Water-resistant organic thermoelectric generator with >10μW output

Flexible p–n thermoelectric generator(TEG)technology has rapidly advanced with power enhancement and size reduction.To achieve a stable power supply and highly efficient energy conversion,absolute chemical stability of n-type materials is essential to ensuring large temperature differences between device terminals and ambient stability.With the aim of improving the long-term stability of the n-type operation of carbon nanotubes(CNTs)in air and water,this study uses cationic surfactants,such as octylene-1,8-bis(dimethyldodecylammonium bromide)(12-8-12),a gemini surfactant,to stabilize the nanotubes in a coating,which retains the n-doped state for more than 28 days after exposure to air and water in experiments.TEGs with 10 p-n units of 12-8-12/CNT(n-type)and sodium dodecylbenzene sulfonate/CNT(p-type)layers are manufactured,and their water stability is evaluated.The initial maximum output of 16.1μW(75 K temperature difference)is retained after water immersion for 40 days without using a sealant to prevent TEG module degradation.The excellent stability of these CNT-based TEGs makes them suitable for underwater applications,such as battery-free health monitoring and information gathering systems,and facilitates the development of soft electronics.

Discrimination conditions and process of water-resistant key strata

Water-preservation mining is one of the most important parts of the ‘Green Mining' technology system,which can realize the effective regulation of groundwater resources by controlling strata movement,changing passive prevention and governance of water disasters to active conservation and utilization of groundwater resources and thus obtaining coal and water simultaneously in mining.The concept of water-resistant key strata further enriches the content of the key stratum theory and provides a theoretical basis for water-preservation mining.In order to realize the idea of water-resistant key strata as a guideline in the design of water-preservation mining and engineering applications,the conditions for discrimination in the process of water-resistant key strata,we have presented a mechanical model,as well as its corresponding computer program,based on a large number of theoretical analyses and field measurements,as well as on a comprehensive consideration of the position,structural stability and seepage stability of key strata.Practical engineering applications indicate that this discrimination method and its corresponding computer program on water-resistant key strata are accurate and reliable and can satisfy the actual design needs of water-preservation mining and thus have instructional importance for water-preservation mining in mining areas lacking water.

涂膜、腻子膜打磨性测定仪校准方法的研究

研究建立了涂膜、腻子膜打磨性测定仪的校准方法。通过对生产厂家和用户的调研,参考相关的国家标准和校准规范,提出一种采用电子秒表、钢直尺、电子天平作为校准设备,校准涂膜、腻子膜打磨性测定仪的摩擦速度示值误差、摩擦行程、打磨头质量、附加砝码质量的方法。选择代表性的涂膜、腻子膜打磨性测定仪,依据该校准方法对计量特性进行实验验证,验证结果符合指标要求。该方法促进了涂膜、腻子膜打磨性测定仪量值溯源的标准化和规范化,推动其校准规范的制定。

高速列车用不饱和聚酯腻子的耐蚀性和老化机理

利用电化学阻抗谱、湿热老化等方法研究了不饱和聚酯腻子的耐蚀性和老化机理。结果表明:在3.5%NaCl溶液中浸泡6 h后,腐蚀溶液便渗入腻子/铝合金界面,并发生电化学腐蚀,不饱和聚酯腻子阻抗下降明显,防护能力下降较快;在湿热老化过程中,不饱和聚酯腻子光泽和色差逐渐增加,表面随着树脂的老化和降解变得光滑且局部产生空洞;不饱和聚酯腻子在老化初期存在着后固化现象;老化和降解更容易在芳香酯的位置发生。

轨道车辆车体自动喷涂腻子工艺研究

为实现轨道车辆车体表面腻子自动喷涂,搭建了机器人自动喷涂平台,采用正交实验法研究了自动喷涂的最优工艺,考察并确定了腻子施工参数,对比分析了自动喷涂腻子与手工操作的优势。结果表明:适用于轨道车辆的自动喷涂腻子的工艺参数为:腻子黏度9512 mPa·s、喷涂压力42 MPa、喷涂距离500 mm、移动速度600 mm/s、扇幅300 mm、膜厚2.00 mm;腻子的施工参数为:腻子加热温度80℃、重涂间隔最大时间96 h、单次喷涂流挂极限干膜厚度≤700μm、无泡极限膜厚2.09 mm、干燥打磨性为自干4 h且80~180目砂纸易打磨,与手工操作相比,自动化喷涂质量一致性好,有效降低用工成本,提高效率,经济效益显著。

