Analysis of cooling effectiveness for heat flux based on reference enthalpy

In order to quickly and accurately compute the wall temperature distribution along the combustor axial line, a method to compute the temperature field of combustion chamber with active regeneratively cooling was presented. On the condition of nonstationary wall temperature, the one-dimensional cooling model based on reference enthalpy was established, and the distribution of the wall heat flux and the wall temperature along the combustor axial line were obtained at different mach numbers by using the heat transfer empirical equation. For the existing two types of cooling system structure, the cooling effectiveness of which was investigated through the presented method. And the satisfactory results obtained show the validity of the method.

Age-related Metabolic Effects of Acetaldehyde on Rats With Reference to Detoxification Enzymes and Sulfhydryl Groups

Induced-acetaldehyde toxic effects on gluatathione [GSH] metabolism and sulfhydryl (SH) groups in liver and in brain of female albino rats with reference to age was studied.The total -SH groups were decreased whereas the specific activities of glutathione-S-transferase [GST] and glutathione peroxidase [GP0] were increased in acetaldehyde treated rats. However, the specific activity levels of glutathione reductase [GR] and Γ-glutamylcysteine synthetase [Γ-GCS] were decreased. In general, acetaldehyde indueed changes in the specific activities of the enzymes that increase with increasing age

Spatiotemporal variations of evapotranspiration and reference crop water requirement over 1957-2016 in Iran based on CRU TS gridded dataset

Agriculture needs to produce more food to feed the growing population in the 21st century.It makes the reference crop water requirement(WREQ)a major challenge especially in regions with limited water and high water demand.Iran,with large climatic variability,is experiencing a serious water crisis due to limited water resources and inefficient agriculture.In order to overcome the issue of uneven distribution of weather stations,gridded Climatic Research Unit(CRU)data was applied to analyze the changes in potential evapotranspiration(PET),effective precipitation(EFFPRE)and WREQ.Validation of data using in situ observation showed an acceptable performance of CRU in Iran.Changes in PET,EFFPRE and WREQ were analyzed in two 30-a periods 1957-1986 and 1987-2016.Comparing two periods showed an increase in PET and WREQ in regions extended from the southwest to northeast and a decrease in the southeast,more significant in summer and spring.However,EFFPRE decreased in the southeast,northeast,and northwest,especially in winter and spring.Analysis of annual trends revealed an upward trend in PET(14.32 mm/decade)and WREQ(25.50 mm/decade),but a downward trend in EFFPRE(-11.8 mm/decade)over the second period.Changes in PET,EFFPRE and WREQ in winter have the impact on the annual trend.Among climate variables,WREQ showed a significant correlation(r=0.59)with minimum temperature.The increase in WREQ and decrease in EFFPRE would exacerbate the agricultural water crisis in Iran.With all changes in PET and WREQ,immediate actions are needed to address the challenges in agriculture and adapt to the changing climate.

The Confirmation of Hypothesis of the Absolute Reference System

The purpose of the research in this article is the examination of the agreement of the hypothesis of the absolute reference system with the results of experiments that have been implemented in the past in order to confirm the special theory of relativity. To achieve this goal, we have chosen for discussing a theoretical topic of electromagnetism, that of electromagnetic mass calculation, and some experiments, some of which concern the transverse Doppler effect in a rotated system, two experiments that concern the kinetic energy measurement of accelerated electrons, one of which is the well known Bertozzis experiment, one experiment that concerns the propagation of Coulomb fields and one more experiment that concerns the effect of annihilation. The basic principles of the hypothesis of the absolute reference system, and the electromagnetic theory derived from these principles, are used to explain the experimental results. In these examples, the hypothesis of the absolute reference system is confirmed, since the experimental results agree with the predictions of this hypothesis. Also, in the discussion of calculation of electromagnetic mass is addressed the difficulty of solving this problem, when someone tries to solve this according to the energy-mass relation of the theory of relativity.

STUDY OF FEASIBILITY OF USING Ag-AgCl ELECTRODE AS REFERENCE ELECTRODE OF THE ISFET

The preparation,principle and measurement results of the complex ISFET withAg-AgCl reference electrode are presented in this paper.Through experiment and theory weendeavor to show the feasibility of using the Ag-AgCl electrode which is without solution contactas reference electrode and the way of overcoming its instability;it gives a rational explanationfor phenomenon of the ion sensitive field effect transistor which does not conform to Nernstianresponse,when we measured cations of Na+, Ca++,etc.with the Ag-AgCl reference electrode.

Electrodynamics in Noninertial Reference Frames

The electrodynamics both in RF with prescribed law of motion and in FR with prescribed structure is considered. Parallel comparison for solutions in “uniformly accelerated” NRF M?ller system and in uniformly accelerated rigid NFR in the space of the constant curvature is carried out. The stationary criterion is formulated. On the basis of this criterion, one of the “eternal physical problems” concerning the field at uniformly accelerated charge motion is considered. The problems of electromagnetic wave spreading, Doppler’s effect and field transformations are discussed.

