毛细滴管-吸量管数滴微型滴定法现场快速测定水的总硬度

毛细滴管-吸量管数滴微型滴定法以自制的液滴体积为0.01～0.02 mL的聚乙烯毛细滴管和5～10 mL吸量管为量器进行滴定,具有仪器简单,滴定快速、准确,试剂消耗量少的特点.不确定度理论证明,用该法测定水的总硬度,相对扩展不确定度Urel(C)约为0.86%;试验结果表明,当滴定剂用量为80～110滴时,回收率为98.8%～101%,RSD为0.36%～0.79%.该法克服了常量法中滴定管、移液管、铁架台和蝴蝶夹等仪器携带不方便的不足,适用于工业用水现场和野外水质的快速分析.     

Power Allocation for NOMA in D2D Relay Communications

Non-orthogonal multiple access(NOMA)is considered as one of the key technologies for the fifth generation(5G)wireless communications.The integration of NOMA and device-to-device(D2D)communications has recently attracted wide attention.In this paper,a relaying D2D communications assisted with cooperative relaying systems using NOMA(DRC-NOMA)is considered.We analyze the ergodic sum-rate for the proposed system and then derive the closed-form expressions.In addition,an optimal power allocation strategy maximizing the ergodic sum-rate is proposed based on these analysis results.Numerical results show the good agreement between the results of analysis and Monte Carlo method.The proposed DRC-NOMA has a great improvement of the ergodic sum-rate in the small regime of average channel gain of D2D pair.     

大直径软岩嵌岩桩侧阻性状实测分析

嵌岩桩的侧摩阻力发挥不但与桩端支承与桩周土性有关,同时还受其他众多因素影响。根据同一场地桩周土性差异不大,而桩底岩土强度有较明显区别的两根达极限承载状态的嵌岩桩试桩资料,分析桩周土侧阻发挥过程。结果表明:对于长径比较大的嵌岩桩,桩周土极限侧阻大小随桩端支承条件不同而改变,且侧阻沿桩身分布呈现两头大中间小的特点,此外上部土层对桩身中部土层的侧阻发挥有一定的影响。     

浸渍树脂快速与自然老化试验对应关系

随着FRP加固结构的广泛应用,其耐久性问题也日益突出并受到关注。浸渍树脂作为复合材料的原料之一以及FRP与结构的粘结材料,其耐久性直接影响FRP加固结构的效果。通过对两种浸渍树脂进行快速老化和自然老化试验,在试验的基础上分析并计算了二者的对应关系。结果表明,树脂在自然环境中受各种老化因素共同的作用要比单一因素作用大得多。     

海水对树脂耐久性影响的分析

研究了海水腐蚀环境对树脂基本力学性能的影响。将两种树脂各25个试件置于实验室条件下的海水腐蚀环境中老化,其间每隔一定时间做拉伸试验,得到两种树脂的强度、弹性模量和伸长率对时间的变化规律,在此基础上经过拟合得到树脂的强度模型并提出强度公式。试验结果表明,海水腐蚀环境对树脂的影响比较大。     

海水对CFRP-混凝土界面影响的试验

主要研究了海水腐蚀环境对CFRP-混凝土界面的基本力学性能的影响。通过面内单剪试验,研究了粘贴碳纤维布的拉剪试块在不同工况下的界面性能,通过对比分析,得到了海水腐蚀环境下界面性能的变化规律。     

榴莲芒果风味果酒酿制

根据榴莲、芒果的香味和风味特点,以榴莲和芒果双果发酵得到榴莲芒果原酒,并采用白酒浸泡榴莲和芒果得到浸泡榴莲芒果原酒,然后对两者进行调配,酿造出品质上乘的榴莲芒果果酒.并对酿制工艺流程及操作条件作了探讨.     

小型地下某金矿危险程度评价系统的分析研究

根据地下金矿的特点,并通过对地下金矿危险有害因素的分析．建立了地下金矿评价指标体系及安全评价模型。对于快速跟踪和准确地预测地下金矿危险程度．提高安全评价的效率和及时提出合理的安全对策措施将发挥作用。     

Preform permeability predictions by self-consistent method and finite element simulation

The self-consistent method and finite element simulations have been used to estimate the permeability of an aligned fiber bundle. The self-consistent method gives out formulas for both longitudinal and transverse permeabilities as functions of the fiber volume fraction. The finite element simulation presents the solutions of various periodic fiber packings. The results for square and hexagonal fiber packings are found coincident with the literature results. It is shown that the permeability is not only related to the fiber volume fraction of porosity, but is also greatly influenced by the packing structure or micro-level disturbance. A unified empirical model is proposed, which uses as variables ultimate fiber volume fraction in addition to fiber volume fraction. The model predications agree with numerical simulation results in different cases.     

一起主变微机差动保护误动情况的调查分析

对一起主变微机保护差动误动的事故进行调查,分析其原因并提出解决的方法。