轨道车辆用无苯化环保水性聚氨酯可喷涂腻子研究

随着无苯化环保理念的不断加强,水性轨道车辆涂料逐渐取代了与之对应的溶剂类涂装材料。为了进一步提高涂料的环保性,以水性聚氨酯为主要材料,在其原本的基础材料上制备了2种可喷涂腻子,并尝试将淀粉引入可喷涂腻子当中,设计实验对其性能分别进行了验证。研究表明,第1种可喷涂腻子具有良好的耐冲击性和耐划伤性;第2种引入淀粉的可喷涂腻子因为其具有较好的耐腐蚀性、耐热性和较高的降解率,因此具有一定的环保性。提高了可喷涂腻子的耐用性和环保性。

建筑内墙腻子技术发展趋势

内墙腻子作为一类具有特色的建筑装饰装修辅材产品,当前其技术领域尤其是耐水腻子领域还有进步的空间。本文就当前建筑内墙腻子的技术现状进行了综述,分析和提出内墙腻子随着需求的个性化和多样化,以及技术的进步,将向着高性能化、环保化、功能化、装饰化、低碳化方向发展。

综合防护方案在桥梁维修加固工程中的应用

介绍了无溶剂环氧腻子与水性氟碳涂料综合防护方案在桥梁维修加固工程中的应用。通过对无溶剂环氧腻子和水性氟碳涂料的特性和优点进行分析,结合实际工程案例,阐述了该方案在提高桥梁结构耐久性和安全性方面的显著效果。该方案的应用可有效解决桥梁裂缝、腐蚀等病害问题,延长桥梁使用寿命,对类似工程的维修加固具有一定的借鉴意义。

防水材料与外墙装饰层材料的粘结性研究

探讨了防水新规下外墙防水材料包括水泥基防水材料、丙烯酸防水涂料、聚氨酯防水涂料与外墙装饰层材料(外墙腻子、瓷砖胶和一体板砂浆)的粘结性能,结果表明,水泥基防水材料与外墙腻子、瓷砖胶和一体板砂浆均具有较好的粘结性,满足相应的粘结强度要求,而丙烯酸防水涂料、聚氨酯防水涂料与外墙腻子、瓷砖胶和一体板砂浆的粘结性均欠佳,粘结强度不符合相关标准的要求。

关于GB 50208-2011中腻子型遇水膨胀止水条物理性能要求的修订建议

分析了GB 50208—2011《地下防水工程质量验收规范》对腻子型遇水膨胀止水条物理性能的要求,指出了其与现行相关标准存在的不协调问题,如7 d膨胀率≤最终膨胀率60%的规定导致合规产品可能无法通过验收检测。在此基础上,针对该验收规范对腻子型遇水膨胀止水条物理性能的要求提出修订建议:取消有关试验条件的规定;取消21 d膨胀率作为最终膨胀率的规定;取消7 d膨胀率≤最终膨胀率60%的要求;明确硬度测试方法。

Analysis of Water Insulating Effect of Compound Water-Resisting Key Strata in Deep Mining

The problem of water preservation in mining and the prevention of water-bursts has been one of the more important issues in deep mining. Based on the concept of water-resisting key strata, the mechanics model of the key strata is established given the structural characteristics and the mechanical properties of the roof rock layers of the working face in a particular coal mine. Four other models were derived from this model by rearranging the order of the layers in the key strata. The distribution characteristics of stress, deformation, pore pressure and the flow vector of all the models are computed using the analytical module of fluid-structure interaction in the FLAC software and the corresponding risks of a water-burst are analyzed. The results indicate that the water-insulating ability of the key strata is related to the arrangement of soft and hard rocks. The water-insulating ability of the compound water-resisting key strata (CWKS) with a hard-hard-soft-hard-soft compounding order is the best under the five given simulated conditions.