Effective Dose Levels from Computed Tomography of the Head during Contrast Studies in Nigeria

Background: Diagnostic reference levels for a number of common diagnostic radiological examinations against which individual centres could compare their performance have been recommended by relevant international agencies. Due to variations in different populations globally, local and national diagnostic reference levels are more reliable. To the best of our knowledge, no centre-specific study has been carried out and national surveys are not available. Objective: To establish a preliminary local and national diagnostic reference level in Nigeria. Methods: A pro-spective and cross-sectional study involving 30 conscious paediatrics and adult patients referred for head computed tomography scan. They were positioned supine and scanned according to the standard protocol for head computed tomography with manual mA selection. The total dose-length products were recorded at the end of the pre-contrast and post-contrast sequences respectively. The pre-contrast dose was taken into cognizance in the determination of the post-contrast value. The effective dose was established by multiplying the dose-length product by 0.0023 mSv.mGy-1.cm-1, a conversion coefficient for brain tissue adopted from the European Commission. Statistical Package for Social Sciences version 17.0 was used to analyze the data. Results: 30 paediatrics and adult patients of mixed gender participated in the study. Their ages ranged from 1 to 74 years with a mean age of 41.47 ± 23.30 years. The pre-contrast effective dose ranged from 1.93 mSv to 3.32 mSv with mean of 2.56 ± 0.51 mSv and 75th percentile of 3.11 mSv while the post-contrast effective dose ranged from 4.06 mSv to 6.97 mSv with mean of 5.27 ± 0.97 mSv and 75th percentile of 6.13 mSv. The mean effective dose from this work and two other isolated studies was 3.0 mSv. Conclusion: Although our quantified doses are below threshold limits for occupational exposures they are higher than the recommended level for the public. A further optimization of scanning protocols by the radiographers could lower the effective dose for patients undergoing contrast head computed tomography in our centre and in the country.

<i>In Situ</i>Analysis of Copper Alloys by Femtosecond Laser Ablation Inductively Coupled Plasma Mass Spectrometry: Constrains on Matrix Effects

Direct analysis of copper-base alloys using laser ablation techniques is an increasingly common procedure in cultural heritage studies. However, main discussions remain focused on the possibility of using non-matrix matched external reference materials. To evaluate the occurrence of matrix effects during in situ microanalysis of copper-base materials, using near infrared femtosecond laser ablation techniques (NIR fs-LA-ICP-MS), two bronzes, i.e., (Sn-Zn)-ternary and (Sn)-binary copper-matrix reference materials, as well as a reference synthetic glass (NIST-SRM-610) have been analyzed. The results have been compared to data obtained on a sulfide-matrix reference material. Similar values in relative sensitivity averages of 63Cu, 118Sn and 66Zn, as well as in 118Sn/63Cu and 66Zn/63Cu ratios were obtained, for all analyzed matrix types, i.e., copper-base-, silicate-, and sulfide-reference materials. Consequently, it is possible to determinate major and minor element concentrations in copper alloys, i.e., Cu, Sn and Zn, using silicate and sulfide reference materials as external calibrators, without any matrix effect and over a wide range of concentrations (from wt.% to ppm). Equally, Cu, Sn and Zn concentrations can be precisely determined in sulfides using homogeneous alloys (reference) materials as an external calibrator. Thus, it is possible to determine Cu, Sn and Zn in copper-base materials and their ore minerals, mostly sulfides, in a single analytical session, without requiring specific external calibrators for each matrix type. In contrast, immiscible elements in copper matrix, such as Pb and Fe show notable differences in their relative sensitivity values and ratios for different matrix-materials analyzed, implying that matrix-matched external calibrations remain to be applied for their trace quantification.

直播电商下厂家、MCN机构及主播动态运营策略

直播电商的营销模式在激活消费市场、推动经济增长等方面具有重要作用。本文综合考虑主播影响力和消费者参考质量效应的影响,针对由厂家、网红孵化机构(multi-channel network,MCN)及主播构成的直播电商体系,分别从参考质量效应、观众打赏、MCN机构补贴以及电商平台补贴角度构建5种决策模型,并对比分析其动态均衡策略及绩效水平。研究结果表明:消费者参考质量效应有利于提高直播电商体系成员的相关努力程度和绩效水平;观众打赏能够在一定程度上激励主播相应努力水平,进而推动直播电商体系整体利润的提高;MCN机构对主播提供补贴的先决条件取决于双方的边际收益和主播所获的观众打赏情况,满足其先决条件后能够在一定程度上消除双重边际效应从而实现直播电商体系的Pareto改善;此外,来自电商平台的补贴能够实现直播电商体系的完全协调,且补贴比率受成员博弈地位、收益情况及观众打赏的共同影响。

