Setting of Agricultural Insurance Premium Rate and the Adjustment Model

First,using the law of large numbers,I analyze the setting principle of agricultural insurance premium rate,and take the case of setting of adult sow premium rate for study,to draw the conclusion that with the continuous promotion of agricultural insurance,increase in the types of agricultural insurance and increase in the number of the insured,the premium rate should also be adjusted opportunely.Then,on the basis of Bayes' theorem,I adjust and calibrate the claim frequency and the average claim,in order to correctly adjust agricultural insurance premium rate;take the case of forest insurance for premium rate adjustment analysis.In setting and adjustment of agricultural insurance premium rate,in order to make the expected results well close to the real results,it is necessary to apply the probability estimates in a large number of risk units;focus on the establishment of agricultural risk database,to timely adjust agricultural insurance premium rate.

Nomenclature,categorization and usage of formulae to adjust QT interval for heart rate

Assessment of the QT interval on a standard 12 lead electrocardiogram is of value in the recognition of a number of conditions. A critical part of its use is the adjustment for the effect of heart rate on QT interval. A systematic search was conducted to identify studiesthat proposed formulae to standardize the QT interval by heart rate. A nomenclature was developed for current and subsequent equations based on whether they are corrective(QTc) or predictive(QTp). QTc formulae attempt to separate the dependence of the length of the QT interval from the length of the RR interval. QTp formulae utilize heart rate and the output QTp is compared to the uncorrected QT interval. The nomenclature consists of the first letter of the first author's name followed by the next two consonance(whenever possible) in capital letters; with subscripts in lower case alphabetical letter if the first author develops more than one equation. The single exception was the Framingham equation,because this cohort has developed its own "name" amongst cardiovascular studies. Equations were further categorized according to whether they were linear,rational,exponential,logarithmic,or power based. Data show that a person's QT interval adjusted for heart rate can vary dramatically with the different QTc and QTp formulae depending on the person's heart rate and QT interval. The differences in the QT interval adjustment equations encompasses values that are considered normal or significant prolonged. To further compare the equations,we considered that the slope of QTc versus heart rate should be zero if there was no correlation between QT and heart rate. Reviewing a sample of 107 patient ECGs from a hospital setting,the rank order of the slope- from best(closest to zero) to worst was QTc DMT,QTc RTHa,QTc HDG,QTc GOT,QTcF RM,QTcF RD,QTcB ZT and QTcM YD. For two recent formulae based on large data sets specifically QTcD MT and QTcR THa,there was no significant deviation of the slope from zero. In summary a nomenclature permits easy reference to QT formulae that adjust for heart rate. Twenty different formulae can produce discordant calculations of an adjusted QT interval. While the formulae developed by Bazett and Fridericia(QTc BZT and QTc FRD respectively) may continue to be used clinically,recent formulae from large population studies specifically QTcD MT and QTcR THa appear to be betterto adjust QT for heart rate in clinical practice.

Selective Area Growth and Characterization of GaN Nanorods Fabricated by Adjusting the Hydrogen Flow Rate and Growth Temperature with Metal Organic Chemical Vapor Deposition

CaN nanorods are successfully fabricated by adjusting the flow rate ratio of hydrogen （H2）/nitrogen （N2） and growth temperature of the selective area growth （SAG） method with metal organic chemical vapor deposition （MOCVD）. The SAG template is obtained by nanospherical-lens photolithography. It is found that increasing the flow rate of 1-12 will change the CaN crystal shape from pyramid to vertical rod, while increasing the growth temperature will reduce the diameters of GaN rods to nanometer scale. Finally the CaN nanorods with smooth lateral surface and relatively good quality are obtained under the condition that the H2：N2 ratio is 1：1 and the growth temperature is 1030℃. The good crystal quality and orientation of GaN nanorods are confirmed by high resolution transmission electron microscopy. The cathodoluminescence spectrum suggests that the crystal and optical quality is also improved with increasing the temperature.

Self-Adaptive Control System for Additive Manufacturing Using Double Electrode Micro Plasma Arc Welding

Wire arc additive manufacturing(WAAM)has been investigated to deposit large-scale metal parts due to its high deposition efficiency and low material cost.However,in the process of automatically manufacturing the high-quality metal parts by WAAM,several problems about the heat build-up,the deposit-path optimization,and the stability of the process parameters need to be well addressed.To overcome these issues,a new WAAM method based on the double electrode micro plasma arc welding(DE-MPAW)was designed.The circuit principles of different metal-transfer models in the DE-MPAW deposition process were analyzed theoretically.The effects between the parameters,wire feed rate and torch stand-off distance,in the process of WAAM were investigated experimentally.In addition,a real-time DE-MPAW control system was developed to optimize and stabilize the deposition process by self-adaptively changing the wire feed rate and torch stand-off distance.Finally,a series of tests were performed to evaluate the control system’s performance.The results show that the capability against interferences in the process of WAAM has been enhanced by this self-adaptive adjustment system.Further,the deposition paths about the metal part’s layer heights in WAAM are simplified.Finally,the appearance of the WAAM-deposited metal layers is also improved with the use of the control system.

