Synthesis of New Cobalt(III) Meso-Porphyrin Complex,Photochemical, X-ray Diffraction,and Electrical Properties for Photovoltaic Cells

The present work describes the preparation and characterization of a new cobalt(III) porphyrin coordination compound named (chlorido)(nicotinoylchloride)[meso-tetra(para-chlorophenyl)porphyrinato]cobalt(III) dichloromethane monosolvate with the formula [Co^III(TClPP)Cl(NTC)]·CH₂Cl₂ (4). The single-crystal X-ray molecular structure of 4 shows very important ruffling and waving distortions of the porphyrin macrocycle. The Soret and Q absorption bands of 4 are very red-shifted as a consequence of the very distorted porphyrin core. This coordination compound was also studied by fluorescence and cyclic voltammetry. The efficiency of our four porphyrinic compounds—the H₂TClPP (1) free-base porphyrin, the [Co^II(TClPP)] (2) and [Co^III(TClPP)Cl] (3) starting materials, and the new Co(III) metalloporphyrin [Co^III(TClPP)Cl(NTC)]·CH₂Cl₂ (4)—as catalysts in the photochemical degradation was tested on malachite green (MG) dye. The current voltage of complexes 3 and 4 was also studied. Electrical parameters, including the saturation current density (J_s) and barrier height (ϕ_b), were measured.     

脉冲大电流放电引爆含能材料产生冲击波的储层改造

介绍了复合电热化学法产生冲击波的机理和冲击波改善储层物性的机制;给出了脉冲大电流引爆含能材料弹丸的结构和典型的放电参数,开展了冲击波致裂储层的实验研究;检测了样品在冲击作用下的动态应变及影响储层解吸附特性的关键参数（包括孔隙度、渗透率、抗拉、抗压强度等）,并在实验前后进行了测量和对比。研究表明,电热化学法产生的冲击波可在圆柱形砂岩样品上产生幅值为1000~1500的应变量,使砂岩出现了宏观裂缝;样品平均孔隙度由15.24%增至15.62%,平均渗透率由1.749 0910-3 m2增至2.467 0810-3 m2;抗压、抗拉和抗剪强度均下降了约30%。     

激光烧蚀硬铝产生等离子体温度和力学效应测量

为了研究激光推进技术中激光与材料相互作用的机制,获取等离子体状态参数及力学参数,采用Nd:YAG被动调Q固体激光器烧蚀硬铝,通过激光诱导等离子体光谱技术测得等离子体光谱和温度,由冲量摆测得力学参数。实验结果显示：在激光功率密度0.534×108 W/cm2时,靶材表面的等离子体温度在等离子体辐射过程中呈二次曲线衰减;改变靶材等离子体点燃阈值附近的激光功率密度时,随着功率密度的增加,等离子体温度、冲量耦合系数也随着增大,当功率密度达到靶材的等离子体点燃阈值时,各参数达到最大,此后随着功率密度增加,由于等离子体对能量的屏蔽作用,导致靶材表面的等离子体温度降低,等离子体获得的动能减少,靶材耦合的冲量降低。     

晶体级联方式宽带三倍频方案的参数优化

针对时间位相调制的宽带激光,采用分步离散傅里叶变换及四阶龙格－库塔算法进行数值模拟计算。讨论了采用KDP晶体级联方式时,入射基频光的光强、带宽以及晶体厚度对三倍频转换效率的影响。对采用一块РⅠ类二倍频晶体、一块Ⅱ类和一块Ⅰ类双混频晶体的级联宽带三倍频方式进行了晶体参数的优化。研究结果表明,使用两块级联的KDP晶体作为混频晶体,不仅能有效地提高带宽较宽条件下三倍频光的转换效率,还可以显著增大宽带三倍频的动态范围。经优化后,带宽1.11 nm时入射基频光强在3～8 GW/cm2范围内的三倍频转换效率可保持在60％～70％,比采用单倍频单混频方案时增大了30％～40％。     

Ni-W-纳米Al2O3复合涂层沉积特性的研究

采用复合电镀的方法制备出Ni-W-纳米Al2O3复合涂层,研究了Al2O3添加量、温度和超声波分散等沉积条件对复合涂层沉积特性如沉积速率、Al2O3复合量和显微硬度的影响.结果表明,随着纳米Al2O3添加量的增加,复合涂层的沉积速率、Al2O3复合量和显微硬度不断增加,但当Al2O3添加量达到15g/L时沉积速度开始下降,Al2O3添加量达到17.5g/L时硬度开始下降;适宜的镀液温度大约为80℃,超声波分散时间大约为1h.     

Identification of Heavy Metals and Organic Micropollutants in Drinking Water Sources in Typical Villages and Towns in Northeast China

This study identified and detected the existence of major pollutants in northeast China. As an alpine region and an agricultural base, this region has representative significance in pollution research. We selected 56 samples from drinking water sources of typical villages and towns, focusing on the analysis of heavy metals and organic micropollutants in northeast China. The analysis results showed that Fe and Mn were the main metal elements exceeding the standard. The exceeding rates were 17.9% and 19.6%. Experiments showed that there were 19 kinds of pesticides, 6 kinds of OPEs, 2 kinds of PAEs, 22 kinds of PPCPs. The detection rate of these 49 kinds of organic micro-pollutants were 1.79~82.14%. The characteristics of organic pollution were extensive and varied. Many underground water samples had high level of micropollutants. The water quality parameters of drinking water sources in villages and towns showed close relation to local geological conditions and agricultural activities. Actions must be taken to control these parameters from the source of pollution.     

