Study on variation of smoke component concentration with water mist applying

Interaction between water mist and fire smoke is studied by experiments in an ISO 9705 room, The variation of 02, CO and CO2 concentration is disclosed, and the mathematical models of smoke component con- centration with water mist pressure and ventilation speed are established according to the experimental results. It is found in the experiment that the smoke component concentration will break when ventilation speed exceeds 1.5 kg/s. This paper provides necessary theory for water mist technology using in smoke restraining.     

纳米碳纤维/聚二甲基硅氧烷复合材料的制备及其力学性能

为制备综合力学性能优异的纳米碳纤维(CNFs)增强聚合物复合材料,利用超声分散设备,采用1.6g/L的十二烷基酸钠(SDS)对纳米碳纤维进行表面处理,制备出不同纳米碳纤维质量分数的纳米碳纤维/聚二甲基硅氧烷复合材料.SEM和复合材料拉伸结果表明SDS分散处理在一定程度上能改善碳纳米纤维与基体的界面结合和分散情况,提高复合材料的拉伸性能.当纳米碳纤维的含量在3wt%左右时,复合材料的拉伸强度达到最大.动态拉伸结果表明对CNFs的表面处理能增加复合材料在动态变形时的内摩擦,且材料的动态力学性能稳定.     

河北平原地区“双替代”农宅低碳化改造多目标优化设计

为缓解区域供能紧张现状、提升清洁取暖工作成效,基于Rhino-Grasshopper可视化编程平台,以采暖碳排放、采暖季室内热舒适、改造全局成本增量为优化目标,构建河北平原地区"双替代"农宅低碳化改造多目标优化设计模型.结果 表明:"双替代"农宅具有较大的性能优化潜力,低碳化改造后Ⅰ类农宅(燃气壁挂炉)的3项目标性能均优于Ⅱ类农宅(空气源热泵);Ⅰ类农宅最优改造方案为120 mm外墙/180 mm屋面防火蜂巢隔离保温板(EPS)+三玻双中空外窗+无吊顶,该方案可减碳91.6％、室内热舒适改善56.8％、全局成本增量-58739元;Ⅱ类农宅最优改造方案为110 mm外墙/160 mm屋面EPS保温板+三玻双中空外窗+室内无吊顶,该方案可减碳90.6％、室内热舒适改善53.6％、全局成本增量-26571元.     

生物炭农田利用领域的研究热点与趋势：基于文献计量学的可视化分析

生物炭素有“黑色黄金”之称,在农业领域得到广泛应用。为了揭示生物炭农田应用领域研究热点与发展趋势,本文利用文献计量学方法和CiteSpace软件系统梳理了该领域主要研究力量(国家、机构、作者),归纳了该领域的主要研究主题。研究发现：1)在生物炭农田利用领域,中国学者表现十分活跃,但国际影响力有待进一步加强。2)经过15年的发展,该领域涌现出大量研究热点和研究前沿,主要有(1)2007-2011年间的研究热点是生物炭的土壤改良效果,该阶段的研究前沿是污泥基生物炭的安全施用与土壤改良效果。(2)2012-2016年间的研究热点是生物炭的碳封存与温室气体减排效应,该阶段的研究前沿是温室气体的转化与减排机理。(3)2017-2021年间的研究热点是生物炭的土壤修复效果,该阶段的研究前沿是生物炭(改性生物炭、生物炭复合物等)对重金属、有机污染物的矿化/降解机理。     

考虑风筒破损对隧道施工过程中CO排出的影响机制

为研究隧道施工通风过程中风筒破损对一氧化碳(CO)排出的影响,依托城开高速鸡鸣隧道,运用孔口流量理论,考虑风筒内流速、孔口与开挖工作面距离和孔口数量3个因素,基于数值模拟方法,研究风筒破损对CO排出的影响。结果表明：在风筒破损面积相同的前提下,漏风率随送风量的增加而增大;开挖工作面处的CO浓度在通风1 min后达到峰值,约为3.5%;风筒破损会对隧道内的CO稀释产生滞后效应,滞后时间为1～3 min并且送风量越小滞后效应越明显,最终导致达到预计通风时间后距洞口约15 m范围内的CO浓度仍高于规范要求;通风长度区域内,3个因素中对CO排出的影响依次为：风筒内流速>孔口与开挖工作面距离>孔口数量;整体隧道内,影响依次为：风筒内流速>孔口与开挖工作面距离>孔口数量。并提出了通风设计和孔洞修补两方面的建议。     

Highly stretchable,sensitive and wide linear responsive fabric-based strain sensors with a self-segregated carbon nanotube (CNT)/Polydimethylsiloxane (PDMS) coating

Flexible strain sensors have received increasing attention with the development of wearable electronic devices. However, integrating wide strain detection range, high sensitivity while maintaining relatively wide linear response range for such sensor system still remain a challenge. A fabric based flexible sensor (S-CNT/PDMS-F) was designed and fabricated, and the sensor can simultaneously achieve high sensitivity, wide linear response and strain detection range by combining self-segregated carbon nanotube (CNT)/polydimethylsiloxane (PDMS) composites and elastic medical bandage. It has been observed that this new sensor system can achieve a high sensitivity with a gauge factor of 615, a large linear responsive range of 0–100% strain (R² ?= ?0.993) and a wide strain detection range of ～ 200%, which is superior to almost all the reported CNT/PDMS flexible strain sensors. Compared to the similar fabric based strain sensor system deploying non self-segregated structure (C-CNT/PDMS-F), our S-CNT/PDMS-F demonstrates higher electrical conductivity and lower electrical percolation threshold and response time of 55 ?ms, as well as more stable and repeatable performance under cyclic loading conditions. The capability of the sensors in monitoring physiological activities and weight distribution has also been demonstrated.     

碳交易市场的利益博弈问题研究 ——基于层次分析法和夏普利值法视角

Through establishing Carbon Trading Platform (Carbon Trading Alliance) in the Carbon Trading Market, each participant can benefit more from the cooperation. But, the distributing mechanism of earnings of the market nowadays has a great influence on the development of Carbon Trading Platform. Based on that, the paper firstly utilize the traditional shapley value method to distribute the cooperative earnings of the Carbon Trading Market. Then, the risking factors taken by alliance members were brought in, and the weights of risks obtained trough the method of AHP, and risking coefficient was received. At last the existing results were corrected and the final distribution results were obtained. Finally, an example is used to verify the theory above. The research results show that the allocation system, taking risking factors into account, can improve the members'' enthusiasm to participate in the Carbon Trading Platform and promote the development and improvement of the Carbon Trading Platform and the market. Therefore, the results of this paper can provide a reference for policymakers of Carbon Trading Market.