Retrieval of Electron Return Time from High-order Harmonics Generated in a Mixture of He and Ne Gases

In terms of single-atom induced dipole moment by Lewenstein model, we present the macroscopic high-order harmonic generation from mixed He and Ne gases with different mixture ratios by solving three-dimensional Maxwell＇s equation of harmonic field. And then we show the validity of mixture formulation by Wagner et al. [Phys. Rev. A 76 （2007） 061403（R）] in macroscopic response level. Finally, using/east squares fitting we retrieve the electron return time of short trajectory by formulation in Kanai et al. [Phys. Rev. Lett. 98 （2007） 153904] when the gas jet is put after the laser focus.

Effects of sowing time on bolting and returning green in welsh onion

Qiyechangbai and Hadacongl were used to study the relationship of the leaf age of overwinter to bolting and, returning green by the difference of sowing time. The results showed that the earlier the seeds were sown, the older leaf age of overwinter was, the higher the rates of returning green and bolting rate were, the earlier the bolting time was. The leaf age of overwinter of Qiyechangbai sown August 31 to September 14 was 2.1-3.1 leaves and the rate of returning green was 86.5%-92.1%, while the leaf age of overwinter of Hadacongl sown September 7 to September 14 was 2.3-2.7 leaves and the rate of returning green was 88.5%-93.8%, both varieties didn＇t bolt. In addition, in the same sowing time, the bolting rate of Hadacong I was higher than that of Qiyechangbai slightly.

Return to sport following tibial plateau fractures: A systematic review

AIM To systemically review all studies reporting return to sport following tibial plateau fracture, in order to provide information on return rates and times to sport, and to assess variations in sporting outcome for different treatment methods.METHODS A systematic search of CINAHAL, Cochrane, EMBASE, Google Scholar, MEDLINE, PEDro, Scopus, SPORTDiscus and Web of Science was performed in January 2017 using the keywords "tibial", "plateau", "fractures", "knee", "athletes", "sports", "non-operative", "conservative", "operative", "return to sport". All studies which recorded return rates and times to sport following tibial plateau fractures were included. RESULTS Twenty-seven studies were included: 1 was a randomised controlled trial, 7 were prospective cohort studies, 16 were retrospective cohort studies, 3 were case series. One study reported on the outcome of conservative management(n = 3); 27 reported on the outcome of surgical management(n = 917). Nine studies reported on Open Reduction Internal Fixation(ORIF)(n = 193), 11 on Arthroscopic-Assisted Reduction Internal Fixation(ARIF)(n = 253) and 7 on Frame-Assisted Fixation(FRAME)(n = 262). All studies recorded "return to sport"rates. Only one study recorded a "return to sport" time. The return rate to sport for the total cohort was 70%. For the conservatively-managed fractures, the return rate was 100%. For the surgically-managed fractures, the return rate was 70%. For fractures managed with ORIF, the return rate was 60%. For fractures managed with ARIF, the return rate was 83%. For fractures managed with FRAME was 52%. The return rate for ARIF was found to be significantly greater than that for ORIF(OR 3.22, 95%CI: 2.09-4.97, P < 0.001) and for FRAME(OR 4.33, 95%CI: 2.89-6.50, P < 0.001). No difference was found between the return rates for ORIF and FRAME(OR 1.35, 95%CI: 0.92-1.96, P = 0.122). The recorded return time was 6.9 mo(median), from a study reporting on ORIF.CONCLUSION Return rates to sport for tibial plateau fractures remain limited compared to other fractures. ARIF provides the best return rates. There is limited data regarding return times to sport. Further research is required to determine return times to sport, and to improve return rates to sport, through treatment and rehabilitation optimisation.

