新型人工天空半球内表面亮度分布的理论

针对旧式人工天空半球内表面亮度分布不合理的现象，提出一种新型人工天空半球的构造方法，并从理论上加以论证。在新型人工天空半球内 ，用均匀扩散透射材料形成环形散射光源，从天顶到地平线依次贴上反光系数递减的材料，可使人工天空半球内表面亮度分布与全阴天的真空天空亮度分布一致。这对于改进现有人工天空半球的亮度分布，提高模型测量采光系数的真实性和准确性，以及模拟不同地区气候散射光环境都有实际意义。     

Approaching strain limit of two-dimensional MoS2 via chalcogenide substitution

Strain engineering is a promising method for tuning the electronic properties of two-dimensional (2D)materials,which are capable of sustaining enormous strain t...     

夏季阴天户外空间表面温度测试及分析

以我国东南沿海某居住小区为研究对象．用红外非接触测温技术测试夏季阴天户外空间周围建筑物各立面温度分布和变化，以及常用的水泥和草地地面在有或无遮挡时的温度变化．用气候监测仪测试全天太阳辐射、空气温度和相对湿度、风速和风向．了解居住小区多种热环境因素的变化．通过测试结果分析，为居住小区户外空间的热环境设计提出相应建议．     

海南不同区域槟榔根际土壤细菌多样性研究

为了解海南省不同区域槟榔根际土壤细菌多样性,采用Illumina MiSeq高通量测序技 术分析了海南省3个槟榔主产区（万宁、陵水、三亚）的槟榔根际土壤细菌群落组成和多样性特征。 由3个地区共获得4 989个细菌操作分类单元（Operational Taxonomic Units,OTUs）,隶属于33门770 属,优势属为伯克霍尔德菌属（Burkholderia）和肠杆菌属（Enterobacter）,相对丰度分别为10.94%～ 46.96%和12.16%～28.14%;陵水地区槟榔根际土壤细菌shannon指数为3.11,高于万宁（2.41）和三 亚（2.07）地区。3个地区在属水平上共有的槟榔根际土壤细菌核心菌属有431个,主要核心菌属为 伯克霍尔德菌属、肠杆菌属和假单胞菌属（Pseudomonas）,分别占总核心菌属的23.40%、17.70%和 11.90%。通过3个两两组间差异分析发现万宁和陵水地区的槟榔根际土壤细菌中伯克霍尔德菌 属、芽孢杆菌属（Bacillus）和假单胞菌属的相对丰度具有显著差异（P < 0.05）,万宁和三亚地区的伯 克霍尔德菌属、肠杆菌属和假单胞菌属的相对丰度具有显著差异（P < 0.05）,陵水和三亚地区的肠 杆菌属和假单胞菌属的相对丰度具有显著差异（P < 0.05）。对3个地区槟榔根际土壤细菌群落中 相对丰度排在前50位的属进行单因素网络分析,结果显示Micropepsaceae、Subgroup-6和独活假丝 酵母属（Candidatus Solibacter）在根系互作网络中与其他细菌类群有密切的互作。研究结果为进一 步研究槟榔根际土壤微生物互作奠定了基础。     

Morning and evening peaks of activity rely on different clock neurons of the Drosophila brain

In Drosophila, a 'clock' situated in the brain controls circadian rhythms of locomotor activity. This clock relies on several groups of neurons that express the Period (PER) protein, including the ventral lateral neurons (LN(v)s), which express the Pigment-dispersing factor (PDF) neuropeptide, and the PDF-negative dorsal lateral neurons (LN(d)s). In normal cycles of day and night, adult flies exhibit morning and evening peaks of activity; however, the contribution of the different clock neurons to the rest-activity pattern remains unknown. Here, we have used targeted expression of PER to restore the clock function of specific subsets of lateral neurons in arrhythmic per(0) mutant flies. We show that PER expression restricted to the LN(v)s only restores the morning activity, whereas expression of PER in both the LN(v)s and LN(d)s also restores the evening activity. This provides the first neuronal bases for 'morning' and 'evening' oscillators in the Drosophila brain. Furthermore, we show that the LN(v)s alone can generate 24 h activity rhythms in constant darkness, indicating that the morning oscillator is sufficient to drive the circadian system.     

环形荧光灯照度计算的理论与实验研究

对环形荧光灯照度计算进行研究，提出一种简单而有效的计算方法－－转换法，通过建立数学模型，得出环形荧光灯对任一平面上任一处直射照度计算公式，并用实验验证该方法和计算公式的正确性，为工程的设计计算提供了方便。     

悬臂式掘进机恒功率变频调速控制器的设计

针对悬臂式掘进机在矿井掘进时情况复杂和负载变化较大的特点,采用高度非线性识别能力的神经网络与遗传算法相融合的方法,实现悬臂式掘进机恒功率变频调速系统的控制.该方法运用遗传算法训练BP神经网络的连接权系数,改进网络性能,提高学习效率,根据系统电流的实际情况对掘进机进行变频调速控制,利用MATLAB/Simulink软件对系统进行仿真分析.结果表明：该方法所设计的以DSP为控制核心的掘进机恒功率调速控制器具有一定的学习和适应能力,能根据电流变化自动调整电机的转速,实现了掘进机恒功率变频调速,提高了掘进机的工作效率和系统的稳定性.     

改进架空屋面隔热效果的理论与实践

提出一种用大量实验数据进行充分验证的全新的隔热层构造设计方案，其隔热效果显著，现场实施方便，并考虑到对现有屋面的改进，具有广泛的推广前景．     

5%草酸介质中5-氨基苯并咪唑对碳钢的缓蚀机理研究

铁路货运作为基础运输的重要方式,目前零部件清洗常用偏酸性清洗剂除垢,易产生酸蚀,影响车辆运行安全。为提高货车零部件使用寿命,对货车零部件用钢进行了全面的腐蚀机理分析。通过腐蚀失重测试、电化学阻抗谱(electrochemical impedance spectroscopy, EIS)实验、理论计算及分子动力学计算等方法,全面研究了货车零部件用碳钢(45#钢)在不同浓度5-氨基苯并咪唑5%草酸溶液中的腐蚀行为。结果表明：5-氨基苯并咪唑浓度越高对45#钢的保护作用越强。为减缓货车零部件腐蚀,可在清洗零部件时适度加入缓蚀剂,增加其缓蚀性能。     

Distributed Event-Triggered Tracking Control of Heterogeneous Discrete-Time Multi-Agent Systems with Unknown Parameters

In this paper, a novel design framework is developed to solve the cooperative tracking problem of heterogeneous discrete-time multi-agent systems with unknown agent parameters and directed communication topologies. First, a distributed event-triggered observer is developed to handle the heterogeneity of the multi-agent systems. An event-triggering mechanism is proposed to reduce the amount of data transmission between neighboring agents. Then, based on the proposed observer, a discrete-time distributed model reference adaptive controller is presented to deal with the unknown parameters of the multi-agent systems. It is shown that by using the proposed observer and the model reference adaptive controller, the proposed design framework could achieve output tracking of the unknown multi-agent systems for any communication graph containing a directed spanning tree. Finally, an example is presented to illustrate the effectiveness of the proposed controller.