辐照对SiGe HBT增益的影响

比较了电子和γ射线辐照后SiGe HBT和Si BJT直流增益β的变化.在Vbe≤0.5V时,较高剂量辐照时SiGe HBT的放大倍数辐照损伤因子d(β)为负;在Vbe≥0.5V时,SiGe HBT的d(β)远比Si BJT的小.SiGe HBT有更好的抗辐照性能.针对测得的一些电子陷阱对辐照致性能变化的影响进行了讨论.     

Synthesis of M (M=Co<Superscript>2+</Superscript>, Co<Superscript>2+</Superscript>/Ni<Superscript>2+</Superscript>)-doped FeS<Subscript>2</Subscript> Nanospheres with Enhanced Visible-light-induced Photocatalytic Activity

Nano-spherical Co²⁺-doped FeS₂ was synthesized through a simple solvothermal method. The products were investigated using XRD, FE-SEM, BET, ICP, EDS, TEM, HRTEM, XPS, and UV-vis spectroscopy. The results indicated that Co²⁺ ion could change the particle nucleation process and inhibited the particle growth of FeS₂. In addition, when the content of doped Co²⁺ was 15%, the degradation efficiency of methylene blue (MB) achieved 60.72% after 210 min irradiation, which increased by 52.01% than that of the undoped FeS₂. Moreover, comparison experiments also demonstrated that the M (M=Co²⁺, Co²⁺/Ni²⁺)-doped FeS₂ photocatalytic activity efficiency sequence was Co²⁺ > Ni²⁺>Co²⁺/Ni²⁺. This is ascribed to the fact that the Co²⁺ doping could induce the absorption edge shifting into the visible-light region and increased the surface area of the samples. The effect mechanisms of M-doping on the band gap and the photocatalytic activity of FeS₂ were also discussed.     

Synthesis of M(M=Co~(2+),Co~(2+)/Ni~(2+))-doped FeS_2 Nanospheres with Enhanced Visible-light-induced Photocatalytic Activity

Nano-spherical Co~(2+)-doped FeS_2 was synthesized through a simple solvothermal method. The products were investigated using XRD, FE-SEM, BET, ICP, EDS, TEM, HRTEM, XPS, and UV-vis spectroscopy. The results indicated that Co~(2+) ion could change the particle nucleation process and inhibited the particle growth of FeS_2. In addition, when the content of doped Co~(2+) was 15%, the degradation efficiency of methylene blue(MB) achieved 60.72% after 210 min irradiation, which increased by 52.01% than that of the undoped FeS_2. Moreover, comparison experiments also demonstrated that the M(M=Co~(2+), Co~(2+)/Ni~(2+))-doped FeS_2 photocatalytic activity efficiency sequence was Co~(2+) Ni~(2+)Co~(2+)/Ni~(2+). This is ascribed to the fact that the Co~(2+) doping could induce the absorption edge shifting into the visible-light region and increased the surface area of the samples. The effect mechanisms of M-doping on the band gap and the photocatalytic activity of FeS_2 were also discussed.     

基于超声波定位的车辆路径监测系统

本文介绍一种基于超声波定位的运动路径监测系统的原理及组成,简要描述其定位算法及求解关键问题,并分析各部分软件设计要点,对实验中观察到的现象做出了展示和分析说明。     

季铵化壳聚糖/[Nbmm]OH碱性复合阴离子膜的制备及性能

以季铵化壳聚糖(QCS)为制膜原料,[Nbmm]OH碱性离子液体为掺杂物,通过溶液浇铸法制备了一系列掺杂碱性离子液体([Nbmm]OH)的交联复合膜(QCS/[Nbmm]OH)。采用红外光谱、热重分析及扫描电镜对复合膜的结构、热稳定性和微观形貌进行分析。同时考察离子液体掺杂量对QCS/[Nbmm]OH复合膜的含水率、力学强度及导电性能等指标的影响。结果表明,随着[Nbmm]OH离子液体掺杂量的增加,复合膜的含水率、离子交换量以及电导率均增加,但是拉伸强度和断裂伸长率略有下降。其中,当离子液体掺杂量为15%(质量分数)时,复合膜在70℃的电导率为0.0115S/cm,拉伸强度为19 MPa,离子交换量为1.25 mmol/g,含水率和溶胀度分别为143%和87%。     

