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公路工程路面垫层施工技术研究

工程技术研究 2024年第2期9卷 67-69页

作者：柴锋甘肃路桥飞宇交通设施有限责任公司甘肃兰州730030

文章在分析公路工程路面垫层施工质量控制标准的基础上,进一步明确了公路工程路面垫层施工技术的要点;以具体工程案例为切入点,深度探讨了在公路工程路面垫层施工各个环节中需要掌握的技术。

关键词：公路工程路面垫层混合料

ETS和SARIMA流行趋势中的性能比较模型在预测北京市猩红热

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科技与健康 2024年第5期3卷 125-128页

作者：柴峰北京市东城区天坛社区卫生服务中心北京100062

收集2004—2019年北京市猩红热月发病人数和人口学资料,采用描述性统计方法和Joinpoint回归调查猩红热的流行病学变化趋势。北京市猩红热发病的平均年度百分比变化为(AAPC=1.866,95%CI:-2.968~6.941;t=0.816,P=0.428),流行趋势总体保持... 详细信息

收集2004—2019年北京市猩红热月发病人数和人口学资料,采用描述性统计方法和Joinpoint回归调查猩红热的流行病学变化趋势。北京市猩红热发病的平均年度百分比变化为(AAPC=1.866,95%CI:-2.968~6.941;t=0.816,P=0.428),流行趋势总体保持稳定,每年的4—6月和11—12月为发病高峰,呈双季节模式。最优SARIMA模型和最优ETS模型预测的平均绝对误差(MAD)、均方根误差(RMSE)、平均绝对百分比误差(MAPE)、平均误差率(MER)、方根百分比误差(RMSPE)五个误差指标分别为0.586、0.623、0.751、0.296、0.785和0.318、0.282、0.438、0.282、0.338,可见ETS模型的预测准确性高于SARIMA模型,可用来对北京市猩红热流行趋势进行预测预警,从而为猩红热动态精准化防控提供参考依据。

关键词：基于状态空间的指数平滑模型季节性差分自回归滑动平均模型猩红热预测性能比较

俯卧位在新生儿呼吸窘迫综合征有创呼吸支持中的临床研究

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中国当代儿科杂志 2024年第6期26卷 619-624页

作者：柴凤云仝实韩梅胡骁朱春雪高翔羽睢宁县人民医院儿科江苏徐州221200 东南大学附属徐州医院新生儿科江苏徐州221009

目的了解俯卧位在新生儿呼吸窘迫综合征(neonatal respiratory distress syndrome,NRDS)有创呼吸支持治疗中的有效性及安全性。方法前瞻性选择2020年6月—2023年9月睢宁县人民医院收治的77例胎龄0.05)。结论与仰卧位相比,俯卧位通气... 详细信息

目的了解俯卧位在新生儿呼吸窘迫综合征(neonatal respiratory distress syndrome,NRDS)有创呼吸支持治疗中的有效性及安全性。方法前瞻性选择2020年6月—2023年9月睢宁县人民医院收治的77例胎龄0.05)。结论与仰卧位相比,俯卧位通气能有效改善需要机械通气NRDS患儿的氧合功能,增加舒适度,减少气管插管细菌定植,且未明显增加不良反应。

关键词：俯卧位通气机械通气新生儿呼吸窘迫综合征新生儿

两相区淬火温度对Ni-Cr-Mo-V系高强船体钢组织及性能的影响

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材料科学与工艺 2024年第3期32卷 10-17页

作者：郭天阳罗小兵项重辰丁汉林柴锋潘涛苏州大学沙钢钢铁学院江苏苏州215021 钢铁研究总院工程用钢研究所北京100081

为改善高强船体钢高屈强比、回火区间窄的问题,研究了两相区二次淬火温度对Ni-Cr-Mo-V系高强船体钢组织及性能的影响。通过改变二次淬火温度,研究实验钢冲击拉伸性能和显微组织的变化规律,并通过OM、TEM、XRD衍射等方法进行表征。结果表... 详细信息

为改善高强船体钢高屈强比、回火区间窄的问题,研究了两相区二次淬火温度对Ni-Cr-Mo-V系高强船体钢组织及性能的影响。通过改变二次淬火温度,研究实验钢冲击拉伸性能和显微组织的变化规律,并通过OM、TEM、XRD衍射等方法进行表征。结果表明,在淬火温度区间内,材料的性能表现出两种变化趋势。当淬火温度在640~700℃时,实验钢的强度随着二次淬火温度的上升而增加,而韧性下降。在该淬火温度范围内,实验钢的机械性能由铁素体+马氏体的双相组织和逆转变奥氏体的含量决定。随着二次淬火温度的上升,双相组织中铁素体的比例从40%降至10%,逆转变奥氏体的含量从11%下降至1%。当二次淬火温度从700℃增加到780℃时,实验钢的强度和韧性变化不明显,原因是二次淬火的温度已经超过了A3温度,实验钢组织转变为单一的马氏体组织,奥氏体晶粒尺寸变化不大(7.3~8.5μm)。综上,在680℃下进行两相区二次淬火可以获得最佳的强度和韧性匹配。

