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儿童青少年手机使用与手机成瘾行为及相关因素分析

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智慧健康 2024年第9期10卷 25-28页

作者：张明丽韩陈香王明磊佟倩汶上县人民医院山东济宁272501 汶上县中小学实践教育中心山东济宁272501

目的研究儿童青少年手机使用与手机成瘾行为并分析影响因素。方法将2021年6月—2022年6月我市儿童青少年(n=367)及其家属展开相应调查,统计儿童青少年手机使用与手机成瘾率以反映手机使用与成瘾现状,回顾性分析、对比发生与未发生手机... 详细信息

目的研究儿童青少年手机使用与手机成瘾行为并分析影响因素。方法将2021年6月—2022年6月我市儿童青少年(n=367)及其家属展开相应调查,统计儿童青少年手机使用与手机成瘾率以反映手机使用与成瘾现状,回顾性分析、对比发生与未发生手机成瘾行为的儿童青少年相关资料,将有差异项带入Logistic回归方程,分析儿童青少年手机成瘾的形成原因,并给予针对性预防措施。结果本次调查抽取的367名儿童青少年中,手机使用例数为359例,占比97.82%,手机成瘾例数为199例,占比54.37%。发生手机成瘾的儿童青少年在父母每周沟通频率、父母监控、手机每日使用时长、手机使用动机等资料方面均有差异(P<0.05),将上述因素带入Logistic回归方程计算发现,以上情况均是引起儿童青少年手机成瘾的影响因素。结论儿童青少年手机使用情况较为普遍,且手机成瘾率较高,儿童青少年手机成瘾与父母每周沟通频率、父母监控、手机每日使用时长、手机使用动机等因素密切相关,家长、老师可据此采取针对性措施实施干预。

关键词：儿童青少年手机使用手机成瘾影响因素

土石交界地层隧道双侧壁导坑法施工围岩压力与变形研究

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甘肃科学学报 2024年第3期36卷 114-121,145页

作者：段旭晗张明礼蒋春海郑钊马昭兰州理工大学土木工程学院甘肃兰州730050 上海市政工程设计研究总院(集团)有限公司上海200092 上海市政工程设计研究总院集团第十市政设计院有限公司甘肃兰州730000

为探究土石交界地层双侧壁导坑法施工围岩变形与压力分布规律,通过现场监测对白塔山隧道围岩压力与收敛沉降变形进行研究分析。结果表明:下台阶施工易导致拱腰和拱脚围岩压力产生突变,最大增量可达70%,而对拱肩影响较小;相较于岩石地层... 详细信息

为探究土石交界地层双侧壁导坑法施工围岩变形与压力分布规律,通过现场监测对白塔山隧道围岩压力与收敛沉降变形进行研究分析。结果表明:下台阶施工易导致拱腰和拱脚围岩压力产生突变,最大增量可达70%,而对拱肩影响较小;相较于岩石地层,黄土层稳定性差,更易受隧道施工扰动影响导致围岩变形大、稳定距离长,黄土层稳定距离比岩石层长4~9 m;土石交界地层围岩压力呈现快速增加→缓慢增加→逐渐稳定的变化趋势,在快速增长阶段岩石层荷载释放率高达80%,大于黄土层荷载释放率;断面围压分布呈现出明显的不对称性,表现为“黄土侧大,岩石侧小”的分布规律。因此,双侧壁导坑法下穿土石交界地层时,建议在下台阶工序交替时保留部分土体进行反压控制,并提高下台阶锚杆布设密度,黄土层应做好超前支护预加固,并提高初期支护强度。

关键词：隧道工程土石交界地层现场监测围岩压力控制措施

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血清降钙素原变化率联合sIL-2R水平诊断尿源性脓毒症的临床价值

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蚌埠医学院学报 2024年第4期49卷 484-488页

作者：刘建琳张铭立魏伟程琳赵艳福河北省张家口市第一医院泌尿外科 075000

目的:探讨血清降钙素原变化率、可溶性白细胞介素2受体(sIL-2R)在尿源性脓毒症中的诊断价值。方法:将78例尿源性脓毒症病人作为观察组,同期住院的81例一般泌尿系感染病人作为对照组。采用酶联荧光分析法检测入院时及入院72 h血清降钙素... 详细信息