Simulation of Water-Resistance of a Clay Layer During Mining:Analysis of a Safe Water Head

Given previous research and prototypical geological conditions of a mining workface,we simulated fis-sure development in clay layers at the bottom of Quaternary strata and above bedrock,sand and water inrush during mining by model experiments. The results show that V-shaped fissures usually occur in the bottom clay layer at the front top of the active face and that the position of these fissures changes periodically with ground pressure intervals. These fissures occur exactly in the area where the horizontal strain is concentrated. The results also demonstrate that the permeability coefficient of the cracked clay decreases while fissures tend to close. The permeability of the cracked bottom clay layer increases rapidly after a turning point in the permeability coefficient-water head curve (K-H curve) under a certain vertical load. Under static water pressure,the permeability coefficient of cracked clay decreases when load increases. A turning point in the K-H curve showed up and can be seen as a cutoff point to de-cide water inrush under a certain load level. Under an instantaneous water head,the greatest ability of the cracked clay to avoid drastic water inflow is a little higher than that under static conditions.

Structural motion of water-resisting key strata lying on overburden

Water-preserved mining is one of the important parts of the ‘Green Mining’ technological system. The purpose of wa-ter-preserved mining is to prevent water from bursting out in coal mines and thus to protect water resources. The principle of wa-ter-resisting key strata (WKS) is proposed to establish a model capable of guiding and developing water-preserved mining technol-ogy. The experimental model of the WKS is constructed following requirements of the Data Image Correlative Method (DICM). Five experimental schemes are designed according to different combined patterns of the WKS. The water-resisting performance of the WKS is analyzed from observation of structural stability. All of them provide referential value for water-preserved mining.

Water-resisting ability of cemented broken rocks

Using the self-designed testing system, the seepage tests for cemented broken rocks were conducted, and the impact of different factors on water-resisting ability was analyzed. The results show that(1) seepage process of the cemented broken rocks can be divided into two categories: in one category, seepage instability occurs after a period of time, in the other, the permeability decreases slowly and tends to be stable,and seepage instability does not occur;(2) cementing performance of cementing agent and grain size distribution are the decisive factors for water-resisting ability, with the increase of cementing performance and the mass percentage of large grains, the water-resisting ability of the specimen strengthens;(3)aggregate type has little effect on seepage stability, for the specimens with different aggregate types,the permeability and the duration of seepage instability have small difference;(4) initial porosity has a certain effect on the water-resisting ability of the specimen, but has no decisive role. With the increase of the initial porosity, the duration of seepage instability decreases.

Pore structure characteristics of the relative water-resisting layer on the top of the Ordovician in Longgu Coal Mine

In order to study the permeability and water-resisting ability of the strata on the top of the Ordovician in Longgu Coal Mine, this paper tested the permeability and porosity of the strata, investigated the fracture and pore structure features of the strata, and identified the main channels which govern the permeability and water-resisting ability of the strata. The permeability of the upper, central and lower strata shows as 2.0504 × 10^-3-2.782762× 10^-3, 4.1092 × 10^-3 -7.3387 × 10^-3 and 2.0891 ×10^-3-3.2705 × 10-3 μm^2, respectively, and porosity of that is 0.6786-0.9197%, 0.3109-0.3951% and 0.9829-1.8655%, respectively. The results indicate that： （I） the main channels of the relative water-resisting layer are the pore throats with a diameter more than 6 μm; （2） the major proportion of pore throats in the vertical flow channel and the permeability first increases and then sharply decreases; （3） the fractures occurring from the top to 20 m in depth of the strata were filled and there occurred almost no fracture under the depth of 40 m; and （4） the ratio of turning point of the main flow channel in the strata on top of Ordovician can be used to confirm the thickness of filled water-resisting lavers.

