LF精炼及后道工序钢中氮、氧含量控制技术研究

论述了各种不同工艺技术对控制钢中较低氮、氧含量水平的作用.指出,LF炉采用泡沫渣工艺和连铸保护浇铸,可有效降低钢中的氮含量;采用LF炉渣洗工艺及控制钢水的浇铸温度等措施,对降低钢中的氧含量有明显的效果.     

多晶体材料晶界孔洞应力场分析

采用率相关晶体塑性模型，对于不同取向晶粒构成的三晶体在晶界处存在孔洞的应力分布情况进行有限元计算分析，结果表明在三晶交界的孔洞周围应力场呈现复杂分布规律，其应力分布与邻近晶粒的取向相关，这与采用均匀材料进行描述时是不同的。计算同时表明，相同条件下，多晶材料晶界处孔洞周围比单晶内孔洞周围的应力集中情况更加严重。     

计及灵活热负荷的综合能源服务商购电策略

作为未来综合能源系统背景下的能源零售主体,综合能源服务商需要对用户不同类型的需求响应（demand response, DR）资源进行有效调控,从而应对不同类型能源市场的价格波动风险,优化市场购电策略,降低能源购置成本。首先根据未来综合能源服务商的基本运营模式,构建了用户不同类型负荷响应特性模型;其次,针对综合能源服务商在运营过程中面临的主要不确定性因素,以其在不同类型市场中能源购置成本最小为目标,构建了计及DR资源的两阶段随机市场购电决策模型。最后通过算例仿真,验证了随机模型的有效性,分析了灵活供热负荷对综合能源服务商购电策略的影响。     

Experimental research on a modular miniaturization nanoindentation device

Nanoindentation technology is developing toward the in situ test which requires miniaturization of indentation instruments. This paper presents a miniaturization nanoindentation device based on the modular idea. It mainly consists of macro-adjusting mechanism, x-y precise positioning platform, z axis precise driving unit, and the load-depth measuring unit. The device can be assembled with different forms and has minimum dimensions of 200 mm × 135 mm × 200 mm. The load resolution is about 0.1 mN and the displacement resolution is about 10 nm. A new calibration method named the reference-mapping method is proposed to calibrate the developed device. Output performance tests and indentation experiments indicate the feasibility of the developed device and calibration method. This paper gives an example that combining piezoelectric actuators with flexure hinge to realize nanoindentation tests. Integrating a smaller displacement sensor, a more compact nanoindentation device can be designed in the future.     

Different Frequency Synchronization Theory and Its Frequency Measurement Practice Teaching Innovation Based on Lissajous Figure Method

According to the requirement of multi-parameter time and frequency measurement without frequency normalization,a different frequency synchronization theory is proposed based on Lissajous figure method and the variation law of Lissajous figure which are used in practice teaching of frequency measurement.The theory can achieve high-precision transmission and comparison of time and frequency and precise locking and tracking of phase and frequency,improve the level of scientific research on time and frequency for postgraduate,and promote practice teaching innovation of time frequency measurement for undergraduate.Utilizing the ratio of horizontal and vertical inflection point of the Lissajous figure,the nominal frequency of the measured signal is precisely calculated.The frequency deviation between the measured frequency and its nominal frequency can be obtained by combining the turning cycle of the Lissajous figure.By observing the phase relationship between the frequency standard signal and the measured signal,the accurate measurement of the frequency isimplemented.Experimental results show that the direct measurement and comparison better than the 10-11 order of magnitude with common frequency source can be fmished between any signal frequencies.The frequency measurement method based on the theory has the advantage of simple operation,quick measurement speed,small error,low noise and high measurement precision.It plays an important role in time synchronization,communications,metrology,scientific research,educational technology practice and equipment and other fields.     

基于混沌系统的椭圆曲线密码算法研究

通过Chebyshev 多项式产生的伪随机数,简化了背包密码体制,同时将背包密码体制与椭圆曲线密码体制结合,产生了一种新型椭圆曲线密码算法,通过对该算法的分析,认为算法简单,安全性高,方案可行。     

岩石高边坡安全监测及稳定性分析

针对某水电站岩石高边坡的工程实际,为了有效的控制高边坡变形和准确的指导施工,在边坡布设了多套位移计和锚杆应力计,并且进行了边坡变形和应力监测。通过大量的边坡监测资料,并且结合变形、地质、开挖等因素,分析了边坡变形特征及锚杆的锚固效果,监测数据的分析主要采用回归方法进行。监测数据表明,边坡的锚固效果良好,边坡的变形得到了有效的控制。通过此岩石高边坡工程的施工监测,阐明信息化施工可以保证边坡的稳定性,正确指导施工。     

锻模热负荷参数的工程计算方法

对锻模热负荷参数的表征与计算进行了研究,选用热强度系数描述锻模材料的抗热损伤能力,回火系数描述锻模材料的热程度,热载系数描述锻模材料的热疲劳程度,应用传热学和热弹塑性理论,推导出了上述热负荷参数的计算公式。并针对锻模的实际使用和损伤情况,利用频谱弹塑性理论,推导出了上述热负荷参数的计算公式。并针对锻模的实际使用和损伤情况,利用频谱分析方法,确立了锻模热负荷参数的工程计算方法。应用该方法,分析研究了几种典型锻模的热负荷状况,计算结果与有限元分析结果相一致,并与统计规律相吻合,能够满足工程需要。     

大型柔性卫星平台的变结构姿态控制

首先利用拉各朗日方程建立了大型柔性卫星的动力学方程，对该动力学方程进行了线性化，并且为了以后设计变结构控制器的需要，设计了状态观测器，然后设计了变结构控制器．在设计过程中，充分考虑了实际工程要求，采用了边界层方法来削弱变结构控制器的抖振，同时考虑了执行机构控制输出受限的情况，采取了利用4个偏置动量轮系统组成三轴零动量飞轮系统对卫星平台进行姿态控制．最后通过数学仿真证明了所设计的控制器的有效性．