Return to sport following scaphoid fractures:A systematic review and meta-analysis

BACKGROUND Scaphoid fracture is the most commonly fractured carpal bone in the athletic patient, accounting for over 85% of all sport-related carpal bone fractures, and is particularly common in sports involving high impact injuries to the wrist. The management of such injuries comprises both conservative and surgical techniques, as guided by fracture location and type. Athletes demonstrate a unique challenge with regards to the management of scaphoid fractures due to their requirement to return to sport, as soon as able.AIM To review systemically all studies recording return to sport following scaphoid fractures, to collate information on return rates to sport(RRS) and mean return times(RTS) to sport and to determine differences in sporting outcome for the various treatment methods.METHODS A systematic search of MEDLINE, EMBASE, CINAHAL, Cochrane, Google Scholar, Physiotherapy Evidence Database, SPORTDiscus, Web of Science and Scopus was performed in August 2018 using the keywords "scaphoid","fracture", "acute", "carpal", "athletes", "sports", "non-operative","conservative", "operative" and "return to sport". All studies that recorded RRS and RTS following scaphoid fractures were included. RTS was recorded as the length of time from commencement of either primary conservative management or primary surgical procedure to return to sport.RESULTS Eleven studies were included: Two randomised controlled trials, six retrospective cohort studies and three case series. Seven studies reported on conservative management(n = 77), and eight studies reported on surgical management(n =83). For conservative management, RRS was 90%(69/77), and the mean RTS was9.6 wk. Three studies allowed to return to sport in cast [RRS 89%(25/28); RTS 1.9 wk], and four studies required completion of cast treatment prior to returning to sport [RRS 90%(44/49); RTS 13.9 wk]. Four studies recorded fracture union data:Union rate 85%(47/55); mean time to union 14.0 wk. For surgical management,RRS was 98%(81/83), and RTS was 7.3 wk. Three studies reported on Percutaneous Screw Fixation [RRS 97%(32/33); RTS 6.5 wk], and five studies reported on Open Reduction Internal Fixation [RRS 98%(49/50); RTS 7.9 wk]. Six studies recorded fracture union data: Union rate 97%(69/71); mean time to union9.8 wk. On meta-analysis, RRS(RR = 1.09; 95% confidence interval(CI): 1.00-1.18;P < 0.045), RTS(MD 2.3 wk; 95%CI: 0.79-3.87; P < 0.002), union rates(RR = 1.14;95%CI: 1.01-1.28; P < 0.030) and mean times to union(MD 4.2 wk; 95%CI: 3.94-4.36; P < 0.001) were all significantly better for the surgical cohort compared to the conservative cohort.CONCLUSION Surgical management of scaphoid fractures can provide significantly improved RRS and RTS to sport compared to conservative management. Both treatments,however, remain acceptable options, and athletes should be fully informed of the benefits and risks of both prior to deciding treatment plans. Immediate return to sport in a cast should be avoided due to the significant risk of non-union.

Returns to Education in China:1989-2011

Using China Health and Nutrition Survey(CHNS) data between 1989 and 2011, this paper measures the returns to education in China based on the Mincer earnings function and reaches the following findings through an analysis of the tendency of continuous variations over a long timeframe: returns to education are on the rise within the range of samples both under relative and absolute scenarios; returns to different levels of education are characterized by increasing marginal return; no significant difference exists between the returns to junior middle school and the returns to primary school education. Further discussions consider that the requirements of job positions for the overall competence of personnel, differentiated decline of corporate demand for recruitment, lack of an evaluation system in the labor market, information asymmetry in the job market, the development strategy adopted in a particular stage of history and the current slow progress of economic transition have jointly led to the underemployment of college graduates and the great enthusiasm of parents investing in higher education for their children. Conclusions of this paper not only have important practical relevance to the ongoing implementation of China's innovation-driven development strategy, but offer inspirations for the new round of educational reform as well.

一维时齐带反射边界零常返扩散过程回返时的矩

基于半直线[0,∞)带反射边界的一维时齐零常返扩散过程,探讨了其击中固定点1后首次回返时的矩,并对回返时Laplace变换所满足的带反射边界条件微分方程的近似解进行了估计;由Tauberian引理获得了回返时概率分布的渐近估计,并得到了回返时的γ阶矩有限时,阶数γ的取值范围.

一般碰撞分支过程的拟平稳分布的存在唯一性

该文考虑一般碰撞分支过程的长时间动态行为.首先表明一般碰撞分支过程的平均灭绝时间一致有界以及平均返回时间有限,进一步得到了它能从无穷远处回来.最后证得过程的条件分布在全变差的形式下指数收敛到拟平稳分布.

