醋酸羟丙基甲基纤维素琥珀酸酯溶液的高压静电场纺丝

研究了醋酸羟丙基甲基纤维素琥珀酸酯(HPMCAS)溶液高压静电场纺丝过程中高聚物分子量、溶液浓度、静电场强度对成纤性和纤维直径的影响,制备出直径范围为0.43μm～1.0μm的纤维。当溶剂、溶液浓度及静电场强度一定时,重均分子量-Mw分别为2.6万、4.8万和7.2万,HPMCAS溶液中只有7.2万者能纺丝得到光滑纤维。在静电场强度、溶剂组成一定条件下,HPMCAS可纺丝浓度范围为8%～15%(质量分数,下同),且随着纺丝溶液浓度的增大,所得纤维的平均直径逐渐增大。当其它条件保持一定时,随着纺丝电压的增大,所得纤维的平均直径呈下降的趋势,所得纤维结晶度略微增大。     

壳聚糖纳米粒子与乙基纤维素的混合静电纺丝及纺丝膜的血液相容性

将粒径2μm的壳聚糖(CTS)用机械球磨法球磨4h制备成粒径385nm的纳米颗粒(NCTS),再与乙基纤维素溶液(EC)混合静电纺丝制备了壳聚糖纳米颗粒/乙基纤维素纳米纤维膜(NCTS/EC),探讨了纺丝电压和接受距离对于纳米纤维膜表观形貌的影响,结果表明,通过控制纺丝电压和接受距离可以获得均匀无串珠的纳米纤维膜。接触角测试结果显示NCTS/EC疏水性能好。凝血时间和血小板吸附实验结果表明NCTS/EC具有较好的血液相容性。     

VSSP法制备PZT陶瓷长纤维及其表征

采用纤维素和锆钛酸铅(PZT)粉体为原料,使用黏胶纺丝法(VSSP)制备了直径250μm的PZT陶瓷长纤维.利用SEM和XRD对纤维素坯和烧结后纤维进行表征并根据正交实验设计法通过实验确定了纤维成型浆料中粉体与纤维素质量比、分散剂用量以及老成时间等因素对成型后纤维素坯直径均匀度的影响,进而确定了制备PZT陶瓷长纤维的优...     

熔融静电纺制备聚丙烯超细纤维的研究

采用熔融静电纺丝技术制备聚丙烯(PP)超细纤维,运用高速摄影技术记录了PP熔融纺丝液在高压静电场力作用下拉伸成丝的整个过程,并借助扫描电子显微镜( SEM)对不同静电压条件下所制备的PP超细纤维进行表征.实验表明,熔融静电纺射流运里大致可以分为稳定直线、分裂鞭动和沉积3个阶段.随静电压的增加,纺丝射流速度以及射流稳定直线运动区域增加,所制备纤维直径明显降低.     

静电纺丝法制备聚苯乙烯微纳米纤维膜及其过滤性能

采用静电纺丝法制备聚苯乙烯(PS)微纳米纤维膜,研究了静电纺丝工艺对PS纤维膜微观形貌、纤维直径以及孔隙尺寸分布的影响,并表征了其对固体颗粒物的过滤性能。结果表明:随着纺丝电压和接收距离的增加,PS纤维膜的直径和孔隙尺寸均减小且分布集中,随着推进速率增加,PS纤维膜的直径和孔隙尺寸逐渐增加且分布范围变宽;当纺丝电压为24kv,收集距离为24cm,推进速率为0.318mL/h时所得PS纤维膜的直径和孔隙中位径分别为940.1nm和1979.4nm,过滤尺寸范围为0.1~35μm的固体颗粒后,剩余颗粒的平均粒径仅为2.19μm。     

氰乙基纤维素的研制及探讨

氰乙基纤维素是较早开发和研制的纤维素醚类,因它具有高电介层独特的性质,应用在许多特定的场合和材料中,但生产ＣＥＣ的工艺较复杂,并且得不到较高取代度的ＣＥＣ,本工艺对老工艺进行改进,减少副反应,使氰乙基化反应较完善,得到高质量的氰乙基纤维素。     

