基于滤波差分的双阈值弱划痕提取算法

高质量光学元件表面缺陷中存在一些深度较浅或者宽度较窄的划痕,在暗场成像检测中,该类划痕产生的散射光灰度值很低,甚至淹没在背景光中,很难被目视或常规机器视觉识别,造成划痕缺陷的漏检。针对该问题,以既有的疵病检测系统为基础,根据划痕灰度的等级特征,提出双阈值法分类处理划痕缺陷。在低阈值的弱划痕处理中,根据弱划痕和背景的频率特征以及空间对比度特征,设计了频域滤波及背景差分算法。通过空间域以及频率域的滤波处理,排除高频噪声以及高亮度噪声,根据几何特征等提取弱划痕图像中的复杂背景。经差分处理后,提取弱划痕并增强对比度,最后与正常灰度级划痕信息一同通过高阈值(正常阈值)进行后续划痕的特征提取,即得到所有的划痕信息,为划痕缺陷总长度计算以及最大长度的分级判定奠定基础。实验结果表明,该算法避免了过低二值化阈值引入的背景等不规则噪声,使得划痕与背景的对比度大大增强。目前该算法已经应用于惯性约束聚变系统中大口径光学表面划痕的定量检测,并且使长度计量的准确度已提升到约80%。     

4-取代-1-(2-甲基-6-(吡啶-3-基)-烟酰)氨基脲类衍生物合成与生物活性研究（英文）

经分子杂交技术合成了一系列4-取代-1-(2-甲基-6-(吡啶-3-基)-烟酰)氨基脲类衍生物.采用噻唑蓝(MTT)比色法研究了目标化合物对人肝癌细胞(QGY-7703)、人肺癌细胞(NCl-H460)和乳腺癌细胞(MCF-7)的体外抗肿瘤活性.1-(2-甲基-6-(吡啶-3-基)烟酰基)-4-(2,4,6-三氯苯基)氨基脲(4n)显示了最优的活性,其半数抑制浓度(IC_(50))为8.89～11.45μmol/L.细胞体内的生物研究显示,4n药物处理能明显增加细胞体内PARP切割水平以及诱导QGY-7703肿瘤细胞的凋亡.     

文教融合，以学促保——以非物质文化遗产的保护传承在化学与社会课程中的呈现为例

非物质文化遗产是我国文化软实力“活”的呈现,为华夏璀璨文化提供根基和养分。本文以我国非物质文化遗产中所蕴藏的化学智慧为线索,让化学、科技、文化在化学类通识课程中相互融合碰撞,让课堂充满知识性与趣味性。论文通过文教融合,实现非物质文化遗产的保护传承,进一步助推非物质文化遗产文化现代化,在保护传承中创新,增强学生对非物质文化遗产的科技和文化自信,最终达到以学促保的目的。     

分光光度法测定化肥中有害成份硫氰酸盐

当SCN 浓度 >5mg/L时对植物尤其是农作物就会产生危害 ,因此 ,控制化肥中SCN- 限量十分必要。测定SCN- 的电位滴定法[2 ] 灵敏度高 ,线性范围宽 ,但样品中Cl- /SCN- >1比例 ,会严重干扰测定 ,必须分离。离子色谱、高效液相色谱大多是针对痕量SCN- ( <1mg/L)测定 ,很有效。化学滴定法要求SCN- > 1 % ,且Cl- 干扰也同样需加以考虑。对于SCN- <0 1mg/L ,甚至 μg/L级的测定 ,更多地用动力学光度法[3] ,但分析样品一定要基体少 (如水样 )。且该法对温度、放置时间要求极严格。本文利用Cu2 +、吡啶 (Py)、SCN- 在氯仿中形成稳定的…     

Vibration-assisted coherent excitation energy transfer in a detuned dimer

The important role of high-energy intramolecular vibrational modes for excitation energy transfer in the detuned photosynthetic systems is studied. Based on a basic dimer model which consists of two two-level systems(pigments)coupled to high-energy vibrational modes, we find that the high-energy intramolecular vibrational modes can enhance the energy transfer with new coherent transfer channels being opened when the phonon energy matches the detuning between the two pigments. As a result, the energy can be effectively transferred into the acceptor. The effective Hamiltonian is obtained to reveal the strong coherent energy exchange among the donor, the acceptor, and the high-energy intramolecular.A semi-classical explanation of the phonon-assisted mechanism is also shown.     

