三维激光扫描技术在隧道限界中的应用

针对新建地铁区间隧道限界是影响地铁安全运营重要因素之一,基于移动式三维激光扫描技术对新建地铁车站、隧道进行三维激光扫描作业,结果表明区间隧道管片椭圆度整体在10‰以内,椭圆度最大为12.5‰,椭圆度最小为1.6‰,整体拼装质量安全可靠;隧道水平直径与标准直径间存在偏差,最大偏差为41.7 mm,最小偏差为-0.8 mm,平均偏差为15.7 mm;对车站滑动门进行限界检测分析,发现共计存在15道滑动门侵界现象,侵界长度最大值为30.2 mm,最小值为2.2 mm,平均值为17.6 mm,侵界均为防踏空胶条不影响行车安全,移动式三维激光扫描技术为列车开通运营提供安全数据支持。

生物波早期综合治疗联合持续右正中神经刺激疗法对重型颅脑损伤昏迷患者催醒过程的影响

目的探究生物波早期综合治疗联合持续右正中神经刺激疗法对重型颅脑损伤昏迷患者催醒过程的影响。方法选取2021-05—2022-05沧州市人民医院收治的110例重型颅脑损伤昏迷患者,按随机数字表法分成对照组及研究组,每组55例。对照组患者采取持续右正中神经刺激疗法,研究组在对照组的基础上加用生物波早期综合治疗,分析2组患者苏醒状况、血浆脑损伤标志物、脑灌注相关指标、格拉斯哥昏迷量表(GCS)评分、格拉斯哥预后量表(GOS)评分、NIHSS评分及预后。结果与对照组[苏醒率(2周:21.82%;4周:45.45%),苏醒时长(27.39±4.63)d]比较,研究组患者治疗2、4周后苏醒率(2周:54.55%;4周:76.36%)有所上升,苏醒时长[(21.47±3.35)d]有所降低(P<0.05)。治疗后2组患者神经元特异性烯醇化酶(NSE)、血浆人S100B蛋白(S-100B)、髓鞘碱性蛋白(MBP)水平、NIHSS评分下降,脑血容量(CBV)、脑血流量(CBF)及GCS、GOS评分上升,研究组改善程度较对照组高(P<0.05)。研究组临床治疗总有效率(89.09%)高于对照组(70.91%),P<0.05。结论经生物波早期综合治疗联合持续右正中神经刺激疗法可有效降低重型颅脑损伤昏迷患者NSE、S-100B、MBP水平,对改善脑血流灌注发挥了积极的促进作用,加快患者苏醒。

“三教改革”理念下任务链教学法探赜

新中国成立后,国家在教育教学领域的改革理念和政策及实践上不断因时因势演进,若以“三教改革”为核心旨意缩略语并结合时代变迁和社会改革进程对其进行梳理和总结,发展脉络清晰显见,而教学法改革始终含蕴其中。任务链教学法于我国实践起步相当早,但理论探讨十分匮乏,通过以实促理之径,探得并提出任务链教学法在实施中应遵循的五个原则,即迭代原则、双进阶原则、可学性原则、可追溯性原则、可穷尽性原则,此外还指出了任务链教学法实践中需避开的三个常见误区,希为其更佳应用提供助力。

PAM-AA与金属离子复合絮凝剂的合成及其在污泥脱水中的应用

以丙烯酰胺(AM)、丙烯酸(AA)和硫酸铝为原料,采用水溶液聚合法合成Al^(3+)复合高分子絮凝剂(PAM-AA).通过正交实验确定最佳聚合条件为:m(AM)∶m(AA)=5∶3,反应温度为65℃,搅拌时间5 h,引发剂的加入量占单体质量3%,产率可达96.3%.在此基础上合成Ca^(2+),Mg^(2+)和Fe^(3+)复合高分子絮凝剂,利用红外光谱(IR)、X射线衍射(XRD)、扫描电子显微镜(SEM)等方法对产物的结构和形貌进行表征.将复合高分子絮凝剂与杀菌剂N,N-二甲基十二烷基苄基氯化铵(1227)用于市政生活污泥脱水中,通过滤饼含水率和污泥比阻,对比研究聚合氯化铝(PAC)、PAM-AA和硫酸铝机械混合物以及Al^(3+)复合高分子絮凝剂对市政污泥脱水性能的影响.结果表明,Al^(3+)复合高分子絮凝剂与1227协同使用,可使污泥滤饼含水率降至63.8%,效果较好.

