摘要：目的采用Meta分析的方法系统评价白噪声对ICU患者睡眠质量的影响。方法通过计算机检索CINAHL、PubMed等11个数据库中关于白噪声对急危重症患者睡眠质量影响的文献,检索时间为建库至2024年3月11日。由2名研究者独立进行文献筛选、资料提取和偏倚风险评估后,采用RevMan 5.4软件对纳入文献进行Meta分析。结果最终9篇文献、792例研究对象被纳入研究,Meta分析结果显示,白噪声可以改善ICU患者睡眠[MD=-4.63,95%CI(-7.11,-2.14),P<0.001],加快入睡速度[MD=21.82,95%CI(8.14,35.50),P<0.001],提高睡眠深度[MD=19.18,95%CI(7.05,31.31),P<0.001],减少夜间觉醒次数[MD=20.36,95%CI(6.46,34.26),P<0.001],加快再入睡[MD=23.72,95%CI(9.22,38.22),P<0.001],提高睡眠质量[MD=21.66,95%CI(8.07,35.25),P<0.001],降低噪声水平[MD=29.27,95%CI(10.74,47.79),P<0.001],可以延长患者睡眠时长,能减轻患者焦虑[MD=-8.11,95%CI(-10.55,-5.68),P<0.001]和抑郁[MD=-5.86,95%CI(-8.76,-2.96),P<0.001]。结论白噪声可以明显改善ICU患者睡眠状况和减轻患者焦虑、抑郁等负面情绪,但纳入研究的文献质量较低,研究间异质性较高,需大样本、设计严谨、高质量的随机对照试验进一步证实。

摘要：Empirical research is playing a significant role in software engineering （SE）, and it has been applied to evaluate software artifacts and technologies. There have been a great number of empirical research articles published recently. There is also a large research community in empirical software engineering （ESE）. In this paper, we identify both the overall landscape and detailed implementations of ESE, and investigate frequently applied empirical methods, targeted research purposes, used data sources, and applied data processing approaches and tools in ESE. The aim is to identify new trends and obtain interesting observations of empirical software engineering across different sub-fields of software engineering. We conduct a mapping study on 538 selected articles from January 2013 to November 2017, with four research questions. We observe that the trend of applying empirical methods in software engineering is continuously increasing and the most commonly applied methods are experiment, case study and survey. Moreover, open source projects are the most frequently used data sources. We also observe that most of researchers have paid attention to the validity and the possibility to replicate their studies. These observations are carefully analyzed and presented as carefully designed diagrams. We also reveal shortcomings and demanded knowledge/strategies in ESE and propose recommendations for researchers.

摘要：This paper proposes a design of passive cooling system for CPR1000 spent fuel pool(SFP). Our design can effectively manage the SFP temperature not to exceed80 C. Then the transient analysis of the CPR1000 SFP with designed passive cooling system is carried out in station blackout(SBO) accident by the best-estimate thermal-hydraulic system code RELAP5. The simulation results show that to maintain the temperature of CPR1000 SFP under 80 C, the numbers of the SFP and air cooling heat exchangers tubes are 6627 and 19 086, *** height difference between the bottom of the air cooling heat exchanger and the top of the SFP heat exchanger is3.8 m. The number of SFP heat exchanger tubes decreases as the height difference increases, while the number of the air cooling heat exchanger tubes increases. The transient analysis results show that after the SBO accident, a stable natural cooling circulation is established. The surface temperature of CPR1000 SFP increases continually until 80 C, which indicates that the design of the passive air cooling system for CPR1000 SFP is capable of removing the decay heat to maintain the temperature of the SFP around 80 C after losing the heat sink.

摘要：目的:针对奶粉基质,评估GB 4789.10—2016《食品安全国家标准食品微生物学检验金黄色葡萄球菌检验》中平板计数法的测量不确定度。方法:参考修订版RB/T 151《食品微生物定量检测的测量不确定度评估指南》设计评估方案,分别评估技术不确定度、基质不确定度和分布不确定度,然后计算合成不确定度和扩展不确定度,最终可以根据实验室需求选择仅考虑技术不确定度,或者考虑全部不确定分量。结果:通过测试结果的统计分析,技术不确定度为0.0733 log10CFU/g;基质不确定度为0.0518 log10CFU/g;分布不确定度需要考虑泊松不确定度和确证不确定度,根据每次检测的结果查表或通过公式计算获得。结论:按照修订版RB/T 151进行不确定度评估,思路清晰,方案设计简洁,执行顺利,非常有利于实验室开展微生物检测方法的不确定度评估工作。

