),其中寒武系为5.43×10^(12)m^(3),震旦系为8.0×10^(12)m^(3)。并指出除了川中地区以外,川南和川东具有巨大的勘探潜力,尤其是位于川南地区德阳—安岳裂陷槽两侧的台缘带和台内颗粒滩是下一步勘探的现实领域。本次研究在理论创新和勘探实践中都具有重要意义。

认知行为干预对伴焦虑状态突发性聋治疗的疗效分析

目的分析认知行为干预对治疗伴焦虑状态突发性聋的疗效。方法选取2020年6月—2022年6月郑州大学第一附属医院收治的突发性聋患者353例,其中低频型108例,高频型72例,平坦型81例,全聋型92例。入院24 h内独立完成焦虑自评量表(SAS)评分,标准分>50分,汉密尔顿焦虑量表(HAMA)评分,标准分>17分接受认知行为干预为A组192例,未接受认知行为干预为B组161例,依据突发性聋诊断和治疗指南(2015)进行治疗。A组患者额外接受认知行为干预治疗。结果A、B两组中,低频型患者治疗有效率分别为90.38%(47/52)、75.00%(42/56),高频型患者治疗有效率分别为64.81%(35/54)、61.11%(11/18),平坦型患者治疗有效率分别为77.27%(34/44)、48.65%(18/37),全聋型患者治疗有效疗有效率分别为76.19%(32/42)、52.00%(26/50),A组中低频型、平坦型、全聋型治疗有效率高于B组;A组治疗总有效率高于B组,差异有统计学意义(P<0.05)。结论认知行为干预可提高伴焦虑状态的低频下降型、平坦型、全聋型治疗有效率及治疗总有效率。

基于集成树和MoE的馈线统计线损率双层估计模型

统计线损率是衡量电力系统经济运行的重要指标。然而,用户用电数据采集异常、数据传输中断等因素会导致统计线损率异常或缺失,这严重阻碍了智能配电网的线损精益化管理与经济高效运行。针对馈线统计线损率合理值的估计问题,该文提出了一种基于集成树和混合专家系统(MoE)的馈线统计线损率双层估计模型。首先,使用最大信息系数以更有效地分析统计线损率与其相关特征间的非线性关系,并采用鲁棒性强的K-Medoids聚类算法对馈线进行精细划分;然后,使用Stacking集成学习框架,基于基估计和元估计双层模型对馈线统计线损率进行两阶段估计,选用决策树和各类集成树模型作为基估计模型对统计线损率进行初步估计,将各基估计模型输出结果输入元估计模型MoE中进行最终估计,使用方均根误差(RMSE)和平均绝对误差(MAE)来衡量模型所估计统计线损率的合理性;最后,通过算例分析表明,与其他模型相比,该文所提馈线统计线损率双层估计模型具有更低的RMSE和MAE,对馈线统计线损率的估计效果更好。

玉米联合收获机清选控制系统设计与试验

玉米联合收获机清选系统工况复杂,存在收获质量差、效率不高等问题。基于此,设计一套清选损失率控制为主同时兼顾含杂率的自动控制系统。首先分析以风机转速、振动筛转速和喂入量为影响因素,损失率、含杂率为评价指标的正交试验数据,获取影响损失率和含杂率的主次因素,提出清选系统自动控制策略;其次,为开展控制策略和算法的研究,建立清选系统中的风机转速、振动筛转速调节装置以及收获机纵向运动的数学模型,设计离散化PID控制算法。最后,基于MATLAB/dSPACE软硬件环境,搭建清选控制系统的硬件在环仿真平台,并进行控制器在环测试。试验证明:本文设定的双目标联合控制策略和控制算法,能够有效降低清选损失率、含杂率,其中清选损失率降到2.7%左右,含杂率为2.8%左右。

钛合金铸锭冒口损失率差异性成因分析及对策研究

VAR熔炼的钛合金铸锭,熔炼末期需要采用补缩工艺制度,降低铸锭冒口损失率,提高成材率。在实际生产过程中,钛合金铸锭冒口损失率受各种因素影响,每个铸锭之间存在较大差异,且波动范围大,损失严重。为了分析钛合金铸锭冒口损失率差异性的影响因素,应用Minitab统计软件,采用多因子方差分析方法进行研究,找出了熔炼工班次、补缩时间班次、探伤操作者、补缩期操作稳定性、补缩过程是否频繁短路等显著影响因子,排除了不显著的因子交互作用,并针对各显著因子,制定了相应的改进对策,有效降低了钛合金铸锭冒口损失率以及铸锭间的差异性,提高了成品率。