Synthesis and properties of Au-Fe3O4 and Ag-Fe3O4 heterodimeric nanoparticles

Monodisperse Au-Fe 3 O 4 heterodimeric nanoparticles (NPs) were prepared by injecting precursors into a hot reaction solution.The size of Au and Fe 3 O 4 particles can be controlled by changing the injection temperature.UV-Vis spectra show that the surface plasma resonance band of Au-Fe 3 O 4 heterodimeric NPs was evidently red-shifted compared with the resonance band of Au NPs of similar size.The as-prepared heterodimeric Au-Fe 3 O 4 NPs exhibited superparamagnetic properties at room temperature.The Ag-Fe 3 O 4 heterodimeric NPs were also prepared by this synthetic method simply using AgNO 3 as precursor instead of HAuCl 4.It is indicated that the reported method can be readily extended to the synthesis of other noble metal conjugated heterodimeric NPs.     

Wireless contactless pressure measurement of an LC passive pressure sensor with a novel antenna for high-temperature applications

In this paper, a novel antenna is proposed for high-temperature testing, which can make the high-temperature pressure characteristics of a wireless passive ceramic pressure sensor demonstrated at up to a temperature of 600°C. The design parameters of the antenna are similar to those of the sensor, which will increase the coupling strength between the sensor and testing antenna. The antenna is fabricated in thick film integrated technology, and the properties of the alumina ceramic and silver ensure the feasibility of the antenna in high-temperature environments. The sensor, coupled with the ceramic antenna, is investigated using a high-temperature pressure testing platform. The experimental measurement results show that the pressure signal in a harsh environment can be detected by the frequency diversity of the sensor.     

横向加热石墨炉原子吸收法测定儿童血液和头发中的铅和铝

采用横向加热石墨炉原子吸收法测定儿童血液和头发中的铅和铝,以磷酸二氢铵和硝酸镁或硝酸镁作基体改进剂,提高了测定铅的灰化温度和灵敏度,消除了基体干扰和记忆效应。方法简便、快速、准确度高。铅和铝的特征量分别为：2.3×10-11 g和2.2×10-11 g,相对标准偏差为3.0%～11.4%,回收率为96%～110%。     

HL-2M装置中心螺线管线圈电源变流器过流保护的仿真研究

利用MATLAB仿真工具,搭建HL-2M中心螺线管(CS)电源系统模型,研究了CS电源变流器过流保护策略。通过仿真研究,为HL-2M CS电源系统中变流器制定了最优的过流保护策略,这为电源安全可靠的运行提供了理论依据。     

A low-cost invasive microwave ablation antenna with a directional heating pattern

Microwave ablation (MWA) is a cancer treatment method. The tumor tissue absorbs electromagnetic energy, which heats and kills it. A microwave ablation antenna plays a critical role in this process. Its radiation field must completely cover the tumor but not the healthy tissue. At present, the radiation pattern of most invasive ablation antennas is spherical. However, in the clinic, the shape of some tumors may be asymmetrical or the antenna cannot be inserted into the center of the tumor for some other reason. In order to solve these problems, a directional heating antenna for microwave ablation is proposed in this paper. The proposed antenna, operating at 2.45 GHz, consists of a monopole and a reflector. The feed is given by a substrate integrated coaxial line (SICL) and coplanar waveguide (CPW). The omnidirectional radiation field of the monopole is reflected by a reflector that is extended from the outer conductors of the SICL to form a directional radiation field. The impedance matching network is designed on SICL to match the antenna to 50 Ω . The antenna is fabricated using a mature printed circuit board (PCB). The reflection coefficient of the antenna in porcine liver tissue measured by a vector network analyzer shows good agreement with the simulations. Then, an ablation experiment in porcine liver is conducted with power of 10 W for 10 min, and the experimental results confirm the validity of the design.