Recent progress of inverted organic-inorganic halide perovskite solar cells

In recent years,inverted perovskite solar cells(IPSCs)have attracted significant attention due to their low-temperature and cost-effective fabrication processes,hysteresis-free properties,excellent stability,and wide application.The efficiency gap between IPSCs and regular structures has shrunk to less than 1%.Over the past few years,IPSC research has mainly focused on optimizing power conversion efficiency to accelerate the development of IPSCs.This review provides an overview of recent improvements in the efficiency of IPSCs,including interface engineering and novel film production techniques to overcome critical obstacles.Tandem and integrated applications of IPSCs are also summarized.Furthermore,prospects for further development of IPSCs are discussed,including the development of new materials,methods,and device structures for novel IPSCs to meet the requirements of commercialization.

Predicting the electromechanical properties of small caliber projectile impact igniter using PZT dynamic damage constitutive model considering crack propagation

Block piezoelectric ceramics(PZTs)are often used in impact igniters to provide activation energy for electric initiators.Under the action of strong impact stress,PZTs release electric energy accompanied by crack initiation,propagation and crushing.At present,the electrical output performance of PZTs in projectile is usually calculated by quasi-static piezoelectric equation without considering the dynamic effect caused by strong impact and the influence of crack propagation on material properties.So the ignition parameters are always not accurately predicted.To tackle this,a PZT dynamic damage constitutive model considering crack propagation is established based on the dynamic impact test and the crack propagation theory of brittle materials.The model is then embedded into the ABAQUS subroutine and used to simulate the electromechanical response of the impact igniter during the impact of a small caliber projectile on the target.Meanwhile,the experiments of projectile with impact igniter impact on the target are carried out.The comparison between experimental and numerical simulation results show that the established dynamic damage model can effectively predict the dynamic electromechanical response of PZTs in the missile service environment.

学前融合教育经历时长对普通幼儿自尊感和自我效能感的影响

在我国学前融合教育理论与实践中,学前融合教育对普通幼儿的影响受到越来越多的关注。本研究以236名普通幼儿为研究对象,采用问卷调查法,考察学前融合教育经历时长对普通幼儿社会意识领域的两个重要方面——自尊感和自我效能感的影响,结果发现有学前融合教育经历的普通幼儿在自尊感和自我效能感的发展上优于没有学前融合教育经历的幼儿,且自尊感和自我效能感随着学前融合教育经历时长的增加而增强;在自尊感的自我主张维度上,无学前融合教育经历的普通幼儿与有1~2年学前融合教育经历的普通幼儿不存在性别差异,但此经历超过2年后,女幼儿显著优于男幼儿;在自我效能感的社会效能感维度上,少于2年学前融合教育经历的女幼儿显著优于男幼儿,而此经历超过2年时不再出现性别差异。为进一步发挥学前融合教育对普通幼儿发展的积极作用,应在营造良好的社会接纳环境,推广学前融合教育的基础上,确立尽早融合、尽早受益的理念,同时关注性别差异,结合幼儿性别特点开展学前融合教育。

Damage of multi-layer spaced metallic target plates impacted by radial layered PELE

Three different kinds of PELE(the penetrator with lateral efficiency) were launched by ballistic artillery to impact the multi-layer spaced metal target plates.The lmpact velocities of the projectiles were measured by the velocity measuring system.The damage degree and process of each laye r of target plate impacted by the three kinds of projectiles were analyzed.The experimental results show that all the three kinds of projectiles have the effect of expanding holes on the multi-layer spaced metal target plates.For the normal structure PELE(without layered) with tungsten alloy jacket and the radial layered PELE with tungsten alloy jacket,the diameters of holes on the seco nd layer of plates are 3.36 times and 3.76 times of the diameter of the projectile,re spectively.For radial layered PELE with W/Zr-based amorphous composite jacket,due to the large number of tungsten wires dispersed after the impact,the diameter of the holes on the four-layer spaced plates can reach 2.4 times,3.04 times,5.36 times and 2.68 times of the diameter of the projectile.Besides,the normal structure PELE with tungsten alloy jacket and the radial layered PELE whit tungsten alloy jacket formed a large number of fragments impact marks on the third target plate.Although the number of fragments penetrating the third target plate is not as large as that of the normal structure PELE,the area of dispersion of fragments impact craters on the third target plate is larger by the radial layered PELE.The radial layered PELE with W/Zr-based amorphous composite jacket released a lot of heat energy due to the impact of the matrix material,and formed a large area of ablation marks on the last three target plates.

