颜填料对涂料降温性能的影响

为了满足军事上深色降温涂料的需要,往往需要向白色涂料中加入一定量的色浆,设计了具有可比性的三种涂料:B涂料、Z涂料、TU涂料,考察了颜填料对深色降温涂料降温性能的影响.最后通过仪器测试,说明了这种影响之间的关系.     

基于QD-SOA-XGM的全光逻辑或非门研究

为了改善基于交叉增益调制效应的量子点半导体光放大器全光逻辑或非门的性能,研究了QD-SOA-XGM全光逻辑门的码型效应特性,用两个连“1”脉冲和单个“1”脉冲的峰值功率来衡量,即P30/P20。研究结果表明:第一级输入电流越小,逻辑或非门的性能越好,而第二级输入电流对或非门性能影响很小;在一定范围内,输入连续光功率越大、有源区长度越长、有源区宽度越宽、最大模式增益越大、损耗系数越小,或非门输出效果越好。     

300 mm快速升降温炉体的研究

介绍了一种快速升降温炉体的研制。由于传统的炉体升温响应较慢,升温耗时耗能,与之相比的快速升降温炉体,在升温性能方面,实现了升温响应快、抑制超调效果好。在降温方面,传统炉体只能依靠自然降温,平均降温速率3~4℃/min,增加了晶圆的工艺时间,增大了设备工艺气体、水、电等资源的消耗,而具有快速降温能力的炉体,很好地克服了传统炉体自然降温方面的不利。在新近研制的300 mm立式氧化设备中,实现了30℃/min的升温速率和15℃/min的降温速率,大大缩短了晶圆的工艺时间,保证了晶圆的成膜质量。     

降温速率对Mn-Ni-Fe-O系热敏陶瓷电学性能的影响

采用草酸盐共沉淀法制备了Mn-Ni-Fe-O体系NTC(Negative Temperature Coefficient)热敏陶瓷,并运用XRD,SEM和电学性能测试等手段研究陶瓷样品的相结构和电学性能,重点考察了降温速率对电学性能的影响。结果表明：慢速降温条件下样品的电阻率低于快速降温的电阻率,降温速率对Mn-Ni-...     

降温速率对Zr0.8Sn0.2TiO4陶瓷微波特性的影响

以Zr0.8Sn0.2TiO4 (ZST)作为主配方,以w(WO3)=0.25％和w(ZnO)=1％作为改性剂,采用传统的固相法工艺,在烧结环节对其进行降温速率的研究.通过对样品的线性收缩率的测量知1 340℃是最佳的烧结温度.在1 340～1 000℃的降温过程中研究了不同的降温速率对ZST微波性能的影响.对不同降温速率的样品进行了密度测量.结果表明,降温速率为10℃/h时,样品的密度5.05 g/cm3最大.通过X线衍射(XRD)分析仪及矢量网络分析仪对其样品晶体结构和微波介电性能进行了分析.实验结果表明,少量的WO3和ZnO加入可使ZST的烧结温度降低到1 340℃;降温速率的减缓会改变晶格尺寸,使晶格体积缩小.微波性能测试最佳结果为在1 340℃烧结、10℃/h降温速率处介电常数为36.88,品质因数与频率之积Q×f值为35 000 GHz(7.8 GHz).     

选择远红外加热辐射涂料要注意经济效果

在八十年代以前,我国对远红外线技术的推广,还处于比较幼稚的阶段。就辐射涂料而育,多是单纯追求辐射率,即认为辐射率越高,辐射强度越大,就越好。因而当时大部分推广者与元件制造厂都认为涂料越黑、越粗糙,越接近黑体,其辐射效果就越好,就会使被烘物吸收得越好,能使能量的利用率达到最高。通过六年来的实践和理论研究证明,用远红外线加热,并不完全是辐射涂料越黑、越粗糖越好。     

静电模块对颗粒物与微生物的净化特性

为了检测空气净化器内静电模块在不同风速、不同湿度下对不同粒径颗粒物以及微生物去除效果,从而对其除尘性能影响因素的分析提供基础性的数据。研究测试了静电模块对PM 0.3、PM 1.0、PM 2.5、PM 10微细粉尘的净化特性及除菌效果。结果表明:在一定范围内,风速越大,则颗粒物衰减越快,当风速为0.5m/s时,衰减速率达到最大,再加大风速,颗粒物衰减的速率下降;当湿度越大时,颗粒物PM 0.3、PM 1.0、PM 2.5、PM 10去除效果下降,相同湿度时,颗粒物粒径越大,越容易去除。风速越高,静电模块除菌的效果越好。风速为0.1m/s时,90 min后,除菌率最终为94.06%,当风速为0.3 m/s、0.5 m/s、0.8 m/s时,除菌率最终可以达到99%。     

