Organic carbon dots (CDs) exhibit tunable electronic structures and exceptional optical properties, supporting both exciton- and charge-driven applications. However, the mechanisms underlying this dual functionality are poorly understood. This study establishes the role of size inhomogeneity in exciton dissociation for the first time. Two distinct CD types were identified, each class with a size deviation. Intradot relaxation within the same type of CDs composes of a fast (∼1 ps) and a slow (∼tens of picoseconds) component among size-deviated subpopulations. Interdot exciton transfer between two types of CDs occurs with a time scale of 4.4 ps but is evident only when the CDs with higher-energy states are excited. It also facilitates exciton dissociation, generating nearly free carriers, confirmed by EPR spectra (g-value = 2.005). These findings highlight the critical role of energy level alignment and selective excitation in mediating exciton dissociation, providing key insights for optimizing CDs in light emission and energy conversion applications.

Due to the high stability, hypotoxicity and tunable optical properties, room temperature phosphorescence (RTP) carbon dots (CDs) have a great range of application in anti-counterfeiting encryption, bioimaging and optoelectronic devices, etc. Nevertheless, the synthesis procedures for RTP CDs are always pricey, burdensome and involve toxic chemicals. Herein, a facile method to produce RTP CDs materials by heat treatment of creatine and boric acid (BA) at 350 degrees C is reported. TEM, XRD, FT-IR and XPS are carried out and the structural characterizations showed that B-C covalent bond and CDs embedded in the rigid B2O3 matrix stabilize the triplet excitons and limit the nonradiative transition. The yellow green RTP CDs/BA displayed an ultralong lifetime of 1.286 s and last more than 5 s to naked eye. What's more, the prepared CDs/BA are successfully applied in anti- counterfeiting and information encryption. This work provides new insights to design metal-free RTP CDs with persistent luminescence for promising remarkable applications.

Long-lifetime room-temperature phosphorescence (RTP) materials have various applications in many fields due to their long-lived emission and large signal-to-noise ratio. However, it is not easy to attain long-lifetime RTP materials owing to the spin-forbidden nature of triplet exciton transitions. Herein, yellow phosphorescence carbon-dot-based composites embedded in a MgO matrix (MgCDs) have been developed, and the lifetimes were up to 1.81 s (more than 11 s to the naked eye) in a solid state and 254 ms (more than 9 s to the naked eye) in water. X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), and XPS analyses were performed, and the structural characterizations indicate that carbon dots (CDs) embedded in the rigid magnesium oxide matrix restrict the vibration and rotation of CDs chromophores and suppress nonradiative recombination of triplet excitons. Further studies unveiled that the barrier effect of the insoluble MgO matrix on oxygen is likely mainly responsible for the observed long-lived RTP in water. In addition, the codoping of N, P, and Mg elements, as well as the carbonization degree, play an important role in the luminescence properties of MgCDs. Last but not least, applications in bioimaging, screen printing, anticounterfeiting, and information protection are also explored. This work offers fresh ideas for developing ultralong lifetime afterglow materials that can be applied in versatile applications.

为确定山东烟区不同部位烤烟叶片感官质量的不同点，本研究采用方差和平均值分析法分析了，山东三个主要烟区不同部位烟叶的17个感官质量指标的差异之处。结果表明：（1）不同部位烟叶品质特征指标之间和风格特征之间均有差异，但两者相比较而言，后者在不同部位间的差异比前者更显著；（2）品质特征的香气质、香气量、透发性、杂气、刺激性指标在三个部位之间均存在显著差异，余味和甜度指标在上部叶表现尤为显著不同之处体现三个部位叶之间均存在显著差异，上部叶品质特征各项指标总体优于其他部位。

在烟叶烘烤技术中,与传统的挂杆式密集烘烤技术相比,箱式烤房烘烤技术具有自动化程度高的显著优点.本文根据实践,提出将传统挂杆式密集烤房改成为箱式密集烤房的方法.

