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101.
在光固化光敏树脂成型过程中,聚四氟乙烯离型膜会在树脂液位的波动影响下发生变形,进而影响光固化制件的精度,因此需要减小离型膜在制件过程的变形量,确保其相对稳定。首先分析树脂液位变化,通过液位变化量,等效出树脂液波动带给离型膜的载荷,建立离型膜受力模型。然后基于离型薄膜的挠度变形理论,应用Ansys软件进行模拟研究,对不施加预应力和施加不同预应力作用下的离型膜变形结果分析,结果表明施加预应力有利于提高离型膜稳定性,且施加预应力为2. 645M Pa时离型膜受到树脂波动影响最小,位置精度变化在0. 01 mm。 相似文献
102.
《Ceramics International》2020,46(8):11898-11904
Nanomaterials with ultraviolet/near-infrared (UV/NIR) shielding property have great potential for developing energy-saving windows. In this work, we report low-cost W18O49 nanorods as UV/NIR shielding material. W18O49 nanorods with the length of ~20 or ~60 nm were prepared by simple solvothermal method, and they exhibited strong size-dependent absorption in the UV/NIR region. By mixing W18O49 nanorods with polydimethylsiloxane (PDMS), W18O49@PDMS films were constructed and they could shield 55.58% of UV and 75.89% of NIR light while transmit 58.03% of visible light. A sealed box with W18O49@PDMS-coated glass as the window exhibited a minimal temperature elevation (△T = 9.2 °C) compared to those coated with pure glass (△T = 18.2 °C) or ITO glass (△T = 12.1 °C), under the irradiation of solar light (0.6 W cm−2). Additionally, the films had a contact angle of 122 ± 2°, showing self-cleaning ability. Therefore, W18O49@PDMS films can act as cost-efficient UV/NIR-shielding and self-cleaning film. 相似文献
103.
《Ceramics International》2020,46(5):6199-6204
Electromagnetic shielding (EMI) materials are becoming more and more important because of the increasingly serious radiation pollution. The preparation of high mechanical strength, ultrathin, lightweight, flexible materials with excellent EMI shielding performance have so far been elusive. Here, we try to prepare an ultrathin, lightweight and flexible film with excellent EMI shielding performance using one-dimensional aramid nanofibers (ANFs) and two-dimensional few-layered Ti3C2Tx through a simple filtration method. The ultimate tensile strength and strain of the film are up to 116.71 MPa and 2.64%. The EMI shielding effectiveness and the specific EMI shielding efficiency are 34.71 dB and 21971.37 dB cm2 g−1, which will be no recession after 1000 times bending. Our results show that a practical EMI shielding material with excellent performances has been successfully prepared, which will be widely applied in wearable electronics, robot joints, and precision instrument protection and so on. 相似文献
104.
105.
探讨氧化羟丙基淀粉浆料性能。利用氧化和羟丙基化复合变性制备了氧化羟丙基淀粉浆料,测试了黏度、取代度及pH值等因素对氧化羟丙基淀粉浆料及浆纱性能的影响。结果表明:氧化羟丙基淀粉浆料具有高浓低黏浆料特性,其黏度热稳定性和成膜性良好;在一定范围内,随着氧化剂用量的增加,黏度逐渐下降,浆膜断裂强度和断裂伸长率降低,耐磨性增加;随着取代度的增加,浆液黏度热稳定性提高,浆膜断裂强度和断裂伸长率都增加,水溶速度加快,浆液黏附力增大;取代度达到0.3的氧化羟丙基淀粉表现出良好的浆膜性能、黏附性能及对纯棉纱良好的浆纱效果。认为:取代度为0.3的氧化羟丙基淀粉具有较好的上浆性能。 相似文献
106.