An EPQ Model with Imperfect Production Systems with Rework of Regular Production and Sales Return

The Economic Production Quantity (EPQ) model is commonly used by practitioners in the fields of production and inventory management to assist them in making decision on production lot size. The common assumptions in this model are that all units produced are perfect and shortages are not allowed. But, in real situation the defective items will be produced in each cycle of production and shortages and scrap are possible. These assumptions will underestimate the actual required quantity. Hence, the defective items can not be ignored in the production process. Rework process is necessary to convert those defective into finished goods. This study proposes EPQ model that incorporates both imperfect production quality and falsely not screening out a proportion of defects, thereby passing them on to customers, resulting in defect sales returns. To active this objective a suitable mathematical model is developed and the optimal production lot size which minimizes the total cost is derived. An illustrative example is provided and numerically verified. The validation of result in this model was coded in Microsoft Visual Basic 6.0.

加速时间视域下学生的身体异化困境及纾解

“加速时间”作为“加速”社会的主要表征,在学校场域内广泛体现,引发了学生身体异化困境,制约了学生全面发展,阻碍了教育目标的实现。社会加速批判理论对分析学校时间境遇中的学生身体困境具有重要的启示意义,为分析学生身体处境提供了新的视角。学校时间的范畴维度包括技术加速、变迁加速、节奏加速,动力维度包括绩效主义的经济引擎、苦学至上的文化引擎、复杂性时间化的社会结构引擎,两个维度的加速共同作用“促成”了学校教育的加速时间,学生身体因此陷入被围困、被支配、被悬空、被挤压的异化困境。加速时间引发的学生身体异化困境更适宜从时间角度来破解,重构学生的时间体验,即从重构情感化时间、尊重学生自我时间、把握教育内在时间以及守护学生的主体时间入手,给予每位学生追寻自己“美好的生活”的可能。

子女出生顺序对家庭资源分配的影响--基于家庭教育投入跨期回报模型

随着“全面两孩”政策的颁布,多子女家庭重新回归历史舞台。由于家庭资源的有限性,未成年时期兄弟姐妹之间存在着潜在竞争关系,而父母则是资源分配的主导者。家庭内部的资源分配关系短期内影响子女受教育水平,长期来看,对中国人力资本发展有着深远影响。本文利用2014年中国健康与养老追踪调查生命历程调查(CHARLS)数据,针对子女出生顺序对家庭资源分配的作用进行系统研究,并构建家庭教育投入跨期回报模型对头胎学历优势现象进行阐释。理论模型发现兄弟姐妹之间存在资源竞争关系,对一个孩子的教育投资增加会导致另一个孩子获得的教育投资减少,并且父母会选择投资出生顺序更靠前的子女。这是因为头胎距离完成教育的时间更短,可以更快地进入就业市场带来实际回报,减轻父母经济压力,而投入更小孩子的教育则需要花费更多时间和资源,等待回报的年限也相对较长。实证结果进一步验证了模型推导结论,在控制了受访者个人特征、家庭经济特征、家庭人口情况和社区虚拟变量的基础上,研究运用有序Probit模型回归发现出生顺序对受教育水平有显著的负效应,顺序靠前的孩子受教育时间普遍更长,该结论在考虑家户虚拟变量、子女数量和家庭成分后仍然稳健。这样的现象在家长受教育水平越高以及男孩身上越显著,而幼子与头胎年龄差距越大,学历水平显著提高。一些潜在机制是父母对头胎教育更严格。此外,虽然头胎有着学历优势,父母却通常偏爱更小的孩子,对他们成年后的帮助也更大,这一发现揭示了家庭中关于资源分配的微妙动态平衡。基于本文研究结论,应进一步完善教育补贴政策,以确保多子女家庭能够获得更全面的教育福利支持,同时开展有关家庭教育观念的培训活动,帮助家长理解和重视每个子女的个性化需求,促使教育资源在家庭中更加公平地分配给每个子女,为每个孩子提供健康成长的机会。

