缆机吊重海量监测数据的吊运混凝土模式识别

海量实时监测数据为缆机实际运行效率分析和工程现场调度优化提供了直接和可靠的研究基础。如何从庞杂的海量数据中准确快速地识别缆机的工作状态和吊运任务,从而提取吊运工作循环,是分析缆机吊运混凝土工作效率的关键问题。本文提出一种基于缆机吊重时序特征的吊运混凝土模式识别方法,以吊重的时序变化特征和状态区间平均吊重值定义缆机起吊、重载运行等工作状态,以工作状态的时序变化特征定义吊运混凝土模式;提取吊重参数的统计规律,定义模式识别标准模板,提出了“状态相似判别加状态罚函数”的吊运混凝土模式识别模型。针对两种特殊情况,即受大风或加速度影响造成缆索摆动时的吊重监测数据“假波动”,和缆机提升或卸料过程中意外停顿造成吊重的“假稳定”,本文构建了一种“孤点判别+多次迭代”的方法,修正状态识别结果。模型应用及工程实测数据分析表明,该模型能够快速准确地识别缆机工作模式、判别缆机吊运混凝土各工作状态的起止点、状态值和平均吊重,为缆机实际运行效率分析和调度优化等提供重要支撑。

寒地办公建筑夹层空间自然采光性能参数化模拟研究

自然采光对提升建筑室内光舒适、降低建筑能耗有重要作用。设有夹层的开放办公空间灵活性强、面积利用率高,空间自然采光状况较为复杂。为研究夹层空间形态对室内自然采光性能的影响,本文以全年有效天然采光照度(UDI_(100-2000))和全天然采光百分比(DA450)为自然采光性能评价指标,基于grasshopper参数化平台,应用Radiance和Daysim展开自然采光性能参数化模拟实验,分析夹层布局位置、夹层面积占比、夹层退窗比例等设计参量对室内自然采光性能的影响,为自然采光性能导向下的开放办公建筑夹层空间设计与改造提供理论和技术支持。实验结果表明:不同的夹层位置对夹层上下空间自然采光性能影响差异较大,南侧夹层布置方式更有利于提高室内UDI_(100-2000)水平,东西侧夹层布置方式下的DA450相对更高;夹层面积的提高会对室内自然采光性能产生不利影响,而夹层面积占比为50%时,夹层的UDI_(100-2000)水平最高;适当提高夹层退离窗的距离有利于改善夹层空间的UDI_(100-2000)水平,夹层退窗比例达到10%~20%时为相对最优。

Salinity effect on the compaction behaviour,matric suction,stiffness and microstructure of a silty soil

To better understand the salinity effect on the compaction behaviour of soil,standard Proctor compaction test was conducted on soil samples with different salinities.Matric suction and small-strain shear modulus,G_(max),were determined and pore size distribution was also investigated on samples statically compacted at different water contents.Results showed that with the decrease of soil salinity from initial value of 2.1‰(g of salt/kg of dry soil)to zero,the maximum dry density increased and the optimum water content decreased,whereas there was no significant change with the increase of soil salinity from 2.1‰ to 6.76‰.Interestingly,it was observed that G_(max) also decreased when the soil salinity decreased from initial value of 2.1‰ to zero and kept almost constant when the soil salinity increased from 2.1‰ to 6.76‰,for dry samples with similar matric suction and also for samples compacted at optimum state and on wet side whose matric suctions were slightly different due to the difference in remoulded water content.Furthermore,the effect of salinity on compaction behaviour and G_(max) decreased for samples compacted from dry side to wet side.The pore size distribution exhibited bi-modal characteristics with two populations of micro-and macro-pores not only for samples compacted on dry side and at optimum state,but also for those compacted on wet side.Further examination showed that the modal size of micro-pores shifted to lower values and that of macro-pores shifted to higher values for saline soil compared to the soil without salt.

Determining osmotic suction through electrical conductivity for unsaturated low-plasticity soils

Determining osmotic suction from the electrical conductivity(EC)of soil pore water was widely reported in the literature.However,while dealing with unsaturated soils,they do not have enough soil pore water to be extracted for a reliable measurement of EC.In this paper,the chilled-mirror dew-point hygrometer and contact filter paper method were used to determine the total and matric suctions for low-plasticity soils with different salinities(0.05‰,2.1‰,and 6.76‰).A new piecewise function was proposed to calculate the osmotic suction,with the piecewise point corresponding to the first occurrence of precipitated salt in mixed salt solutions(synthetic seawater).EC,ion and salt concentrations used for osmotic suction calculation were transformed from the established relationships of mixed salt solution instead of experimental measurement.The calculated osmotic suction by the proposed equation and the equations in the literature was compared with the indirectly measured one(the difference between the measured total and matric suctions).Results showed that the calculated osmotic suction,especially the one calculated using the proposed function,was in fair agreement with the indirectly measured data(especially for specimens with higher salinity of 6.76‰),suggesting that the transformation of EC and concentrations from the established relationship is a good alternative to direct measurement for lowplasticity soil.In particular,the proposed method could be applied to unsaturated low-plasticity soils which do not have enough soil pore water for a proper EC measurement.

RhIr@MoS2 nanohybrids based disposable microsensor for the point-of-care testing of NADH in real human serum

Dihydronicotinamide adenine dinucleotide(NADH)is an important enzyme in all living cells,which is found to be abnormally expressed in cancer cells.Since it is redox-active,an electrochemical detection method would be suitable for monitoring its concentration in biological fluids.Here we present a strategy for specific determination of NADH in real human serum by using RhIr@MoS2 nanohybrids based microsensor.To implement the protocol,RhIr nanocrysrals are in-situ grown onto MoS2 interlayers forming a nanohybrid structure(RhIr@MoS2).After being locally deposited on an electrochemical microsensor,it could be used for the analysis of NADH.The developed RhIr@MoS2 nanohybrids based microsensor possesses the ability for analyzing NADH at the applied potential of 0.07 V(much lower than most reported values).The detection limit is evaluated as low as 1 nmol/L even in bovine serum albumin(BSA)media.In addition,the sampling analysis of human serum from cancer patients and health controls shows that the microsensor displays good diagnostic sensitivity and specificity,illustrating that this developed detection technique is a relatively accurate method for measuring NADH in biological fluids.The proposed electrochemical microsensor assay also owns the benefits of convenience,disposable and easy processing,which make it a great possibility for future point-of-care cancer diagnosis.