The effect of chitosan–gelatin coating and film on the rancidity development in rainbow trout (Oncorhynchus mykiss) fillets during refrigerated storage (4 ± 1 °C) was examined over a period of 16 days. Composite and bilayer coated and film wrapped fish samples were analysed periodically for microbiological (total viable count, psychrotrophic count) and chemical (TVB-N, POV, TBARS, FFA) characteristics. The results indicated that chitosan–gelatin coating and film retained their good quality characteristics and extend the shelf life of fish samples during refrigerated storage .The coating was better than the film in reducing lipid oxidation of fillets, but there was no significant difference between them in control of bacterial contamination. 相似文献
107.
为了解决PVA浆料难以生物降解的问题,研制开发了可替代PVA的乳液丙烯酸酯共聚浆料.利用红外光谱仪对合成的多元共聚浆料的结构进行了分析确认.对浆液浆膜性能进行了测试,与接枝淀粉、PVA制成混合浆对涤棉混纺纱进行了替代PVA的上浆试验.结果表明:乳液多元共聚浆料具有较低的粘度;与接枝淀粉配合使用对涤棉混纺纱线上浆可完全取代PVA,浆纱耐磨性、强伸性良好. 相似文献
108.
Bong-Kuk Sea Suek-Yuel Choo Tae-Jong Lee Shigeharu Morooka Seung-Koo Song 《Korean Journal of Chemical Engineering》1995,12(4):416-420
SiC-coated film onto carbon fibers as a barrier of oxidation resistance and reaction between carbon fibers and metals was
investigated. The chemical vapor deposition of silicon carbide onto carbon fibers was performed at various temperatures ranging
from 700 to 1000°C using triisopropylsilane vapor carried by hydrogen gas. The strength of the SiC-coated carbon fibers was
decreased due to deterioration of fibers and chemical attack of hydrogen on the surface of carbon fibers during the coating
process. The oxidation and the thermal resistance of the SiC-coated carbon fibers compared to the uncoated carbon fibers were
improved at temperature range of 600–800°C and 1000–1200°C, respectively. Morphological change by air oxidation at temperature
range of 500–800‡C was also investigated for the SiC-coated and the uncoated carbon fibers, respectively. The SiC-coated film
between carbon fiber and aluminum was sufficient as a barrier of reaction on carbon fiber reinforced aluminum at temperature
of above 1000°C. 相似文献
109.
橡胶减摆器的环境适应性研究 总被引:1,自引:0,他引:1
采用电液伺服试验机进行了橡胶减摆器高低温动态特性测试,研究了橡胶减摆器在不同温度环境下动态特性的变化规律,为其在高寒和热带地区的应用提供依据;同时对其湿热、霉菌和盐雾环境适应性进行了测试,为其在潮湿和海洋环境中的应用提供了依据。研究结果表明,当温度在-55~20℃之间时,橡胶减摆器的低温动态刚度与室温下的比值在1~1.7之间;当温度在20~70℃之间时,橡胶减摆器的高温动态刚度与室温下的比值在0.86~1之间;橡胶减摆器具有较好的高低温动态性能;湿热、霉菌和盐雾试验结果表明,橡胶减摆器的环境适应性优良。 相似文献
110.
通过新型的旋转芯棒薄膜吹塑设备制备了低密度聚乙烯(LDPE)/高密度聚乙烯(HDPE)复合薄膜,并研究了该设备模具流道环流协同作用对吹塑聚乙烯薄膜结构和性能的影响。结果表明,制备的聚乙烯薄膜呈现一种互锁片晶结构;芯棒转速的提高对聚乙烯薄膜样品的结晶度、片晶厚度也有一定增益作用,使得结晶更完善;聚乙烯薄膜的拉伸性能和撕裂性能随芯棒转速提高都有所提升,尤其是横向力学性能,横向拉伸性能最大提升幅度为25.75%,横向撕裂性能最大提升幅度为27.64%;同时,该技术实现了在不影响聚乙烯薄膜的纵向热收缩率的情况下,大幅提高其横向热收缩率,提升幅度可达128.41%。 相似文献