基于情景规划的国家公园气候变化 应对：美国经验及对中国的启示

应对气候变化已成为全球共识,国家公园和自然保护地既是应对气候变化的重要阵地,也是受气候变化影响的敏感区域,但中国目前的研究和实践均还较薄弱,亟须借鉴域外经验。系统梳理了美国国家公园体系中,气候变化对自然、文化和社区的影响,概述了美国国家公园管理局的气候变化应对行动,指出情景规划是重要的气候变化应对工具。总结了美国国家公园在气候变化中开展情景规划的流程,提炼其规划特征,并以魔鬼塔国家纪念区为案例,详析其情景规划实践过程。在此基础上,总结了中国国家公园及体制试点区可能面临的气候变化风险,对比了情景规划与传统规划的区别,明确目前推广条件的欠缺,指出应逐步推广情景规划,并从实现科研储备、奠定实践基础、建立规划体系三方面提出可能的路径,对中国开展国家公园和自然保护地应对气候变化的相关工作具有借鉴意义。     

薛湖煤矿矿井充水主控因素与矿井涌水量预测研究

河南薛湖煤矿在开采过程中受到了水害的影响,为了确保煤矿安全、高效生产,分析了矿井水文地质条件,研究了矿井冲水的主控因素,并对矿井涌水量进行预测计算。研究结果表明,薛湖煤矿矿区发育六大含水层（组）和三大隔水层（组）,煤系地层的二叠系砂岩裂隙含水层是危害矿井生产的主要含水层,随着生产的进行,顶板砂岩水多被疏干,对生产的安全不会造成很大的影响。二2主采煤层的直接充水水源为二叠系二2煤层顶板砂岩裂隙承压水,间接充水水源为二2煤层底板和奥陶系灰岩岩溶裂隙承压水,矿井的自身采空区积水是薛湖矿的充水水源之一。二2煤的导水途径主要有裂隙、断层和封闭不良钻孔3种,高角度正断层可能成为导水通道。越往深部开采水压将会越大,构造和裂隙的发育增加了底板水涌入矿井的危险。选取比拟法和稳定流解析法对采区矿井涌水量进行计算,比拟法计算的全矿井正常涌水量656 m 3/h、最大涌水量787 m 3/h比较符合近年来矿井充水的实际情况,可以作为下一步矿井开采的依据。但随着开采水平的不断延深,太灰岩溶水向矿井突水的概率也将大大提高,若出现短期内多点突水情况,将会超过比拟法预算的最大涌水量。     

一种基于形状的机械零件模型检索方法

分析了经典D2形状描述符的原理。针对经典D2描述符的不足,提出利用三维模型面片的法向量方向分布特征构造一个具有旋转不变性的形状描述符N2,并用一种相关反馈算法将N2描述符和D2描述符组合起来以获得更好的检索准确度。该方法充分利用了机械模型自身的特点,实验表明其检索准确性显著高于经典D2描述符,同时具有良好的计算效率。     

适用于发展性故障的故障分量提取算法

提出了适用于发展性故障的故障分量提取算法。该算法首先计算发展性故障发生前保护安装处的故障分量,再根据发展性故障发生前保护安装处的电流和获取的故障分量求得非故障状态网络中的支路电流;发生发展性故障后,利用保护安装处的全电流减去求得的支路电流得到发展性故障后的故障分量电流。该算法不受电网参数波动和负荷变化的影响。在IEEE 9节点系统模型基础上,BPA仿真验证了算法的正确性。     

A mathematical model for simulating heat and moisture transfer within porous cotton fabric drying inside the domestic air-vented drum dryer

A mathematical model was developed to describe the processes of coupled heat and mass and momentum transfer occurring in convective drying of 100% porous cotton fabric. In this model, the variation in both air and fabric properties were expressed as a function of temperature and moisture content. The resulting systems of transient non-linear partial differential equations in the space-time domain together with the set of initial values and boundary conditions were numerically solved by utilizing the finite difference method. A series of laboratory drying experiments were performed using a computer-controlled dehydration system, which was developed to obtain data of drying kinetics under varying operating conditions for the validation of the predicted results from the proposed model. The experimental results has shown a very good agreement with the predictions of the model, which indicates that the proposed numerical model can be used with confidence as a tool in optimizing the design and operation of the fabric drying system. A parametric study was performed using the modeling tool has demonstrated the impact of key operational parameters on the drying kinetics, which has significant meaning on improving fabric’s appearance smoothness and decreasing the damage. It is expected that the model can be applied for other fiber products and processes involving similar phenomena.     

Formation and mechanism of silicon nanostructures by Ni-assisted etching

Instead of noble metal like Pt, Au and Ag, cheap Ni nanoparticles (Ni NPs) were used to fabricate silicon nanostructures. Ni was found to be etched off during the etching process, while forming silicon nanostructures with very low reflectance of 1.59 % from 400 to 900 nm. The formation mechanism of silicon nanostructures by Ni-assisted etching was presented from the point of view of the low electronegativity of Ni. The Ni NPs were found being etched off during the assisted etching process, which implies that the transfer rate of electrons from Si to Ni is slower than that from Ni to O^? in the case of using Ni as assisted metal. The reason of sparser and deeper silicon nanostructures etched in lower H₂O₂ concentration solution is that the Ni NPs can be lasted for longer time in the etching solution with lower H₂O₂ concentration so that more silicon atoms will be oxidized and then removed for those under Ni NPs due to the hole transfer and those where uncovered by Ni NPs due to the hole diffusion.     

高超声速飞行器的非概率可靠性分析

为探究高超声速飞行器整体结构可靠性及其可靠性的影响因素，确保飞行器执行任务时的结构安全，将应力-强度干涉模型与区间数相结合，提出了子域子区间新方法分析高超声速飞行器结构强度可靠性。首先，分析高超声速飞行器在不同飞行状态下各受力面的力矩；其次，将飞行器结构近似为等效悬臂梁，考虑其所受力矩、宽度和飞行高度的不确定性，并表示为区间数；然后，考虑飞行器结构强度随时间退化，基于应力-强度干涉模型进行非概率可靠性分析，建立飞行器结构动态可靠性模型；最后，提出子域子区间法分析结构强度的指数退化特性和飞行动态对结构可靠性的影响。仿真结果表明，子域子区间法相比于传统蒙特卡罗法，在相同采样点数情况下，精确度会更高，验证了所提方法的可行性和有效性；飞行器可靠性随着飞行器结构强度指数递减而逐渐减小；飞行器的飞行动态会对结构可靠性产生主要影响，其中随着飞行高度的升高飞行器可靠性会逐渐增加，随着速度以及迎角的增大而逐渐减小。     

迷迭香天然食用抗氧化剂的研究（Ⅰ）：油脂的劣化及其防止

本文扼要论述了食用油脂的劣化现象、油脂自动氧化的机理、影响油脂劣化的因素、油脂稳定性的试验方法、油脂氧化程度的测定方法、油脂劣化的防止措施及开展迷迭香天然食用抗氧化剂研究的必要性。     

铅晶电极的制备及性能

简述了铅晶电极的制备工艺,研究了铅晶电极的性能.结果表明,与涂膏式电极相比,铅晶电极具有活性物质的晶粒较小、比表面积较大、不容易硫酸盐化和充放电性能较好等优点.     

KI—HAC体系微库仑中间体的研究及应用

本文就KI—HAC体系溶液组成、电流效率、偏置电压、电解电压以及微库仑池的结构等作了系统的研究,并应用该体系对抗坏血酸进行了测定,结果与DCPI标准方法一致。