Ultrasmall Semiconducting Polymer Dots with Rapid Clearance for Second Near‐Infrared Photoacoustic Imaging and Photothermal Cancer Therapy

Phototheranostic agents in the second near‐infrared (NIR‐II) window (1000–1700 nm) are emerging as a promising theranostic platform for precision medicine due to enhanced penetration depth and minimized tissue exposure. The development of metabolizable NIR‐II nanoagents for imaging‐guided therapy are essential for noninvasive disease diagnosis and precise ablation of tumors. Herein, metabolizable highly absorbing NIR‐II conjugated polymer dots (Pdots) are reported for the first time for photoacoustic imaging guided photothermal therapy (PTT). The unique design of low‐bandgap D‐A π‐conjugated polymer (DPP‐BTzTD) together with modified nanoreprecipitation conditions allows to fabricate NIR‐II absorbing Pdots with ultrasmall (4 nm) particle size. Extensive experimental tests demonstrate that the constructed Pdots exhibit good biocompatibility, excellent photostability, bright photoacoustic signals, and high photothermal conversion efficiency (53%). In addition, upon tail‐vein intravenous injection of tumor‐bearing mice, Pdots also show high‐efficient tumor ablation capability with rapid excretion from the body. In particular, both in vitro and in vivo assays indicate that the Pdots possess remarkable PTT performance under irradiation with a 1064 nm laser with 0.5 W cm^?2, which is much lower than its maximum permissible exposure limit of 1 W cm^?2. This pilot study thus paves a novel avenue for the development of organic semiconducting nanoagents for future clinical translation.     

A New Clathrate: Synthesis and Crystal Structure of the [36]ene-O6N8/THF (1:2) Clathrate

A new clathrate inclusion compound of 2,3:11,12:20,21:29,30-tetrabenzo-1,13,16,19,31,34-hexaoxa-5,6,8,9,23,24,26,27- octaaza-7,25-dithioketone-2,3:4,5:9,10:11,12:22,23:27,28:29,30-cyclo-[36]ene([ 36]eneO₆N₈), which contains THF, has been prepared and crystallizes in the monoclinic space group P2₁/n with a = 9.829(5)Å, b = 24.23(1)Å, c = 10.181(9)Å, = 92.93(5)-. Each unit cell contains two [36]ene-O₆N₈ molecules and four THF molecules. The [36]ene-O₆N₈ molecule lies on the crystallographic centre of symmetry and a pair of the THF molecules with half-chair conformation are located within rectangular channels formed by the macrocycle molecules.     

电力多媒体视频会议系统故障诊断知识库建立的研究

本文从运维实际工作出发,针对现场视频会议维护经验,探索建立电力多媒体视频会议系统故障诊断知识库,对故障诊断知识库构建、知识库动态数据更新进行了详细阐述,以期提升维护人员维护效率,提高电力行业中视频会议系统的运营管控能力,使电力系统不断的发展。     

RPMA low-power wide-area network planning method based on data mining

A network planning method based on data mining was proposed for RPMA low-power wide-area network with large density of base stations and uneven traffic distribution.First,a signal quality prediction model was established by using the boosting regression trees algorithm,which was used to extract the coverage distribution spacial pattern of the network.Then ,the weighted k-centroids clustering algorithm was utilized to obtain the optimal base station deployment for the current spacial pattern.Finally,according to the total objective function,the best base station topology was determined.Experiment results with the real data sets show that compared with the traditional network planning method,the proposed method can improve the coverage of low-power wide-area networks.     

新型基区结构高反压功率晶体管的优化

依据电参数指标要求,针对高压-高增益硅功率晶体管基区结构和终端结构进行优化研究。提出了一种可用于改善集电极-发射极击穿电压(V_(BRCEO))和电流放大倍数(β)矛盾关系的带埋层的新型基区结构,并针对埋层基区结构对高压-高增益硅功率晶体管电性能及可靠性的影响进行了研究。仿真结果表明:新型基区结构不仅可以很好地折中晶体管β与V_(BRCEO)之间的矛盾关系,而且还能在较大的埋层基区宽度、埋层基区掺杂峰值浓度范围内使晶体管获得较低且一致性较好的饱和压降;具有新型基区结构的晶体管在改善正偏的情况下抗二次击穿能力具有明显优势。由仿真得到的器件结构参数,研制出的样片的β,V_(BRCEO)和集电极-基极击穿电压(V_(BRCBO))均满足电参数指标要求。     

Out-of-Plane Resistance Switching of 2D Bi2O2Se at the Nanoscale

Two-dimensional (2D) bismuth oxyselenide (Bi₂O₂Se) with high electron mobility shows great potential for nanoelectronics. Although the in-plane properties of Bi₂O₂Se have been widely studied, its out-of-plane electrical transport behavior remains elusive, despite its importance in fabricating devices with new functionality and high integration density. Here, the out-of-plane electrical properties of 2D Bi₂O₂Se at nanoscale are revealed by conductive atomic force microscope. This work finds that hillocks with tunable heights and sizes are formed on Bi₂O₂Se after applying a vertical electric field. Intriguingly, such hillocks are conductive in the vertical direction, resulting in a previously unknown out-of-plane resistance switching in thick Bi₂O₂Se flakes while ohmic conductive characteristic in thin ones. Furthermore, the transformation is observed from bipolar to stable unipolar conduction in thick Bi₂O₂Se flake possessing such hillocks, suggesting its potential to function as a selector in vertical devices. This work reveals the unique out-of-plane transport behavior of 2D Bi₂O₂Se, providing the basis for fabricating vertical devices based on this emerging 2D material.     