多径衰落信道下BOC信号捕获性能分析

针对多径衰落信道下BOC(二进制偏移载波)信号的捕获问题,通过对多径衰落信道建模,运用目前较优越的捕获算法对各信道下的捕获性能进行比较。结合莱斯因子K、多径径数L以及多径延迟,分析了多径衰落信道对B OC信号捕获产生的影响。理论分析和仿真结果表明,K值越大,捕获函数峰值越大,捕获性能越好;L值越小,出现副峰越少,捕获性能越好。     

超细矿渣对低品质水泥性能的改善效果

在低品质水泥中掺15%或25%超细矿渣组成复合胶凝材料,将用该复合胶凝材料配制的混凝土与用普通水泥配制的混凝土进行性能对比研究。结果显示:超细矿渣能够明显改善低品质水泥的性能,且超细矿渣掺量越大,性能改善效果越明显;用复合胶凝材料配制的混凝土的强度、抗氯离子渗透性和抗碳化性能达到或超过用普通水泥配制的混凝土。掺超细矿渣的复合胶凝体系硬化浆体的后期微结构非常致密,超细矿渣所起的化学作用明显。     

GPRS数据业务性能分析

基于D-BMAP/D/1排队模型分析GPRS数据业务在简化的一步接入模式以及不同服务速率下的性能,包括RLC/MAC缓冲区队列的平均长度、小分组(Mini-Packet)的平均时延和丢弃率等.分析结果表明:当定时器T₃₁₈₂时间变长时,时延缩短,丢弃率降低;处于空闲状态的移动台产生新会话的概率越大,时延越长;缓冲区容量增加,丢弃率明显降低.但是随着每个会话中分组呼叫数目的变化,时延变化不显著.     

背面银浆用银粉对晶硅太阳电池性能的影响

分别采用液相化学还原法和机械球磨法制得球形银粉和片状银粉,研究了银粉的形貌、分散性及振实密度对背面银浆烧结膜和电池光电性能的影响。结果表明:片状银粉制备的背银浆料附着力最好、电池光电转换效率最高,球形银粉次之,树枝型银粉最差。高分散和高振实密度银粉能显著提高电池片的光电转换效率。     

Microtubule‐Templated Biomimetic Mineralization of Lepidocrocite

Protein microtubules (MTs) 25 nm in diameter and tens of micrometers long have been used as templates for the biomimetic mineralization of FeOOH. Exposure of MTs to anaerobic aqueous solutions of Fe²⁺ buffered to neutral pH followed by aerial oxidation leads to the formation of iron oxide coated MTs. The iron oxide layer was found to grow via a two‐step process: initially formed 10–30 nm thick coatings were found to be amorphous in structure and comprised of several iron‐containing species. Further growth resulted in MTs coated with highly crystalline layers of lepidocrocite with a controllable thickness of up to 125 nm. On the micrometer size scale, these coated MTs were observed to form large, irregular bundles containing hundreds of individually coated MTs. Iron oxide grew selectively on the MT surface, a result of the highly charged MT surface that provided an interface favorable for iron oxide nucleation. This result illustrates that MTs can be used as scaffolds for the in‐situ production of high‐aspect‐ratio inorganic nanowires.     

Micropatterned Down‐Converting Coating for White Bio‐Hybrid Light‐Emitting Diodes

White hybrid light‐emitting diodes (WHLEDs) are considered as a solid approach toward environmentally sustainable lighting sources that meet the “Green Photonics” requirements. Here, WHLEDs with protein‐based down‐converting coatings, i.e., Bio‐WHLEDs, are demonstrated and exhibit worthy white color quality, luminous efficiency, and stability values. The coatings feature a multilayered cascade‐like architecture with thicknesses of 1–3 mm. This limits the efficiency due to the low optical transmittance. Thus, submillimeter coatings, where the location of the proteins is well‐defined, are highly desired. It is in this context where the thrust of this work sets in. Here, a straightforward way to design microstructured single‐layer coatings, in which the proteins are placed at our command by using 3D printing, is presented. Based on comprehensive spectroscopic and rheological investigations, the optimization of the matrix and the plotting to prepare different micropatterns, i.e., lines, open‐grids, and closed‐grids, is rationalized. The latter are applied to prepare Bio‐WHLEDs with ≈5‐fold enhancement of the luminous efficiency compared to the reference devices with a cascade‐like coating, without losing stability and color quality. As such, this work shows a new route to exploit proteins for optoelectronics, setting a new avenue of research into the emerging field of Bio‐WHLEDs.     

