面向交通流量预测的时空超关系图卷积网络

交通流量预测是智能交通系统中的重要研究课题,然而,交通对象（如站点、传感器）之间存在的复杂局部时空关系使得这项研究颇具挑战。尽管以往的一些研究将流量预测问题转化为一个时空图预测问题从而取得了较大的进展,但是它们忽略了交通对象们跨时空维度的直接关联性。目前仍缺乏一种全面建模局部时空关系的方法。针对这一问题,首先提出一种新颖的时空超图建模方案,通过构造一种时空超关系来全面地建模复杂的局部时空关系;然后提出一种时空超关系图卷积网络（STHGCN）预测模型来捕获这些关系用于交通流量预测。在四个公开交通数据集上进行了大量对比实验,结果表明,相比ASTGCN、时空同步图卷积网络（STSGCN）等时空预测模型,STHGCN在均方根误差（RMSE）、平均绝对误差（MAE）、平均绝对百分比误差（MAPE）这三个评价指标上均取得了更优的结果,不同模型运行时间的对比结果也表明,STHGCN有着更高的推理速度。     

荆江门弯道近期滩槽演变特点及影响因素分析

三峡水库运用改变了下泄水沙条件,坝下游弯曲河型均呈现“凸冲凹淤”演变规律,以致碍航问题日益突出。为研究弯曲河型滩槽演变特点及其成因,以下荆江河段荆江门弯道为例,利用三峡蓄水后近15 a实测地形资料,采用逻辑推理及统计分析方法分析其影响因素并预测了航道变化趋势。结果表明:三峡工程运用后,凸岸边滩年际间呈持续冲刷趋势,冲刷位置不断下移导致河段展宽引起航道条件恶化;在平滩流量(20 000~25 000 m³/s)持续时间＞15 d的年份,凸岸边滩冲刷后退,反之淤长;冲淤幅度与年均来沙量,尤其细沙(d≤0.125 mm)含量密切相关,基本呈同步变化趋势;荆江一期工程实施后,在当前水沙条件下凸岸边滩会继续受冲,形成枯水双槽,航道条件将恶化。水沙过程的改变是弯曲河型滩槽演变的主要原因,遇大水且来沙量较少的年份,荆江门河段很可能出浅碍航,这可为下荆江弯曲河段航道治理提供一定的参考价值。     

A review of the health effects and exposure-responsible relationship of diesel particulate matter for underground mines

The increasing use of diesel-powered equipment in confined spaces(underground mines) has the potential to over expose underground miners under the threat of diesel particulate matter(DPM). Miners in underground mines can be exposed to DPM concentrations far more than works in other industries. A great number of animal and epidemiological studies have shown that both short-term and long-term DPM exposure have adverse health effect. Based on reviews of related studies, especially some recent evidence, this paper investigated the long and short-term health effects based on animal studies and epidemiological studies. The exposure-response relationship studies were also explored and compared to the current DPM regulation or standards in some countries. This paper found that the DPM health effect studies specifically for miners are not sufficient to draw solid conclusions, and a recommendation limit of DPM concentration can be put in place for better protection of miners from DPM health risk. Current animal studies lack the use of species that have similar lung functions as human for understanding the cancer mode of action in human. And finally, the DPM health hazard will continue to be a challenging topic before the mode of action and reliable exposure-response relationship are established.     

基于弹性网络模型的蛋白质结构-功能关系

蛋白质结构-功能关系研究是结构生物学领域的热点问题之一,具有重要的理论和实际应用价值.弹性网络模型(elastic network model,ENM)是获取蛋白质结构本身固有动力学性质,进而揭示其生物学功能的有效方法,在蛋白质结构-功能关系研究中得到了广泛应用.简要介绍了ENM的基本原理及其在蛋白质结构-功能关系中的应用,主要包括蛋白质功能性运动分析和关键位点识别等.     

