荧光法生物气溶胶监测仪性能验证及应用

利用荧光法生物气溶胶监测仪设备分别进行总粒子计数效率、荧光粒子计数效率评价，并在实验室和实际应用场景利用多种微生物气溶胶进行验证。通过菌落计数法和显微镜观察2种传统的离线检测方法与实时在线生物气溶胶监测仪的数值比对，发现实时生物气溶胶监测技术与传统方法检测结果具有较好的一致性。同时应用生物气溶胶监测仪对不同应用场景中的生物粒子进行监测，验证了检测结果的的可靠性。     

生物气溶胶监测仪生物计数评价装置的搭建和方法研究

生物气溶胶监测仪基于生物分子激光诱导荧光的原理监测生物性颗粒物的存在和数量,其发展对公共卫生安全以及国防安全的早期预警具有重要意义。通过设计并搭建一套生物气溶胶监测仪的校准装置,雾化菌液后,利用菌落计数法评价生物气溶胶监测仪的关键技术指标,研究了菌种,菌液浓度,荧光强度等因素对监测结果的影响。结果表明:搭建的装置产生的生物气溶胶足够均匀稳定,通过采样菌落计数法对气溶胶浓度进行定值,初步实现对生物气溶胶监测仪的校准。     

微生物采样器采样效率测试方法研究

为更好的满足市场上不同类型的微生物气溶胶采样器测试需求,进一步指导生物气溶胶采样器的设计、制造、实际应用,提升国产生物气溶胶采样器的研发水平和测试精度,介绍了通过发生粒子模拟微生物气溶胶测试微生物采样器采样效率的荧光法和计数法两种测试装置的组成、测试方法以及数据处理步骤等。同时采用两种测试方法对国产的AGI-30微生物采样器和安德森六级微生物采样器进行测试,得到两款采样器的采样效率结果,以及不同采样条件对采样效率的影响。数据结果表明,AGI-30微生物采样器的采样效率随着发生颗粒粒径的增大而增加,对5μm颗粒的采样效率可达90%以上,且随着采样流量的增大,采样效率逐渐减小。此外,采样时间对采样效率也有明显的影响。安德森六级微生物采样器对8种不同粒径的粒子的采样效率均较高,基本在99%左右,存在随着粒径增大,采样效率增大的趋势。此外,通过两种测试方法的比较,可以明确荧光法和计数法与传统微生物培养法相比较更为简便,且测试过程安全、数据可靠,能够快速得到测试结果。同时荧光法与计数法相比实验过程存在较多步骤,且存在荧光淬灭问题,因此两种方法相比较,可优先选择计数法对生物采样器进行采样效率测试。     

生物气溶胶监测仪的校准方法比较

生物气溶胶监测仪利用荧光光谱法检测空气中的生物性物质,对疾病防控以及生物防恐预警意义重大.研究发现目前的国产生物气溶胶监测仪在采集空气中的生物颗粒时并不能区分不同细菌状态,得到的为总细菌数.通过实时定量PCR法和菌落计数法检测BioSampler采集瓶中的微生物,发现总细菌数和可培养的细菌数差异显著.利用扫描电子显微镜...     

河北地区秋季大气气溶胶物理特征分析

利用2005年10月20日在河北省石家庄和邯郸地区进行的一次飞机探测资料,初步分析了石家庄和邯郸上空的气溶胶粒子数浓度、粒径、粒子谱垂直分布特征,对石家庄与邯郸之间的水平飞行气溶胶粒子数浓度资料进行分析,并对石家庄、邯郸的气溶胶粒子谱进行函数拟合。结果表明:各高度层气溶胶粒子数浓度基本上都是石家庄高于邯郸,各高度层粒子平均直径基本上都是石家庄低于邯郸。两地气溶胶粒子数浓度、粒子平均直径随高度的分布有不同特点。石家庄、邯郸气溶胶粒子谱谱型,低层相似,基本都是单调下降,高层粒子谱谱型为多峰型。3100m高度层粒子数浓度在水平方向上分布不均匀,城市附近上空气溶胶粒子数浓度相对较大,郊县气溶胶粒子数浓度相对较小。随着高度增加,粒子数浓度减小,水平方向的绝对变化越来越小。利用幂函数N(D)=AD-B可以对不同高度气溶胶粒子谱进行较好的拟合。     

生物气溶胶采样器采样效率计量评价方法研究进展

对生物气溶胶中微生物的采集、种类鉴别与浓度监测是评估生物气溶胶风险性的关键步骤。生物气溶胶采样器对气溶胶中活性微生物粒子的有效采集，是进行气溶胶危险因子分析的前提。通过对生物气溶胶采样器性能、采样物理效率和采样生物效率的不同计量评价方法进行分析和综述，以期为评价方法的规范一致和标准化提供参考。     