基于节能减排的电池脱钩技术及应用项目研究

工信部发放5G商用牌照后,全国大规模开展5G工程建设。5G基站设备具有功率大、小微型、覆盖小、数量多等特点。随着基站个数的增多,基站设备总耗电量巨大,电费占运营成本很大的比例。当基站处于负载相对较小或者空载时,如果仍然保持在工作状态,将会浪费大量的电能;当基站供电线路出现问题时候,需运维人员到场逐步排查方能处理好。传统的基站用电问题解决费时费力、系统联动性差、及时性差、无法预测、数据不可控,电力问题将成为运营商5G网络投资的巨大压力。将分析目前5G基站建设用电问题,以节能减排、降本增效为目的,基于基站数据分析、大数据技术等手段,结合基站分布情况、潮汐负载等数据特征,提出一套基于时间序列合理有效智能的基站电池脱钩启停管理方案的研究。     

Synthesis and structural characterization of a (N,N′-bis[2(S)-pyrrolidylmethyl]-propane-1,3-diamine) nickel (II) complex

The nickel(II) complex [Ni(C₄H₃NCH=N–(CH₂)₃–N=CHC₄H₃N)], (1) containing the symmetrical N₄ tetradentate Schiff base ligand, which is the 2:1 condensation product of pyrrole-2-carboxaldehyde and 1,3-diaminopropane respectively, was prepared. Structural investigation shows that it is monomeric, having space group P2₁/c, a = 7.989(7), b = 17.406(14), c = 9.193(5) Å, = 90, = 100.39(6), = 90, and Z = 4. The coordination geometry around the nickel atom is slightly distorted square planar and the conformation of the six-membered ring containing the metal,azomethine nitrogens and three carbon atoms of the connecting 1,3-diaminopropane is a symmetric boat.     

Synthesis and structure of a (4,4′-bipyridine) lanthanide(III) complex with tetraimine (2+2) macrocycle from 2,6-diformyl-4-chlorophenol and 1,3-diamino-2-hydroxypropane

A novel (2+2) macrocyclic Schiff base lanthanide(III) complex [La(H₄L)(NO₃)₃]·(4,4-bipy)·2H₂O has been synthesized by template condensation of 1,3-diamino-2-hydroxypropane and 2,6-diformyl-4-chlorophenol. The compound crystallizes in the orthorhombic space group Pnma with a = 16.400(3), b = 12.985(3), c = 19.118(4) Å, and Z = 4. In the macrocycle, La³⁺ was coordinated by two imino nitrogen atoms, two phenolic oxygen atoms, one pedant alcoholic oxygen atom, and six nitrate oxygen atoms. It is interesting that the neutral lanthanide macrocyle forms a saddlelike supramolecule with 4,4-bipyridine.     

Intramolecular N−H...O hydrogen bonding,quinoid effect,and partial π-electron delocalization in N-aryl Schiff bases of 2-hydroxy-1-naphthaldehyde: the crystal structures of planar N-(α-naphthyl)- and N-(β-naphthyl)-2-oxy-1-naphthaldimine

The structures of N-(-naphthyl)-2-oxy-1-naphthaldimine1 and N-(-naphthyl)-2-oxy-1-naphthaldimine2 have been investigated by X-ray analysis and by spectroscopic methods. Crystals of1 are monoclinic, space groupPn, with cell dimensionsa=10.823(3),b=5.826(2),c=11.899 (3) Å, and =99.66(3)°. Compound2 crystallizes in the orthorhombic space groupPca2₁ witha=17.564(3),b=6.314(2), andc=13.663(4) Å. The IR spectra exhibited neither N–H nor O–H stretching frequencies. The existence of theintramolecular hydrogen bonding of N–H...O type was predicted by spectroscopic experiment but unequivocally established by diffraction experiment in both cases1 and2. The molecules1 and2 are significantly planar with considerable quinoid effect at the 2-oxy-naphthaldimine moiety. Although essentially planar, both molecules1 and2 show the delocalization of -electrons only in the central part of the molecules including C=N imino group with pendent ring carbon atoms.Intermolecular attractions in the crystals belong to weak van der Waals interactions-between discrete planar molecules spatially arranged into the expectedherringbone motif in the solid state.