Advances in prostate cancer research models:From transgenic mice to tumor xenografting models

The identification of the origin and molecular characteristics of prostate cancer(PCa)has crucial implications for personalized treatment.The development of effective treatments for PCa has been limited;however,the recent establishment of several transgenicmouse lines and/or xenografting models is better reflecting the disease in vivo.With appropriate models,valuable tools for elucidating the functions of specific genes have gone deep into prostate development and carcinogenesis.In the present review,we summarize a number of important PCa research models established in our laboratories(PSA-Cre-ERT2/PTEN transgenic mouse models,AP-OX model,tissue recombination-xenografting models and PDX models),which represent advances of translational models from transgenic mouse lines to human tumor xenografting.Better understanding of the developments of these models will offer new insights into tumor progression and may help explain the functional significance of genetic variations in PCa.Additionally,this understanding could lead to new modes for curing PCa based on their particular biological phenotypes.

Effect of the processing route on the microstructure and mechanical behavior of superlight Mg-9Li-1Zn alloy via friction stir processing

In this study, the effect of the processing route using a friction stir processing(FSP) method on the microstructure and mechanical behavior of a Mg-9Li-1Zn alloy was systematically investigated. In the FSP method, the odd-numbered(1st and 3rd) process directions and even-numbered(2nd and 4th) passes were alternated to distribute the strain throughout the whole processed zone uniformly. Consequently, the processed zone had a much more uniform microstructure and hardness distribution than the processed zone obtained using the conventional FSP method. Using this method, the grain size of a Mg-9Li-1Zn sheet alloy was refined from ~31 μm to ~0.21 μm with uniformly distributedα and β phases. The processed alloy exhibited a high strength-ductility synergy with an ultimate tensile strength(UTS) of 220.1 MPa and total elongation of 70.0% at a strain rate of 10^(-3)s^(-1), overwhelmingly higher than those of the base metal, 155.6 MPa in UTS and 36.0%in elongation. The in-situ SEM-DIC analysis and TEM observation demonstrated that such an outstanding ductility with moderate strength is caused by grain boundary sliding, the dominant deformation mechanism of the ultra-fine-grained sample after FSP. The processing route with reverse processing direction was proven to be efficient in producing the ultrafine grain size microstructure and improving the mechanical properties of superlight Mg-9Li-1Zn alloy.

Hydroiodic Acid Additive Enhanced the Performance and Stability of PbS-QDs Solar Cells via Suppressing Hydroxyl Ligand

The recent emerging progress of quantum dot ink(QD-ink)has overcome the complexity of multiple-step colloidal QD(CQD)film preparation and pronouncedly promoted the device performance.However,the detrimental hydroxyl(OH)ligands induced from synthesis procedure have not been completely removed.Here,a halide ligand additive strategy was devised to optimize QD-ink process.It simultaneously reduced sub-bandgap states and converted them into iodide-passivated surface,which increase carrier mobility of the QDs films and achieve thicker absorber with improved performances.The corresponding power conversion efficiency of this optimized device reached 10.78%.(The control device was 9.56%.)Therefore,this stratege can support as a candidate strategy to solve the QD original limitation caused by hydroxyl ligands,which is also compatible with other CQD-based optoelectronic devices.