目的:探讨血清降钙素原变化率、可溶性白细胞介素2受体(sIL-2R)在尿源性脓毒症中的诊断价值。方法:将78例尿源性脓毒症病人作为观察组,同期住院的81例一般泌尿系感染病人作为对照组。采用酶联荧光分析法检测入院时及入院72 h血清降钙素原水平并计算降钙素原变化率,采用酶联免疫吸附法检测入院时血清sIL-2R、C反应蛋白(CRP)水平,采用全自动血液体液分析仪检测白细胞计数(WBC)、中性粒细胞计数、淋巴细胞计数;尿源性脓毒症病人血清sIL-2R、降钙素原变化率与尿路感染常规检测项目的相关性采用Pearson相关分析;采用ROC曲线分析血清sIL-2R、降钙素原变化率对尿源性脓毒症的诊断效能;采用多因素logistic回归分析影响尿源性脓毒症的因素。结果:观察组血清sIL-2R、WBC、CRP、中性粒细胞计数水平显著高于对照组,降钙素原变化率、淋巴细胞计数显著低于对照组(P<0.01)。尿源性脓毒症病人血清sIL-2R与降钙素原变化率呈负相关关系(P<0.01);sIL-2R与淋巴细胞计数呈负相关关系(P<0.01),与WBC、CRP、中性粒细胞计数呈正相关关系(P<0.01);降钙素原变化率与淋巴细胞计数呈正相关关系(P<0.01),与WBC、CRP、中性粒细胞计数呈负相关关系(P<0.01)。sIL-2R、降钙素原变化率单独及联合诊断尿源性脓毒症的曲线下面积分别为0.849、0.851、0.908,sIL-2R、降钙素原变化率截断值分别为43.51 pg/mL、35.59%。sIL-2R是发生尿源性脓毒症的独立危险因素,降钙素原变化率是发生尿源性脓毒症的保护因素。结论:血清sIL-2R水平联合降钙素原变化率可作为诊断尿源性脓毒症的重要指标。

关键词：尿源性脓毒症可溶性白细胞介素2受体降钙素原

基于模型预测控制的车辆路径跟踪控制技术研究

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农业装备与车辆工程 2024年第1期62卷 71-75,104页

作者：唐传茵章明理樊实夏冀沣吴龙杰东北大学机械工程与自动化学院辽宁沈阳110819 东北大学理学院辽宁沈阳110819

以车辆三自由度动力学模型为研究对象,对自动驾驶车辆模型预测控制算法进行研究。结合魔术轮胎模型线性区域和小角度假设理论对车辆动力学模型进行简化处理,设计基于模型预测控制算法的路径跟踪控制器。使用MATLAB/CarSim联合仿真平台,... 详细信息

以车辆三自由度动力学模型为研究对象,对自动驾驶车辆模型预测控制算法进行研究。结合魔术轮胎模型线性区域和小角度假设理论对车辆动力学模型进行简化处理,设计基于模型预测控制算法的路径跟踪控制器。使用MATLAB/CarSim联合仿真平台,选用多组工况进行仿真试验。设定车辆的速度分别为低速、中速、高速3种状态,并且使用线性二次型最优控制器进行换道工况路径跟踪,与模型预测控制器进行控制效果对比与分析,结果表明,模型预测控制算法路径跟踪控制效果更加优秀。

关键词：路径跟踪模型预测控制线性二次型最优控制联合仿真

Thermal–moisture dynamics and thermal stability of active layer in response to wet/dry conditions in the central region of the Qinghai–Tibet Plateau,China

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Research in Cold and Arid Regions 2023年第1期15卷 27-38页

作者： mingli zhang ZhiXiong Zhou Zhi Wen FengXi Zhou Zhao Ma BingBing Lei College of Civil Engineering Lanzhou University of TechnologyLanzhouGansu 730050China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environmental and ResourcesChinese Academy of SciencesLanzhouGansu 730000China Geological Hazards Prevention Institute Gansu Academy of SciencesLanzhouGansu 730000China College of Civil Engineering Lanzhou Jiaotong UniversityLanzhouGansu 730070China

