有机复合光电导材料及器件研究进展

有机光电导复合材料已经成为当前国际上有机光电材料科学研究的前沿与热点之一。复合化是大幅度提高有机半导体材料光电导性能的有效手段,本文主要从有机光电导材料的复合化角度,综述了新型高效的多种有机复合光电导材料体系的制备及其光电导性能,初步解释了其相应的复合原理和光电导机理,并介绍了其在单层型光电导器件中的研究进展。最后提出了制备高性能有机光电导复合材料及单层型光电导器件的几点建议。     

纳米二氧化钛的水热法制备及在染料敏化太阳能电池中的应用

分别在盐酸和冰醋酸溶液中水解钛酸四正丁酯,得到前驱体,通过水热法制备锐钛矿型二氧化钛纳米晶体.以纳米二氧化钛为电子传输体组装染料敏化电池,通过XRDI、CP、DRS、TEM、SEM和电池的光电性能测试,研究制备的二氧化钛对电池光电性能的影响.结果表明,水热反应温度对染料敏化太阳能电池光电性能有较大影响,在有机酸介质中制备的二氧化钛具有较高的光电转换效率.     

基于碳量子点的光电器件应用新进展

碳量子点(CQDs)作为一种新型荧光碳纳米材料,由于其较高的电子迁移率、较长的热电子寿命、极快的电子取出速度,可调的带隙宽度、较强的稳态荧光等独特的光电性质和可溶液加工、成本低廉的特点,使得CQDs在光电器件领域具有广阔的应用前景,近年来受到人们的广泛关注,重要的研究成果不断涌现。本文首先简要介绍了CQDs的合成方法、化学结构及其光电性质,然后总结了CQDs在发光二极管(LEDs)、太阳能电池(SCs)和光电探测器(PDs)等光电器件领域的研究进展,最后对CQDs的发展方向进行了展望。     

有机光电导(OPC)材料分子设计的研究

本文在分析了有机光电导材料的分子结构, 电子分布状态以及电荷转移与光电导性能之间关系的基础上, 进行了有机光电导材料的分子设计, 并以酞菁聚合物的合成和光电导性的研究实施进行了验证。     

用于光电催化水分解的氧化亚铜基光电阴极研究进展

随着不可再生资源的消耗及环境污染日趋严重,开发环境友好、可再生的新能源受到广泛关注。氢可通过燃料电池进行发电,被认为是理想的洁净能源载体。耦合可再生能源,如光能、风能、海洋能等,进行光电水分解制氢是有效途径之一。氧化亚铜(Cu₂O)具有合适的能带结构、制备简单、资源丰富,成为光电阴极半导体的研究热点。然而,Cu₂O光电阴极面临光生电荷复合较快、光腐蚀严重等挑战,导致其光电效率低、稳定性差。本综述首先简要介绍光电水分解制氢原理以及Cu₂O的能带结构适配性,其次总结氧化亚铜的制备方法;重点概述提高Cu₂O光电效率和稳定性的策略,包括形成氧化亚铜-n型半导体p-n结、添加助催化剂、引入空穴传输层等;结合近年来表征技术的发展,介绍先进的光电阴极表征手段;最后,对光电阴极未来的研究方向进行展望。     

有机光电突触材料、器件及应用

随着大数据和物联网(IoTs)的迅猛发展,人工智能(AI)技术受到了广泛关注.可克服冯·诺依曼瓶颈和提高串行计算机性能的光电神经形态器件在半导体器件和集成电路领域的发展迅猛.光信号具有低功耗、低串扰、高带宽和低计算要求等优点,可视为额外端口以丰富突触可塑性的调节自由度.光电器件的光电性能在很大程度上依赖于光电材料的设计...     