Improvement on the performance of perovskite solar cells by doctor-blade coating under ambient condition with hole-transporting material optimization

Numerous fabrication methods have been developed for high-efficiency perovskite solar cells(PSCs). However, these are limited to spin-coating processes in a glove box and are yet to be commercialized. Therefore, there is a need to develop a controllable and scalable deposition technique that can be carried out under ambient conditions. Even though the doctor-blade coating technique has been widely used to prepare PSCs, it is yet to be applied to high-efficiency PSCs under ambient conditions(RH ~45%, RT ~25 °C). In this study, we conducted blade-coating fabrication of modified high-efficiency PSCs under such conditions. We controlled the substrate temperature to ensure phase transition of perovskite and added dimethyl sulfoxide(DMSO) to the perovskite precursor solution to delay crystallization, which can facilitate the formation of uniform perovskite films by doctor-blade coating. The as-prepared perovskite films had large crystal domains measuring up to 100 μm. Solar cells prepared from these films exhibited a current density that was enhanced from 17.22 to 19.98 m A/cm^2 and an efficiency that was increased from 10.98% to 13.83%. However, the open-circuit voltage was only 0.908 V, probably due to issues with the hole-transporting layer. Subsequently, we replaced poly(3,4-ethylenedioxythiophene) polystyrene sulfonate(PEDOT:PSS) with Ni O x as the hole-transporting material and then prepared higher-quality perovskite films by blade-coating under ambient conditions. The as-prepared perovskite films were preferably orientated and had large crystal domains measuring up to 200 μm;The open-circuit voltage of the resulting PSCs was enhanced from 0.908 to 1.123 V, while the efficiency increased from 13.83% to 15.34%.

Snail部分通过下调TEL2促进鼻咽癌转移

背景与目的转移是鼻咽癌(nasopharyngeal carcinoma,NPC)患者治疗失败的主要原因。我们之前报道,SERPINE1的负调节因子TEL2可以抑制鼻咽癌转移到淋巴结。方法我们进行了一系列体内和体外实验来阐明Snail和TEL2之间的调控关系,分别在3株Snail低表达的鼻咽癌细胞系(S26、6?10B、HK1)与2株Snail高表达的鼻咽癌细胞系(S18、5?8F)中检测了TEL2的表达水平。我们采用荧光素酶和染色质免疫沉淀方法分析Snail和TEL2的相互作用,采用侵袭实验检测Snail/TEL2途径在细胞迁移和鼻咽癌细胞侵袭中的作用,采用裸鼠尾静脉注射鼻咽癌细胞来检测肺转移情况。结果 Snail异位表达下调了TEL2的mRNA和蛋白水平,shRNA敲低Snail则可上调TEL2的表达水平。荧光素酶和染色质免疫沉淀实验表明Snail可与TEL2的启动子直接结合。Snail异位表达增强了NPC细胞的迁移和侵袭,并且TEL2过表达削弱了这种作用。TEL2过表达也减弱了缺氧诱导的细胞迁移和侵袭并且增加了转移性肺结节的数量。Snail过表达减少了转移性肺结节的数量。结论 TEL2是Snail的新靶点,可抑制Snail诱导的鼻咽癌的迁移、侵袭和转移。

Tailoring structural properties of carbon via implanting optimal co nanoparticles in n-rich carbon cages toward high-efficiency oxygen electrocatalysis for rechargeable zn-air batteries

Rational construction of carbon-based materials with high-efficiency bifunctionality and low cost as the substitute of precious metal catalyst shows a highly practical value for rechargeable Zn-air batteries(ZABs)yet it still remains challenging.Herein,this study employs a simple mixing-calcination strategy to fabricate a high-performance bifunctional composite catalyst composed of N-doped graphitic carbon encapsulating Co nanoparticles(Co@NrC).Benefiting from the core-shell architectural and compositional advantages of favorable electronic configuration,more exposed active sites,sufficient electric conductivity,rich defects,and excellent charge transport,the optimal Co@NrC hybrid(Co@NrC-0.3)presents outstanding catalytic activity and stability toward oxygen-related electrochemical reactions(oxygen reduction and evolution reactions,i.e.,ORR and OER),with a low potential gap of 0.766 V.Besides,the rechargeable liquid ZAB assembled with this hybrid electrocatalyst delivers a high peak power density of 168 mW cm^(−2),a small initial discharge-charge potential gap of 0.45 V at 10 mA cm^(−2),and a good rate performance.Furthermore,a relatively large power density of 108 mW cm^(−2) is also obtained with the Co@NrC-0.3-based flexible solid-state ZAB,which can well power LED lights.Such work offers insights in developing excellent bifunctional electrocatalysts for both OER and ORR and highlights their potential applications in metal-air batteries and other energy-conversion/storage devices.

