新型抗烧蚀酚醛树脂的研究

采用不同的甲醛（F）/苯酚（P）比和复合碱性催化合成了邻对位羟甲基比例（o/p）不同的酚醛树脂。利用该酚醛树脂中邻对位交联程度变化可以优化炭化过程中苯醌式结构中间体稠环化历程。从而通过适当调整酚醛树脂受烧蚀而发生炭化时的交联密度，使炭化过程稳定，易于石墨化、提高了抗烧蚀性能。F/P比在1.6～1.8时，纯酚醛树脂的炭化率玻璃纤维/酚醛树脂复合材料的质量烧蚀率变化较小，烧蚀形貌显著改善，是比较理想的配料比。     

新型抗烧蚀酚醛树脂的研究

采用不同的甲醛（F）／苯酚（P）比和复合碱性催化剂合成了邻对位羟甲基比例（o/p)不同的酚醛树脂。利用该酚醛树脂中邻对位交联程度变化，可以优化炭化过程中苯醌式结构中间体稠环化历程，从而通过适当调整酚醛树脂受烧蚀而发生炭化时的交联密度，使炭化过程稳定，高温下易于石墨化，提高了抗烧蚀性能。F／P比在1.6-1.8时，纯酚醛树脂的炭化率与玻璃纤维／酚醛树脂复合材料的质量烧蚀率变化较小，烧蚀形貌显著改善，是比较理想的配料比。     

高残炭热固性酚醛树脂的合成及表征

以萘酚部分替代苯酚合成了高残炭热固性酚醛树脂。研究了萘酚用量、催化剂用量、反应温度和时间对残炭率的影响,确定了合成工艺条件。用IR和TGA对产品的化学结构与热性能进行了分析测定,结果表明,树脂分子链中不稳定的醚键含量低于普通酚醛树脂,产品的分解温度为460℃,残炭率可达61.3%,适用于碳/碳复合材料和耐烧蚀材料的树脂基体。     

碳纤维/有机硅改性环氧树脂复合材料性能研究

介绍了一种碳纤维/有机硅改性环氧树脂复合材料的性能研究情况.对该复合材料的力学性能、热常数和烧蚀性能进行了初步测试.结果表明,其拉伸强度达到558MPa,拉伸模量达到44.0GPa,层间剪切强度为16.6MPa,导热系数不超过0.3 W/(m*K),氧-乙炔烧蚀的线烧蚀率为0.049mm/s,质量烧蚀率为0.0595g/s.通过与常用的碳/酚醛材料比较,碳纤维/有机硅改性环氧树脂复合材料的性能较优.     

一步法合成有机硅改性酚醛树脂及其粘接性能

采用有机硅树脂中加入氢氧化钠使之水解后再加入苯酚、甲醛缩聚制备热固性有机硅改性酚醛树脂,而不同于两步法制备热固性有机硅改性酚醛树脂和由硅烷水解低聚物与酚醛树脂缩合制备热固性有机硅改性酚醛树脂。本文中通过IR,DSC,TG以及剪切强度和剥离强度,对这种热固性有机硅改性酚醛树脂的粘接性能,耐热性能,耐久性能和固化工艺进行考核,证明这种方法制备的树脂粘接强度高,耐热性能优异,耐久性能良好,可以作为耐热结构胶粘剂在航空航天领域应用。     

高成炭酚醛树脂的合成与性能研究

本文以甲醛和苯酚为原料，氨水为催化剂制备高成炭率酚醛树脂。系统地考察了甲醛／苯酚摩尔比、反应温度、保温时间工艺参数对酚醛树脂的收率、固含量、游离甲醛含量、粘度、固化损失率以及成炭率等的影响，确立了制备高成炭率酚醛树脂的工艺方法和工艺条件。在该优化工艺条件下制备的酚醛树脂700℃，氮气气氛下的成炭率高达73．8％，远远高于相同条件下市售的普通酚醛树脂成炭率（57．5％）。     

