Solvent engineering towards scalable fabrication of high-quality perovskite films for efficient solar modules

Over the last decade,remarkable progress has been made in metal halide perovskite solar cells(PSCs),which have been a focus of emerging photovoltaic techniques and show great potential for commercialization.However,the upscaling of small-area PSCs to large-area solar modules to meet the demands of practical applications remains a significant challenge.The scalable production of high-quality perovskite films by a simple,reproducible process is crucial for resolving this issue.Furthermore,the crystallization behavior in the solution-processed fabrication of perovskite films can be strongly influenced by the physicochemical properties of the precursor inks,which are significantly affected by the employed solvents and their interactions with the solutes.Thus,a comprehensive understanding of solvent engineering for fabricating perovskite films over large areas is urgently required.In this paper,we first analyze the role of solvents in the solution-processed fabrication of large-area perovskite films based on the classical crystal nucleation and growth mechanism.Recent efforts in solvent engineering to improve the quality of perovskite films for solar modules are discussed.Finally,the basic principles and future challenges of solvent system design for scalable fabrication of high-quality perovskite films for efficient solar modules are proposed.

Advances in Research of Mechanism of Herb-Drug Interactions

With the concurrent consumption of herbal medicines and conventional drugs,herb-drug interactions(HDIs)have become the most important clinical consequence of this practice.A general overview and the significance of pharmacokinetic and pharmacodynamic HDIs are provided,detailing basic mechanism,especially the metabolic enzymes and drug transporters,such as CYP450 and P-gp.

TiO2纳米粉体的掺杂改性及光催化性能研究——伯苓班无机综合实验

南开大学化学学院伯苓班本科生的无机综合实验课程中,开展"TiO2纳米粉体的掺杂改性及光催化性能研究"实验,学生自主选择掺杂元素及含量,以溶胶-凝胶方法制备不同金属及非金属掺杂的TiO2纳米粉体,采用扫描电镜、透射电镜、X射线衍射、紫外漫反射等手段表征所得材料,以甲基橙溶液模拟有机废水,研究催化剂在紫外光下的催化降解活性,选取性能最佳催化剂,测试其在模拟日光下的光解水性能。通过开展贴近科研前沿的实验内容,对伯苓班学生进行系统的科研训练,培养他们的综合科研能力。

Recent advances of flexible perovskite solar cells

In few years only, the efficiency record of perovskite solar cells（PSCs） has raised quickly from 3.8% to over 22%. This emerging photovoltaic technology has primarily shown its great potential of industrialization. Flexible PSCs are thought to be one of the most priority options for mass production, related to the intrinsic advantage of perovskite thin films which could be deposited by facile solution processes at low temperature. Flexible PSCs have at least four advantages in comparison to the rigid counterpart：（1） it can generate higher power output at lighter weight,（2） it is easily portable,（3） it can be easily attached to architectures or textiles with diverse shapes, and（4） it is compatible with roll-to-roll fabrication in a large scale. In this review, we have summarized recent development of the key materials and technologies applied in flexible PSCs. The key materials including flexible substrates, transparent and conductive electrodes, and interfacial materials; some key technologies about roll-to-roll manufacture, encapsulation technology have been overviewed. Finally, a prospect on possible application directions of flexible PSCs has been discussed.

Evaporated potassium chloride for double-sided interfacial passivation in inverted planar perovskite solar cells

Defect-induced charge carrier recombination at the interfaces between perovskite and adjacent charge transport layers restricts further improvements in the device performance of perovskite solar cells(PSCs).Defect passivation at these interfaces can reduce trap states and inhibit the induced nonradiative recombination.Herein,we report a double-sided interfacial passivation via simply evaporating potassium chloride(DIP-KCl)at both the hole transport layer(HTL)/perovskite and perovskite/electron transport layer(ETL)interfaces in inverted planar PSCs.We demonstrate that the bottom KCl layer at the HTL/perovskite interface not only reduces the interfacial defects and improves the interfacial contact,but also leads to increased perovskite crystallinity,while the top KCl layer at the perovskite/ETL interface efficiently passivates the perovskite top surface defects and facilitates electron extraction at this interface.Thus,suppressed nonradiative recombination and faster charge extraction at both interfaces close to the perovskite layer can be achieved by using our DIP-KCl strategy.As a result,inverted PSCs based on DIP-KCl present an increased efficiency from 17.1% to 19.2% and enhanced stability,retaining over 90% of their initial efficiency after aging at maximum power point tracking for 1000 h.This work provides a simple and efficient way for defect passivation to further increase the efficiency and stability of PSCs.