The amount of rainfall varies unevenly in different regions of the Qinghai-Tibet Plateau, with some regions becoming wetter and others drier. Precipitation has an important impact on the process of surface energy balance and the energy-water transfer within soils. To clarify the thermal-moisture dynamics and thermal stability of the active layer in permafrost regions under wet/dry conditions, the verified water-vapour-heat coupling model was used. Changes in the surface energy balance, energy-water transfer within the soil, and thickness of the active layer were quantitatively analyzed. The results demonstrate that rainfall changes significantly affect the Bowen ratio, which in turn affects surface energy exchange. Under wet/dry conditions, there is a positive correlation between rainfall and liquid water flux under the hydraulic gradient;water vapour migration is the main form under the temperature gradient, which indicates that the influence of water vapour migration on thermalmoisture dynamics of the active layer cannot be neglected. Concurrently, regardless of wet or dry conditions,disturbance of the heat transport by conduction caused by rainfall is stronger than that of convection by liquid water. In addition, when rainfall decreases by 1.5 times(212 mm) and increases by 1.5 times(477 mm), the thickness of the active layer increases by 0.12 m and decreases by 0.21 m, respectively. The results show that dry conditions are not conducive to the preservation of frozen soil;however, wet conditions are conducive to the preservation of frozen soil, although there is a threshold value. When this threshold value is exceeded, rainfall is unfavourable for the development of frozen soil.

关键词： Active layer Wet/dry conditions Qinghai-Tibet Plateau(QTP) Thermal-moisture dynamics Permafrost thermal stability Numerical modelling

血清ACTH水平、降钙素原变化率对尿源性脓毒症预后的价值

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国际泌尿系统杂志 2024年第3期44卷 436-440页

作者：魏伟张铭立刘建琳程琳赵艳福张家口市第一医院泌尿外二科张家口075000

目的:探讨血清促肾上腺皮质激素(ACTH)水平、降钙素原(PCT)变化率对尿源性脓毒症的预后价值。方法:选取2021年1月至2022年3月本院收治的因上尿路结石行经皮肾镜或输尿管镜手术治疗后产生尿源性脓毒症的76例患者为研究对象,根据患者确诊... 详细信息

目的:探讨血清促肾上腺皮质激素(ACTH)水平、降钙素原(PCT)变化率对尿源性脓毒症的预后价值。方法:选取2021年1月至2022年3月本院收治的因上尿路结石行经皮肾镜或输尿管镜手术治疗后产生尿源性脓毒症的76例患者为研究对象,根据患者确诊后14 d的生存情况分为生存组(67例)和死亡组(9例)。采用酶联免疫吸附(ELISA)法检测患者的血清ACTH水平以及确诊当天和确诊后第2天患者的血清PCT水平,计算PCT变化率。采用Spearman相关性分析患者的血清ACTH水平、PCT变化率与序贯器官衰竭评分(SOFA)的相关性。采用Cox回归分析影响尿源性脓毒症患者预后的危险因素。结果:死亡组的谷丙转氨酶、谷草转氨酶、总血红素、活化部分凝血活酶时间(APTT)、血肌酐、白细胞计数高于生存组,而血红蛋白低于生存组,差异均有统计学意义(均P<0.05)。与死亡组比较,生存组患者的血清ACTH水平和SOFA评分降低,PCT变化率明显升高(均P<0.001)。Spearman相关性分析结果显示ACTH水平与SOFA评分呈正相关(r=0.533,P<0.001),PCT变化率与SOFA评分呈负相关(r=-0.600,P<0.001)。多因素Cox回归分析结果表明,ACTH高表达、低PCT变化率是影响尿源性脓毒症患者不良预后的危险因素(均P<0.05)。结论:尿源性脓毒症患者的ACTH水平明显升高,PCT变化率显著降低,二者与尿源性脓毒症患者预后密切相关。

关键词：促肾上腺皮质激素降钙素原尿源性脓毒症

Investigation on Thermal Insulation and Mechanical Strength of Lightweight Aggregate Concrete and Porous Mortar in Cold Regions

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Journal of Renewable Materials 2022年第12期10卷 3167-3183页

作者： Jianan Wu Ke Xue Zhaowei Ding Lei Lang Kang Gu Xiaolin Li mingli zhang Desheng Li Ningbo City College of Vocational Technology NingboChina College of Water Conservancy and Hydropower Engineering Sichuan Agricultural UniversityYa’anChina State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghaiChina College of Civil Engineering and Architecture Jiaxing UniversityJiaxingChina Department of Civil Engineering Lanzhou University of TechnologyLanzhouChina Department of Civil Engineering College of ScienceNanjing University of Science and TechnologyNanjingChina