碳纤维丝束结构对碳纤维/酚醛复合材料烧蚀性能的影响EI北大核心CSCD

以酚醛树脂为基体,以平纹碳布和短切碳纤维两种结构形式的碳纤维为增强剂,制备碳纤维增强的碳/酚醛复合材料。采用氧/乙炔烧蚀实验对复合材料的耐烧蚀性能进行了对比性研究,采用电子拉力试验机对复合材料的弯曲性能进行表征,采用扫描电镜对复合材料烧蚀形面进行观察,并通过固体火箭发动机对复合材料的烧蚀性能进行考核验证。研究结果表明:以这两种结构形式的碳纤维为增强剂制备的碳/酚醛复合材料,其氧乙炔质量烧蚀率的大小与碳纤维丝束的大小具有正相关的特性,碳纤维丝束越小碳纤维质量烧蚀率越低,当碳纤维增强剂处于单丝状态时,复合材料的氧乙炔质量烧蚀率达到最低为0.046 g/s,并且碳纤维的型号规格对复合材料氧乙炔质量烧蚀率的影响变小。固体火箭发动机实验表明,单丝状态下的碳纤维/酚醛复合材料的抗烧蚀冲刷性能明显优于束状碳纤维/酚醛复合材料。     

酚醛树脂基复合材料的等离子烧蚀性能

利用等离子烧蚀试验系统,对纤维增强酚醛树脂复合材料进行烧蚀试验,并对不同复合材料的烧蚀率和微观形貌进行测试和分析。等离子烧蚀试验条件为:功率60kW,热流密度25000kW/m~2,烧蚀时间8s。结果表明:碳纤维、高硅氧纤维、玻璃纤维增强酚醛树脂复合材料的等离子线烧蚀率分别为:0.180mm/s、0.666mm/s、0.613mm/s,质量烧蚀率分别为:0.167g/s、0.310g/s、0.338g/s,线烧蚀率和质量烧蚀率相对偏差都在5%以内。利用扫描电子显微镜和X射线能谱仪对烧蚀样品的微观形貌进行分析,对不同纤维增强酚醛树脂基复合材料的等离子烧蚀机理进行了探讨。     

2.5D石英纤维增强硼酚醛树脂可陶瓷化复合材料的制备与烧蚀性能

通过预浸料模压工艺制备了2.5D石英纤维增强硼酚醛树脂可陶瓷化复合材料,采用TG测试、马弗炉静态烧蚀测试、力学测试、氧-乙炔试验、场发射扫描电镜等方法对2.5D纤维增强硼酚醛树脂可陶瓷化复合材料的热稳定性、力学性能、耐烧蚀性能进行分析测试,并与2D纤维增强硼酚醛树脂可陶瓷化复合材料进行对比。结果表明,陶瓷填料对复合材料的热性能有显著改善,失重第一阶段温度和残碳率明显增加;马弗炉热解后2D结构样品缺陷多,层间出现破坏,弯曲强度为14~20 MPa,2.5D结构样品热解后保持了良好的整体结构,弯曲强度为16~24 MPa;通过氧乙炔烧蚀试验,2.5D结构样品烧蚀30 s质量烧蚀率为0.0413 g/s,线烧蚀率为0.032 mm/s,烧蚀60 s质量烧蚀率为0.0218 g/s,线烧蚀率为0.023 mm/s,测试结果均优于与之对比的2D结构样品,通过SEM和EDS分析,2.5D结构样品优异的抗热应力分层性能和纤维表面结构对复相陶瓷的稳定性是其低烧蚀率的主要原因。      

改性酚醛树脂制备工艺参数的研究

以苯酚、甲醛为原料,NazCO3为催化剂,利用正硅酸乙酯(TEOS)改性酚醛树脂.讨论了工艺参数对制备改性酚醛树脂的影响.结果表明:增加缩聚反应时间或提高催化剂Na2CO3的质量百分含量,改性酚醛树脂的固含量和残碳率不断提高,其黏度也随着增大;增加TEOS的质量百分含量,改性的酚醛树脂固含量和残碳率的数值先变大后变小,当TEOS的质量百分含量为1.2%时,其固含量和残碳率的数值为最大值;而酚醛树脂的黏度总随着TEOS的质量百分含量的增加而增大.     

Effect of Permeable Crystalline Material on Steel Reinforcement Corrosion of Concrete

Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.     

The Research and Application About "Dry Peeling Off" Technology for Airplane Surface Paint Layer

In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.     