Support principles of NPR bolt/cable and control techniques of large-deformation disasters

Deep mining has been paid much more attention because of the depletion of shallow mining resources.Traditional bolts could be invalid to accommodate large displacement and deformation in geomaterials.Consequently, alternative support and reinforcement bolts need to be studied and their constitutive models also need to be developed to help understanding for the complex stress-strain responses of rock masses under loadings. The effect of Negative Poisson's Ratio(NPR) that is attributed to the swelling phenomenon along the lateral direction may appear in metal materials under tensional loadings. Thence NPR materials often have an advantage over NPR ones in mechanical behavior such as impact resistance, antishearing, and energy absorbed. From the characteristics of NPR materials, a series of bolt and cable supports with the effect of NPR and constant-resistance have been recently developed. We here firstly introduce the structural features of NPR support. Then the constitutive model of NPR support is presented and its corresponding equation of energy equilibrium. Its basic principle interacted on rock masses is further discussed. Finally, NPR cables are employed to support the slope of an open-pit mine. The applications show that NPR cables can ease failure within the slope and play an important role in predicting and providing early warning of slope failure, together with a monitoring system of slope stability.     

钢球全表面展开机构模型建立及其运动分析

针对镜面钢球缺陷检测装置中的球体全表面展开问题,建立展开机构接触模型并对球体运动进行分析,证明展开机构结构合理可行。首先由坐标变换建立数学模型,基于Matlab对模型空间接触位置进行计算,将展开运动合理简化,得到钢球和展开轮之间转动的同步关系;其次,对展开运动过程进行等效变换,寻找传动过程中能使钢球稳定展开的最优参数关系;最后,依据迭代法对球面上点的运动轨迹进行数值仿真,获得其具体规律为偏角固定的螺旋线。最终结果表明展开机构能够实现球体的全表面展开。     

纵向涡发生器攻角对翅片传热性能的影响

为了提高翅片式换热器的强化传热性能,对不同攻角的纵向涡发生器的翅片区域进行了研究.采用流体仿真软件FLUENT对发生器的翅片区域建立六面体网格模型,对不同攻角的纵向涡发生器的努塞尔数、阻力因子、综合性能分别进行数值分析和对比.结果显示:随着纵向涡发生器的攻角增加,纵向涡翅片的努塞尔数增强的越来越明显,其中纵向涡发生器攻角为45°的翅片努塞尔数最大;同时随着纵向涡发生器的攻角增加,阻力因子也随之增加;带纵向涡发生器的翅片的传热效果强于不带纵向涡发生器的翅片;通过比较综合评价因子,攻角为45°的纵向涡翅片在雷诺数为2000~6000内,综合性能最好.     

Organic additive implantation onto cement hydration products

In polymer modified cementitious materials, it is hard to set up a chemical connection between the added polymer and the cement moiety. In this study FS （functional silane） was adopted to form this connection as a bridge component which has the functional group forming bonds with polymer. To testify the connection between FS and cement moiety, Q2/Q1 ratio （Qx： intensity ratio） investigation was carried out by the means of quantitative solid state 29Si MAS NMR. The results show that the Q2/Q1 ratio has increased with the addition of FS which indicates that the silicon chain length has increased, and the quantity of silicon atoms at site of Q2, chain site, has enhanced, showing that the silicon atom of FS has connected to the silicon chain of cement moiety by the bond ＂-Si-O-Si-＂ formation.     

供应链关系资本对企业创新绩效的影响研究——基于需求拉动型吸收能力的视角

针对受国外技术和市场牵引较严重的4个制造类企业,构建了供应链关系资本、需求拉动型吸收能力和创新绩效三者间的概念模型,实施问卷调查,用结构方程模型验证假设。得到的结果表明：以信任为基础的供应链关系资本能够促进企业及时获取和掌握市场信息和技术知识,从而提高创新绩效。但是,样本企业供应链关系资本中的关系承诺维度对知识吸收的促进作用有待加强;需求拉动型吸收能力的知识转化和利用环节对于创新进程的促进作用有待提高。     

师德修养与教师幸福的关系探析

师德是教师获得幸福的必要条件,是教师幸福的基础。教师幸福是师德修养深层次的体现,是师德修养的深化。关于师德修养和教师幸福的关系,在教育界一直被讨论。通过对师德修养和教师幸福内涵进行分析,进而探讨其两者的关系,从而对两者有更加深刻的理解,对于提升师德修养,增强教师的幸福感,进而对当前教育教学改革产生一定理论意义和实践价值。