Tentative tariff rate for partial import and export products adjusted

The tentative tariff rate for partial import and export products was adjusted since November 1^(st) of 2006.Total 58 imported commodities will be imposed lower tentative

基于大数据技术的大蒜品质智能化调控研究

以进一步提升大蒜种植的智能性、品质性为目标,选取大数据处理及应用技术,针对大蒜种植过程的调控系统展开设计。考虑大蒜种芽、种植土壤条件等基础特点,结合不同种植调控下的大蒜培育状况,基于大数据架构平台组成,搭建用于智能化品质大蒜调控的数据处理模型。设计布局大数据应用的软件控制模块,配置相应的系统硬件结构,重点针对种芽朝向进行调控。展开品质化作业试验,结果表明:基于大数据技术的大蒜品质智能化调控系统设计,能够很好地运用数据计算与处理算法对大蒜种植运动过程各数据进行准确监测,通过及时的调控措施满足种芽朝向调整正确率要求,单粒合格率可达到95.40%,蒜芽漏充率可降低至3.15%,种植效率相对提升了6.37%,具有很好的推广价值。

Accelerated Iterative Learning Control for Linear Discrete Systems with Parametric Perturbation and Measurement Noise

An iterative learning control algorithm based on error backward association and control parameter correction has been proposed for a class of linear discrete time-invariant systems with repeated operation characteristics,parameter disturbance,and measurement noise taking PD type example.Firstly,the concrete form of the accelerated learning law is presented,based on the detailed description of how the control factor is obtained in the algorithm.Secondly,with the help of the vector method,the convergence of the algorithm for the strict mathematical proof,combined with the theory of spectral radius,sufficient conditions for the convergence of the algorithm is presented for parameter determination and no noise,parameter uncertainty but excluding measurement noise,parameters uncertainty and with measurement noise,and the measurement noise of four types of scenarios respectively.Finally,the theoretical results show that the convergence rate mainly depends on the size of the controlled object,the learning parameters of the control law,the correction coefficient,the association factor and the learning interval.Simulation results show that the proposed algorithm has a faster convergence rate than the traditional PD algorithm under the same conditions.

Experimental Analysis of the Flow Characteristics of an Adjustable Critical-Flow Venturi Nozzle

The response of an adjustable critical-flow Venturi nozzle is investigated through a set indoor experiments aimed to determine the related critical flow rate,critical pressure ratio,and discharge coefficient.The effect of a variation in the cone displacement and liquid content on the critical flow characteristics is examined in detail and it is shown that the former can be used to effectively adjust the critical flow rate.The critical pressure ratio of the considered nozzle is above 0.85,and the critical flow control deviation of the gas flow is within±3%.Liquid flow can reduce the gas critical mass flow rate accordingly,especially for the cases with larger liquid volume and lower inlet pressure.The set of results and conclusions provided are intended to support the optimization of steam injection techniques in the context of heavy oil recovery processes.

老油田“3+2”大幅度提高采收率技术内涵、机理及实践

传统方式的化学驱项目一般采取“2+3”的协同方式,也就是先通过水驱井网调整一次到位,再实施化学驱,受剩余油认识和预测精度的影响,会出现部分低产低效井,化学驱含水谷底平台期短,提高采收率幅度有限。为此,胜利油田通过基础攻关和探索实践,创新提出了化学驱与动态优化调整加合增效的“3+2”大幅度提高采收率技术,该技术是指在化学驱过程中,充分发挥和利用驱油体系扩大波及体积、提高驱油效率、调整动态非均质性的特点,主动培育、壮大动态剩余油富集区(“油墙”),适时井网调整、重构流场、均衡注采,高效动用、采出“油墙”,最大程度延长化学驱含水谷底平台期,实现三次采油和二次采油(“3+2”)适配优化、大幅度提高采收率的目的。通过大量物理模拟和数值模拟研究,明确了“井网-驱油剂-剩余油”适配优化提高采收率的机理。该技术在胜坨油田二区东三段5砂组进行了应用,通过优化“3+2”井网调整方式、驱油体系和注入参数等,预计区块含水谷底平台期从3 a延长至8 a,最终采收率为60.5%,比原方案采收率再提高7.5百分点。该技术是老油田大幅度提高采收率的关键技术,可以为中外同类型油藏延长化学驱见效高峰期提供指导和借鉴。

