爆破位置对深凹露天矿山炮烟扩散的影响研究

深凹露天矿山由于其特殊的结构,爆破产生的炮烟扩散稀释较为困难,严重危害生产作业人员的生命安全与健康。基于实际矿山构建了深凹露天矿山的二维物理及数学模型,采用非稳态数值分析方法研究了不同爆破位置下,深凹露天矿山采坑内爆破炮烟的扩散规律。研究结果表明：不同爆破位置下,露天采坑内均出现复环流,爆破点位置是影响露天采坑内风流结构特征的重要因素；露天采坑内的炮烟最高浓度均随着时间变化而逐渐下降,但下降的速率逐步减小,呈现三个阶段的下降趋势；爆破位置位于背风侧时露天采坑内的炮烟最高浓度和降至安全浓度所需时间远高于迎风侧三个爆破位置；随着背风侧爆破点距采坑底部距离的减小,炮烟最高浓度及降至安全浓度所需时间先降低后增加,炮烟最高浓度及降至安全浓度所需时间随着迎风侧爆破位置距采坑底部距离的减小而增加。研究结果对于指导深凹露天矿山企业合理组织爆破后的生产作业和保障作业人员安全具有重要意义。     

Self-healing,elastic and deformable novel composite phase change polymer based on thermoplastic elastomer SEBS for wearable devices

Journal of Materials Science - Form-stable composite phase change materials (C-PCMs) prepared by microencapsulation method and porous matrix adsorption method need for compression molding after...     

盾构隧道施工物料无人运输发展现状及关键技术

盾构隧道施工物料无人运输有助于提升运输效率、降低运输成本、减少运输安全事故率。与公路汽车无人驾驶、港口车辆无人驾驶、轨道交通无人驾驶等逐步成熟的无人驾驶技术不同，在隧道场景下实施施工物料无人运输存在运输物料种类繁多、运输调度困难、地下定位信号拒止、狭窄车道频繁会车、行车路面工况复杂、地上地下联动响应慢等诸多挑战。从实现盾构隧道施工物料无人运输的关键问题分析入手，综述当前盾构隧道施工物料运输方式、运输需求、无人运输发展现状及存在的挑战，提出盾构隧道施工物料无人运输的五大关键技术：多种类物料智能货控能效管理技术，无人化垂直装卸门机控制技术，多传感器融合同步定位与地图构建技术，隧道复杂环境路径规划与自主避障技术，隧-地一体化联动响应的高可靠性无线通信技术。     

A novel 4D resolution imaging method for low and medium atomic number objects at the centimeter scale by coincidence detection technique of cosmic-ray muon and its secondary particles

The muon radiography imaging technique for high-atomic-number objects(Z) and large-volume objects via muon transmission imaging and muon multiple scattering imaging remains a popular topic in the field of radiation detection imaging. However, few imaging studies have been reported on low and medium Z objects at the centimeter scale. This paper presents an imaging system that consists of three layers of a position-sensitive detector and four plastic scintillation detectors. It acquires data by co...     

Modification of the wood-plastic composite for enhancement of formaldehyde clearance and the 3D printing application

As the formaldehyde is one of the main indoor pollutants, the purpose of this study is to effectively remove indoor formaldehyde pollution by using environmentally friendly 3D printing ornaments. The wood 3D printing filaments cellulose/polylactic acid composite (Cellu/P) was selected as the starting material, and 3-aminopropyltriethoxysilane (APTES) was used for chemical modification to obtain a series of cellulose composite materials with amino groups. The modified composite materials (APTES@Cellu/P) were characterized by Fourier transform infrared, X-ray diffraction, scanning electron microscope, energy dispersive spectroscopy, thermogravimetric analysis, and mechanical tests, and a formaldehyde removal experiment was performed. The feasibility of 3D printing was evaluated, and the process of 3D printing-functionalized customized ornaments was proposed, and then a school emblem was used for modeling, printing, and surface modification. Compared with the commercially traditional activated carbon, 3D printing-customized ornaments of APTES@Cellu/P material has a better formaldehyde removal effect, and can even avoid the secondary pollution that is common to the activated carbon.     

Sustainable phenolic thermosets coatings derived from urushiol

The over-exploitation of finite fossil resources and/or the increased environmental and sustainable awareness inspire scientists and technologists to search for inexpensive alternatives from renewable chemicals. Phenol formaldehyde (PF) resins, the oldest type of synthetic polymers with good mechanical properties and heat resistance, are widely used in the production of coatings, laminates, molding compositions, and glues. Here, biobased urushiol-derived PF resins were synthesized from the alkali-catalyzed reaction between urushiol and formaldehyde. The chemical compositions and molecular structures of resole resins were characterized by carbon-13 nuclear magnetic resonance and Fourier transform infrared spectroscopy, and their curing behaviors were studied by differential scanning calorimetry. The as-prepared urushiol-derived resole resins had methylol (Ph−CH₂OH), ortho- and para-hemiformal groups (Ph−CH₂OCH₂OH), and the para−para/ortho−para/ortho−ortho links of methylene groups (Ph−CH₂−Ph), whereas the resole resins had low curing temperatures at about 100–113°C. Additionally, given the long side alkyl group moiety on the aromatic rings of urushiol, the films of cured urushiol-derived resole resins had low glass transition temperatures of 132 ± 2°C. Furthermore, the as-prepared urushiol-derived coatings exhibited excellent physical and mechanical properties.     