Surveillance Video Key Frame Extraction Based on Center Offset

With the explosive growth of surveillance video data,browsing videos quickly and effectively has become an urgent problem.Video key frame extraction has received widespread attention as an effective solution.However,accurately capturing the local motion state changes of moving objects in the video is still challenging in key frame extraction.The target center offset can reflect the change of its motion state.This observation proposed a novel key frame extraction method based on moving objects center offset in this paper.The proposed method utilizes the center offset to obtain the global and local motion state information of moving objects,and meanwhile,selects the video frame where the center offset curve changes suddenly as the key frame.Such processing effectively overcomes the inaccuracy of traditional key frame extraction methods.Initially,extracting the center point of each frame.Subsequently,calculating the center point offset of each frame and forming the center offset curve by connecting the center offset of each frame.Finally,extracting candidate key frames and optimizing them to generate final key frames.The experimental results demonstrate that the proposed method outperforms contrast methods to capturing the local motion state changes of moving objects.

Clinical Observation and Network Pharmacology Study on Analgesic Effect of Qianghuo Chushi Decoction on Fasciitis

[Objectives]To observe the clinical analgesic effect of Qianghuo Chushi Decoction(QHCSD)on patients with fasciitis,and explore its possible molecular mechanism based on network pharmacology.[Methods]120 enrolled patients were randomly divided into experimental group and control group,and were separately treated with QHCSD formula granules and Diclofenac Sodium Enteric-coated Tablets for 4 weeks.The patient’s pain visual analogue scale(VAS)was used as the curative effect indicator.The molecular action mechanism of QHCSD was predicted based on network pharmacology,the active components of QHCSD were screened using TCMSP database,potential targets were predicted by PharmMapper server,compound-target network and protein interaction network were constructed,and GO-based enrichment analysis and KEGG-based biological pathway enrichment analysis were performed.[Results]After treatment,the pain scores in each group were significantly lower than those before treatment(P<0.01),the score of the experimental group was significantly lower than that of the control group(P<0.01),and the total effective rate of the experimental group was 83.33%,which was significantly higher than that of the control group(78.33%,P<0.05).Based on 108 active components in QHCSD,a compound-target network was constructed.The PPI network contained 155 nodes and 527 interaction relationships,and key nodes included FOS,ESR1,NCOA1,RELA,EGFR,MAPK8,IL-6,etc.The GO pathway mainly involved steroid hormone and its receptor activity,RNA polymerase II transcriptional regulator binding,nuclear receptor activity,protein heterodimerization activity and other pathways.KEGG metabolic pathways included PI3 K-Akt signaling pathway,Kaposi’s sarcoma-associated herpesvirus(KSHV)infection and other pathways.[Conclusions]QHCSD has a significant analgesic effect on fasciitis,and the PI3 K-Akt signaling pathway may be the key pathway for its analgesic effect.