摘要：The cooling control of the melt during the casting process is of great significance. A comprehensive closed-loop cooling control of castings by adopting a skeletal sand mold design was proposed. The skeletal sand mold consisting of an adaptive shell, functional cavities and a support was designed and created based on the finite difference meshes of a casting. It was applied to a round wall test casting. Two kinds of skeletal sand molds, one with lattice support and the other with enforcing ribs for this casting were designed and printed out by the 3 D printing(3 DP) method. Aluminum alloy A356 was cast by using these two sand molds. The first mold was cooled by natural convection, the other one by water spray cooling. Two sound castings were obtained. The sand mold temperature, cooling curves, microstructures, mechanical properties, residual stress and deformation were measured, compared and discussed. Water spray cooling hastened the cooling rate by 62%, increased the content of Mg and Cu in the α-Al matrix, improved the mechanical properties, and altered the surface residual stress state.

摘要：首先以手工剪纸动物形象为对象,通过分析其造型分解出构成剪纸的纹样,然后用计算机方法构成这些纹样库.用户在创作时首先构造出剪纸动物形象的轮廓,然后在纹样库中选出适当的纹样嵌入到剪纸轮廓内的指定位置上.文中系统可以广泛应用于装饰图案设计、电子贺卡、广告以及游戏、动画等领域.

摘要：针对光伏逆变器在采用传统低电压穿越控制策略时出现的缺乏负序动态无功电流支撑和功率倍频波动的现象,依据最新光伏并网技术规定中正负序动态无功电流支撑的要求,设计出q轴正负序电流指令;为了同时实现抑制有功功率2倍频波动的效果,计算出d轴正负序电流指令。该策略兼顾了逆变器通流能力与波动抑制,达到了同时满足正负序动态无功电流支撑能力且抑制功率二倍频波动的效果。基于此低电压穿越控制策略,对光伏电站的短路电流特性进行解析。通过建模仿真,将所提策略与现有低电压穿越控制策略进行对比分析,验证了策略的有效性以及短路电流解析式的正确性。

摘要：Gradual distraction with an external fixator is a widely used treatment for severe postburn ankle contracture(SPAC).However,application of external fixators is complex,and conventional two-dimensional(2D)imaging-based surgical planning is not particularly helpful due to a lack of spatial *** purpose of this study was to evaluate the surgical planning process for this procedure with patient-specific three-dimension-printed models(3DPMs).In this study,patients coming from two centers were divided into two cohorts(3DPM group *** group)depending on whether a 3DPM was used for preoperative surgical *** duration,improvement in metatarsal-tibial angle(MTA),range of motion(ROM),the American Orthopedic Foot and Ankle Society(AOFAS)scores,complications,and patient-reported satisfaction were compared between two *** 3DPM group had significantly shorter operation duration than the control group((2.0±0.3)h vs.(3.2±0.3)h,P<0.01).MTA,ROM,and AOFAS scores between the two groups showed no significant differences pre-operation,after the removal of the external fixator,or at *** feet were achieved and gait was substantially improved in all patients at the final ***-tract infections occurred in two patients(one in each group)during distraction and were treated with wound care and oral *** in the 3DPM group reported higher satisfaction than those in the control group,owing to better patient-surgeon *** planning using patient-specific 3DPMs significantly reduced operation duration and increased patient satisfaction,while providing similar improvements in ankle movement and function compared to traditional surgical planning for the correction of SPAC with external fixators.

摘要：Three types of laminates were designed by alternately stacking AZ91 extruded sheets in different states for extrusion to improve the mechanical *** tensile tests revealed that the combination of solid-solution-treated sheets with the aging-treated sheets achieved high tensile strength and ductility,i.e.,ultimate tensile strength of~386 MPa and elongation of~19.8%,*** backscatter diffraction(EBSD)and TEM results indicated that the aging-treated layers with more nano-sized precipitates and small grain size provided high strength and reasonable ductility,while the solid-solution-treated layers with low dislocation density facilitated strain ***,the strong interface bonding between the successive layers played an important role in the enhanced ductility.

摘要：采用在信号流图的适当节点中注入新信号的设计方法，成功地设计出多功能ＣＣⅡ电流模式滤波器，该电路能同时实现低灵敏度的低通、带通、高通、带阻和全通滤波功能，计算机仿真表明所设计电路的正确性和实用性．