基于RTK测速的油菜直播机随速可控可调排种控制系统研究

针对油菜精量直播机连续作业过程中设定作业速度条件下,作业速度波动导致排种量与目标播量不一致的问题,设计了一种基于“RTK测速+落种检测+电机实时调控”的油菜精量直播机随速可控可调排种控制系统,确定了影响调速性能的关键参数,构建了步进电机调速模型;运用GNSSToolKitLite上位机开展ZED-F9P GNSS模块静态速度漂移试验,得到该模块静态速度漂移量服从均值为0.054 m/s、方差为0.029 m^(2)/s^(2)的正态分布。利用自动数粒仪与JPZS-16型排种性能试验台进行试验,得到正负气压组合式排种器转速为5~60 r/min时,落料计数器播种量检测值与实际值平均绝对误差小于10%;通过台架试验确定了不同排种器调速模型,得到不同排种器最佳工作转速、电机转速与目标播量的函数关系。不同排种器随速控制适应性台架试验结果表明:当作业速度为3~12 km/h时,系统搭载高速机械离心式与油麦兼用气送式排种器总排量稳定性变异系数小于1.21%。田间试验结果表明:当作业速度为5~12 km/h时,本系统搭载高速机械离心式与窝眼轮式排种器总排量稳定性变异系数小于9.7%,满足随速播种要求,可为油菜精量播种控制系统结构改进提供参考。

美联储调息与人民币汇率变化研究

为改善高通货膨胀的经济环境,2022年美联储宣布加息,不仅影响美国国内而且影响了包括中国在内的开放型经济国家。为提高实证分析结论的准确性,通过构建VAR模型,以此轮美联储加息为背景,选取2006年1月至2023年8月美元兑人民币汇率以及美国联邦基金利率等数据,逐步研究美联储调整利率后部分变量对人民币汇率的影响。研究结果表明,美联储调息的直接影响效果最为显著,且短期的影响效应大于长期。为此,在新发展阶段下,应建立强大的宏观审慎监管体系,适时干预外汇市场,以促进汇率改革与人民币汇率稳定。

永磁同步电机抗干扰复合滑模控制器的设计

目的 在灌装、封口等包装作业过程中,提高永磁同步电机的快速响应和抗干扰能力,同时减少控制系统的抖振现象。方法 提出一种复合滑模控制策略,设计一种能适应滑模面和系统状态变化的分段速率滑模趋近律,将其与新型积分滑模面结合,设计一种带速度环的滑模控制器。同时,设计一个干扰观测器,用于估计闭环系统的扰动,并将估计后的扰动实时补偿到控制器的输出电流中,构建复合控制器。结果 仿真结果表明,设计的控制器能够显著提高收敛速度,并有效减少了控制系统的抖振,从而提高了动态质量。此外,干扰观测器与控制器结合的复合控制器可以提高系统的抗干扰能力,从而进一步提高了控制性能。结论 文中提出的复合滑模控制策略可以有效提高永磁同步电机调速系统的动态性能,减少控制系统的抖振,为实现高效、稳定的控制提供了有效的解决方案。

考虑运行图抽线调整的城际铁路动车周转计划编制

针对现有城际铁路动车组周转计划编制方法未考虑运行线客座率分布,导致抽线调整时难以单独停运低客座率车次而不影响高客座率车次的问题,本文提出一种适用于运行图抽线调整的动车组周转计划优化编制方法。以最小化动车组使用数量及交路中运行线客座率差异为目标,考虑满足一级修等约束条件,构建非线性整数规划模型;通过线性化处理并结合Hierholzer's算法筛选合格解的方式,高效求解模型。案例分析表明:相较于只考虑动车组使用数量的传统方法,该模型在不增加动车组使用数量的情况下,可以显著降低各交路中运行线客座率的差异。优化后的交路中运行线客座率极差提高了68.67%,交路中运行线客座率方差之和降低至对比方案的66.27%。抽线调整时,采用优化方案能够更精确地优先取消低客座率运行线,有效保留高客座率运行线。在抽线条数分别设定为1,2,3的情况下,优化方案停开的运行线中,客座率低于60%的运行线的占比均保持在77%以上,而对比方案中该比例均未超过45%;优化方案中被取消车次的平均客座率比对比方案分别降低了4.48%、5.88%和6.01%。