关键词：两相区淬火强度韧性屈强比逆转变奥氏体

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碳含量对船体钢耐蚀性的影响

现代交通与冶金材料 2024年第2期4卷 89-94页

作者：高峰周乃鹏李健罗小兵柴锋杨才福钢铁研究总院工程用钢研究院北京100081

通过干湿循环腐蚀试验模拟热带海洋大气环境,采用光学显微镜、扫描电子显微镜、X射线衍射、动电位极化曲线、阻抗谱测试等表征手段,研究了不同碳含量对船体钢耐蚀性的影响。结果表明,降碳会减少钢中珠光体含量,使腐蚀产物中具有稳定结... 详细信息

通过干湿循环腐蚀试验模拟热带海洋大气环境,采用光学显微镜、扫描电子显微镜、X射线衍射、动电位极化曲线、阻抗谱测试等表征手段,研究了不同碳含量对船体钢耐蚀性的影响。结果表明,降碳会减少钢中珠光体含量,使腐蚀产物中具有稳定结构的α-FeOOH的比例增加,从而提高基体的电位,并使得腐蚀产物膜层电阻和电荷转移电阻增大,形成粘附性好、稳定、致密的锈层,表现出良好的耐蚀性。

关键词：船体钢碳含量耐蚀性热带海洋大气

Effect of modifying matrix microstructures and nanosized precipitates on strengthening mechanisms and ductile-to-brittle-transitiontemperature in a 1000 MPa Ni-Cr-Mo-Cu steel

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Journal of Iron and Steel Research(International) 2022年第8期29卷 1257-1276页

作者： Fei Zhu Li Yang feng chai Xiao-bing Luo Cai-fu Yang Zheng-yan Zhang Department of Structural Steels Central Iron and Steel Research InstituteBeijing 100081China Material Digital R&D Center China Iron and Steel Research Institute GroupBeijing 100081China

A superior combination of yield strength(1001 MPa)and-20℃ impact toughness(166 J)was obtained in Nb-V-Timicroalloyed Ni-Cr-Mo-Cu steel treated by direct quenching and tempering route(DQT).The tested steels treated by DQT route and re-austenitization and tempering route(QT)were compared with each other in terms of mechanical properties and microstructures characterized by optical microscopy,transmission electron microscopy,X-ray diffraction,electron back-scattered diffraction method and so *** and Vickers hardness of the tested steel treated by the above two routes vary with isothermal aging temperature(400-600℃),shown as under-aged state,peak-aged state and overaged *** DQT specimens show higher strength and Vickers hardness than QT specimens with the same aging ***,the largest difference of yield strength between DQT and QT specimens was shown in DQT600 and QT600 ***600 or QT600 specimens refers to direct quenched(DQ)or quenched(Q)specimens isothermally aged at 600℃.The main disparities in quenched microstructure between DQ and Q specimens are mainly in morphology of prior austenite grains,dislocation density of martensite matrix and solution amount of Nb and Mo elements dissolving in martensite matrix,which play key roles in affecting microstructure and mechanical properties of DQT and QT *** dislocation density of matrix and finer average diameter of both MC(M is any combination of Nb,Mo and V)and Cu-rich particles were shown in DQT600 specimens than in QT600 *** from dislocations and nanosized MC and Cu-rich particles mainly leads to the largest difference of yield strength between DQT600 and QT600 *** addition,strong dislocation strengthening and precipitation strengthening in DQT600 specimen also elevated its ductile-to-brittle-transition-temperature,compared with QT600 specimen.

