脉状矿床开采维护矿山整体稳定性的一般原则和方法

含金石英脉群类型的矿床，当采深达到一定程度而采空区又未进行适当处理时，矿山的整体稳定性应予以充分注意。可采取的措施和方法有：在采矿设计中，尽量改善采场围岩的应力环境；为防止岩移“突破口”的形成，处于某些关键部位的采场，应适当进行支护、充填或加固。     

基于间歇测量的状态估计稳定性和精度研究*

针对分布式控制系统状态估计过程出现的测量值丢失问题,本文量化分析测量值丢失对估计稳定性和精度的影响。首先,根据随机测量模型重新推导带测量值丢失的卡尔曼滤波器,得到估计误差协方差迭代式。然后,将随机误差协方差迭代式建模为修正的黎卡提微分方程,提出了估计稳定性和精度分析方法。最后,列举不同的系统实例,证明临界包到达率的存在性,当测量值到达率大于临界值时,平均误差协方差从发散过渡到有界,进而得到估计精度与包达率之间的函数关系。     

An automatic parameter calibration method for the SWAT model in runoff simulation

Runoff simulation is highly significant for hydrological monitoring, flood peak simulation, water resource management, and basin protection. Runoff simulation by distributed hydrological models, such as the soil and water assessment tool (SWAT) model which is the most widely used, is becoming a hotspot for hydrological forecasting research. However, parameter calibration is inefficient and inaccurate for the SWAT model. An automatic parameter calibration (APC) method of the SWAT model was developed by hybrid of the genetic algorithm (GA) and particle swarm optimization (PSO). Multi‐station and multi‐period runoff simulation and accuracy analysis were conducted in the basin of the Zhangjiang River on the basis of this hybrid algorithm. For example, in the Yaoxiaba Station, the calibration results produced an R² of 0.87 and Nash Sutcliffe efficiency (NSE) index of 0.85, while verification results revealed an R² of 0.83 and NSE of 0.83. Results of this study show that the proposed method can effectively improve the efficiency and simulation accuracy of the model parameters. It can be concluded that the feasibility and applicability of GA‐PSO as an APC method for the SWAT model were confirmed via case studies. The proposed method can provide theoretical guidance for many hydrological research fields, such as hydrological simulation, flood prevention, and forecasting.     

EDA技术的应用型本科教学模式的分析与设计

从理论教学和实训要求出发,分析了现阶段EDA课程设置的现状及问题,提出了基于FPGA技术的EDA应用型本科教学模式.首先从该模式的设计思路出发,设计了基于FPGA技术的EDA应用型教学模式的教学设计及实训设计,并对比分析该教学模式与传统模式在教学过程中取得的效果.实践证明,将基于FPGA技术的EDA应用型教学模式运用于EDA课程教学可以有效提高课堂教学效果,值得推广与应用.     

用失效的C－Pd催化剂生产氯化钯

介绍了用锌镁粉直接还原与处理失效废弃的Ｃ－Ｐｄ催化剂，并用自制混酸直接生产氯化钯的工艺。该工艺比传统的铝粉置换法更快捷，钯收率更高。     

Guaranteeing hard real-time traffic with legitimately short deadlines with the timed token protocol

Synchronous bandwidth, defined as the maximum time a node is allowed to send its synchronous messages while holding the token, is a sensitive parameter for deadline guarantees of synchronous messages in any timed token network. In order to offer such guarantees, synchronous bandwidth has to be allocated carefully to each individual node. This paper studies the synchronous bandwidth allocated to those synchronous message streams whose deadlines are less than twice the Target Token Rotation Time (TTRT). A new approach for allocating synchronous bandwidth to such streams, which can be used with any previously published local synchronous bandwidth allocation (SBA) for guaranteeing a general synchronous message set with its minimum deadline (D_min) no less than 2 · TTRT, is proposed. The proposed scheme can be applied efficiently in practice to any general synchronous message set with D_min > TTRT. Numerical examples are presented to demonstrate the enhanced performance of this new local scheme over any of the previously published local SBA schemes.     

热处理对铁素体不锈钢组织和性能的影响

研究了不同热处理工艺对铁素体不锈钢的组织与性能的影响.结果表明 铁素体不锈钢固溶处理时,温度在900 ℃以下组织无明显变化,其硬度随着温度的上升变化缓慢;900 ℃左右发生再结晶,硬度显著降低;在475 ℃热处理后析出物增多,硬度增加,耐腐蚀性能严重下降,即有明显475 ℃脆性现象.     

C194铜合金的强化机制研究

为了研究C194铜合金的强化机制，对比分析了两种成分略有不同的C194铜合金带材的力学性能及其微观组织。研究发现C194合金组织中的析出相包括α—Fe和Fe3P两种，其中α—Fe是C194铜合金的主要强化相，而不是Fe3P。如果合金中P含量较高，则多余的P与合金元素Fe结合形成金属间化合物Fe3P，并以粗大颗粒形式析出，这将导致起主要强化作用的α-Fe相数量减少，从而使材料强度降低，同时由于P对合金的导电、导热性能均有显著影响，对材料综合性能不利，因此在生产中应严格控制P的含量，且尽量取下限，抑制Fe3P的形成和析出，促进α-Fe在时效过程的弥散析出，从而达到理想的强化效果。     

抚顺西露天矿北帮地面长期剧烈变形原因的分析

抚顺矿区西部煤田为井工矿与露天矿联合开采方式。自70年代末期开始，地面变形持续增大，由此造成周边工厂及各种建筑设施受到严重破坏。到目前为止，国家及相关企业已投资几亿元用于控制变形的发展及相应的安全保护措施。该文将综合分析各个影响因素的作用特点及其在变形中所起的作用，最终归纳出地面长期剧烈变形的主导性因素，以便为该类矿山的后续开采提供参考依据，同时为确保周边安全提供决策依据。     

一种用于水基压裂液伤害性评价的型煤制备方法

目前对于水基压裂液伤害性评价的方法主要是针对碎屑岩,没有专门针对煤的评价方法,就其原因在于难以制备实验用的煤心,也没有统一的制样方法。由于部分煤样裂缝发育、结构疏松难以制成柱塞样品最终导致伤害实验无法完成。因此,在大量实验的基础上我们采用四步制样法挑选出粒度为40目~70目的煤样,用30 MPa~40MPa的制样压力将煤样压制成型煤煤心,并利用热收缩管和导流垫块对煤心封装成形。通过该方法制备成的型煤煤心既克服了以往样品装卸困难,也保证了实验的重复性和数据的可考性,用该方法制备的型煤煤心已成功应用于水基压裂液对煤层伤害性评价。