高取代度氰乙基纤维素与二醋酸纤维素共混中空纤维纳滤膜的研制

采用高取代度氰乙基纤维素与二醋酸纤维素共混为膜材料,丙酮、二氧六环混合溶剂,以有机醇为主、加入适量其他添加剂为致孔剂,通过冰水凝胶浴干湿法纺丝,制得性能良好的中空纤维纳滤膜,该膜在给水质量浓度1 800 mg/L、操作压力为0.6 MPa、水温25℃条件下,对二价盐CaCl2、一价盐NaCl的水溶液的脱盐率分别大于90%和小于60%,水通量均大于3.5 mL/(cm2.h).还讨论了膜液的组成和纺丝条件对膜性能的影响.     

聚酰亚胺纳米纤维的制备及性能表征

为了研究一步法所纺聚酰亚胺(PI)纳米纤维的结构与性能,采用静电纺丝技术,以热塑性聚酰亚胺粉末为原料,N,N-二甲基甲酰胺(DMF)、N,N-二甲基乙酰胺(DMAc)、吐温80等按一定比例混合的溶液为溶剂,制备了平均直径在0.313~0.785μm的2种PI纳米纤维,并对其结构和性能进行表征。结果表明,所纺纳米纤维表面无微孔,纤维直径随纺丝液浓度的增加而增加;随纺丝电压和纺丝距离的增加而先减小后增加。此外,不同溶剂体系所纺PI纳米纤维的结构和性能存在很大差异,PI DMF-DMAc纳米纤维的结构规整性、力学性能(断裂强度24.8 MPa)和热稳定性(热分解温度535℃)均高于PI Tween80-DMF-DMAc纳米纤维(其断裂强度为16.5 MPa,热分解温度为421℃)。     

O-氰乙基壳聚糖修饰的开管毛细管电色谱柱的制备与表征

制备了O-氰乙基壳聚糖修饰的开管毛细管电色谱柱。O-氰乙基壳聚糖的最佳浓度为7.5 mg/mL,通过电渗流表征了柱的稳定性和重现性较好,相对标准偏差(RSD)日内小于0.2%(n=3)、日间小于0.6%(n=3)、柱与柱之间小于1.0%(n=3)、批次与批次之间小于3.4%(n=3)。用红外光谱和扫描电镜进行了结构及形貌表征。4种核苷酸在修饰后的毛细管电色谱柱上得到了较好的分离,柱效达到37,000 plate/m-140,000 plate/m。结果表明,所建立的开管柱制备方法简单有效、稳定性好。     

荧光Lyocell纤维的制备和性能

通过共混方法将经预处理的荧光粉均匀分散在NMMO溶液中,采用Lyocell工艺通过干湿法纺丝成功制备了荧光Lyocell纤维,探讨了荧光粉用量对纺丝液流变性能及纤维的结构与性能的影响。结果表明,随着荧光粉用量的增加,Ly-ocell纺丝液的表观黏度先下降后上升,当荧光粉用量达到m(荧光粉)/m(纤维素)=3/100时,纺丝液的黏度呈最低值。此外,随着荧光粉用量的增加,纤维的荧光性能随之提高,但纤维内荧光颗粒的团聚现象逐渐加剧,导致纤维的力学强度和结晶度逐渐降低。     

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.     

＂Three Transformations＂ and Standardization

During his inspection in Henan Province in May, Chinese President Xi Jinping stressed to ＂push forward the transformation from China Speed to China Quality, from Made in China to Created in China, and from Chinese Products to Chinese Brand＂. The ＂Three Transformations＂ are the specific requirements and goal of China＇s national development in the context that market should play a decisive role in the allocation of resources.     

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.     

SAC Delegation Visits AENOR and Signs Cooperation Agreements

正SAC Administrator Tian Shihong led the Chinese delegation to visit the Spanish Association for Standardization and Certification(AENOR)on September 15,2014.Mrs.Begona Cristeto,the Vice-Minister of Industry,Energy and Tourism of Spain,and Mr.Avelino Brito,the President and CEO of AENOR greeted the delegation.The two sides had a deep and friendly discussion on strengthening the cooperation between China and Spain in the standardization field and promoting the standardization work to support the development of economy and trade in the two countries.