Thermal insulation is an important indicator to evaluate the construction material in cold region *** we know,adding the industrial waste as lightweight aggregate or creating the pore inside the cement-based composite could make the texture loose,and the thermal insulating capacity of the material would be improved with this *** these methods,the industrial by-product and engineering waste could be cycled in an efficient ***,after service the fragmented cement composites paste could be used as aggregate in the thermal insulating concrete *** the porous texture is not favorable for the mechanical strength and long-term durability in a cold *** balance the above three requirements from two opposite directions,different processing methods were applied to create the thermal insulation concrete/***,the organic/inorganic lightweight aggregate,including the Expanded Polystyrene(EPS),Expanded Perlite(EP),and Ceramsite(CRMST)particles,were applied to create the Lightweight Aggregate Concrete(LWAC).As the comparative tests,the expanded Superabsorbent Polymer(SAP)hydrogel and Air-Entraining Agent(AEA)were also introduced to create the porous *** above concrete/mortar was tested in the normal state and under the Freeze-Thaw cycle to explore the engineering performance in cold *** the experimenting process,the thermal insulation,mechanical strength,and frost resistance of these cement-based composites were investigated,and an optimal thermal insulation concrete/mortar was determined.

关键词： Thermal insulation mechanical strength cement-based composite freeze-thaw cycle frost resistance

FORMING DYNAMIC EQUATIONS OF ELASTIC LINKAGE AND INVESTIGATION OF MODEL ERROR

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Chinese Journal of Mechanical Engineering 1995年第1期8卷 30-37,14页

作者： Zou Huijun(Shanghai Jiaotong University)zhang mingli(Shanghai Maritime University)

Dynamic equations of elastic linkage are formed by means of Kane equation and finitemethod. Eight main influential factors on the dynamic response of elastic linkage are considered inthese equations. Model error caused by the eight factors are investigated. Some useful conclusionsabout model error are derived from theoretical analysis and the numerical calculation of twenty-sixexamples.

关键词： KED Model Error

Internal Loads and Bioavailability of Phosphorus and Nitrogen in Dianchi Lake,China

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Chinese Geographical Science 2018年第5期28卷 851-862页

作者： WU Yalin HUANG Tao HUANG Changchun SHEN Yinyin LUO Yang YANG Hao YU Yanhong LI Ruixiao GAO Yan zhang mingli College of Geography Science Nanjing Normal University Nanjing 210023 China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210023 China Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control Nanjing 210023 China Kunming China International Research Center for Plateau Lake Yunnan Institute of Environmental Science Kunming 650200 China

Sediments have a significant influence on the cycling of nutrient elements in lake environments. In order to assess the distribution characteristics and estimate the bioavailability of phosphorus and nitrogen in Dianchi Lake, organic and inorganic phosphorus and nitrogen forms were analysed. The 210 Pb radiometric dating method was employed to study temporal changes in the phosphorus and nitrogen pools in Dianchi Lake. The result show that the total phosphorus(TP) and total nitrogen(TN) were both at high concentrations, ranging from 697.5–3210.0 mg/kg and 1263.7–7155.2 mg/kg, respectively. Inorganic phosphorus(IP) and total organic nitrogen(TON) were the main constituents, at percentages of 59%–78% and 74%–95%, respectively, in the sediments. Spatially, there was a decreasing trend in phosphorus and nitrogen contents from the south and north to the lake centre, which is related to the distribution pattern of local economic production. The burial rates of the various phosphorus and nitrogen forms increased in same spatially and over time. Particularly in the past two decades, the burial rates doubled, with that TN reached to 1.287 mg/(cm^2·yr) in 2014. As the most reactive forms, nitrate nitrogen(NO_3-N) and ammonia nitrogen(NH_4-N) were buried more rapidly in the south region, implying that the potential for releasing sedimentary nitrogen increased from north to south. Based on their concentrations and burial rates, the internal loads of phosphorus and nitrogen were analysed for the last century. A TP pool of 71597.6 t and a TN pool of 81191.7 t were estimated for Dianchi Lake. Bioavailable phosphorus and nitrogen pools were also estimated at 44468.0 t and 5429.7 t, respectively, for the last century.

关键词： sediment phosphorus nitrogen burial rate internal load bioavailability Dianchi Lake