Comparison between 1,2-Dihydropyridine and 1,4-Dihydropyridine on Hydride-Donating Ability and Activity

In this paper, detailed comparisons of the driving force in thermodynamics and intrinsic force in the kinetics of 1,2-dihydropyridine and 1,4-dihydropyridine isomers of PNAH, HEH, and PYH in hydride transfer reactions are made. For 1,2-PNAH and 1,4-PNAH, the values of the thermodynamic driving forces, kinetic intrinsic barriers, and thermo-kinetic parameters are 60.50 and 61.90 kcal/mol, 27.92 and 26.34 kcal/mol, and 44.21 and 44.12 kcal/mol, respectively. For 1,2-HEH and 1,4-HEH, the values of the thermodynamic driving forces, kinetic intrinsic barriers, and thermo-kinetic parameters are 63.40 and 65.00 kcal/mol, 31.68 and 34.96 kcal/mol, and 47.54 and 49.98 kcal/mol, respectively. For 1,2-PYH and 1,4-PYH, the order of thermodynamic driving forces, kinetic intrinsic barriers, and thermo-kinetic parameters are 69.90 and 72.60 kcal/mol, 33.06 and 25.74 kcal/mol, and 51.48 and 49.17 kcal/mol, respectively. It is not difficult to find that thermodynamically favorable structures are not necessarily kinetically favorable. In addition, according to the analysis of thermo-kinetic parameters, 1,4-PNAH, 1,2-HEH, and 1,4-PYH have a strong hydride-donating ability in actual chemical reactions.     

Impact of Different Storage Regimes on the Levels of Physicochemical Characteristics,Especially Free Acidity in Talh (Acacia gerrardii Benth.) Honey

This study investigates how storage conditions (temperature and duration) may affect the physicochemical parameters, especially free acidity (FA), of Talh honey originating from Acacia gerrardii that have naturally high FA levels. Fresh Talh honey samples were kept at 0, 25, 35, and 45 °C, and analyzed monthly over a period of eight months. The Talh honey was monofloral with 69% A. gerrardii pollen content. The free acidity (FA) of freshly harvested Talh honey samples was higher (93 ± 0.3 meq/kg) than that of standard limits (≤50 meq/kg) and remained stable at 0 °C throughout the storage period. A significantly increase in FA started to occur after storage for 6 months at 25 °C (103 ± 0.2 meq/kg), 2 months at 35 °C (108 ± 0.3 meq/kg), and 1 month at 45 °C (112 ± 0.3 meq/kg). After 8 months of storage, the highest FA level was recorded at 45 °C (159 ± 0.5 meq/kg), followed by 127 ± 0.3 meq/kg at 35 °C, 105 ± 0.2 meq/kg at 25 °C, and 94 ± 0.3 meq/kg at 0 °C. It was found that 0 °C was an appropriate temperature for storing honey for long time. The electrical conductivity (EC) of fresh Talh samples (1.46 ± 0.0 mS/cm) was above the accepted limit (≤0.8 mS/cm), which was slightly increased (non-significant) throughout the storage period under all the storage temperatures. Hydroxymethylfurfural (HMF), diastase activity (DN), and reducing sugars (RSs) showed normal levels only at 0 °C and 25 °C throughout the storage period. However, HMF exceeded the standard limits after the first month at 45 °C (127 ± 9.6 mg/kg) and after the second month at 35 °C (90 ± 23.5 mg/kg), DA decreased below standard limits after the second month (5 ± 1 DN) under 45 °C and after the seventh month under 35 °C (7 ± 2 DN, and RSs decreased below 60% after 2 months under 45 °C and after 6 months at 35 °C. The physicochemical parameters (moisture content, pH, color, and sucrose) were the least affected and were within the standard range throughout the storage period under all the storage temperatures. The levels of FA and EC in fresh Talh samples were higher than the acceptable limits. The moisture content, pH, color, and sucrose content were not affected by storage conditions and remained within the acceptable limits. HMF, DA, and RSs were significantly affected by storage conditions only at 35 and 45 °C. The storage of honey at low temperatures (0 and 25 °C) for up to eight months presented the least amount of changes in the honey, and the honey was unchanged from its fresh status. Honey storage at 35 and 45 °C resulted in significant changes. It is recommended that Talh honey, which normally has high acidity levels, should be stored at temperatures not exceeding 25 °C.     

重频超宽带脉冲干扰低噪声放大器

理论分析和仿真研究了重频超宽带脉冲对低噪声放大器（LNA）的干扰特征,给出了高斯脉冲幅度、脉宽及重频等参数对LNA干扰效果的规律,对工作于40~80 MHz频段的接收机LNA开展了相关验证实验。结果表明：干扰特征主要由LNA工作频带和脉冲参数决定;不同脉冲参数对干扰的效果影响不同,脉冲幅值的影响最显著;在验证实验研究的参数范围内,增大高斯脉冲幅度、脉宽和重频均有利于增强对LNA的干扰效果。     

Far-Field Detection of Near-Field Circular Dichroism Enhancements Induced by a Nanoantenna

Nanophotonics can enhance the inherent weak signal exhibited by chiral molecules in circular dichroism (CD) spectroscopy experiments. One mechanism to achieve this CD enhancement is based on increasing the optical chirality produced by nanophotonics antennas in their near-field, where chiral molecules are placed. However, ascertaining whether this CD enhancement is reached presents significant experimental challenges due to the complexity of measuring near-field optical chirality. Here, it is demonstrated that a local and single measurement of the degree of circular polarization in the far-field enables quantifying near-field CD enhancements. Thereby, based on this far-field measurement, the optimal response of the antenna is predicted for enhanced chiral sensing. Experimental validation of this near-to-far-field relation is provided for silicon spherical nanoantennas. The experimental results, supported by analytical theory and exact numerical simulations, can be interesting for the experimental characterization of devices capable of enhancing CD from a single far-field Stokes measurement.