基于场景流的可变速率动态点云压缩

针对现有的动态点云压缩神经网络需要训练多个网络模型的问题,提出基于场景流的可变速率动态点云压缩网络框架.网络以原始动态点云为输入,利用场景流网络进行运动向量估计,在压缩运动向量和残差的同时,引入通道增益模块对隐向量通道进行评估和缩放,实现可变速率控制.通过综合考虑运动向量损失和率失真损失,设计新的联合训练损失函数,用来端到端地训练整个网络框架.为了解决动态点云数据集缺少真实运动信息标签的问题,基于AMASS数据集制作带有运动向量标签的人体数据集,用于网络的训练.实验结果显示,与现有的基于深度学习动态点云压缩方法相比,该方法的压缩比特率下降了几个数量级,与静态压缩网络单独处理每帧的重构效果相比,该方法有5%~10%的提升.

无量纲化方法选择及最优无量纲化方法构建

文章针对综合评价过程中无量纲化方法难以选择的问题,首先,基于分布特征不变性和变异特征不变性对无量纲化方法进行初步筛选,结果发现,只有伸缩法能同时保持指标的分布特征和变异特征不变;其次,构建无量纲化有效性的统计检验方法,并检验各种伸缩法的有效性,结果发现,并非所有的伸缩法都能有效消除指标间的量纲差异;然后,建立无量纲化信息损失速率的度量模型,提出无量纲化方法选择的主要步骤,并以无量纲化应在有效消除指标间量纲差异的情况下尽可能减小指标内的信息损失速率为原则,构建一种最优无量纲化模型;最后,通过大量的数值模拟实验来进行无量纲化方法选择,并求解最优无量纲化模型。结果发现,基于以上步骤能更加科学准确地进行无量纲化方法选择;构建的最优无量纲化方法不同于任何一种现有的无量纲化方法,其不仅可以有效消除指标间的量纲差异,而且可以防止对数据的过度处理,造成不必要的信息损失。

金针菇玉米胡萝卜复合香肠的配方及蒸煮损失率研究

以猪肉和鱼肉为主要研究原料,添加大豆分离蛋白、玉米淀粉、金针菇、玉米粒和胡萝卜等辅料,经腌制、混合、灌制、烘烤和蒸煮等工艺制作金针菇玉米胡萝卜复合香肠。以感官评分和蒸煮损失率为指标,利用单因素实验研究各因素对复合香肠品质的影响,再利用响应面实验进行优化,确定复合香肠的最优配方。实验结果表明:各因素的添加量分别为鱼肉泥50.24%、大豆分离蛋白3.17%、玉米淀粉8.38%、金针菇8%、胡萝卜泥5%和玉米粒8%,在此条件下制成的复合香肠形态完整,口感良好,具有金针菇、玉米和胡萝卜的独特风味,营养丰富,更能满足大众需求。

基于产量损失率的气井合理配产方法研究

合理配产对气井生产具有非常重要的作用。现有的配产方法一般是按照无阻流量的1/6∼1/3来进行。在研究气体在地层中的非达西效应的基础上,提出了产量损失率的概念,通过量化非达西效应造成的产量损失,建立了气井产量损失率与无因次产量的图版。对于每一个配产,可得到与其相应的产量损失率,非达西效应对气井产量的影响就有了定量化的表征。因此,可根据产量损失率来进行合理配产。对于某些高压气藏,由于地层压力高,气体压缩程度大,地层条件下非达西效应并不强,产量损失率比较低,这类气井就可以将产量配高一些。该配产方法可实现量化储层气体非达西渗流损失,实现气井合理配产。该研究成果能在气井常规配产方法的基础上,进一步优化气井配产制度,更好地满足气井长期稳产、高效开发的需求,为气藏开发提供有益的借鉴。

提高大红山铜矿铜回收率及降低介耗的研究

针对玉溪矿业有限公司大红山铜矿一选厂浮选给矿产品中合格粒级含量过低、过磨粒级含量较高、铜选别回收率较低等问题,在研究选厂给矿性质的基础上,基于球径半理论公式推导了该段磨矿作业中钢球的最佳配比,并将该方案分别在实验室和现场进行验证。对于推导出的一段球磨机初装方案m(Φ70 mm)︰m(Φ50 mm)︰m(Φ40 mm)︰m(Φ30 mm)=15︰25︰35︰25,在实验室试验和工业试验中进行验证,结果表明:该方案能够提高-0.020+0.010 mm可选粒级及-0.074+0.018 mm易选粒级的含量,有效减少了过粉碎现象,降低了介质消耗,提高了铜精矿回收率,实现了降本增效。