Guanidine分子在燃料电池用阴离子交换膜中的应用

以壳聚糖(CS)和2,3-环氧丙基三甲基氯化铵(GTA)为原料,制备季铵化壳聚糖(QCS),将其与小分子游离胍(Guanidine)共混,借助戊二醛(GA)的化学交联作用,将季铵化壳聚糖中的氨基以及胍中的氨基交联,形成网状结构,由此制得含有不同含量Guanidine分子的交联QCS-G阴离子交换膜。实验过程中,对该膜的含水率、溶胀度、力学强度、电导率及耐碱稳定性等进行了详细的考察。结果表明,游离胍的引入可有效地提高膜的电导率和耐碱稳定性,同时降低了膜的溶胀度及含水率。其中小分子游离胍质量分数为2.5%的膜(QCS-G2.5%)在70℃时的电导率可达到6.58×10~(-2)S/cm;在10 mol/L NaOH溶液中浸渍72 h后该膜70℃测得的电导率损失仅为3.8%,离子交换量损失仅为3.82%,表明该膜的耐碱性能较好。     

q-CS/TEOS复合膜的制备及吸附性能的研究

以正硅酸乙酯为无机组分,季铵化壳聚糖为有机组分,通过溶胶-凝胶法制备一系列不同正硅酸乙 酯质量分数的季铵化壳聚糖/正硅酸乙酯(q-CS/TEOS)复合阴离子交换膜。利用红外光谱分析(FT-IR)对膜的 化学结构进行表征。另外,利用得到的杂化膜对水溶液中的Cr(Ⅵ)离子进行吸附性能考察。实验对吸附时间、体系 pH 值、溶液温度等因素对吸附性能的影响进行考察。结果表明,正硅酸乙酯质量分数为38%的杂化膜在吸附时间 180min、pH 值5.0~8.0、溶液温度35℃的条件下对Cr(Ⅵ)离子吸附性能较好。     

混合废塑料裂解油作乙烯生产原料的可行性分析

为扩大乙烯原料来源,同时为废塑料回收利用开辟新途径,通过实验分析了混合废塑料裂解汽油馏分的性质,探讨将其作为裂解法制乙烯原料的可能性。族组成分析结果表明,与热裂解工艺相比,使用催化裂解工艺使混合废塑料裂解,汽油馏分中轻烃（Ｃ５～８）和氢的含量均较高,芳烃含量显著降低,烷烃,特别是异构烷烃含量显著增加,环烷烃含量增大。３种催化剂的作用效果各不相同,在Ａｌ２Ｏ３存在下催化裂解所得汽油馏分与石脑油（工业裂解制乙烯原料）的性质接近,烷烃、氢质量分数分别为 ５３％,２０％,特性因数为１１．９３,预测作裂解原料可能会获得较高乙烯收率。     

交联剂对季铵化壳聚糖膜结构与性能的影响

以季铵化壳聚糖为制膜原料,分别以戊二醛和乙二醇二缩水甘油醚为交联剂,制备2种不同交联剂交联的季铵化壳聚糖膜,考察2种交联膜的含水率、离子交换量、电导率、机械强度等性能。结果表明,使用交联剂后膜的含水率、溶胀度、离子交换量均随交联剂用量的增加而降低,机械强度（拉伸强度和断裂伸长率）随交联剂用量的增加先增大再减小。使用乙二醇二缩水甘油醚为交联剂的季铵化壳聚糖膜,其导电性能、机械性能以及含水率等指标均优于使用相同剂量的戊二醛为交联剂的季铵化壳聚糖膜。     

基于PLC的校园照明智能控制系统设计

大学的电能消耗中,照明用电占了绝大部分,其中道路和景观照明容量大,工作时间长,且常采用手动控制方法,造成了浪费.为此,针对学生的活动规律,在新校区道路和景观照明设计时,采用了PLC智能控制.学生公寓熄灯之前一段时间,道路照明和景观灯全部开启;之后的时间,适当降低道路照度要求,一部分景观灯关闭;另外,寒暑假期间,也采用了不同的时段控制方式.该照明智能控制系统运行以来,通过测算,每年节约电能达25%以上,灯具的使用寿命也有所提高,系统稳定可靠,完全满足了学校的照明要求,达到了预想的结果.