电子浆料用超微细玻璃粉的等离子体改性

以六甲基二硅氧烷为单体,利用高频等离子体在超微细低熔磷酸盐玻璃粉体表面聚合硅氧聚合物包覆薄膜。用水和粉体压片之间的接触角变化表征了等离子体工艺参数对粉体表面能的影响。结果表明改性后粉体配制电子浆料的细度、黏度、流变特性提高显著。改性后可以改变或控制超微细粉体的表面能大小,从而可调节电子浆料的流变性和印刷适性。     

色散效应对钝化硅太阳电池减反射膜系设计的影响

在考虑折射率色散效应基础上,以加权平均反射率作为评价函数,通过智能优化算法对空间硅太阳电池减反射膜进行优化设计,得到了最佳的膜厚参数,并与不考虑色散下设计的减反射膜进行了比较。对MgF2/TiO2,SiO2/TiO2双层减反射膜,与不考虑色散情形相比,考虑色散下优化后的最小加权平均反射率分别减小了36.6%和37.6%;对具有厚度为15 nm的SiO2钝化层的硅太阳电池的MgF2/TiO2,SiO2/TiO2减反射膜重新优化设计,与不考虑色散情形相比,考虑色散下优化后的最小加权平均反射率分别减小了43.9%和33.7%;对具有不同厚度钝化层的空间硅太阳电池,在考虑色散下进行了减反射膜的优化设计。结果发现,随着钝化层厚度的增加,所得减反射膜的最小加权平均反射率也随之增大,减反射效果越来越弱。最后,在考虑与未考虑色散情形下,将钝化层膜厚也作为反演参量后重新设计。结果表明:在色散情形下所设计的减反射膜更佳,对于MgF2/TiO2/SiO2（钝化层）膜系,最佳膜厚参量为d1（MgF2）=97.6 nm,d2（TiO2）=40.2 nm,d3（SiO2）=4.9 nm;对于SiO2/TiO2/SiO2（钝化层）,最佳膜厚参量为d1（SiO2）=85.1 nm,d2（TiO2）=43.4 nm,d3（SiO2）=1.8 nm。     

CuInSe2薄膜太阳能电池非真空印刷制备技术研究

对CuInSe2(CISe)薄膜太阳能电池的吸收层进行了非真空印刷制备技术研究。使用机械化学法合成CISe前驱粉末,采用ethyl-cellulose作为分散试剂配置印刷浆,使用丝网印刷技术沉淀CISe吸收层,对沉淀的吸收层进行N2氛围的快速热退火处理,使用XRD、UV、SEM及J-V等手段对CISe吸收层进行了分析表征。结果表明:简单高效的机械化学法可获得主(112)晶向CISe前驱粉末;经丝网印刷并干燥后的CISe吸收层中含有大量有机分散剂,退火可蒸发有机分散剂并有效改善CISe结晶度,但过长的退火会增加晶体缺陷;实验制得一典型CISe薄膜太阳能电池的短路电流密度、开路电压、填充因子和转换效率分别为4.48mA/cm2、355mV、0.41和0.65%。     

多层印制电路板网印内埋电阻技术研究

利用网印导电碳浆的方法制作电阻,通过层压工艺实现电阻在多层印制电路板中的内埋.研究了导电碳浆的固化温度及固化时间与电阻值的关系,分析了导电碳浆固化程度及棕化后烘板对层压工艺可靠性的影响,测试了高温高湿与冷热冲击对内埋电阻阻值稳定性的影响.结果表明:导电碳浆固化条件选择固化温度170℃,固化时间4h,以及棕化后105℃烘...     

Detection of iron-oxide layer on the surface of iron nitride using high-resolution electron microscopy and Fourier filtering

High-resolution electron microscopy (HREM) was used to detect the surface Fe3O4 iron-oxide layer formed on [011] Fe4N iron nitride due to electron irradiation in the transmission electron microscope. The existence of a surface oxide layer was confirmed by both image processing and through-focus observation. Images of the iron oxide were revealed using the process of fast Fourier transformation (FFT) of experimental HREM images, filtering of the FFT patterns and inverse FFT. By through-focus observation, HREM images of iron oxide were obtained based on the tuning of contrast transfer function. Fourier filtering is effective for examining the beginning of phase transformation, because at this stage the diffraction spots of iron oxide are too weak to be detected. At the time when the iron oxide layer has developed to some extent, through-focus observation is useful to obtain an image of oxide layers.     

Improvement of Bondability by Depressing the Inhomogeneous Distribution of Nanoparticles in a Sintering Bonding Process with Silver Nanoparticles

Low-temperature bonding by sintering of Ag nanoparticles (NPs) is a promising lead-free bonding technique used in the electronic packaging industry. In this work, we prepare Ag nanoparticle (NP) paste using both an aqueous method and a polyol method. Sintering bonding trials were then conducted using different forms of Ag NPs. The results showed that use of the aqueous-based Ag NP paste led to inhomogeneous distribution of NPs, known as the ??coffee-ring effect.?? This led to low strength of fabricated joints. We investigated the influence of the coffee-ring effect and ways to depress it by changing the bonding material composition. Our results show that, when using polyol-based Ag NP paste as the bonding material, the coffee-ring effect was successfully depressed due to increased Marangoni flow. The corresponding shear strength of joints was increased significantly to 50?MPa at bonding temperature of 250°C.