尘埃粒子计数器全粒径范围内计数效率的校准

为实现对尘埃粒子计数器全粒径范围内的计数效率校准,分别对尘埃粒子计数器(OPC)-凝结核粒子计数器(CPC)-气溶胶静电计(FCAE)的逐级溯源方法和光学显微镜计数方法进行技术研究,建立一套完整的校准方法和装置。结果表明:装置具有很好的溯源性,能保证国内关于尘埃粒子计数器计数效率的计量技术的准确性。     

气旋式生物气溶胶采样器采集物理效率评价方法研究

为了评价气旋式生物气溶胶采样器的采集效率,搭建了颗粒物浓度均匀、稳定的静态箱法评价装置,对国内2款气旋式生物气溶胶采样器的采集物理效率进行了测量,最终拟合得到采集效率曲线。测量结果表明:在品牌一采样器的固定采样流量下,其采集物理效率曲线的Da50(采集效率为50%时的空气动力学直径)为0.91μm;品牌二采样器具有5种可调的采样流量,在不同流量下Da50分别为1.60μm、1.36μm、1.19μm、1.06μm和1.05μm。对比了使用初始容量分别为15mL和7.5mL的采样液得到的品牌二采样器的采集物理效率,发现采样液初始容量较少时,采集物理效率偏低。为气旋式生物气溶胶采样器性能的评价方法提供了参考。     

表面可修饰的荧光复合微球的制备及表征

采用反相悬浮乳液法合成了丙烯酸(AA)含量不同的N-异丙基丙烯酰胺(NIPAM)共聚丙烯酸(AA)的聚合物模板P(NIPAM-co-AA), 以此作为微反应器, 分别用两种不同的方法制备了P(NIPAM-co-AA)-co-Alq3 (八羟基喹啉铝)荧光复合微球, 再用四乙氧基硅烷(TEOS)对其表面进行修饰, 获得了表面功能化的P(NIPAM-co-AA)-Alq3-SiO₂荧光复合微球。用SEM、 IR、 FM和XRD等手段对其结构和性能进行表征。结果表明: 所制备的荧光复合微球单分散性好、 荧光发光效率较高且性能稳定, 同时具有较大的比表面积; 功能化的荧光复合微球可用于高通量药物筛选和识别生物大分子等生物医学领域。      

单分散荧光磁性多功能微球的制备与表征研究

通过分散聚合法制备微米级单分散聚甲基丙烯酸甲酯(PMMA)微球,以此为空白载体,交替包覆聚乙烯亚胺(PEI)和修饰有柠檬酸钠的Fe3O4纳米粒子,得到了磁性微球(PMMA-M)。通过偶联反应分别成功制备了罗丹明B(RhB)、羧基荧光素(CFRC)与氨丙基三乙氧基硅烷(APTES)的荧光硅烷化试剂,采用Stober法将荧光硅层成功包覆在磁球表面。最终制备了单分散、超顺磁的荧光核/壳/壳型聚合物微球(PMMA-M-F)。通过透射电子显微镜观察微球形貌圆整,振动样品磁强计表明微球的饱和磁化强度高达9.8emu/g,并且具有超顺磁性。激光共聚焦显微镜显示多功能微球具有荧光。     

基于静态箱法的PM2.5切割器捕集效率评价及拟合曲线优化研究

研究了基于静态箱法的PM2.5切割器捕集效率评价系统。通过设计并搭建评价系统,使用标准规定的8种粒径的聚苯乙烯小球进行雾化发尘,在静态箱中产生符合测量要求的气溶胶环境,使用空气动力学粒径谱仪对切割前后的颗粒物进行计数测量、最终获取切割器的捕集效率曲线,并选择最佳插值拟合算法进行数据拟合。通过对国产以及进口的切割器分别进行评价实验,获取了切割器的捕集效率。该研究结果有助于规范切割器的生产与使用,为后续开展其他类型切割器的评价提供参考。     

Mass-measurement-type optical particle counting method for determination of number concentration of liquid-borne particles

We have developed a measurement method that enables accurate determination of the number concentration of liquid-borne particles by adopting simultaneous particle counting and mass measurement. The new measurement method consists of an optical particle counter (OPC) for particle counting, an electronic balance for mass measurement, a syringe pump for sampling, and a pulse height analyzer for signal processing. We refer to this method as the mass-measurement-type optical particle counting (M-OPC) method. The M-OPC method facilitates both metrological traceability of the mass of measured suspensions and evaluation of the counting efficiency of OPCs. Using the M-OPC method, we evaluated the measurement accuracy of two different types of OPCs: a light-scattering type and a light-extinction type. The validity of the measurement results obtained with the M-OPC method was examined by comparison with the results of an independent microscopic method using a scanning electron microscope (SEM). The M-OPC method also offers the possibility of calibrating the number concentration of particles in suspensions with diameters from the sub-micrometer to micrometer range by combining multiple OPCs. This method is expected to be used as the national primary standard at the National Metrology Institute of Japan of the National Institute of Advanced Industrial Science and Technology.     

