一种谐振式露点测量方法

针对大气湿度测量问题,提出一种基于谐振式的露点测量方法,并设计了一套独立的露点传感装置.利用QCM原理将石英晶体谐振器作为湿敏元件,用半导体制冷器对其进行制冷,使其表面出现结露现象,导致石英晶体谐振器的谐振频率出现突变,以此达到对露点的识别,同时测取结露时刻石英晶体表面的温度,从而获得当前环境下的露点温度.通过实验验证了此方法的可行性与准确性,并将获取的实验数据与实际提供的环境数据进行对比分析,相对湿度误差达到±1.37%RH,此方法具有精度和灵敏度双高的优点,并且成本低、可操作性强.     

PEG-based bioresponsive hydrogels with redox-mediated formation and degradation

A hydrogel which will undergo macroscopic transition responding to redox stimuli is prepared. Mercapto precursors are prepared from 4-armed polyethylene glycol and after deprotection of thiolate anions, they can transform into disulfide crosslinked hydrogels within 3 min by responding to oxidant H₂O₂. Desirable elasticity is exhibited with a wide range of storage modulus from 50 Pa to 14 kPa through rheological investigation. In addition, the hydrogels are found to be hydrolytically stable but degrade within 75 days when exposed to reductant such as glutathione (GSH). So gelation time and degradation behavior can be regulated by concentrations of precursor, oxidant, reductant, temperature, and pH value. Notably, interest arises from the long-period degradation under low GSH concentration of 0.01 mM that is similar to extracellular level, but not the fast disintegration under high concentration intracellular, providing the possibility of “smart” degradation responding to those cell-secreted biomacromolecules during the process of tissue regeneration. Furthermore, both hydrogels and their degradation products show cell viability above 90% culturing with C2C12 cells, representing nontoxic properties. Such a stimuli-responsive degradation strategy will give promising application in tissue repair and regeneration; especially enable the achievement of matching the degradation kinetics with physiological environment.     

CNTs增强Cr基复合电刷镀层的性能

以45号钢为基体,采用电刷镀制备了Cr-CNTs复合镀层。通过X射线衍射仪(XRD)、扫描电镜(SEM)、扫描电子显微镜附带能谱仪(EDS)等技术对镀层的晶粒尺寸,截面与表面形貌及CNTs在镀层表面的分布进行了表征。此外,利用显微硬度计、电化学工作站、磨损试验机等仪器对镀层的硬度、抗腐蚀性、耐磨性等进行了测试。研究结果表明:Cr-CNTs复合镀层组织致密无明显缺陷,CNTs弥散分布于镀层中,在胞状组织的交界处出现了富集;适量CNTs的加入在一定程度上细化了镀层的晶粒;在CNTs弥散强化和细晶强化等作用下,复合镀层的硬度提高了23.8%,腐蚀速率降低了49.2%,而且耐磨性能也得到了显著的改善。     

一种新的安全协议验证方法

提出了一种基于Petri网的安全协议形式化描述和安全性验证的方法．该方法的特点是利用逆向状态分析和Petri网的状态可达性分析，判定协议运行过程中可能出现的不安全状态以及这些状态是否可达．通过实例证明了这种方法的有效性．     

钢铁零件挤压铸造的工业化应用

我国钢铁零件挤压铸造目前已经进入针对具体零件推广应用的新时期,主要生产设备和工艺技术正在向专业化方向发展,轮盘盖、叉架座和箱体类钢铁零件的挤压铸造都已获得成功应用。实践证明,该工艺适用性强、成本低、绿色度高,适于生产高品质要求的中小工件。今后的研究重点是钢铁零件挤压铸造工艺设计准则研究和从热.力.材三方耦合的角度进行专用涂料的系列化研究、模具设计的科学化和模具材料的最优化研究。     

一种自动清洗玻璃窗的机器人

基于51单片机的控制原理,研制了一种自动清洗玻璃窗的机器人及其控制系统,包括清洗机器人的结构设计、控制系统设计、样品的工作过程简介.实验表明,该清洗机器人结构简单、控制可靠、清洗效果较好,可以推广到家居和楼宇的清洗领域.     

汽车怠速方向盘振动控制研究

在分析汽车怠速工况下方向盘振动产生机理基础上,针对某款AT轿车怠速开空调时方向盘振动过大的问题,分别对激励源、主要传递路径及转向系统模态进行分析。得出驱动轴传递力偏大及方向盘固有频率与发动机激励频率耦合是导致该车怠速工况方向盘振动大的主要原因。在此基础上,提出并实施发动机怠速目标转速降低50 r/min、驱动轴万向节节型由DO型改为GI型及转向柱结构加强三个方案,有效降低驱动轴传递力及提高转向系统固有频率,使该车方向盘怠速振动得到有效控制。     

食管内照射支架治疗晚期食管癌六年回顾性分析

目的 观察食管置入内照射支架的疗效及安全性。方法 回顾分析３２例晚期食管癌患者置入食管内照射支架后支架置入的时间和置入成功率、即时疗效、近中期疗效、生存期、并发症、体重、血象、免疫指标、平均住院时间和住院费用。结果 支架置入术操作时间平均（１８ ± ５） ｍｉｎ,置入成功率１００％,释放过程中无放射粒子脱落,吞咽困难缓解率为１００％,４例患者出现再狭窄,１例出现支架移位,术后１个月卡氏评分达６０ 分以上的患者增至９０％,术后生存时间平均（８．７ ± ６．６）个月,平均住院日为（７．８ ± ３．７） ｄ,平均住院费为（１．２ ± ０．３）万元。结论 １２５Ｉ 种子源食管内照射支架临床应用安全有效,操作便捷,能有效延长患者生存期。     

Ultraviolet-shielding and conductive double functional films coated on glass substrates by sol-gel process

Ultraviolet-shielding and conductive double functional films were composed of CeO2-TiO2 film and SnO2:Sb film deposited on glass substrates using sol-gel process.Ce(NO3)3·6H2O and Ti(C4H9O4),SnCl4 and SbCl3 were used as precursors of the two different functional films respectively.The CeO2-TiO2 films were deposited on glass substrates by sol-gel dip coating method,and then the SnO2:Sb films with different thickness were deposited on the pre-coated CeO2-TiO2 thin film glass substrates,finally,the substrates coated with double functional films were annealed at different temperatures.The optical and electrical properties of the CeO2-TiO2 films and the double films were measured by UV-Vis spectrometer and four probe resistance measuring instrument.The crystal structures and surface morphology of the films were characterized using XRD and optical microscope,respectively.The obtained results show that the ultraviolet-shielding rate of the glass substrates with CeO2-TiO2 films is not less than 90%,and transmittance in visible lights can reach 65%.With the thickness of the SnO2:Sb film increasing,its conductivity became better,and the surface resistance is about 260 Ω/ when the SnO2:Sb films were deposited 11 cycles of the dip on the pre-coated CeO2-TiO2 glass.The ultraviolet-shielding rate of the glass substrates with double functional films is higher than 97%,and the peak transmittance in the visible lights is 72%.Additionally,with increasing the heat treatment time,the Na+ of the glass substrates diffuses into the films,resulting in the particle size of SnO2 crystal smaller.     

NQR方法中平面型天线探测爆炸物研究

为增加基于核四极矩共振（NQR）技术探测爆炸物的手段,对爆炸物探测系统中的天线进行了研究,并确定了平面型天线的形状、尺寸以及探测方法。实际测试表明,探测结果准确,试验结果也将对研究便携式爆炸物探测装置以及军事探雷等实际应用具有指导意义。