本文阐述了潍坊烟区现代烟叶农场发展现状,分析了存在的问题,结合探索与实践提出了建议,包括创新"党支部+合作社"土地流转模式与稳定烟田资源、探索农场有效运行模式与持续保障烟田产出能力、推行全程机械化与持续保障烟农降本增效、搭建智慧烟叶平台与推进烟叶生产标准化、发展适度规模种植与保证烟叶产出质量、持续加强烟农队伍培育与夯实烟叶可持续发展根基等,并总结了取得的成效,以期为推动现代烟草农业发展提供参考.

微生物菌肥是一种绿色、无污染肥料,近年来得到了广泛的应用.为探究微生物菌肥在烟草种植中的应用,介绍了微生物菌肥的特点、功能及作用机理,阐述了微生物菌肥对土壤改良的作用、对烟草生长发育及烟叶品质影响等,并对微生物菌肥的未来发展趋势作出展望.

为了明确适于培育"中棵烟"适龄壮苗的育苗密度,以烤烟品种云烟87为试验材料,研究了不同孔径(25、30、35、40 mm)的漂浮育苗盘对烟苗成苗素质及大田关键生育期农艺性状、相关生理指标和烤后烟产量与质量的影响.结果表明,40 mm孔径漂浮育苗盘成苗素质最好,25 mm孔径漂浮育苗盘还苗情况最好,各处理从团棵期起大田长势差异不显著,30 mm孔径漂浮育苗盘产量、产值、上等烟比例最高.适当降低育苗密度既有利于提高育苗品质,又有利于烟株在大田长势和品质的形成,临朐丘陵地区漂浮育苗方式下生产"中棵烟"所需最佳育苗密度(苗间距)为25～30 mm.

以三聚氰胺为前驱体制备了石墨型氮化碳(MCN)材料,并通过超声辅助浸渍法,将MCN与还原氧化石墨烯(rGO)和二硫化钼(MoS2)纳米片复合,成功制备了 rGO/MoS2-CN三元复合材料.采用SEM、XRD、UV-vis和BET等多种手段对材料进行系统表征分析.以磺胺嘧啶(SDZ)、磺胺甲恶唑(SMX)、磺胺异恶唑(SSX)和磺胺二甲嘧咤(SMZ)四种磺胺类抗生素为目标物,考察了rGO/MoS2-CN在可见光条件下的催化活性.结果表明rGO/MoS2-CN与MCN相比,对SDZ、SSX、SMX和SMZ的降解效率大幅提升,可见光照60min,降解百分比分别提高51.22％、52.62％、38.47％和45.05％.rGO/MoS2-CN比表面积的增加有利于电子的传输与分离,对可见光吸收利用能力也显著增强.此外,系统研究了催化剂用量、抗生素初始浓度、pH值变化、微塑料颗粒等对目标抗生素降解率的影响.通过活性物种捕获实验,明确了参与抗生素降解的主要活性物种,阐述了降解机理.rGO/MoS2-CN材料的制备和应用有助于减轻水体抗生素残留给环境造成的危害.

本文以山东省潍坊市某些试验田为例,通过无人机搭载多光谱传感器获取影像,采用U-Net++深度网络模型进行烟田识别,并对不同时期烟田长势监测进行对比.结果表明:基于无人机影像的烟田识别精度在98％以上;地势、壤质等自然条件以及管理便捷性等因素对烟田长势影响较大.

目前山东烟区主要种植品种为云烟97,通过以云烟97为研究对象,深入探究不同成熟度的烟叶在烘烤过程中的组织结构和形态变化情况,为烟叶采收最佳时期的确定提供理论支持.试验结果表明,不同成熟度的烟叶的组织结构变化存在差异,但是整体主要集中于烘烤的变黄期及定色期.其中,在变黄后期及定色时,烟叶快速失水,叶片干燥速度加快导致栅栏组织及海绵组织迅速变小,是叶片变为优质干烟叶的主要原因.