Bio-Based,Self-Crosslinkable Eucommia ulmoides Gum/Silica Hybrids with Body Temperature Triggering Shape Memory Capability

At present, the synthesis of body temperature triggering shape memory polymers usually requires elaborate structural design, which limits their wide application. Herein, starting from bio-based Eucommia ulmoides gum (EUG), a series of EUG/silica hybrids (ESHs) are prepared through a facile one-pot process, in which EUG is epoxied and then self-crosslinked with SiO₂ by epoxy ring-open reaction. Varying the amount of H₂O₂, the shape memory transition temperature (T_trans) of ESHs is adjusted to 47.4–36.6 ℃, which is close to human body temperature (37 ℃). Among them, ESH-17 exhibited the best body temperature triggering shape memory ability (T_trans = 36.6 ℃), which can restore the permanent shape within 60 s at 37 ℃ with a shape fixity ratio of 99% and shape recovery ratio near 100%. In addition, the shape memory mechanism is discussed and shows some application scenarios of ESHs. The as-produced materials can be used as smart biomaterials such as self-tightening sutures, self-sealing root canal filling materials, and so on.     

安徽地区汉族心血管疾病患者SLCO1B1与ApoE基因多态性分布及其在他汀类药物临床个体化应用中的意义

目的：探讨脂质及药物代谢相关基因SLCO1B1和ApoE的基因多态性在安徽地区汉族心血管疾病患者中的分布，以评估他汀类药物个体化用药的效益/风险比。方法：利用PCR-荧光探针法技术检测2019年1月至2020年8月合肥市第二人民医院736例心血管疾病患者外周血基因组中SLCO1B1基因的rs2306283（388A>G）和rs4149056（521T>C）位点和ApoE基因的rs429358（388T>C）和rs7412（526C>T）位点的基因多态性分布特点，并与已报道的中国其他地区汉族心血管疾病患者的数据进行比较，分析不同地区间的基因型分布差异。结果：检测到安徽地区汉族心血管疾病患者中SLCO1B1基因型有6种，分别为*1a/*1a型（6.11%）、*1a/*1b型（29.08%）、*1b/*1b型（44.57%）、*1a/*15型（4.08%）、*1b/*15型（15.49%）、*15/*15型（0.68%），未检测到*1a/*5型、*5/*5型和*5/*15型；ApoE基因有6种表型，分别为E2/E2型（0.41%）、E2/E3型（11.96%）、E2/E4型（1.09%）、E3/E3型（67.66%）、E3/E4型（17.93%）、E4/E4型（0.95%）。两种基因的基因多态性频率分布满足Hardy-Weinberg遗传平衡，具有群体代表性。本研究人群中携带SLCO1B1正常肌病风险型的比例最高，约占79.76%；SLCO1B1中度肌病风险型和高度肌病风险型的人群比例较低，分别为19.57%和0.68%。ApoE大众类基因型比例最高，约占68.75%；ApoE保护类基因型及风险类基因型的人群比例分别为12.37%和18.88%。不同性别间SLCO1B1和ApoE基因表型患者差异无统计学意义。与华南地区心血管疾病患者相比，安徽地区ApoE基因多态性分布差异有统计学意义（P<0.05）。结论：安徽地区736例心血管疾病患者SLCO1B1和ApoE基因型分别以他汀药物剂量耐受性较高的正常肌病风险型和对他汀药物敏感的大众类基因型为主，服用他汀类药物诱发肌病的风险较低，降脂疗效较好；且两种基因的多态性分布均不受性别的影响，但ApoE基因多态性分布特征可能在地域上存在差异。因此，检测SLCO1B1和APOE基因多态性对于临床评估效益/风险比有重要的指导意义。     

基于SMA驱动的连续体手术机器人研究综述

连续体机器人是一种能在工作空间中连续弯曲的机器人,因其能在非结构化和狭窄的环境中灵活运动而得到广泛的关注.形状记忆合金(Shape memory alloy,SMA)材料具有良好的形状记忆效应和超弹性,通过施加不同的温度便能够实现对SMA的形状控制,是作为连续体机器人驱动装置的理想材料.基于SMA驱动的连续体机器人有着结构体积小,控制简便,运动范围广,自由度高,易于避障等优点,十分适用于环境复杂的医疗手术环境之中.对SMA的驱动原理和方式进行了分析,介绍了基于SMA驱动的连续体机器入在医疗手术方面的研究现状及建模方法,最后,对发展趋势进行了展望.