实验室检验质量管理工作中LIMS系统对检验回报合格率的影响

目的分析实验室检验质量管理工作中应用实验室信息管理系统(Laboratory Information Management System,LIMS)对检验回报合格率存在的影响。方法从本实验室于2022年1月-2023年12月进行检验的标本中选取328份,根据时间分为常规组(2022年1月-2022年12月,常规检验质量管理)、观察组(2023年1月-2023年12月,通过LIMS系统完成检验质量管理),各164份。比较两组标本检验报告情况、不良事件发生情况及实验室工作人员满意度。结果对比两组标本检验报告情况,观察组危急值回报率(95.73%)、危急值报告及时率(96.95%)、检验回报合格率(97.56%)均更高(χ^(2)=6.821,4.525,5.878,P<0.05);组间不良事件发生率对比,观察组(3.05%)更低(χ^(2)=4.525,P<0.05);相较于LIMS系统实施前,实施后实验室工作人员工作效率[(9.12±0.55)分]、管理效果[(9.16±0.57)分]、风险把控[(9.27±0.54)分]评分均更高(t=2.369,2.270,2.291,P<0.05)。结论在LIMS系统下开展实验室检验质量管理工作,可提高检验回报合格率、危急值回报率及危急值回报及时率,降低不良事件发生风险,实验室工作人员管理满意度随之提高,实践价值显著。

基于小波变换的离心压缩机回流管线异常振动监测方法

为了避免回流管线振动信号的时频分辨率丢失,利用小波变换对离心压缩机回流管线振动信号进行预处理,并在其中引入了频率切片函数和尺度因子,利用其使原始的振动信号在时域和频域上以联合分布的形式存在,且信号切片函数随着原始信号的振动频率适应性调整.在异常振动监测阶段,充分考虑了旋涡进入回流管线时产生的激励作用,结合小波变换处理后的信号,实现对回流管线异常振动的监测.在测试结果中,离心压缩机回流管线的振动工频以及水平、垂直方向上的振动峰值监测结果均表现出了较高的准确性.

The Space Dilation: Analyzing Progressive Speed Reduction and Its Relativistic Parallels

This paper presents a conceptual exploration that draws an intriguing parallelbetween a hypothetical travel scenario and the principles of special relativity. The scenario involves a traveler who reduces their speed by an amount proportional to the distance traveled. Despite initially traveling at a high speed towards a given destination, the continual reduction in speed results in an asymptotic approach to the goal, analogous to the unattainable speed of light in relativity. Mathematically, the scenario is expressed through the Harmonic Series, demonstrating that the total travel time increases without bound, making the destination theoretically unreachable within a finite timeframe. This exploration mirrors the relativistic velocity addition and time dilation effects, providing a compelling analogy for understanding asymptotic limits. By highlighting the profound implications of diminishing returns and unattainable goals, this paper aims to stimulate further discussion and exploration of these fascinating parallels.

长三角一体化背景下停工留薪期内返岗工资支付问题

长三角区域分别通过地方政府规章或地方人社部门出具的规范性文件等形式明确了工伤职工停工留薪期期限的认定方式,但对劳动者在停工留薪期内提前返岗能否兼得剩余停工留薪期工资及劳动报酬却没有明确规定。在这种情况下,有必要从法理层面予以审视、辨析。从权利性质而言,停工留薪期工资具有社会保险的福利属性,其与劳动报酬请求权不存在交叉或竞合关系;从获得前提而言,停工留薪期工资不以提供劳动为条件,而劳动报酬则相反;从指向标的而言,停工留薪期内返岗获取劳动报酬的实质是额外提供了劳动。故二者兼得在法理上具有可行性、在劳动法律体系上具有一致性、在支付主体上具有合理性。但在司法实践中,应根据劳动者有无处分权利之意思表示判断应否支持其兼得剩余停工留薪期工资与劳动报酬。

基于大流量止回阀实验系统的快速预测模型

针对传感器在数据获取中的局限性和无法用于对实验系统进行全面的数据收集问题,对大流量止回阀实验系统的快速预测模型技术进行了研究,建立了实验系统的快速预测模型,进行了快速预测模型的结果分析。首先,搭建了实体模型,根据大流量止回阀实验系统的结构,结合实验系统的工作原理对其进行了简化,并进行了有限元分析;然后,利用快速预测模型的关键技术构建了实验系统数据库,进行了实验系统的样本采集;通过比对不同机器学习算法的预测准确率,选择了随机森林算法,并建立了实验系统内压与应力应变的关系;最后,进行了快速预测模型的结果分析,并完成了实验系统整体预测实验和实验系统部件单独预测实验。研究结果表明:采用随机森林(RF)算法建立的快速预测模型,拟合优度(R 2)达到了0.99,相较于深度神经网络(DNN)算法和梯度提升树(GBDT)算法,拟合优度(R 2)提高了68.97%和51.47%。实验系统整体预测与实验系统部件单独预测的对比试验结果表明:整体预测模型的预测速度更快,且精度可以达到97.43%。