共吸附对卟啉、酞菁/二氧化钛复合电极光电特性的影响

制备了ZnTSSP／TiO2、GaTSPC／TiO2和共吸附ZnTSSP、GaTSPc／TiO2电极，并研究了它们的光电特性．结果表明，共吸附的ZnTSSP、GaTSPc／TiO2电极不仅拓宽了光电响应范围，而且提高了光电转换效率，特别是提高了GaTSPc的光电转换效率．其原因可能是GaTSPc的聚集体没有敏化作用，而卟啉和酞菁分子与TiO2共吸附可以减少GaTSPc的聚集，有效地增强了GaTSPc的敏化能力     

自制光电比色计及其在中学化学实验中的应用

针对大多数中学缺乏光电比色计和分光光度计的现状,基于朗伯比尔定律和3D打印技术自制光电比色计,测定透明有色溶液的吸光度和浓度。利用自制光电比色计测定了琥珀酸亚铁片中铁的含量和硫酸铜晶体中结晶水的含量,实验结果表明自制光电比色计的精度高、准确性好。将3D打印技术引入化学实验创新改进,体现了跨学科融合和创新设计的思想。     

宽谱响应的混合碳纳米管光电探测器的制备和性能

基于表面等离子体增强的机理,利用银纳米线及半导体性单壁碳纳米管通过微纳加工手段制备了一种混合光电探测器,使用扫描电子显微镜、拉曼光谱分析仪、半导体装备分析仪及光电流谱技术等手段分别表征了制得混合光电探测器的微观形貌、响应光谱特征、光吸收性能和光响应性能及光电流光谱性能。结果表明,制得混合光电探测器沟道薄膜形貌均匀紧密,沉积成膜的碳纳米管直径约为1.4 nm,主要由半导体性单壁碳纳米管所构成。该杂化的光电探测器在可见光到近红外光谱范围内都表现出优良的宽谱响应特性。在近红外波段(约1 050 nm)下,混合光电探测器的光响应度可以达到34.9 mA/W,远优于无银纳米线光电探测器(7.45 mA/W)。并且混合器件在受到532 nm激光激发时的响应时间约为200μs,同时保持了超快的光响应性能。与无银纳米线光电探测器相比,混合光电探测器在宽谱范围内的光响应性能增强,其中,在光电流模式下的光响应性能最高增强7.5倍。     

钙钛矿基近红外光电探测器

近年来,具有ABX₃晶体结构的金属卤化物钙钛矿材料因其可调带隙、高吸收系数、长载流子传输距离等光电学特性而在光电探测领域表现出良好应用前景,尤其是基于纯Sn或者Sn/Pb混合阳离子制备的杂化钙钛矿在760～1050nm范围的近红外光电响应性能非常优异,展现出高灵敏度、低暗电流和高探测率等多方面优势。为进一步拓宽钙钛矿的近红外以及红外响应波长范围,研究人员探索了将有机材料、晶体硅/锗、Ⅲ-Ⅴ族化合物、Ⅳ-Ⅵ族化合物、上转换荧光材料等作为互补光吸收层与钙钛矿结合制备异质结来构筑出宽谱响应的近红外光电探测器。基于以上研究,本文总结了当前拓宽钙钛矿光电探测器的光谱范围的有效途径。同时,对钙钛矿材料的近红外光电探测器的未来发展前景作出了展望。     

