活性炭粉末电极电容除盐与膜电容除盐对比

为研究电容法除盐技术(CDI)与膜电容法除盐技术(MCDI)除盐效果的差异,获得具有较优除盐特性的电除盐体系,选用成本较低的活性碳粉末作为电容法除盐体系的电极材料,研究CDI与MCDI对不同质量浓度盐水的处理效果．结果表明,随着处理盐溶液质量浓度的提高,CDI与MCDI的电吸附量均有提高,且MCDI电吸附效果的优势更为明显. 当盐水质量浓度由0.05 g／L上升到0.5 g／L时,MCDI的电吸附量由99.4 μmol／g升至694.4 μmol／g,而CDI的电吸附量仅由80.3 μmol／g变化至135.7 μmol／g．     

不同温度下AZ31镁合金绝热剪切变形局域化

为了了解镁合金在不同温度高应变率载荷作用下发生变形局域化的特点,进而揭示镁合金在高速冲击载荷作用下发生绝热剪切的特殊规律,采用分离式Hopkinson压杆对挤压态AZ31镁合金进行了常温及高温的高速冲击压缩试验,而后对不同温度冲击后的试样通过光学显微镜、扫描电镜和透射电镜进行变形机制的分析.结果表明:常温下试样在受到剪切力后,在剪切区的裂纹周围产生了大量的孪晶;高温下试样的剪切区内产生了明显的绝热剪切带,并且在剪切带周围发现了大量平行的孪晶.在TEM下观察到剪切带内为等轴晶晶粒,在剪切区内发生了动态再结晶过程.     

高压同步电动机异步全压启动的建模与仿真

高压同步电动机异步全压启动是一种简单经济的启动方法.基于同步电动机的Park方程数学模型,建立了标幺值和有名值混合形式下同步电动机的状态方程组.利用Matlab编写了异步全压启动程序,并采用四阶龙格库塔法求解微分方程组,克服了Simulink建模存在的过程复杂、计算精度低、仿真时间长等缺点.此外,案例分析的仿真曲线表明了本文方法的正确有效性.     

超高频RFID标签命令头解析模块设计

该文针对超高频RFIDISO 18000-6C标准,分析了移位寄存器解析方案的冗余状态,提出了采用有限状态机优化超高频RFID标签命令头解析面积的方法。采用Verilog HDL,通过设置6组命令,进行了常用方案和新提出方案逻辑门数量的对比,从而反应出标签芯片电路面积的变化。实验结果表明,当指令数量在12 32条之间时,用有限状态机解析命令头的电路面积比用移位寄存器解析的面积小15%33%。     

Atmospheric CO2 retrieval with a look-up-table based method by combining near and thermal infrared spectra

In order to precisely retrieve the atmospheric CO2 , a retrieval method based on both near infrared （NIR） and thermal infrared （TIR） is established firstly. Then a look-up-table （LUT） based fast line-by-line radiative transfer model （RTM） was integrated into the retrieval procedure to accelerate radiative transfer calculations. The LUT stores gas absorption cross-sections as a function of temperature, pressure and wavenumber. It could greatly reduce calculating time in radiative transfer compared to direct line-by-line method. Then retrieval was simulated using NIR, TIR and both bands. The retrieved CO2 profiles suggest joint approach could reconstruct CO2 profile better than those using NIR or TIR alone. Joint retrieval using both bands simultaneously could provide better constrain to CO2 vertical distribution in the whole troposphere.     

W型辐射管的燃烧优化以及流固耦合分析方法研究

采用Fluent软件模拟W型辐射管内部流体的燃烧状况,在不同空气过剩系数、不同燃气流量以及不同空气预热温度工况下,对辐射管内燃烧流场进行了数值模拟,得出合理可行的空气过剩系数、燃气流量和空气预热温度.在此基础上通过流固耦合分析求出辐射管的结构变形及应力分布.比较全面地对辐射管进行了分析,对类似问题具有一定的参考价值.     

求解梁大变形问题的一种精细分析方法

在梁发生大变形后的平衡位置取一微段进行分析,从变形前后的几何关系与变形后的平衡方程出发建立计算模型,推导出求解梁大变形问题的一阶控制微分方程组,为处理梁大挠度变形问题提供了一种新的半数值半解析算法．为保证求解的精确与稳定,文中采用精细积分法与增量优化迭代的方法求解该一阶控制微分方程组．数值算例结果表明,本文的计算模型与求解方法精度高,稳定性好．     

燃煤火力电厂脱硫废水零排放可行性研究

燃煤电厂脱硫废水因高含盐量、成分复杂、高腐蚀性、回用困难的特点成为制约燃煤电厂废水零排放的关键因素。三种脱硫废水零排放可行性技术方案,通过对比工艺流程、经济指标和占地因素等指标,发现熟石灰、碳酸钠两级软化＋卧式MVC蒸发浓缩＋卧式MVC蒸发结晶是最优方案,可获得高品质工业盐再利用,作为未来基建项目脱硫废水零排放系统工艺方案。     

Correspondence of bubble size and frother partitioning in flotation

The size of bubbles created in the flotation process is of great importance to the efficiency of the mineral separation achieved. Meanwhile, it is believed that frother transport between phases is perhaps the most important reason for the interactive nature of the phenomena occurring in the bulk and froth phases in flotation, as frother adsorbed in the surface of rising bubbles is removed from the bulk phase and then released into the froth as a fraction of the bubbles burst. This causes the increased concentration in the froth compared to the bulk concentration, named as frother partitioning. Partitioning reflects the adsorption of frother on bubbles and how to influence bubble size is not known. There currently exists no such a topic aiming to link these two key parameters. To fill this vacancy, the correspondence between bubble size and frother partitioning was examined. Bubble size was measured by sampling-for-imaging （SFI） technique. Using total organic carbon （TOC） analysis to measure the frother partitioning between froth and bulk phases was determined. Measurements have shown, with no exceptions including four different frothers, higher frother concentration is in the bulk than in the froth. The results also show strong partitioning giving an increase in bubble size which implies there is a compelling relationship between these two, represented byCFroth/CBulk andD32. TheCFroth/CBulk andD32 curves show similar exponential decay relationships as a function of added frother in the system, strongly suggesting that the frother concentration gradient between the bulk solution and the bubble interface is the driving force contributing to bubble size reduction.     

Microstructure and properties of electronic packaging shell with high silicon carbide aluminum-base composites by semi-solid thixoforming

The electronic packaging shell with high silicon carbide aluminum-base composites was prepared by semi-solid thixoforming technique. The flow characteristic of the Si C particulate was analyzed. The microstructures of different parts of the shell were observed by scanning electron microscopy and optical microscopy, and the thermophysical and mechanical properties of the shell were tested. The results show that there exists the segregation phenomenon between the Si C particulate and the liquid phase during thixoforming, the liquid phase flows from the shell, and the Si C particles accumulate at the bottom of the shell. The volume fraction of Si C decreases gradually from the bottom to the walls. Accordingly, the thermal conductivities of bottom center and walls are 178 and 164 W·m-1·K-1, the coefficients of thermal expansion（CTE） are 8.2×10-6 and 12.6×10-6 K-1, respectively. The flexural strength decreases slightly from 437 to 347 MPa. The microstructures and properties of the shell show gradient distribution.