共享经济下的网约车动态风险管理优化

针对网约车中的两类感知风险:安全风险和服务风险,考虑网约车突发事件以及消费者的参考服务质量效应,构建“政府+平台”风险管理动态博弈模型,利用微分博弈理论,求解了政企合作、非合作以及政府成本分担契约下的双方最优风险投资策略及绩效。研究发现:政企协同风险管理可以最大程度降低网约车风险和提高系统绩效;政府成本分担契约可以实现系统效益的帕累托改进并有效降低网约车安全风险;前瞻性政府和企业会依据危机前后的环境做出最优的策略调整,强调危机前风险防范的重要性,并力图在风险率和折损率较低时加大风险投资力度;参考服务效应不利于降低网约车安全风险,但在一定程度上可以提高其服务质量以缓解危机给系统绩效带来的负面影响。

SNARC效应的空间参照机制

SNARC效应是人脑处理和解释数字信息时,数字信息与空间属性产生的一种联结现象。该效应自被发现以来,就成为认知心理学的研究热点之一。然而,关于该效应产生的空间机制仍存在争议。从SNARC效应的自我空间参照和非自我空间参照两个角度进行梳理,并基于空间参照的层级系统和内外系统两种假设,深入分析SNARC效应空间参照的组织系统。未来可在深入探讨SNARC效应在垂直方向上的空间参照机制和组织系统的基础上,进一步研究SNARC效应在水平与垂直两个方向的空间参照行为与神经机制的特点及相互关系。

处置效应还是过度反应?——来自中国A股投资者参考点依赖与股票收益的证据

本文基于A股市场股票数据,研究了投资者参考点依赖和股票收益的关系。研究结果表明:以短期历史价格为参考点时,未实现资本利得(投资者浮盈浮亏)与收益正相关,而以长期历史价格为参考点时,未实现资本利得与收益负相关,且分别可由处置效应和过度反应解释;未实现资本利得对过去收益正交后,与未来收益的正向关系更强;基于专业投资者持股数据构建的未实现资本利得与收益的正向关系更强;本文的发现不能被V型出售概率所解释。本研究为A股市场政策制定和参考点依赖的投资者决策提供了参考依据。

同群效应下的企业创新决策:理性预期或参考点依赖

研究企业在同群效应下会积极创新还是保守创新,有助于制定相关政策,以激发企业创新活力、优化群体创新环境。构建理论模型、结合实证检验,研究同群效应下的企业创新决策,发现同群效应下的企业创新决策表现为参考点依赖。前期创新投入与同群企业距离越远,企业创新积极性越高;创新成功率低于同群企业越多,企业创新积极性越高。随着创新成功率差值变化,投入距离对创新积极性的影响存在门槛效应。通过工具变量、替换变量、更换样本、重新划分群体等方法证明了结论稳健。进一步分析发现,在信息质量更差、竞争强度更大的群体中,企业的参考点依赖倾向更强。

城门失火,殃及池鱼?新产品促销性脱销的相似品贬值效应

虽然新产品促销性脱销导致其暂时性缺货,会给相似品提供了替代和涨价的机会,但是新产品促销性脱销也会对相似品产生拖累效应,导致消费者对其评价降低。但目前相关的关注和研究较为匮乏。基于前景理论与控制动机理论,通过构建有调节的双中介模型,文章深入探寻了新产品促销性脱销影响相似品贬值的内在机理与边界条件,并且通过实验方法进行了实证检验。通过3个实验,结果发现:(1)新产品促销性脱销确实会让相似品产生贬值,并且价格促销性脱销较之于非价格促销性脱销更容易让相似品产生更大的贬值;(2)参照依赖与控制剥夺会共同中介新产品促销性脱销对相似品贬值的影响,其中前者起着消极中介效应,而后者起着积极中介效应;(3)消费者权力感(包括特质权力感与状态权力感)会调节参照依赖与控制剥夺的双中介效应,低权力感者更容易让参照依赖中介效应占优,而高权力感者更容易让控制剥夺中介效应占优。这些研究结论不仅对丰富和完善新产品促销、产品稀缺效应、虚位诱导效应等理论具有重要的意义,而且对指导和改善厂商的新产品营销、消费者理性看待新产品促销性脱销和监管机构的市场监管有重要的管理启示。