Effect of projectile parameters on opening behavior of PELE penetrating RC target

When a penetrator with enhanced lateral effect(PELE) impacts on a reinforced concrete(RC) target,the target is damaged with a large opening.An understanding of how PELE projectile parameters affect the opening dimension,is essential for effective design of the PELE projectile.In this study,under the condition that the impact velocity and target parameters(strength and thickness) were fixed values,the important influence factors of the PELE(jacket wall thickness B,jacket material strength Y1,filling material strength Y2 and angle of monolithic jacket θ) were determined by a dimensional analysis.Tests and simulations of the PELE penetrating the RC target were conducted to analyze the influence of these factors on opening diameter(D,an equivalent diameter under relative kinetic energy).Based on the test and simulation results,it is found that the influence of these factors B,Y1 and θ on the deformation mode of the jacket shows a similar trend:as values of the three factors decrease,the jacket deforms from small bending deformation to large one,and then to curling deformation.This causes the opening diameter to first increase with the decrease of these three factors,and then decreases.It is well known that the bending resistance of the jacket is related to these factors B,Y1 and θ.Therefore,a plastic limit bending moment(M0) of the jacket was quoted to characterize the influence of these factors on the bending deformation of the jacket and the opening diameter of the target.The influence factor Y2 causes D to first increase with the increase of Y2,and then decreases.A formula was developed to predict the opening diameter,whose influence parameters were considered in a dimensionless way.It has been shown that the dimensionless opening diameter D/d1 is dependent on two dimensionless parameters■ and■,where d1 and fc are the outer diameter of the projectile and the compressive strength of the target,respectively.

Improving the Performance of PbS Quantum Dot Solar Cells by Optimizing ZnO Window Layer

Comparing with hot researches in absorber layer,window layer has attracted less attention in PbS quantum dot solar cells(QD SCs). Actually, the window layer plays a key role in exciton separation, charge drifting, and so on.Herein, ZnO window layer was systematically investigated for its roles in QD SCs performance. The physical mechanism of improved performance was also explored. It was found that the optimized ZnO films with appropriate thickness and doping concentration can balance the optical and electrical properties, and its energy band align well with the absorber layer for efficient charge extraction. Further characterizations demonstrated that the window layer optimization can help to reduce the surface defects, improve the heterojunction quality, as well as extend the depletion width. Compared with the control devices, the optimized devices have obtained an efficiency of 6.7% with an enhanced V_(oc) of 18%, J_(sc) of 21%, FF of 10%, and power conversion efficiency of 58%. The present work suggests a useful strategy to improve the device performance by optimizing the window layer besides the absorber layer.

Social bots and mass media manipulated public opinion through dual opinion climate

Opinion dynamics models based on the multi-agent method commonly assume that interactions between individuals in a social network result in changes in their opinions.However,formation of public opinion in a social network is a macroscopic statistical result of opinions of all expressive individuals(corresponding to silent individuals).Therefore,public opinion can be manipulated not only by changing individuals'opinions,but also by changing their states of expression(or silence)which can be interpreted as the phenomenon"spiral of silence"in social psychology.Based on this theory,we establish a"dual opinion climate"model,involving social bots and mass media through a multi-agent method,to describe mechanism for manipulation of public opinion in social networks.We find that both social bots(as local variables)and mass media(as a global variable)can interfere with the formation of public opinion,cause a significant superposition effect when they act in the same direction,and inhibit each other when they act in opposite directions.

