Error induced by the estimation of the corneal power and the effective lens position with a rotationally asymmetric refractive multifocal intraocular lens

AIM : To evaluate the prediction error in intraocular lens(IOL) power calculation for a rotationally asymmetric refractive multifocal IOL and the impact on this error of the optimization of the keratometric estimation of the corneal power and the prediction of the effective lens position(ELP).METHODS: Retrospective study including a total of 25 eyes of 13 patients(age, 50 to 83y) with previous cataract surgery with implantation of the Lentis Mplus LS-312 IOL(Oculentis Gmb H, Germany). In all cases, an adjusted IOL power(P IOLadj) was calculated based on Gaussian optics using a variable keratometric index value(n kadj) for the estimation of the corneal power(P kadj) and on a new value for ELP(ELP adj) obtained by multiple regression analysis.This P IOLadj was compared with the IOL power implanted(P IOLReal) and the value proposed by three conventional formulas(Haigis, Hoffer Q and Holladay Ⅰ).RESULTS: P IOLReal was not significantly different than P IOLadj and Holladay IOL power(P 】0.05). In the Bland and Altman analysis, P IOLadj showed lower mean difference(-0.07 D) and limits of agreement(of 1.47 and-1.61 D)when compared to P IOLReal than the IOL power value obtained with the Holladay formula. Furthermore, ELP adj was significantly lower than ELP calculated with other conventional formulas(P 【0.01) and was found to be dependent on axial length, anterior chamber depth and P kadj. CONCLUSION: Refractive outcomes after cataract surgery with implantation of the multifocal IOL Lentis Mplus LS-312 can be optimized by minimizing thekeratometric error and by estimating ELP using a mathematical expression dependent on anatomical factors.

Numerical Analysis of Magnetic-Shielding Effectiveness for Magnetic Resonant Wireless Power Transfer System

Magnetic radiation phenomena appear inevitably in the magnetic-resonance wireless power transfer （MR-WPT） system, and regarding this problem the magnetic-shielding scheme is applied to improve the electromagnetic performance in engineering. In this study, the shielding effectiveness of a two-coil MR-WPT system for different material shields is analyzed in theory using Moser＇s formula and Schelkunoff＇s formula. On this basis a candidate magnetic-shielding scheme with a double-layer structure is determined, which has better shielding effectiveness and coils coupling coefficient. Finally, some finite element simulation results validate the correctness of the theoretical analysis, and the shielding effectiveness with the double-layer shield in maximum is 30？dB larger than the one with the single-layer case.

A DISCUSSION ABOUT THE EFFECTIVENESS ON USING A VARIATE-TRANSFORMATION TO FIND OUT SOLUTIONS OF MODE Ⅲ CRACK PROBLEMS IN POWER HARDENING MEDIA

By the use of the transformations of physical plane to strain plane and physical planeto stress plane,an analytic expression of the asymptotic solution near a modeⅢcrack tipin a power hardening medium can be obtained.In this paper the effectiveness of thetransformation is discussed.Analytical results show that the transformation is effectiveexcept for a special limit case of power hardening media—the ideal plastic materials.

Effects of sequential decay on collective flows and nuclear stopping power in heavy-ion collisions at intermediate energies

In this study, the rapidity distribution, collective flows, and nuclear stopping power in ^(197)Au+^(197)Au collisions at intermediate energies were investigated using the ultrarelativistic quantum molecular dynamics(UrQMD) model with GEMINI++ code. The UrQMD model was adopted to simulate the dynamic evolution of heavy-ion collisions, whereas the GEMINI++ code was used to simulate the decay of primary fragments produced by UrQMD. The calculated results were compared with the INDRA and FOPI experimental data. It was found that the rapidity distribution, collective flows, and nuclear stopping power were affected to a certain extent by the decay of primary fragments, especially at lower beam energies. Furthermore, the experimental data of the collective flows and nuclear stopping power at the investigated beam energies were better reproduced when the sequential decay effect was included.