天线整流罩对GNSS观测值与定位精度影响研究

当前大部分城市为保护卫星连续运行参考站(CORS)系统基准站天线安装了整流罩,但天线整流罩对观测值以及基准站坐标影响的研究仍显不足。为解决基于广州CORS(GZCORS)的网络RTK高程测量存在较大偏差的问题,基于2016—2021年观测站数据,以及拆除基准站天线罩前后的观测数据质量与定位效果相关分析,对天线整流罩对GNSS观测值与高程定位精度的影响进行了深入探究,并分别进行了静态仿动态和城市车载动态定位测试验证。研究结果显示,天线整流罩在一定程度上会增加原始观测值的多路径效应影响,降低约10%的数据可用率,并对基准站高程定位结果产生1~14 cm的系统性偏差,进而影响用户RTK高程定位效果。定位结果显示,拆除基准站天线罩后,基于GZCORS的RTK水平定位均方根误差(RMS)为1 cm左右,高程定位精度RMS为2 cm左右;城市场景下车辆动态定位精度RMS为15~20 cm,满足车道级定位性能。

参考价格效应下两期绿色供应链定价和协调

在一个由绿色制造商和零售商构成的两期供应链系统中,考虑了参考价格效应,运用博弈论研究了绿色供应链的定价、绿色决策和协调问题。通过对集中和分散两种决策情形均衡结果的比较,发现集中比分散更有利于供应链的经济绩效和绿色产品的市场扩张,产品绿色水平的确定和决策结构无关。研究进一步设计两部收费契约实现了两期绿色供应链的完全协调。定价策略方面,协调前供应链成员都倾向于差异化定价,引入协调契约后,零售商的定价策略未发生改变,而制造商则转变为一致定价。此外,还研究了参考价格效应对供应链的影响,指出了一个高的参考价格敏感度有益于市场需求和供应链系统的经济效益。

土壤污染的乡土景观绿化修复效果评价方法研究

随着工业化城市的发展,土壤污染问题凸显,威胁环境和人体健康。乡土景观绿化修复是有效的土壤污染治理方法,逐渐受到关注。因此,文章研究考虑土壤污染的乡土景观绿化修复效果评价方法。首先,介绍区域概况、评价指标的建立及计算方法以及样品数据的采集与监测;然后,对比参照系统,展开研究区域的土壤质量监测、植物数据监测与记录,并获取乡土景观绿化修复效果评价结果;最后,根据评价结果总结考虑土壤污染的乡土景观绿化修复效果。

考虑消费者购买参考效应的新能源汽车最优推广政策研究

本文通过构建政府-企业-消费者三方博弈模型,考察了消费者具有购买参考效应时两类新能源汽车推广政策(绿色税和价格折扣)的效果及差异,并进一步讨论了政府的最优政策选择。研究显示:(1)无论消费者购买参考效应取何值,绿色税和价格折扣政策的实施均有利于新能源汽车的推广(即新能源汽车销量的增长)。(2)当消费者偏好新能源汽车时,政府最优的政策选择不受消费者购买参考效应的影响,绿色税政策始终是政府的最优选择;当消费者偏好燃油汽车时,政府最优的政策选择受消费者购买参考效应的影响,即在消费者购买参考效应较小时,绿色税政策为政府的最优选择;在消费者购买参考效应较大时,价格折扣政策为政府的最优选择。(3)燃油汽车边际污染损害程度和新能源汽车绿色度是影响新能源汽车最优推广政策设计的重要因素,同时燃油汽车边际污染损害程度、新能源汽车绿色度与最优推广政策之间的关系受消费者购买参考效应调节。

考虑参考质量效应的双渠道绿色供应链投资决策与合作策略选择

在消费者参考质量效应下,以制造商、电商平台和线下零售商组成的双渠道绿色供应链为研究对象,考虑产品绿色度和品牌商誉的动态性,采用微分博弈方法研究绿色供应链的投资决策与合作策略选择。研究发现:消费者的参考质量水平过度地依赖品牌商誉,会降低绿色技术投资水平、全国性广告投入水平、线上广告投入水平和线下服务投入水平,加快品牌商誉的衰减速率,降低产品绿色度和品牌商誉,进而导致供应链成员利润受损;“纵向合作&横向联盟”是最优合作策略,具有提高品牌商誉和供应链利润的优势;提高线上渠道所占市场份额比例能够提升产品绿色度、品牌商誉和供应链利润,降低线下服务成本,尤其是在“纵向合作&横向联盟”模式下。因此,供应链企业应引导消费者线下体验、线上购物,这样既能提升消费者购物体验,又有利于绿色供应链的发展。

Dynamic Pricing with Stochastic Reference Price Effect

We study a dynamic pricing problem of a firm facing stochastic reference price effect.Randomness is incorporated in the formation of reference prices to capture either consumers’heterogeneity or exogenous factors that affect consumers’memory processes.We apply the stochastic optimal control theory to the problem and derive an explicit expression for the optimal pricing strategy.The explicit expression allows us to obtain the distribution of the steady-state reference price.We compare the expected steadystate reference price to the steady-state reference price in a model with deterministic reference price effect,and we find that the former one is always higher.Our numerical study shows that the two steady-state reference prices can have opposite sensitivity to the problem parameters and the relative difference between the two can be very significant.