Fundamental Mass Flow Measurement of Solid Particles

A generic mass flow measurement device was developed as a variation on the theme of counting. In a hypothetical infinitely sparse mass flow, the number of passing particles could be counted in a time frame and multiplied by the mean mass per particle to obtain a mass flow per time unit. In a mass flow of realistic density, however, particles travel in cluster formation and direct counting of individual particles is impossible. If a method could be available that reconstructs the original number of particles in a cluster, the mass flow can be computed for realistic clustered mass flows. This reconstruction algorithm was developed in this research; it uses the measured cluster lengths to reconstruct the total number of particles in each passing cluster. The lengths of the clusters were measured with an optoelectronic device. The reconstruction algorithm was developed using simulation, augmented by clustering theory. For identical diameter particle flow, simulation results showed that the number of particles in a cluster could be reconstructed using a very simple reconstruction formula. This formula uses only the total number of clusters per time frame and the total number of individual particles measured in the same time frame. However, identical diameter flow is not realistic, since even identical particles are measured with a certain error. Reconstruction of the realistic distributed diameter particle flow was approximated using the identical particle method. The optical mass flow sensor has major advantages over traditional methods. It is virtually insensitive to vibrations, contamination, temperature drift, and misalignment and the underlying measurement concept is well understood. But most importantly, the sensor does not require calibration. The mass flow of identical particles (4.5 mm air gun pellets) was measured with an error smaller than 3% even for high density flow rates.     

Fundamental Mass Flow Measurement of Solid Particles

A generic mass flow measurement device was developed as a variation on the theme of counting. In a hypothetical infinitely sparse mass flow, the number of passing particles could be counted in a time frame and multiplied by the mean mass per particle to obtain a mass flow per time unit. In a mass flow of realistic density, however, particles travel in cluster formation and direct counting of individual particles is impossible. If a method could be available that reconstructs the original number of particles in a cluster, the mass flow can be computed for realistic clustered mass flows. This reconstruction algorithm was developed in this research; it uses the measured cluster lengths to reconstruct the total number of particles in each passing cluster. The lengths of the clusters were measured with an optoelectronic device. The reconstruction algorithm was developed using simulation, augmented by clustering theory. For identical diameter particle flow, simulation results showed that the number of particles in a cluster could be reconstructed using a very simple reconstruction formula. This formula uses only the total number of clusters per time frame and the total number of individual particles measured in the same time frame. However, identical diameter flow is not realistic, since even identical particles are measured with a certain error. Reconstruction of the realistic distributed diameter particle flow was approximated using the identical particle method. The optical mass flow sensor has major advantages over traditional methods. It is virtually insensitive to vibrations, contamination, temperature drift, and misalignment and the underlying measurement concept is well understood. But most importantly, the sensor does not require calibration. The mass flow of identical particles (4.5 mm air gun pellets) was measured with an error smaller than 3% even for high density flow rates.     

生物气溶胶雾化器对大肠杆菌活性影响的评价

生物气溶胶的研究依赖于稳定可靠的雾化过程。从颗粒数量浓度、粒径大小分布、细菌可培养性和细胞膜破损等方面评价不同气溶胶发生器的性能, 并探讨进气流量的影响。结果表明在气溶胶发生过程中的机械应力严重损害细胞膜的完整性,使得细菌的可培养率降低90%以上,并且随着进气流量的增加,细胞碎片的比例增加,细胞膜损伤更为严重。由于生物气溶胶的研究不仅需要高浓度的微生物,更要保证细胞的完整性和可培养性,因此以上研究将对生物气溶胶发生器的性能评价和选择提供依据。     

在线式光电自动计数方法及应用

利用激光器和光电管设计了激光光电传感器,当有工件通过时光被遮挡住,光电管输出一个脉冲,对此脉冲信号进行计数即为工件数。基于这种光电检测方法研制了一台在线式光电自动计数仪,并对激光光源进行缩束准直,解决了小工件计数的难点。实验表明,该仪器计数准确、检测速度快,实用性强。     

A Highly Effective DPA Attack Method Based on Genetic Algorithm

As one of the typical method for side channel attack, DPA has become a serious trouble for the security of encryption algorithm implementation. The potential capability of DPA attack induces researchers making a lot of efforts in this area, which significantly improved the attack efficiency of DPA. However, most of these efforts were made based on the hypothesis that the gathered power consumption data from the target device were stable and low noise. If large deviation happens in part of the power consumption data sample, the efficiency of DPA attack will be reduced rapidly. In this work, a highly efficient method for DPA attack is proposed with the inspiration of genetic algorithm. Based on the designed fitness function, power consumption data that is stable and less noisy will be selected and the noisy ones will be eliminated. In this way, not only improves the robustness and efficiency of DPA attack, but also reduces the number of samples needed. With experiments on block cipher algorithms of DES and SM4, 10% and 12.5% of the number of power consumption curves have been reduced in average with the proposed DPAG algorithm compared to original DPA attack respectively. The high efficiency and correctness of the proposed algorithm and novel model are proved by experiments.