青藏高原湖泊影响锂元素迁移和富集的矿物、元素及环境因素——以西藏郭扎错钻孔沉积物为例

作为我国战略性矿产的锂矿,主要赋存于青藏高原盐湖中。湖泊系统中,锂的富集和迁移规律关系到锂矿的高效提取和未来锂矿的储量估算。本文以西藏咸水湖郭扎错的钻孔沉积物为例,结合AMS14C年代和Mg元素含量变化,系统分析了孔隙水、碳酸盐矿物和硅酸盐矿物的锂含量变化,探讨了矿物、镁元素、环境变化和早期成岩作用等对锂元素迁移和富集的影响。郭扎错沉积物中锂和镁大部分存在于硅酸盐矿物中,锂和镁较高的相关性说明二者存在于相同的硅酸盐矿物中,如粘土矿物。大约90%的锂赋存在硅酸盐矿物中,约8.5%的锂赋存在碳酸盐矿物中,孔隙水中的锂含量占比仅约1.5%。碳酸盐矿物中Mg/Li摩尔比值为78–270,是孔隙水中10多倍,而硅酸盐矿物中的Mg/Li摩尔比值稳定在24–29之间。水–沉积物相互作用促进硅酸盐矿物中锂的释放,咸水环境下释放的锂多于淡水环境下。碳酸盐矿物中,锂和镁主要存在于方解石中。镁离子对锂离子的迁移具有阻碍作用,低温、高盐度下的阻碍作用更强。湖泊沉积物可能是湖水锂的一个重要来源。     

石柱黄连及根际土壤中矿质元素特征分析

研究石柱黄连不同器官及其根际土壤中矿质元素特征,探究黄连根茎矿质元素间及其与土壤环境的相关性。采用电感耦合等离子体质谱法(ICP-MS)、电感耦合等离子体发射光谱法(ICP-OES)及原子荧光光谱法(AFS)测定了15组石柱黄连植株和根际土壤中18种矿质元素含量,所得数据运用SPSS 22.0统计软件分析。石柱黄连根际土壤中锰、磷、镁、镉、汞等元素含量的变异性较大,部分采样点土壤中镉含量超过农用地土壤污染风险筛选值。在检测的18种元素中,黄连植株中钙、镁、磷、钾含量最高,其次是铁、锰、锌,再次是锶、铜、镍,最后是铅、钒、钴、镉、钼、铬、砷、汞。须根对大部分矿质元素的富集能力强于根茎或地上部;黄连根茎对锌的富集能力强于须根或地上部;地上部对钙、磷、钾、铬的富集能力强于须根或根茎。Spearman分析表明黄连根茎矿质元素间、黄连根茎与土壤中矿质元素有一定相关性,部分具有统计学意义(P＜0.05)。石柱黄连不同器官中矿质元素含量有明显差异,以此建立的指纹图谱可用于区分黄连根茎及须根的粉末样品;黄连根茎中矿质元素间主要表现为协同作用,黄连根茎与土壤中矿质元素既有协同作用又有拮抗作用。     

Effects of dilute acid and steam explosion pretreatments on the cellulose structure and kinetics of cellulosic fraction hydrolysis by dilute acids in lignocellulosic materials

Worldwide, yellows diseases impact plants important in human nutrition, the natural environment, and the culture and commerce of humans. Since the presumed pathogens, mycoplasma-like organisms (MLOs), have not been isolated in pure culture in vitro, their study must proceed by other experimental approaches. In a study of disease affecting grapevines in Europe and North America, polymerase chain reactions (PCR) and restriction analyses of PCR-amplified DNA were used to detect and differentiate strains of MLOs associated with grapevine yellows. MLOs were detected both in naturally diseased grapevines and in experimentally inoculated host plants. The data indicated an unexpected genomic diversity among grapevine-infecting MLOs, and supported their classification with MLOs in the aster yellows, X-disease, and elm yellows groups. The presence of diverse MLOs in grapevines provokes consideration that these MLOs may be present in overlapping geographic ranges and that multiple MLO infections may occur in individual plants, increasing the complexity of grapevine yellows epidemiology and control and the significance of sensitive MLO detection in planting stock and phytosanitary-regulated germplasm.     