The ASEAN experience of the purchasing power parity theory

We used panel data analysis to evaluate the relative purchasing power parity(PPP)hypothesis of the ten ASEAN member countries between 1973 and 2015.We incorporated the cross-sectionally augmented panel unit root test as proposed by Pesaran(J Appl Econ 22:265-312,2007).For panel cointegration analysis,we employed the four error-correction-based Westerlund(Oxf Bull Econ Stat 69:709-748,2007)panel cointegration tests.The Westerlund(Oxf Bull Econ Stat 69:709-748,2007)tests are general enough to permit a large degree of heterogeneity,both in the long-run cointegrating relationship and in the short-run dynamics,and dependence within as well as across the cross-sectional units.To check the robustness of the results,we further estimated the cointegration test excluding Indonesia and Brunei.The findings support our initial results.Further,all the results overwhelmingly support the relative PPP hypothesis.Consequently,the monetary authority would be able to implement a self-regulating monetary policy.It would also be able to control the exchange rates.

The Relationship between the Ethiopian Economic Growth and the Decrease in Purchasing Power of Consumers

There is no clear theory which states fixed relationship between inflation and growth.Controversy by quantity and institutional inflation theories also confirm this.According to quantity theorists,there is a long-run trade-off between inflation and economic growth but the supporters of institutional theory of inflation,are less sure about presence of negative relationship about inflation and growth.Thus,the relationship between inflation and economic growth is debatable both in the world and specifically to Ethiopia.Therefore,the objective of this critical review is to determine the relationship between the current status of the Ethiopian economy and the consumer price index by considering the economic development indictors and consumer price index.The nexus of inflation and economic growth is one of the most important macroeconomic policy problems that take the attention of researchers,policy makers and different scholars.Conducting this review will benefit developing countries by discovering what their current status is,as far as a person with a higher level of consumption is regarded as having a higher level of economic wellbeing than someone with a lower level of consumption.This study falls within the ambit of the pragmatism philosophical stance and exploratory in nature.This study applied the inductive method of reasoning and used secondary data.The Study found that there is a negative relationship between the Ethiopian economic growth and the purchasing power of consumer(consumer price index)synonymously measured by the inflation-macroeconomic growth trade-off.The review reveals that Ethiopian economy is highly growing and the consumer price index(purchasing power of consumers)is decreasing.This shows that the purchasing power consumer(consumer price index)in Ethiopia is not solely determined by the macroeconomic development,which in turn requires further investigation.It is recommended therefore that future research works will explore more on the relationship between the Ethiopian economic growth and the purchasing power of consumer or clearly can explore the effect of economic growth on the purchasing power of consumers(consumer price index).

An Effective Thermal Splicing Method to Join Fluoride and Silica Fibers for a High Power Regime

A repeatable and simple thermal splicing method for low loss splice between fluoride and silica fibers is presented. The minimum splicing loss of 0.58 dB is achieved experimentally with this approach, Meanwhile, the power capacity of this splicing joint is also tested with a high power fiber laser. The maximum input power is up to 15 W, only limited by the available power of the laser source. To the best of our knowledge, this is the first report on thermal splicing between fluoride and silica fibers operating in a high power regime without any complicated ion-assisted deposition process.

Power-Effective in the Cell Sectorization Using Wide-Beam and Narrow-Beam for Multi-hop Relay Network

Multi-hop relay is a significant topic in the wireless communication and it is provisioned in the 802.16j standards.At present,the major research on multi-hop relay is focused on the capacity,coverage,coordination,throughput,etc.But in this paper,a new concept about power-effective was discussed.Then,two power-effective coverage extension methods using two sectorized cellular approaches were introduced,i.e.,the widebeam three sector cell(WBTC) and the narrow-beam three sector cell(NBTC).Under such topologies,the consumption of power and optimal numbers of base stations(BSs) and relay stations(RSs) with respect to various user traffic densities were investigated.Finally,it is found that the performance of WBTC is better than NBTC.

Synergistic effect of total ionizing dose on single-event gate rupture in SiC power MOSFETs

The synergistic effect of total ionizing dose(TID) and single event gate rupture(SEGR) in SiC power metal–oxide–semiconductor field effect transistors(MOSFETs) is investigated via simulation. The device is found to be more sensitive to SEGR with TID increasing, especially at higher temperature. The microscopic mechanism is revealed to be the increased trapped charges induced by TID and subsequent enhancement of electric field intensity inside the oxide layer.