Simplified Compact Perovskite Solar Cells with Efficiency of 19.6% via Interface Engineering

For the commercialization of perovskite solar cells(PSCs), it is more appealing to develop high-performance simplified PSCs where perovskite films are just sandwiched between the back and front electrodes, in order to simplify the fabrication process and to reduce the cost. However, to date, this kind of devices shows rather low performance, and there are few researches on this subject.Herein, we report on a kind of compact PSCs(CPSCs) that are free of independent charge transport layers(CTLs). The devices are realized by the use of organic monolayer-modified effective electrodes, along with the use of [6,6]-phenyl-C61-butyric acid methyl ester(PCBM)-assisted anti-solvent technique to obtain ultra-thin(~10 nm) PCBM-embedded perovskite films. Compared to control devices, CPSCs achieve a promising champion power conversion efficiency of 19.6% with largely reduced hysteresis. Moreover, the unencapsulated CPSC shows good stability under ambient atmosphere, with only 10% efficiency loss after 60 days’ storage. This work indicates that, by delicate design, CPSCs with smaller materials consumption in device architecture can perform competitively as conventional PSCs. Further reduction in the actual usage of costly CTL materials can be expected upon our CPSCs by developing more facile and economic methods to prepare ultra-thin CTLs.

Influence of the attitude of cylindrical tungsten alloy fragment on the ability of penetrating thin metal target plate

The cylindrical tungsten alloy fragment is often prefabricated in the directional warhead to improve the killing ability or interception ability of the warhead.To study the influence of the attitude of fragments on the ability to penetrate thin metal target plates,theoretical calculation,and numerical simulation are used to study the ultimate penetration velocity of cylindrical tungsten alloy fragments with different aspect ratios impacting thin metal target plates vertically with a different attitude.The angle between the axis of a cylindrical tungsten alloy fragment and the normal direction of the target plate is defined as the attitude angle of the fragment perpendicular to the target plate.It is found that when the attitude angle changes from 0°to 90°,the ultimate penetration velocity of fragments increases first and then decreases.When the length-to-diameter ratio of fragments is 1.0,1.2,and 1.5,the relative errors between the minimum and maximum values of the ultimate penetration velocity are about 11.99%,15.75%,and 14.35%,respectively.The ultimate penetration velocity of fragments increases with the increase of the projection area of fragments on the target plate.

BDS空间信号异常实时检测与排除方法

北斗卫星导航系统(BeiDou navigation satellite system, BDS)空间信号异常是影响其空间信号质量评估的重要因素,检测并排除空间信号异常不仅是构建BDS空间信号故障模型的重要手段,更有利于保障BDS导航定位的完好性.传统基于事后精密星历与广播星历比对的方法存在时延较大、采样率低等问题,本文提出了一种基于Kalman滤波的载波相位平滑伪距算法,并基于BDS空间信号用户测距误差的统计特性建立了实时估计BDS空间信号用户测距误差方法,从而实时检测并排除BDS空间信号异常.基于国际全球导航卫星系统服务(international GNSS service, IGS)地面观测网1 Hz采样率数据的实验结果表明,所提出方法对BDS空间信号用户测距误差的估计精度为1.15 m,可以有效识别由卫星轨道和时钟故障引起的空间信号异常.

锂离子电池电解液功能性添加剂设计及应用

为提高锂离子电池的电化学性能,开发适合不同电解液的功能性添加剂是重要手段之一。功能性添加剂可以在不增加电池成本的情况下,显著改变电池的电化学性能,如改善循环性能,提高可逆容量和电解液电导率。本文分别从溶剂和添加剂两方面进行系统分析,介绍了锂离子电池电解液功能性添加剂的现状与进展,并提出面临的问题。本文以功能性添加剂的不同官能团为出发点,分析其作用机理,并分类探讨了阻燃添加剂、高电压添加剂等的优缺点、应用和前景。最后对锂离子电池电解液的溶剂及其添加剂的发展进行了展望。