秸秆配施氮肥还田对水稻土酶活性的影响

通过田间试验研究秸秆还田时间及配施氮肥比例对水稻土酶活性的影响,以期为培育水稻土肥力和稳定稻田生态系统功能提供理论依据。试验设置2个秸秆还田时间(WS,冬季还田;SS,春季还田)和4个氮肥配施量(N0,秸秆还田,试验期内全程不添加矿质氮;NB,常规施肥,还田时不添加矿质氮;N30B,秸秆还田时添加早稻基肥用量的30%矿质氮;N60B,秸秆还田时添加早稻基肥用量的60%矿质氮)。研究结果表明:1冬季秸秆翻耕还田能增加冬闲期6种与土壤碳周转相关酶(β-葡萄糖苷酶、β-纤维二糖苷酶、β-木糖苷酶、多酚氧化酶、过氧化物酶和蔗糖酶)的活性,冬闲期冬季秸秆还田条件下土壤酶活性均高于春季还田,生育期内冬季秸秆翻耕还田措施对土壤β-葡糖苷酶和过氧化物酶有增加作用;2秸秆还田并配施氮肥措施显著地增加冬闲期和生育期β-纤维二糖苷酶的活性,但配施氮肥的3个比例间土壤酶活性并无显著差异;3除多酚氧化酶外,其他5种酶均与其有机碳投入量呈显著正相关。因此,冬季秸秆还田及配施氮肥能在一定程度上调控与碳周转相关的土壤酶活性,对推广冬闲期秸秆翻耕还田及保障作物的产量具有重要的生态学意义。

急性期精神分裂症返回抑制的时间进程

利用线索-靶子模式研究急性期精神分裂症返回抑制的时间进程。研究对象包括健康对照组、早期精神分裂症组和慢性精神分裂症组。结果表明:(1)健康志愿者和早期精神分裂症患者均有完好的返回抑制现象,而慢性精神分裂症患者存在返回抑制缺陷,返回抑制出现时间延迟,持续时间缩短。(2)精神分裂症的返回抑制缺陷与疾病慢性化指标(病程、既往发作次数和住院次数)之间存在相关性。结果支持早期精神分裂症和慢性精神分裂症在急性期存在不同的返回抑制特征,早期精神分裂症的返回抑制保存完好,而慢性精神分裂症的返回抑制存在缺陷;精神分裂症返回抑制缺陷可能发生发展于疾病的慢性过程中,而不是发生于疾病初期;精神分裂症的注意缺陷是独立的缺陷症状。

高功率微波作用下介质窗表面电子运动2维仿真

建立了真空中高功率微波作用下介质窗表面电子运动2维仿真模型,充分考虑了微波电磁场及介质表面静电场等影响因素。通过对不同电子出射初始角度和微波场参数(电场幅值、频率及电子出射时电场相位)对电子运动状态影响的仿真分析,得到了二次电子倍增过程中电子在复合场下的运动轨迹、电子重新返回介质表面的撞击能量及返回时间等状态参数,获得了电子运动状态参数随电子出射角度和微波场参数的变化规律。研究发现:电子出射角度对其运动状态有显著影响,电子存在运动轨迹最大的某一出射角度,该角度下电子拥有最大的撞击能量;微波电场幅值的增加将使电子撞击能量增加,返回时间减小,微波电场相位的变化使电子的撞击能量和返回时间呈周期振荡,这从本质上解释了电子数量在二次电子倍增过程中以微波频率两倍周期振荡的原因;随着微波频率的增加电子将由简单的类抛物线运动转变为复杂的振荡运动。

220kV断路器失灵保护动作延时优化

针对传统220 kV断路器失灵保护整定值在部分情况下无法满足系统稳定对故障切除时间要求的问题,基于220kV断路器失灵保护的特点和系统对故障切除时间的要求,分析了主保护动作时间、开关分闸时间、燃弧时间、电流元件返回时间等影响故障切除时间的因素及其时间边界,评估了跳母联断路器、线路跟跳两段时限与跳相邻断路器配合的必要性,提出了综合考虑系统极限切除时间、失灵延时下限时间的断路器失灵保护动作延时优化方案,兼顾了失灵保护配合和系统稳定需要,并提供了故障持续时间的计算方法。