Characteristics of Heavy Minerals and Quantitative Provenance Identification of Sediments from the Muddy Area Outside the Oujiang Estuary Since 5.8 kyr

The heavy mineral compositions of the sediments in core D04 with a length of 20.2 m from the muddy area outside the Oujiang Estuary along the coast of Zhejiang-Fujian Provinces have been analyzed. Core D04 can be divided into three units: DU1(0–7.4 m), DU2(7.4–11.4 m) and DU3(11.4–20.2 m). The results showed that the heavy minerals are authigenic pyrite(65.6%)– hornblende(16.0%) – epidote(4.6%) assemblages. The core sediments are mainly composed of clayey silt, which belongs to the clinoform deposit formed since 5.8 kyr, indicating a weak hydrodynamic environment. The deposition rates changed in the trend of high-low-high upward. Quantitative analysis shows that the core sediments were mainly from the suspended sediments of the Changjiang(Yangtze) River, accounting for 79.2%, with only 10.0% from Oujiang, and 10.8% from other provenance. The Oujiang-derived sediments were gradually increased from the bottom unit DU3(3.1%) to the top unit DU1(17.8%), but the Changjiang-derived sediments were gradually decreased. The source changes are closely related to the development of Yangtze River Delta and Wenzhou Bay, climate changes and human activities. During the period of 2.1–3.7 kyr, the sediment supply was greatly reduced due to the poor reclamation capacity of the river basins, resulting in a low deposition rate. Since 2 kyr, the enhancement of human activities in the Yangtze River Basin and the Oujiang River Basin led to more soils to be eroded and transported to the study area. Due to the short distance of the site of core D04 from the Oujiang River mouth, the study area received more Oujiang-derived sediments when upper unit(DU1) deposited than the lower units(DU2 and DU3).

Distribution and Provenance of Detrital Minerals in Southern Coast of Shandong Peninsula

Detrital minerals of 137 offshore and 22 river sediment samples collected from Qingdao coastal areas have been analyzed. Four mineral assemblage provinces can be classified by Q-mode cluster analysis. Factor analysis identifies two major factors that account for the total variability in most common minerals: 1) based on the relationship of quartz, hornblende, actinolite, micas, and authigenic pyrite, 41.55% of the variability is related to sediment sources; 2) based on the relationship of epidote, garnet, sphere, and ilmenite, 23.21% can be related to strong hydrodynamic conditions that control transport and sedimentation. By comparing mineral compositions of river waters in the study area, the following four mineral provenances can be identified. The Qingdao-Laoshan nearshore area has a quartz-feldspar-epidote-hornblende-limenite-limonite-sphene assemblage, which is largely attributed to relict sediment and coastal erosion. The Jimo-Haiyang nearshore area has a quartz-feldspar-hornblende-epidote-limonite-mica-actinolite assemblage, derived largely from the Wulong River and Rushan River, and is also affected by the Huanghe River, while the Qianliyan Island area in the deeper offshore area separated by a mud belt has a similar assemblage. The Haiyang-Rushan nearshore area has a quartz-feldspar-hornblende-epidote-micas-limonite assemblage, indicating multiple sources from the Rushan River, the Wulong River, the Huanghe River, and coastal erosion. The central area, located in an eddy center, has a mica-authigenic pyrite-hornblende-quartz-feldspar assemblage, indicating multiple sources dominated by Huanghe River distal sediments.

基于三维激光扫描的高层建筑建模研究

三维激光扫描技术能够快速获取目标表面大量的点云数据,通过对这些点云数据利用和处理,能够反映出目标的属性和三维模型。高层建筑发展速度不断增加,其复杂性、庞大性增加了建模难度。于是文章借助三维激光扫描技术,对高层建筑建模进行研究。首先对三维激光扫描系统的基本原理进行分析,然后基于三维激光扫描建立某高层建筑模型,结果表明构建的高层建筑模型效果较好、构建速度较快。

结合三维激光扫描点云生成BIM模型技术在建筑中的应用

三维激光扫描技术和BIM技术作为当今科技发展的产物,两者的结合应用推动了建筑行业数字化的发展。本文以某地一座古代院落为研究对象,利用三维激光扫描技术进行整体建筑扫描,将得到的点云数据进行数据处理和转化,经绘制建筑特征线得到二维图纸资料,在此基础上建立完整的三维建筑模型,并与其他信息相融合,实现了已有建筑的数字化和信息化,对今后的建筑修缮、保护和使用提供了全面有效的信息。研究表明:三维激光扫描技术与BIM技术的结合应用具有效率更高、精度更高、信息化程度更高的特点,对同类工程的应用提供参考价值,为未来的空间测绘、数字城市建设等方面提供了新方法。

重钢中厚板厂中间坯水冷装置自动控制系统的开发与应用

双机架中厚板轧制中的待温过程是实现多阶段控制轧制的重要环节。中间坯空冷待温能够提高产品性能,也会导致生产效率降低。重钢中厚板厂利用中间坯水冷装置进行人工加速冷却,可以有效缩短中间坯待温时间,提高中间坯冷却效率,结合适当的空冷均温,实现了中间坯的均匀冷却,但是中间坯水冷装置在轧制过程中的人工干预过多,致使轧制节奏、轧制工艺受到影响。重钢联合北京科技大学,基于中厚板厂中间坯水冷装置布置及自动控制系统架构,将中间坯水冷模型控制系统与粗、精轧机主控制系统进行优化整合设计,减少了中间坯水冷装置在轧制过程中的人工干预,提高了整个中厚板轧机区的自动化控制水平。