Degradation of effective carrier-power-to-noise densityratio based on code trackingspectral sensitivitycoefficient for GNSS radio frequencycompatibilityin C band

The frequency band between 5 010 MHz and 5 030 MHz allocated as C band has been used as a candidate in the global navigation satellite systems （GNSS） along with more and more naviga- tion services in L band. The potential benefits and technical requirements of C band for satellite navi- gation have been analyzed before. However the degradation of effective carrier-power-to-noise densi- ty ratio（ A （C/No ）eu） based on code tracking spectral sensitivity coefficient（ CT_SSC ） as a compati- bility assessment methodology for potential GNSS radio frequency compatibility in C-Band has not been discussed clearly. So the compatibility of the signals in the C band between BeiDou （BD） B1 C and GPS L1C, L1C/A, Galileo E1Os as the interoperability or classical signals in L band is analyzed. Simulation results reveal the interference degree between BD III B1C and GPS L1C/A, L1C, Galileo E1OS. The results can also reveal that the multiplexed binary offset carrier （MBOC） and binary phase shift keying （BPSK） modulation is not appropriate for C band.

农产品加工企业市场势力与技术创新

农产品加工企业创新是乡村产业高质量发展的重要驱动,但鲜有文献从市场势力视角研究农产品加工企业创新激励。为此,基于创新决策模型解释企业市场势力对技术创新的影响及机制,并采用2008—2021年农产品加工业上市公司数据,运用DLW市场势力测度方法,建立动态面板模型进行实证检验。结果显示:第一,市场势力对农产品加工企业技术创新存在显著促进作用,在使用Bartik工具变量和2SLS方法处理内生性后,该促进作用依然显著;第二,市场势力通过溢价效应和成本效应等机制共同推动农产品加工企业技术创新;第三,市场势力对技术创新的促进作用随着城市交通便利度、企业产权属性等不同呈现出异质性特征。需要从培育领军企业、加强交通基础设施建设、发挥国有企业创新引领作用等方面制定相关政策,以促进农产品加工企业创新,从而助推乡村产业高质量发展。

新能源发电系统控制技术研究

随着经济社会发展,人们用电需求在不断增长,需要将有限的电能资源进行合理利用,找寻新的发电技术和途径,新能源电力技术及控制技术需要得到新的发展。在发电、输电、配电及用电环节中,电力机制发挥着极为重要的作用,能够组建起电能生产与消费的一体化环节。可以运用发电装置将自然界中的可再生能源转变成为电能,用户可以通过输电系统获得电能,给日常生活提供能量供应。传统发电方式难以大规模存储电能,需要控制电能输出方式。新能源发电与传统发电方式存在较大的差异性,新能源的发电输出功率是可控的。该文主要叙述新能源电力系统运行的基本特点,并说明电力系统的主要控制技术及控制策略,为后续新能源电力工程的顺利发展奠定强有力基础。

新能源汽车动力电池回收利用过程减碳成效测算

为量化评价新能源汽车动力电池回收利用过程的环境效益,为报废动力电池管理体系和回收再利用相关标准的完善提供支撑,助力国家“双碳”目标的实现,以三元锂电池为研究对象,选取典型的动力电池回收利用场景,将三元锂电池的生命周期划分为4个阶段:原材料获取、制造装配、使用和报废回收,并建立相应的GaBi模型,基于湿法回收A、湿法回收B、火法-湿法联合回收3种不同回收利用方式进行三元锂电池生命周期评价模型搭建与回收再利用过程减碳成效测算。研究结果表明,三元锂电池回收再利用过程有较好的减碳成效,基于3种不同回收工艺的三元锂电池回收再利用可以减少CO_(2)排放量分别为:湿法回收A为60.71kgCO_(2)/kWh;湿法回收B为150.00kgCO_(2)/kWh;火法-湿法联合回收为153.57 kg CO_(2)/kWh。基于这3种不同回收工艺的CO_(2)减排效果从优至劣依次为:湿法-火法联合回收、湿法回收B和湿法回收A。合理的动力电池回收利用方式可以显著减少其回收利用过程中的碳排放量,从而产生更好的环境效益。

高功率微波大口径相控阵天线拍波辐射方法研究

相控阵天线是未来高功率微波辐射系统的重要形式之一,是当前研究的热点。为了获得超高等效全向辐射功率,高功率微波天线均为大口径形式。而大口径相控阵天线在辐射高功率微波拍波过程中,存在波束分裂、增益下降问题。针对该问题,本文提出了一种大口径相控阵天线拍波辐射结构,采用“子阵-面阵”两级馈电形式,解决了拍波辐射过程中波束分裂问题,有效提高了高功率微波系统的综合性能。该方法极大地节约了移相器数量,节省了系统成本,降低了系统复杂度,有利于实现高功率微波系统的小型化,提高系统的可靠性。