Numerical analysis of the destruction of water-resisting strata in a coal seam floor in mining above aquifers

With the increase in mining depth many mining areas in China have entered a period necessitating mining above aquifers. Production safety in coal mines in northern China is under serious threat from Ordovician karst water on coal seam floors, in order to analyze the destruction of water-resisting strata in floors of coal seams being mined and to achieve safe mining above deep aquifers, we established a numerical model of water-resisting strata, considering the structural characteristics and mechanical properties of a floor layered with hard and soft rock. We simulated the distribution characteristics of deformation, failure and seepage using the analytical module of fluid-structure interaction of FLAt：. We also obtained the corresponding stress distribution, deformation and flow vectors. Our results indi- cate that： （1） the advance of the working face causes water-resisting strata in goaf floors to form a deep double-clamped beam, subject to homogeneous loading at the bottom; （2） the two sides of the rock beam are subject 1~0 shear failure; （3） both sides of the rock seam at the bottom of the water-resisting strata are subject to tension and the greater the working face advance, the more serious the failure; C4） the original balance of the stress and seepage fields are broken and redistributed due to mining activities, especially the interaction of the abutment pressure in both sides of the goal; the lateral pressure on the goal floor and the water pressure on the floor of the aquifer promote floor heave and shear failure on both sides of the floor, forming a water-inrush passage. Our study results can provide references for the mechanism of water-inrush on mine floors.

Treatment of Unicameral and Aneurysmal Bone Cysts by Minimally Invasive Percutaneous Injection of Grafton DBF Putty Using the Kyphon Cement Delivery System

Background: Simple Unicameral and Aneurysmal Bone Cysts are benign lesions that may heal spontaneously especially after fracture which may be the first symptom. However, often size increases causing pain, and complications of fractures can severely compromise the patient. Aim: The results in a series of cases treated minimally invasive using a new device for the application of allogenic bone material appear highly promising and shall be presented. Patients and Methods: Eight consecutive patients with symptomatic Unicameral Bone Cysts (UBC) were treated by percutaneous instillation of Grafton? DBF Putty (demineralised allogenic bone containing fibers) mixed with autologous bone marrow using the Kyphon? Cement Delivery System (Medtronic), which allows the injection of this high viscosity paste by controlled high pressure. Five patients with Aneurysmal Bone Cysts (ABC) were treated accordingly after inactivation by Aethoxysclerol 3% and lacking bone formation. Using this approach a high rate of bone regeneration was observed in these patients at 8 months to 5 years follow-up (f/u). Conclusion: The presented technique of a minimally invasive biologic treatment led to highly satisfying results using the Grafton? DBF Putty with its higher potential for bone regeneration than demineralized bone matrix not containing fibres (DBM).

用Putty连接Linux主机

随着Linux在服务器端应用的普及，Linux系统管理越来越依赖于远程。在各种远程登录工具中，Putty是出色的工具之一。

碳排放权价值评估与运用——以粤电力为例

在国家实施“碳中和”与“碳达峰”战略目标的背景下,碳资产的不断涌现也为资产评估带来了新的机遇和挑战。本文以广东电力发展股份有限公司为例,利用Putty-Clay Vintage评估模型计算了该公司的碳排放权价值,对评估方法的适应性进行了综合分析。研究发现:第一,碳排放权具有商品属性;第二,企业碳排放权价值的评估可利用PCV模型计算结果估算获得。

高铁车体顶部腻子自动打磨工艺研究

为减少人工作业时间,提高腻子打磨系统自动化作业的水平,通过仿真分析、打磨工艺参数优化、打磨路径和程序设计、砂纸寿命核算等,获得适用于高铁车体顶部区的腻子自动打磨系统。系统对高铁模型车顶部区域的打磨覆盖率为86.31%,无碰撞风险;打磨时的最优工艺参数为轨迹行距55cm,法向压力90N,车顶打磨速度400mm/s,侧顶打磨速度300mm/s,磨盘转速9000r/min,砂纸粒径120目;单车顶部打磨时间在30min内,车顶及侧顶打磨用砂纸可连续打磨15min和12min。该套系统打磨效率及砂纸利用率较高,打磨后涂层外观良好,符合质量要求。