木材固碳量与含碳率研究进展

木材碳学是近年来兴起的一门科学, 其主要研究内容包括木材碳素的储存量、木材储能、人工林木材固碳增汇与优质木材培育技术及木质产品固碳延伸等方面。文中简述了木材碳学研究中木材固碳量与含碳率、木材固碳量的影响因素、木材固碳量与木材热值的关系以及木质材料固碳量和固碳延伸等方面的研究现状, 并对今后的研究方向进行了展望。     

基于Ansys的泥浆泵连杆的有限元分析

运用刚体平面运动学理论对泥浆泵动力端进行受力分析,结合PROE、ANSYS建立了连杆的几何模型和有限元模型,重点讨论了连杆大、小头载荷和惯性力的处理方法,给出了加载方程及其计算过程,并使用APDL语言实现了复杂载荷的程序化加载。在此基础上,运用有限元理论对连杆进行了静力学分析,得到了连杆在在典型工况下的应力状态及其危险部位,为进一步对曲轴连杆的设计和改进提供了可靠依据。     

网络环境下实行人机结合混合式大学英语教学探析

本文分析了网络环境下大学英语教学面临的困境,论述了混合式英语教学的内涵、理论基础和实行人机结合混合式英语教学的作用。     

Ballistic 2-d imaging through scattering walls using an ultrafast optical kerr gate

An ultrafast optical shutter was used to image ultrasmall objects hidden behind scattering walls by a procedure that selects in time the ballistic component and rejects the scattered diffusive light. Scattering walls used in this experiment included human breast tissue, chicken breast tissue, and a water suspension of polystyrene particles with scattering coefficients up to 21.7. Submillimeter resolution was achieved for two-dimensional ballistic images of a single point, a double-point fluorescence source, and a bar test chart in or behind these different turbid media.     

Calculation Method of Hydraulic Characteristics for Direct-Return Chilled Water System

In order to optimize design and operation, it is necessary to calculate accurately hydraulic characteristics large central air-conditioning systems. Simplified Model can not be applied to hydraulic calculation of large pipe network topological structure for its large calculation error. Taking into account the regulating characteristics of terminal branch temperature regulating valve, a direct-return chilled water system is studied, an accurate mathematical model of pipe network hydraulic characteristics has been established and a computer logic algorithm with virtual flow has been given. A direct-return pipe network with ten AHU branches is used as simulation calculation object, the pipe network supply-return water pressure difference is calculated, and also the temperature regulating valve opening and actual flow of each branch are calculated in the condition of different supply-return water pressure difference. The calculated results accord with the natural characteristics of high pressure difference unbalanced for direct-return pipe network. The calculation method can ensure calculation convergence.     

林草措施在西北地区水土保持中的作用及实施探讨

依据西北地区的自然条件,阐述了开展林草措施的重要性及在水土保持中的作用,提出了林草措施实施当中应当注意的问题及解决方案。     

玉米收获机发展现状、存在问题及解决途径

本文通过分析国内外玉米收获机的现状、提出了解决问题的途径.     

南帕斯凝析油卸船的安全措施

针对南帕斯凝析油接卸作业过程中易产生较高含量有毒气体的问题,分析了凝析油的基本性质和硫化物分布情况,以识别其有毒气体成分.描述了接卸作业前和码头接卸作业两个阶段的注意事项:接卸作业前应对各个作业环节进行风险识别,制定应急方案,并确保设备完整;码头接卸作业前先进行作业准备,划定作业警戒区且保证消防通道畅通,接卸作业时,持续进行硫化氢检测,接卸作业后,及时对管道进行置换.最后,指出检尺口和卸船舱口为主要泄漏风险部位,提出了解决措施.     

双胍盐对柑桔青霉病防治效果试验

两年的抑菌、刻伤接种和果实贮藏试验表明,双胍盐对柑桔青霉病的防治效果与伊迈唑相接近,可作为苯并咪唑类的替换药剂。