高精度管道漏风量测试仪的设计及实验研究

现有的国产漏风量测试仪普遍存在测量精度低、自动化水平低的问题,为此,基于漏风量测试仪的原理,开展了漏风量测试仪的结构设计、系统设计及整机实验研究。首先,对漏风量的测量过程、喷嘴流量测量原理进行了研究,推导了喷嘴流量测量公式,并根据相关标准设计了角接取压方式的喷嘴结构,基于仪器操作便捷性要求,对整机结构进行了设计;其次,采用空气密度补偿公式完成了高精度流量自适应测量,设计了基于自锁式电磁阀的换向调零电路,采用换向调零法对压差传感器零点漂移进行了补偿,使用小波阈值去噪算法消除了信号噪声,提高了流量的测量精度;采用抗积分饱和比例积分微分(PID)算法对流量进行了闭环控制;最后,研制了管道漏风量测试仪样机,开展了压差与流量测量精度与重复性实验。实验及研究结果表明:该高精度漏风量测试仪工作状态稳定,压差测量精度为±0.4%,流量测量精度为±2%;该漏风量测试仪的测量精度优于国内同类仪器,符合国家标准要求,具有良好的市场前景。

基于CFD与TRNSYS的圆形猪舍内环境控制研究

为了给寒冷地区密闭圆形猪舍提供内环境控制策略,试验以地处寒冷地区的张家口市某在建密闭圆形猪舍为研究对象,通过ANSYS FLUENT软件搭建计算流体力学(computational fluid dynamics,CFD)仿真模型,利用CFD模型计算猪舍在最低通风量标准条件下舍内污染气体质量浓度与风速分布,研究通风量对舍内污染气体质量浓度的影响;利用TRNSYS 17软件搭建猪舍温控仿真模型,以月舍温、月舒适时间占比和月暖通不保证率为评价指标,研究非供热策略、供热策略和调整养殖密度策略下猪舍全年通风量对舍内环境温度与舒适性的影响,筛选较为合适的猪舍全年温控策略,并对最适温控策略进行优化研究。结果表明:在圆形猪舍内每60°布置一组送、排风侧立管的“上送侧排”通风方案中,污染气体浓度随通风量增大而降低;在全年最低通风量[0.35 m~3/(h·kg)]标准条件下,养殖区域猪只背部高度平面的平均风速为0.3 m/s,猪只呼吸高度平面NH_(3)、H_(2)S、CO_(2)质量浓度最大值分别为1.02,0.021,525 mg/m~3,上述参数均满足猪舍养殖环境要求,即通风量、污染物浓度、猪只吹风感之间得到较好平衡。调整养殖密度策略比供热策略的全年平均月舒适时间占比高1.5百分点,全年平均月暖通不保证率低0.2百分点;调整养殖密度策略在夏季的平均月舒适时间占比比非供热策略高4.3百分点,月平均舍温低0.3℃,因此育肥猪舍采用调整养殖密度策略调节猪舍温度更为合适。猪舍采用调整养殖密度策略调节猪舍温度时,将5,9月份的通风量从0.50 m~3/(h·kg)提升至0.68 m~3/(h·kg),使这两个月份的月平均舍温均下降2.3℃,月暖通不保证率分别从1.6%和7.2%下降至0.9%和3.6%,月舒适时间占比分别从35.9%和26.1%提升至70.4%和59.4%;夏季采用遮光板辅助降温措施可使午间猪舍温度降低0.3~1.2℃,使猪舍温度更加舒适。说明应用新风全热交换器和湿帘-风机系统并适当调整通风量或养殖密度可以达到密闭圆形猪舍的环境控制要求。

斑块面积对干燥-复水条件下藓类植物生理活性的影响

干扰会导致生物结皮斑块破碎并退化。为明确生物结皮斑块破碎诱发生物结皮退化机理,以黄土丘陵区土生对齿藓(Didymodon vinealis)结皮为研究对象,研究了干燥-复水条件下,单株和直径1 cm、2 cm、3 cm、4 cm、5 cm的藓结皮斑块内土生对齿藓的干燥速率、渗透调节物质、丙二醛和光合色素含量等的变化,以期揭示干扰后生物结皮退化的生物学机理。结果表明(1)除单株外,干燥速率随斑块面积减小而增加,直径1 cm斑块内藓的干燥速率是直径5 cm的2倍。(2)反复干燥-复水25天后,直径小于5 cm的斑块内藓的可溶性糖、可溶性蛋白和叶绿素含量低于直径5 cm斑块内藓的含量,丙二醛含量随斑块面积变化无明显规律。(3)干燥速率与斑块面积、可溶性糖、可溶性蛋白及叶绿素含量均呈极显著负相关。以上结果表明,藓结皮斑块面积通过影响斑块内藓类植物干燥速率进而影响其渗透调节和光合作用能力。藓结皮斑块面积减小,藓类植物干燥速率增大,生理活性降低,是藓结皮斑块破碎诱发其退化的原因。研究从藓类植物生理的角度,阐明了干扰后藓类植物衰亡的生理学原因,为生物结皮的保护和管理提供了科学依据。