Quality Study of Honeycomb Core Shaping Without Wax Stabilization

Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.     

In-process thermal treatment of polylactic acid in fused deposition modelling

Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.     

Investigation of the Corrosion Behaviors of HVOF-Sprayed Carbide Cernet Coatings in Molten Al-Zn-Si Alloy Bath

In continuous hot-dip galvanization process the corrosion and chemical stability of the sink roll in the galvanizing bath are important problem which effects on the quality and productivity. In order to protect the sink roll the carbide cermet and/or ceramic coatings were deposited on the surface of the sink roll. The WC-, Cr3 C2-cermet coatings were deposited by high velocity oxygen fuel (HVOF) spray, respectively. The coating samples were immersed in molten Zn-alloy containing 50 wt % aluminum at 833 K for 24 hr and 144 hr, respectively. The inter-diffusion and inter-reaction of Zn, Al and elements in coating and corrosion behaviors of these coatings were investigated by XRD, SEM and EPMA etc. The corrosion mechanisms of the carbide cermet coatings and ceramic coatings in molten High Al-Zn-alloy were approached.     

Fundamental study of adhesion of ice to cooling solid surface (Discussion on influence of copper oxide layer on ice adhesion force)

In many situations, ice often adheres to a cooling solid surface, frequently causing serious accidents. It is critical to clarify the mechanism of ice adhesion to the cooling surface in order to prevent ice adhesion. In a past study, the shearing stresses of two kinds of test plates with a copper surface having the higher thermal conductivity were measured. The shearing stress corresponds to ice adhesion force. Both shearing stresses were significantly different; however, the cause remains unclear.Therefore, the present study focuses on an oxide layer as the main factor causing the difference of both shearing stresses; the influence of the oxide layer formed on shearing stress was discussed. And in the removal and reformation processes of the oxide layer, the time variation of the shearing stress was clarified. Moreover, the relationship between the state of the copper surface and the shearing stress was also clarified by surface analysis.     

重塑标准推行格局 推动LED照明的普及（英文）

正When you are enjoying the green,energy-saving and healthy lighting of IKEA LED luminaire,you may not realize that most of IKEA’s LED bulbs are produced by the LED luminaire smart manufacturing system of Hangzhou Zhongwei Photoelectricity CO.,LTD(ZVISION).No longer enclosed in the laboratory,the product standards are brought into the factory workshop and even to the entire production process.Thus,the standards are promoted and applied in a favorable way by enterprises,benefitting consumers with high quality products.     

Chinese Experts Contribute to ISO＇s New Toy Standards

正The international standard,ISO 8124-6,Safety of toys–Part 6:Certain phthalate esters in toys and children’s products,was officially issued by ISO worldwide on August 15.It was the first time for Chinese experts to lead the ISO standard development in toys industry.The standard was drafted by a group of Chinese experts from SAC/TC for toys and relevant Chinese departments and finally completed by a dedicated international group of experts.ISO 8124-6 makes a substantive breakthrough in the aspects of the scope of toys,limitation of plasticizer types,control of test cost,accuracy of test,operation convenience,etc.,offering the operational guidance for toy manufactures and testing laboratories.     

中国质量(北京)大会(英文)

正Themed on"quality,innovation,development",the first China Quality Conference(Beijing)was held in the Great Hall of the People on September 15.Chinese Premier Li Keqiang delivered an important speech at the conference.State Councilor Yang Jing and Wang Yong attended the conference with over 600 domestic and international representatives from foreign,regional and international quality organizations     

National Working Meeting on Land and Resources Standardization

正The National Working Meeting on Land and Resources Standardization was held in Beijing on July 15,2014.Wang Min,the Deputy-Minister of the Ministry of Land and Resources,and Yin Minghan,the Chief-Engineer of SAC addressed the meeting.Representatives from relevant competent departments and technical committees were present.The meeting aims to summarize work,discuss existing problems and make clear working thoughts,promoting standardization work of land and resources to a new level.Wang Min pointed out that the standardization work of land and resources should be centered on the basic principles of"protecting land and resources dutifully,intensively and economically utilizing land and resources,and making all-out efforts to safeguard the public’s rights and interests",highlighted the