基于数字化校区道路二维码系统的自主学习途径研究

利用信息化技术以及互联网平台提高学生自主学习能力是现代教育发展的趋势。数字化校区道路二维码系统是在收集校区道路信息的基础上构建道路信息资源库。将道路信息转化为二维码,将包含道路信息资源库学习资料的二维码标在校区道路牌上,构建数字化校区道路二维码系统,方便学生自主学习。通过二维码通关测试题激发学生的探索欲,检验学生的自学情况。开发数字化校区道路系统,校园处处可学习,营造智慧校园。对于开设交通专业的学校有借鉴意义。

强时频无碰撞区跳频序列理论界

在准同步跳频通信系统中,无碰撞区跳频序列具有良好的Hamming相关性能,但是当时延超出无碰撞区时,该性能将无法得到保障。为了给跳频序列集在时频二维无碰撞区之外Hamming相关性优化提供标准,导出了包含频隙个数、序列长度、序列数目、时频二维无碰撞区之外跳频序列集最大异相Hamming自相关函数值和最大互相关函数值的理论界。提出了强时频二维无碰撞区跳频序列集的概念。分析了一类强时频二维无碰撞区跳频序列集的Hamming相关性。

中部6省入境旅游流流量与流质成长规律及时空演化分析

为研究中部地区及6省份入境旅游流流量与流质的成长规律、特征和发展类型态势演化,对其入境旅游实现量与质的同步发展提供参考.根据1998—2015年中部地区及6省份入境旅游流的相关数据,考查流量与流质指数、首位度、绝对集中指数、标准差和变异系数等,并基于旅游流"量"与"质"综合评价视角,构建旅游流二维四象限发展类型矩阵分析模型.结果表明,1998—2015年中部地区入境旅游流流量与流质呈现反向演化特征;入境旅游流流量的首位度整体上呈现合理结构,绝对集中度指数表现空间集聚类型性低度垄断型,入境旅游流流量的绝对差异相对平稳,入境旅游流流量相对差异较为稳定;入境旅游流流量成长演化分别表现出整体上升型、整体降低型和波动起伏型3种态势;中部地区入境旅游流表现出较为明显的阶段性与层次性特征,演变态势历经了"不平衡型—量质皆弱型—量质皆优型"的转变过程;入境旅游流流量与流质的匹配态势演化正逐步呈现出向合理的空间结构演化.

两种1,2,3-三唑衍生物的配合物合成策略:晶体结构和表面分析（英文）

在不同反应条件下反应得到了两种1,2,3-三唑衍生物的配合物[co(H_2O)6][Co(L^1)_3]_2·4H_2O(1)和Cu(L^2)_2(2)(HL^1=5-methyl-1-phenyl-1H-1,2,3-triazole-4-carboxylic acid;HL^2=1-(4-iodophenyl)-5-methyl-1H-1,2,3-triazole-4-carboxylic acid)。通过X射线单晶衍射和红外光谱确定了晶体结构,同时对配合物1和2进行了表面作用分析(Hirshfeld surface analysis),在二维指纹图谱中可以清楚的看到配合物中的主要分子间作用。

HESSIAN MATRIX BASED SADDLE POINT DETECTION FOR GRANULES SEGMENTATION IN 2D IMAGE

Segmenting the touching objects in an image has been remaining as a hot subject due to the problematic complexities, and a vast number of algorithms designed to tackle this issue have come into being since a decade ago. In this paper, a new granule segmentation algorithm is developed using saddle point as the cutting point. The image is binarized and then sequentially eroded to form a gray-scale topographic counterpart, followed by using Hessian matrix computation to search for the saddle point. The segmentation is performed by cutting through the saddle point and along the maximal gradient path on the topographic surface. The results of the algorithm test on the given real images indicate certain superiorities in both the segmenting robustness and execution time to the referenced methods.

A Note on q-Deformed Two-Dimensional Yang-Mills and Open Topological Strings

In this note we make a test of the open topological string version of the OSV conjecture in the toric Calabi-Yau manifold X = O（-3） → P^2 with background D4-branes wrapped on Lagrangian submanifolds. The Dbrahe partition function reduces to an expectation value of some inserted operators of a q-deformed Yang Mills theory living on a chain of P^1 ＇s in the base p2 of X. At large N this partition function can be written as a sum over squares of chiral blocks, which are related to the open topological string amplitudes in the local p2 geometry with branes at both the outer and inner edges of the toric diagram. This is in agreement with the conjecture.