关键词： Cu-bearing high-strength low-alloy steel Direct quenching Nanosized precipitate Strengthening Ductile-to-brittle-transition-temperature

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秸秆木醋液的制备及其斑蝥复合剂抗菌活性

湖北农业科学 2024年第5期63卷 56-60页

作者：柴凤兰张帆王文辉许兆斐河南应用技术职业学院/开封市秸秆生物质绿色综合利用重点实验室河南开封475001 河南工业大学化学化工学院郑州450001

分别以玉米和芝麻秸秆为原料,采用低温分段热解技术制备了不同热解温度下的秸秆木醋液(SWV),测定了秸秆木醋液的基本性质,将秸秆木醋液与斑蝥原液复配制备了木醋液-斑蝥原液复合剂,并分别进行了抗菌活性试验。结果表明,在设定的热解温... 详细信息

分别以玉米和芝麻秸秆为原料,采用低温分段热解技术制备了不同热解温度下的秸秆木醋液(SWV),测定了秸秆木醋液的基本性质,将秸秆木醋液与斑蝥原液复配制备了木醋液-斑蝥原液复合剂,并分别进行了抗菌活性试验。结果表明,在设定的热解温度范围内,玉米秸秆和芝麻秸秆木醋液总收率分别为20.92%和18.75%,最佳热解温度分别为180℃和220℃。抗菌活性试验表明,2种秸秆木醋液-斑蝥原液复合剂具有较好的广谱抗菌活性。就大肠杆菌而言,玉米秸秆木醋液-斑蝥原液复合剂、芝麻秸秆木醋液-斑蝥原液复合剂体积比均为1∶2(220℃木醋液)的抗菌活性最佳;就金黄色葡萄球菌而言,玉米秸秆木醋液-斑蝥原液复合剂体积比为1∶8(180℃木醋液),芝麻秸秆木醋液-斑蝥原液复合剂体积比为1∶4(240℃木醋液)的抗菌活性最佳。复合剂对金黄色葡萄球菌的抗菌活性明显优于大肠杆菌,秸秆木醋液对斑蝥原液的抗菌活性有明显的增强作用。

关键词：玉米芝麻秸秆木醋液斑蝥原液复合剂抗菌活性

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WATuning:A Workload-Aware Tuning System with Attention-Based Deep Reinforcement Learning

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Journal of Computer Science & Technology 2021年第4期36卷 741-761页

作者： Jia-Ke Ge Yan-feng chai Yun-Peng chai Key Laboratory of Data Engineering and Knowledge Engineering of Ministry of Education Renmin University of China Beijing 100872China School of Information Renmin University of ChinaBeijing 100872China College of Computer Science and Technology Taiyuan University of Science and TechnologyTaiyuan 030027China

Configuration tuning is essential to optimize the performance of systems(e.g.,databases,key-value stores).High performance usually indicates high throughput and low *** present,most of the tuning tasks of systems are performed artificially(e.g.,by database administrators),but it is hard for them to achieve high performance through tuning in various types of systems and in various *** recent years,there have been some studies on tuning traditional database systems,but all these methods have some *** this article,we put forward a tuning system based on attention-based deep reinforcement learning named WATuning,which can adapt to the changes of workload characteristics and optimize the system performance efficiently and ***,we design the core algorithm named ATT-Tune for WATuning to achieve the tuning task of *** algorithm uses workload characteristics to generate a weight matrix and acts on the internal metrics of systems,and then ATT-Tune uses the internal metrics with weight values assigned to select the appropriate ***,WATuning can generate multiple instance models according to the change of the workload so that it can complete targeted recommendation services for different types of ***,WATuning can also dynamically fine-tune itself according to the constantly changing workload in practical applications so that it can better fit to the actual environment to make *** experimental results show that the throughput and the latency of WATuning are improved by 52.6%and decreased by 31%,respectively,compared with the throughput and the latency of CDBTune which is an existing optimal tuning method.

关键词： attention mechanism auto-tuning system reinforcement learning(RL) workload-aware

Effect of Cr on Characteristic of Rust Layer Formed on Low Alloy Steel in Flow-accelerated Corrosion Environment

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Journal of Iron and Steel Research(International) 2016年第6期23卷 602-607页

作者： feng chai Shan JIANG Cai-fu YANG Department of Engineering Steels Central Iron and Steel Research Insititute

The flow-accelerated corrosion experiments were carried out to research the effect of Cr on the rust layers formed on the carbon steel and Cr-containing steel,as well as the structure of rust layer of the two experimental *** influence of Cr on the flow-accelerated corrosion resistance and the corrosion morphology of inner rust layer formed on the Cr-containing steel were studied by the methods of polarization curves,scanning electron microscope,transmission electron microscope,and X-ray photoelectron *** distribution of Cr and its form of existence in the inner rust layer were *** results show that corroded mass loss of Cr-containing steel is lower than that of carbon steel and its inner rust layer is *** exists in the form of Fe2CrO4 and is enriched in the inner rust *** concentration could make the inner rust layer exhibit the tendency of *** phenomenon is related to fine *** inner rust layer becomes more compact because of the formation of fine Fe2CrO4,and the protectiveness of inner rust layer could be improved remarkably.

关键词： accelerated photoelectron amorphous remarkably steels finer enriched cathodic hence attributed