排序方式: 共有38条查询结果,搜索用时 15 毫秒
1.
本文简述了对某类机动飞机进行噪声环境测量及其数据归纳的方法;根据编制的噪声载荷谱和受载特点,选择适当的噪声源,进行声疲劳试验,考核飞机结构声疲劳特性,并对测量、试验结果进行分析,评定了几种抗声疲劳性能较高的结构形式。 相似文献
2.
3.
为了实现传统白光LED光源与植物照明用光源之间的快速转换,采用高温熔融造粒的方式制备了不同质量分数CaAlSiN_3∶Eu~(2+)(CASN∶Eu~(2+))掺杂的荧光聚碳酸酯(PC)透光罩,并进行了结构和光学分析。制备了荧光PC透光罩配备的T8型LED灯管,测试了其EL光谱、相关光学性质以及对于生菜的种植效果。结果表明,CASN∶Eu~(2+)荧光粉在掺杂过程中性质稳定,该灯管随着配备的透光罩的荧光粉掺杂浓度的提高,相对应的WLED的色坐标从(0.3272,0.3467)变化到(0.3895,0.3824),色温从5757K下降到3807K,显色指数从70.3上升到77.6,但光效略有减弱。配备了荧光粉质量分数为4‰透光罩的T8型白光LED灯管的光质更适合生菜生长。 相似文献
4.
5.
6.
在灯具设计中,特别是开发投光灯、轨道灯等类型灯具时,经常会遇到系列化设计问题。在不修改基本外形结构的情况下,要想获得不同发光角度、照度均匀,提出了一种通过鳞甲片改变出光角度的反射罩设计方案,包括鳞片参数的计算、基面合理分隔方法、实际仿真模拟。最终给出同样基面,发散角(FWHM)为20°、40°、60°,光能利用率均达到75%,匀光效果85%左右的设计结果,证明该设计方法可行性。 相似文献
7.
8.
The title compound 10-(4,5-dibenzylthio-1,3-dithiol-2-ylidene)anthracen-9(10H)- one (C31H22OS4) has been synthesized, and its crystal structure was prepared by crystallization from CH2Cl2-MeOH. The crystal belongs to the triclinic system, space group Pi with a = 10.9758(3), b = 11.4241(4), c = 11.7460(2)A^°, α = 62.379(2), β = 81.227(3), γ = 80.321(2)°, Mr = 538.73, V = 1281.69(7) A^°^3, Z = 2, Dc = 1.396 g/cm^3, F(000) = 560,μ = 0.395 mm^-1, the final R = 0.0291 and wR = 0.0739. The molecular structure is severely distorted from planarity. The central ring of anthraquinone moiety adopts a boat conformation, while the two outer benzene rings are tilted in the opposite direction to form a dihedral angle of 23.65°. The photocurrent generation was measured and an anodic photocurrent response was obtained. The electronic spectrum was studied by using TDDFr method on the basis of optimized geometries with B3LYP method. The obtained results are in good agreement with the experimental values. 相似文献
9.