The Therapeutic Potential of Celastrol in Central Nervous System Disorders: Highlights from In Vitro and In Vivo Approaches

Celastrol, the most abundant compound derived from the root of Tripterygium wilfordii, largely used in traditional Chinese medicine, has shown preclinical and clinical efficacy for a broad range of disorders, acting via numerous mechanisms, including the induction of the expression of several neuroprotective factors, the inhibition of cellular apoptosis, and the decrease of reactive oxygen species (ROS). Given the crucial implication of these pathways in the pathogenesis of Central Nervous System disorders, both in vitro and in vivo studies have focused their attention on the possible use of this compound in these diseases. However, although most of the available studies have reported significant neuroprotective effects of celastrol in cellular and animal models of these pathological conditions, some of these data could not be replicated. This review aims to discuss current in vitro and in vivo lines of evidence on the therapeutic potential of celastrol in neurodegenerative diseases, including Alzheimer’s and Parkinson’s diseases, amyotrophic lateral sclerosis, Huntington’s disease, multiple sclerosis, and cadmium-induced neurodegeneration, as well as in psychiatric disorders, such as psychosis and depression. In vitro and in vivo studies focused on celastrol effects in cerebral ischemia, ischemic stroke, traumatic brain injury, and epilepsy are also described.     

谈科学探究中的归纳与演绎

逻辑推理过程与事物的认识过程同时存在,科学探究离不开逻辑推理过程。归纳和演绎是认识过程中的两种逻辑推理形式,在学生的科学探究活动中,尤其是在提出问题、猜想与假设、设计实验方案与解释结论阶段,归纳和演绎发挥着重要的作用。本文重点论述了寻求现象原因的求异归纳推理、探寻化学物质通性及变化规律的不完全归纳推理、探求个别物质性质的演绎三段论、解释个别现象的演绎解释推理过程在科学探究中的重要作用。     

毛细管电泳技术在疾病预防控制领域的应用、发展与挑战

自1989年出现商品化的仪器以来,毛细管电泳（CE）技术在多个应用领域都取得了长足的进步与发展,重复性和准确性方面也有很大提升。能力验证样品分析的满意结果也显示了CE具备法规要求的准确定量能力。在疾病预防控制领域（简称"疾控"）CE也展现出很多独具特色的应用,成为不可或缺的技术之一。在聚合酶链式反应产物分析、核酸序列测定、DNA变异和分型分析、食源性致病微生物分析及疫苗分析等工作中CE发挥了重要作用。应对突发疫情或公共卫生事件如食物中毒时,除了通过非靶标分析尽快锁定目标物外,还需要对大量样品做出快速而准确的分析,高通量和高灵敏的CE就十分适合解决这一问题。在公共卫生理化检验以确保食品、保健食品、特殊医学用途食品、化妆品和消毒产品等的安全中,CE也发挥了不可或缺的作用。作为一种使用较少危险化学品的环境友好方法,在需要按照标准或规范进行的疾控实验室常规检测中,CE仍受制于标准方法的缺失,未能发挥其应有的作用。但简单、快速、经济、耐用、高效的CE分离一旦与高灵敏通用检测器联用,必将更加从容地应对疾控领域中的各种挑战,发挥更大的作用。本文综述了2010~2019年CE在疾控领域的应用,分析了CE在疾控领域发展的机遇和挑战,对CE在疾控领域的发展前景进行了展望。     

Physiological changes in barley plants under combined toxicity of aluminum, copper and cadmium

Crop production on acid soil is markedly reduced, further, a multiple heavy metal pollution except Al on acid soil is detected in many areas. The present study was undertaken to assess the toxicities of Al, Cd, and Cu separately and in combinations, three heavy metals very often coexisting on acid soil, and to identify their interactions in two kinds of barley seedlings differing in Al tolerance. The plant growth, metals accumulations, total soluble protein and sugar contents, MDA contents and the activities of SOD and POD were estimated in roots and leaves after 5-week supply of the heavy metals excess in the nutrient solution. The results indicated that the stress treatments including low pH (pH 4.5) alone all adversely affected plant growth and disturbed the cell metabolism seriously. The development of toxic symptoms corresponded to a high accumulation of Al, Cd, Cu and to a poor increase in soluble sugar contents but to a high increase in MDA contents, to the decrease in soluble protein contents and to the much elevated SOD and POD activities in both roots and leaves. In addition, binary metal combinations of Al + Cd and Al + Cu both produced the synergistic response for the growth of barley seedlings, in particular for Shang 70-119, while, ternary metal combination of Al + Cu + Cd produced different interactions in two kinds of genotypes, thus, the significant synergistic response was seen in Shang 70-119, but the antagonistic response was detected in Gebeina. The different responses to ternary metal combination of two genotypes may result from the different metal bioaccumulation patterns, hence, the existence of Cd and Cu promoted Al accumulation in Shang 70-119 but inhibited Al accumulation in Gebeina.     