Application of multi-channel two-dimensional transient Rayleigh wave exploration in goaf detection

The transient Rayleigh wave exploration has high detection accuracy in shallow exploration. The effect of detection array is comprehensive reflection of the velocity of rock and soil mass. Therefore, the roiling multi-channel transient acquisition system has been adopted in this study, which turns one dimensional transient Rayleigh wave exploration into two dimensions, consequently, the two-dimensional velocity distribution of rock and soil mass under the survey line has been achieved. Through comparing with the shallow seismic reflected wave exploration, the result indicates that the rolling multi-channel transient acquisition system has accurate resolution. Thus, in the process of the shallow reflected wave exploration, if the surface wave has developed, the coalition between the reflected wave exploration and the two-dimensional transient Rayleigh wave exploration should actualize the accuracy of exploration.

The Two-dimensional Time Coordinate System and Time Prediction Research of M≥6.7 Strong Earthquakes in the Sichuan-Yunnan Region

Since the 20 thcentury,the time intervals of M ≥6.7 strong earthquakes in the SichuanYunnan region show obvious regularity.Using the years of the strong events,a twodimensional time coordinate system is generated,based on which,the time prediction model is constructed for strong earthquakes in the Sichuan-Yunnan region.Prediction analysis shows that there is risk of generating four earthquakes with M ≥ 6.7 in the Sichuan-Yunnan region in the future 16 years,and there are strong signals for M ≥6.7earthquakes for periods 2012-2021 and 2025-2029.The strong earthquakes may occur around 2014-2015,2019 and 2027.

应用于X-43A飞行器中的FADS系统部分测压孔失效原因分析

应用于X-43A飞行器中的嵌入式大气数据传感(Flush Air Data Sensing,FADS)系统,由于部分测压孔测得的表面压力值明显低于数值计算或风洞试验的数值,所以,FADS系统并没有完全利用所有的测压孔,只是利用正常工作的测压孔来配合惯性导航系统(INS)解算攻角。对于部分失效的测压孔,并不是由硬件故障及测压管路故障引起的,而是由于部分测压孔配置区域的流动结构引起的。就FADS系统中部分测压孔失效的原因进行了分析,对于改进应用于其它同类飞行器的FADS系统的测压孔配置具有指导意义。

2-D P-wave velocity structure of lithosphere in the North China tectonic zone: Constraints from the Yancheng-Baotou deep seismic profile

We obtained the 2-D P-wave velocity structure of the lithosphere in the eastern North China Craton, Shanxi fault subsidence zone, and Yinchuan-Hetao fault subsidence zone by ray tracking technology based on six groups of clearly identified crustal phases and one group of lithospheric interface reflection phases from seismic recording sections of 21 shots along the 1300-km-long Yancheng-Baotou deep seismic wide-angle reflection/refraction profile. The results indicate significant differ- ences between the lithospheric structure east and west of the Taihang Mountains, which is a gravity-gradient zone as well as a zone of abrupt change in lithospheric thickness and a separation zone of different rock components. East of the Taihang Mountains, the Mesozoic and Cenozoic lithospheric structure of the North China Craton has undergone strong reformation and destruction, resulting in the lithosphere thickness decreasing to 70-80 km. The North China Basin has a very thick Cenozoic sedimentary cover and the deepest point of crystalline basement is about 7.0 kin, with the crustal thickness decreasing to about 31.0 kin. The crystalline basement of the Luxi uplift zone is relatively shallow with a depth of 1.0-2.0 km and crustal thickness of 33.0-35.0 km. The Subei Basin has a thicker Cenozoic sedimentary cover and the bottom of its crystalline basement is at about 5.0-6.0 km with a crustal thickness of 31.0-32.0 km. The Tanlu fault is a deep fracture which cuts the lithosphere with a significant velocity structure difference on either side of the fault. The Tanlu fault plays an important role in the lithospheric destruction in the eastern part of the North China Craton. West of the Taihang Mountains, the crustal thickness increases sig- nificantly. The crust thickness beneath the Shanxi fault depression zone is about 46 km, and there is a low-velocity structure with a velocity of less than 6.1 km s-~ in the upper part of the middle crust. Combined with other geophysical study results, our data shows that the lithospheric destruction at the Shaanxi-Shanxi fault depression zone and the Yinchuan-Hetao rift surround- ing the Ordos block is non-uniform. The lithosphere thickness is about 80-90 km in the Datong-Baotou area, 75-137 km at the Dingxiang-Shenmu region, and about 80-120 km in the Anyang-Yichuan area. The non-uniform lithospheric destruction may be related to the ancient tectonic zone surrounding the Ordos block. This zone experienced multi-period tectonic events in the long-term process of its tectonic evolution and was repeatedly transformed and weakened. The weakening level is related to the interactions with the Ordos block. The continental collision between the Cenozoic India and Eurasia plates and N-E thrust- ing by the Qinghai Tibet Plateau block is causing further reformation and reduction of the lithosphere.

