基于MapInf0建立大比例尺符号库的方法研究

叙述了基于MapInfo建立地理信息系统地图符号库的必要性和意义，提出了利用MapInfo的二次开发工具MapBasic4．0和计算机图形学理论进行地图符号库的设计与开发的一种方法，可以有效地减少原有MapInfo下符号化的烦琐工作流程，降低地图符号化工作的劳动强度，提高了制图的自动化程度，在工程实践中具有重要意义．     

盘管外融冰问题的数学模型及数值分析

本文分析了盘管外融冰问题并建立其数学模型;利用该模型模拟了盘管外融冰过程,并对模拟结果进行了分析。分析表明,该模型比较合理,更加接近蓄冷槽内融冰过程的实际情况;循环水量对融冰持续时间有较大影响。所得结论可为今后蓄冷系统的优化计算分析提供理论根据。     

昌邑—大店一带活动断裂对地质灾害影响研究

为研究活动断裂对地质灾害的影响,选取华北板块鲁西地块与苏鲁造山带东界昌邑—大店断裂为研究对象,通过野外面积调查、构造剖面测量、工程地质样品分析测试、综合研究等手段,详细调查了区内活动构造的特征、地质灾害的发育特征,在此基础上讨论了活动断裂对地质灾害影响机制,认为受昌邑—大店构造的影响,地裂缝分布主要沿构造带分布,区内地...     

Semi-supervised transfer discriminant analysis based on cross-domain mean constraint

In this paper, a novel semi-supervised feature extraction algorithm, i.e., semi-supervised transfer discriminant analysis (STDA) with knowledge transfer capability is proposed, based on the traditional algorithm that cannot get adapted in the change of the learning environment. By using both the pseudo label information from target domain samples and the actual label information from source domain samples in the label iterative refinement process, not only the between-class scatter is maximized while that within-class scatter is minimized, but also the original space structure is maintained via Laplacian matrix, and the distribution difference is reduced by using maximum mean discrepancy as well. Moreover, semi-supervised transfer discriminant analysis based on cross-domain mean constraint (STDA-CMC) is proposed. In this algorithm, the cross-domain mean constraint term is incorporated into STDA, such that knowledge transfer between domains is facilitated by making source and target samples after being projected are located more closely in the low-dimensional feature subspace. The proposed algorithm is proved efficient and feasible from experiments on several datasets.     

基于GIS耦合HEC-RAS的城市洪水灾害风险评估——以重庆市主城区长江、嘉陵江段为例

本文通过GIS耦合HEC-RAS模拟洪水淹没情况,采用自然灾害风险评价的理论和方法 ,综合重庆主城区九个区的自然、社会经济、防灾减灾等数据,得出主城区洪水灾害风险指数,并基于GIS绘制出重庆主城区洪水灾害风险区划图,为后续制定应急预案和防洪规划提供依据。     

Highly efficient MOF-templated Ni catalyst towards CO selective methanation in hydrogen-rich reformate gases

Highly efficient and non-noble metal-based Ni/ZrO₂ catalyst templated with Ni/UiO-66 precursor was successfully prepared and applied to CO selective methanation in H₂-rich gases. This catalyst showed excellent activity and selectivity in an extremely wide temperature window of 215–350 °C, and it also had high stability with no deactivation during a long-term stability test (120 h). The increased specific surface area, smaller crystallite size (3.5 nm) and higher dispersion (15.3%) of Ni nanoparticles, and the enhanced chemisorption capability for CO might contribute to its excellent performance.     

SplitPass: A Mutually Distrusting Two-Party Password Manager

Using a password manager is known to be more convenient and secure than not using one, on the assumption that the password manager itself is safe. However recent studies show that most popular password managers have security vulnerabilities that may be fooled to leak passwords without users’ awareness. In this paper, we propose a new password manager, SplitPass, which vertically separates both the storage and access of passwords into two mutually distrusting parties. During login, all the parties will collaborate to send their password shares to the web server, but none of these parties will ever have the complete password, which significantly raises the bar of a successful attack to compromise all of the parties. To retain transparency to existing applications and web servers, SplitPass seamlessly splits the secure sockets layer (SSL) and transport layer security (TCP) sessions to process on all parties, and makes the joining of two password shares transparent to the web servers. We have implemented SplitPass using an Android phone and a cloud assistant and evaluated it using 100 apps from top free apps in the Android official market. The evaluation shows that SplitPass securely protects users’ passwords, while incurring little performance overhead and power consumption.     

Regulating the Interfacial Electronic Coupling of Fe2N via Orbital Steering for Hydrogen Evolution Catalysis

The capability of manipulating the interfacial electronic coupling is the key to achieving on-demand functionalities of catalysts. Herein, it is demonstrated that the electronic coupling of Fe₂N can be effectively regulated for hydrogen evolution reaction (HER) catalysis by vacancy-mediated orbital steering. Ex situ refined structural analysis reveals that the electronic and coordination states of Fe₂N can be well manipulated by nitrogen vacancies, which impressively exhibit strong correlation with the catalytic activities. Theoretical studies further indicate that the nitrogen vacancy can uniquely steer the orbital orientation of the active sites to tailor the electronic coupling and thus benefit the surface adsorption capability. This work sheds light on the understanding of the catalytic mechanism in real systems and could contribute to revolutionizing the current catalyst design for HER and beyond.