Pesticide residues in groundwaters and soils of agricultural areas in the Águeda River Basin from Spain and Portugal

This research has evaluated the agricultural impact of the use of pesticides in small agricultural areas in the Águeda river basin, which straddles the Spanish-Portuguese border. Sixteen pesticides frequently used in the area, including herbicides, fungicides and insecticides and some of their degradation products, were monitored in 52 groundwater samples and 42 soil samples taken around them, using a developed multi-residual analytical method based on SPE-LC-MS. Sampling was carried out in two different seasons (winter and summer). The results indicated the presence of pesticides at several levels, both in groundwaters and soils. Thirteen of the pesticides studied were detected in one or more of the groundwater samples analysed, but only three pesticides were detected in the soil samples. Terbuthylazine, cyprodinil, tebuconazole and chlorpyrifos were the pesticides most frequently detected in groundwaters, whereas terbuthylazine, metalaxyl and tebuconazole were the sole compounds detected in soils. The distribution of the concentrations in groundwaters indicated that up to 80% and 70% of the samples collected in the summer on the Spanish and Portuguese sides, respectively, exceed the quality standards of 0.1 µg L^?1 for one or more individual compounds and, in turn, up to 64% and 40% exceed the quality standards of 0.5 µg L^?1 for all compounds. The presence of pesticide residues in the groundwaters and soils analysed may well be explained by the use of these compounds in agricultural practices.     

伊敏褐煤中微量元素的地球化学特征及其无机-有机亲和性分析

采用脱矿物质、提取腐殖酸等方法结合ICP-MS对伊敏15_上、16_下煤中的32种微量元素的含量及其赋存特征进行了分析。与地壳克拉克值及中国侏罗-白垩纪煤和世界褐煤中微量元素含量相比,伊敏褐煤中微量元素没有明显富集。脱矿物质处理后,Ni明显富集,As略比原煤高,其他微量元素都低于原煤。原煤提取腐殖酸和脱矿物煤提取腐殖酸中Ni、Mo、Cd、Sn、W明显富集,这表明Ni、Mo、Cd、Sn、W和腐殖酸形成了稳定的有机态化合物。原煤提取腐殖酸残煤和脱矿物煤提取腐殖酸残煤中V、Ni、As富集,表明V、Ni、As与煤的大分子结构形成了稳定的有机态化合物。根据微量元素和灰分的相关性系数,把微量元素分为以下几类:无机富集元素Cr、U;亲无机元素Cu、Cd、In、Sn、Ga、Y、Zr、Hf、Bi、Th;偏无机元素Be、Sc、Rb、Sr、Nb、Cs、Ta、Pb;偏有机元素V、As、Tl、Ba、Se;亲有机元素Li、Co、W;有机富集元素Ni、Zn、Mo、Sb。     

Crack Damage in Polymers and Composites: A Review

Polymer-based materials are extensively used in various applications such as aircrafts, civilian structures, oil and gas platforms and electronics. They are, however, inherently damage prone and over time, the formation of cracks and microscopic damages influences the thermo-mechanical and electrical properties, which eventually results in the total failure of the materials. This paper provides an overview of the principal causes of cracking in polymer and composites and summarizes the recent progress in the development of non-destructive techniques in crack detection. Furthermore, recent progress in the development of bio-inspired self-healing methods in autonomic repair is discussed.