1990~2019年中国室内固体燃料导致的脑卒中疾病负担

基于2019年全球疾病负担数据库,采用标化死亡率和标化伤残调整寿命年(DALY)率描述疾病负担,利用Joinpoint回归模型分析1990~2019年中国归因于固体燃料来源的室内空气污染(HAPSF)所致脑卒中疾病负担的时间变化趋势,然后通过时间序列模型(ARIMA)预测未来五年变化情况.结果发现,1990~2019年中国归因于HAPSF的标化死亡率和标化伤残调整寿命年(DALY)率均呈下降趋势,平均年百分比变化率(AAPC)分别为-6.56和-6.53(P<0.05).2019年中国归因于HAPSF的脑卒中标化死亡率和标化DALY率分别为7.41/10万和163.08/10万,85~89岁的年龄区间内疾病负担达到峰值,其中男性比女性的疾病负担更重.时间序列(ARIMA)模型预测结果显示,未来5年(2020~2024)中国归因于HAPSF脑卒中标化死亡率和标化DALY率均仍呈下降趋势.尽管过去30年以及预计未来5年我国由HAPSF引发的脑卒中疾病负担有所减轻,但男性和老年人依然是高风险人群,建议针对高危人群实施有效干预策略,进一步降低HAPSF诱发的脑卒中造成的疾病负担.

1990-2019年金砖国家慢性阻塞性肺疾病疾病负担研究

背景作为新兴经济体,金砖国家(巴西、俄罗斯、印度、中国和南非)慢性阻塞性肺疾病(COPD)疾病负担的显著增加成为其共同面临的卫生挑战。目的本研究旨在了解金砖国家因COPD所致疾病负担现状、既往变化趋势和归因危险因素,为我国评价和制定COPD防控策略、加强金砖国家卫生合作提供依据。方法利用2019年全球疾病负担研究(GBD 2019),对1990—2019年金砖国家COPD的患病率、死亡率、伤残寿命调整年(DALY)率的变化趋势进行描述,使用Joinpoint软件计算其年度变化百分比(APC)与平均年度变化百分比(AAPC),运用人群归因危险百分比(PAF)估计不同危险因素导致COPD疾病负担的比例。结果2019年金砖国家疾病负担均随年龄增长呈上升趋势,在45岁以上增长迅速且存在一定性别差异;1990—2019年金砖国家COPD患病率均呈上升趋势,除印度外其他金砖国家的死亡率和DALY率均观察到下降趋势;金砖国家标化患病率、标化死亡率和标化DALY率的AAPC均呈下降趋势,中国下降幅度最大,AAPC分别为-1.14%、-4.22%和-4.17%(P<0.05);烟草使用是巴西、俄罗斯、中国和南非COPD疾病负担的首位危险因素,PAF均超过50%,而印度的首位危险因素为空气污染。结论金砖国家COPD疾病负担依然沉重,且不同国家内部存在差异;金砖国家COPD防治行动取得积极成果,但总体改善程度不及亚太高收入国家;中国COPD疾病负担总量下降趋势明显,但防控形势依旧严峻;金砖国家应更加关注中老年群体的COPD防治,同时持续关注因烟草使用和环境污染等引起的健康效应问题。

基于可调文氏管的液氧流量闭环控制特性研究

针对液氧供应系统流量精准控制困难的问题,开发了一套流量闭环控制系统并应用于液氧供应系统中。为实现系统按预设目标流量进行输出,进行了四类试验:无控制试验、流量闭环控制试验、PID参数影响试验与流量阶跃调节试验,研究了贮箱压力、液氧温度、针锥位置、调节范围与PID参数等因素对液氧流量闭环控制特性的影响。结果表明,通过反馈实时测得的液氧质量流量,流量闭环控制系统控制可调文氏管节流面积变化,实现了液氧流量±1%的精准控制,解决了由于系统压力波动及液氧温度变化等原因导致的液氧流量供应不稳定的问题,并实现了液氧在5∶1流量变比内的精准阶跃调节。