Snail promotes metastasis of nasopharyngeal carcinoma partly by down-regulating TEL2

Background:Metastasis is the major cause of treatment failure in patients with nasopharyngeal carcinoma(NPC).We previously reported that TEL2,a negative regulator of SERPINE1,could inhibit NPC metastasis to lymph nodes.Method:A series of in vivo and in vitro assays were performed to elucidate the regulation between Snail and TEL2.TEL2 expression was analyzed in three representative NPC cell lines expressing low levels of Snail(S26,6-10B,HK1)and two cell lines expressing high levels of Snail(S18,5-8F).Luciferase and chromatin immunoprecipitation assays were used to analyze the interaction between Snail and TEL2.The roles of the Snail/TEL2 pathway in cell migration and invasion of NPC cells were examined using transwell assays.Metastasis to the lungs was examined using nude mouse receiving NPC cells injection through the tail vein.Results:Ectopic Snail expression down-regulated TEL2 at the mRNA and protein levels,whereas knockdown of Snail using short hairpin RNA up-regulated TEL2.Luciferase and chromatin immunoprecipitation assays indicated that Snail binds directly to the TEL2 promoter.Ectopic Snail expression enhanced migration and invasion of NPC cells,and such effects were mitigated by TEL2 overexpression.TEL2 overexpression also attenuated hypoxia-induced cell migration and invasion,and increased the number of metastatic pulmonary nodules.Snail overexpression reduced the number of metastatic pulmonary nodules.Conclusions:TEL2 is a novel target of Snail and suppresses Snail-induced migration,invasion and metastasis in NPC.

Black phosphorus-based van der Waals heterostructures for mid-infrared light-emission applications

Mid-infrared(MIR)light-emitting devices play a key role in optical communications,thermal imaging,and material analysis applications.Two-dimensional(2D)materials offer a promising direction for next-generation MIR devices owing to their exotic optical properties,as well as the ultimate thickness limit.More importantly,van der Waals heterostructures-combining the best of various 2D materials at an artificial atomic level-provide many new possibilities for constructing MIR light-emitting devices of large tuneability and high integration.Here,we introduce a simple but novel van der Waals heterostructure for MIR light-emission applications built from thin-film BP and transition metal dichalcogenides(TMDCs),in which BP acts as an MIR light-emission layer.For BP–WSe_(2) heterostructures,an enhancement of~200% in the photoluminescence intensities in the MIR region is observed,demonstrating highly efficient energy transfer in this heterostructure with type-Ⅰ band alignment.For BP-MoS_(2) heterostructures,a room temperature MIR light-emitting diode(LED)is enabled through the formation of a vertical PN heterojunction at the interface.Our work reveals that the BP-TMDC heterostructure with efficient light emission in the MIR range,either optically or electrically activated,provides a promising platform for infrared light property studies and applications.

One-step synthesis of recoverable CuCo2S4 anode material for high-performance Li-ion batteries

A facile one-step hydrothermal method has been adopted to directly synthesize the CuCo2S4 material on the surface of Ni foam.Due to the relatively large specific surface area and wide pore size distribution,the CuCo2S4 material not only effectively increases the reactive area,but also accommodates more side reaction products to avoid the difficulty of mass transfer.When evaluated as anode for Li-ion batteries,the CuCo2S4 material exhibits excellent electrochemical performance including high discharge capacity,outstanding cyclic stability and good rate performance.At the current density of 200 mA·g^-1,the CuCo2S4 material shows an extremely high initial discharge capacity of 2510 mAh·g^-1,and the cycle numbers of the material even reach 83 times when the discharge capacity is reduced to 500 mAh·g^-1.Furthermore,the discharge capacity can reach 269 mAh·g^-1 at a current of 2000 mA·g^-1.More importantly,when the current density comes back to 200 mA·g^-1,the discharge capacity could be recovered to 1436 mAh·g^-1,suggesting an excellent capacity recovery characteristics.