NEW DESIGN AND ANALYSIS OF FINITE DIFFERENCE DOMAIN DECOMPOSITION ALGORITHM FOR THE TWO-DIMENSIONAL HEAT EQUATION

It is presented in this paper that the new design and its analysis of finite difference domain decomposition algorithms for the two-dimensional heat equation, and the numerical results have shown the stability and accuracy of the algorithms, where SauFyev asymmetric schemes have been used at the interface points. The Algorithm II in this paper has further extended those developed by Dawson and the others, Zhang and Shen.

Contact and injection engineering for low SS reconfigurable FETs and high gain complementary inverters

The newly emerged two-dimensional(2D) semiconducting materials, owning to the atomic thick nature and excellent optical and electrical properties, are considered as potential candidates to solve the bottlenecks of traditional semiconductors. However, the realization of high performance 2D semiconductorbased field-effect transistors(FETs) has been a longstanding challenge in 2D electronics, which is mainly ascribing to the presence of significant Schottky barrier(SB) at metal-semiconductor interfaces. Here, an additional contact gate is induced in 2D ambipolar FET to realize near ideal reconfigurable FET(RFET)devices without restrictions of SB. Benefitting from the consistently high doping of contact region, the effective SB height can be maintained at ultra-small value during all operation conditions, resulting in the near ideal subthreshold swing(SS) values(132 mV/decade for MoTe2 RFET and 67 mV/decade for WSe2 RFET) and the relatively high mobility(28.6 cm2/(Vs) for MoTe2 RFET and 89.8 cm2/(V s) for WSe2 RFET). Moreover, the flexible control on the doping polarity of contact region enables the remodeling and switching of the achieved unipolar FETs between p-type mode and n-type mode. Based on such reconfigurable behaviors, high gain complementary MoTe2 inverters are further realized. The findings in this work push forward the development of high-performance 2D semiconductor integrated devices and circuits.

Numerical Method on Load Sharing Problem of Thick Laminate Joints

Accurately and efficiently predicting the load sharing of multi^bolt thick laminate joints is necessary to quicken the optimization of the large-scale structures over various design variables, and a two-dimensional （2D） finite element method （FEM） is introduced to meet such a demand. The deformation contributions of the joint zone are analyzed and calculated separately, including the shearing deformation of the fasteners shank, the bending deformation of the fasteners shank, and the bearing deformation of the fasteners and joint plates. These deformations are all transferred and incorporated into the components of the fastener＇s flexibility. In the 2D finite element model, the flexibilities of the beam elements and bush elements are used to simulate different components of the fastener＇s flexibility. The parameters of the beam elements which include the bending moment of inertia and intersection area, and the parameters of the bush elements which include the stiffness in different directions, are all obtained through equalizing the fasteners flexibilities. In addition, the secondary bending effect introduced by the single-lap joints is also taken into account to verify the flexibilities of the fasteners in practical application. The proposed FEM is testified to be more accurate than the traditional 2D FEMs and more efficient than the three-dimensional （3D） FEM in solving load sharing problem of multi-bolt single-lap thick laminate joints. With the increase of joint plates＇ thickness, the advantages of the proposed method tend to be more obvious. The proposed 2D FEM is an effective tool for designing bolted joints in large-scale composite structures.

The Brillouin zones and band gaps of a two-dimensional phononic crystal with parallelogram lattice structure

We present a detailed theoretical study on the acoustic band structure of two-dimensional （2D） phononic crystal. The 2D pho- nonic crystal with parallelogram lattice structure is considered to be formed by rigid solid rods embedded in air. For the circu- lar rods, some of the extrema of the acoustic bands appear in the usual high-symmetry points and, in contrast, we find that some of them are located in other specific lines. For the case of elliptic rods, our results indicate that it is necessary to study the whole first Brillouin zone to obtain rightly the band structure and corresponding band gaps. Furthermore, we evaluate the first and second band gaps using the plane wave expansion method and find that these gaps can be tuned by adjusting the side lengths ratio R, inclined angle 0 and filling fraction F of the parallelogram lattice with circular rods. The results show that the largest value of the first band gap appears at θ=90° and F--0.7854. In contrast, the largest value of the second band gap is at θ=60° and F=0.9068. Our results indicate that the improvement of matching degree between scatterers and lattice pattern, ra- ther than the reduction of structural symmetry, is mainly responsible for the enhancement of the band gaps in the 2D phononic crystal.