基于雷洛昔芬的多重刺激响应性单组分室温磷光分子晶体

Simultaneously achieving room-temperature phosphorescence(RTP) and multiple-stimuli responsiveness in a single-component system is of significance but remains challenging. Crystallization has been recognized to be a workable strategy to fulfill the above task. However, how the molecular packing mode affects the intersystem crossing and RTP lifetime concurrently remains unclear so far. Herein, four economic small-molecular compounds, analogues of the famous drug raloxifene(RALO), are facilely synthesized and further explored as neat single-component and stimuli-responsive RTP emitters via crystallization engineering. Thanks to their simple structures and high ease to crystallize, these raloxifene analogues function as models to clarify the important role of molecular packing in the RTP and stimuliresponsiveness properties. Thorough combination of the single-crystal structure analysis and theoretical calculations clearly manifests that the tight antiparallel molecular packing mode is the key point to their RTP behaviors. Interestingly, harnessing the controllable and reversible phase transitions of the two polymorphs of RALO-OAc driven by mechanical force, solvent vapor, and heat, a single-component multilevel stimuli-responsive platform with tunable emission color is established and further exploited for optical information encryption. This work would shed light on the rational design of multi-stimuli responsive RTP systems based on single-component organics.

Achieving highly efficient long-wavelength phosphorescence emission of large singlet-triplet energy gap materials by host-guest doping

High-efficiency long-wavelength phosphorescence emissions of large singlet-triplet energy gap(ΔE_(ST))materials are essential for applications in biology and display.However,few long-wavelength phosphorescence emissions of largeΔE_(ST)materials have been reported due to the weak spin-orbit coupling(SOC)and strong non-radiative transitions.Herein,we develop a strategy to achieve highly efficient long-wavelength room temperature phosphorescence(RTP)emission of largeΔE_(ST)materials,which display bright red RTP emission with above 400μs lifetime and 6.5%phosphorescent quantum efficiency.Our experiments and theoretical calculations reveal that the fishbone-like packing and the zig-zag interactions provide favorable conditions for suppressing the non-radiative transitions of triplet state excitons,and heavy atoms effectively promote the intersystem crossing(ISC)process for highly efficient long-wavelength phosphorescence emission.The universality of the method for highly efficient long-wavelength RTP emission of largeΔE_(ST)materials was further investigated in various guests.Moreover,these materials with largeΔE_(ST)manifest the advantages of large color contrast on the display and utilization potentiality in information encryption.This strategy paves the way for the high contrast display and development of information encryption with RTP emission.

Structure-regulated fluorine-containing additives to improve the performance of perovskite solar cells

Perovskite solar cells(PSCs)have seen remarkable progress in recent years,largely attributed to various additives that enhance both efficiency and stability.Among these,fluorine-containing additives have garnered significant interest because of their unique hydrophobic properties,effective defect passivation,and regulation capability on the crystallization process.However,a targeted structural approach to design such additives is necessary to further enhance the performance of PSCs.Here,fluoroalkyl ethylene with different fluoroalkyl chain lengths(CH_(2)CH(CF_(2))nCF_(3),n=3,5,and 7)as liquid additives is used to investigate influences of fluoroalkyl chain lengths on crystallization regulation and defect passivation.The findings indicate that optimizing the quantity of F groups plays a crucial role in regulating the electron cloud distribution within the additive molecules.This optimization fosters strong hydrogen bonds and coordination effects with FA+and uncoordinated Pb^(2+),ultimately enhancing crystal quality and device performance.Notably,1H,1H,2H-perfluoro-1-hexene(PF_(3))with the optimal number of F presents the most effective modulation effect.A PSC utilizing PF_(3)achieves an efficiency of 24.05%,and exhibits exceptional stability against humidity and thermal fluctuations.This work sheds light on the importance of tailored structure designs in additives for achieving high-performance PSCs.

基于血清药物化学和网络药理学的荜茇抗胃溃疡药效物质基础分析

荜茇(PL)是具有药食两用性的常用中药,中医临床多生用,具有温中散寒、行气止痛的功效,用于胃脘冷痛、胃寒呕吐等,同时也是蒙医、藏医和印度传统常用药物。在本研究中,首先建立大鼠胃溃疡动物模型,考察荜茇对胃粘膜的保护作用,进而将血清药物化学与网络药理学相结合,挖掘荜茇药效物质基础,从荜茇中筛选药效物质和潜在作用靶点。研究结果表明,荜茇对乙醇诱导的胃溃疡具有显著的保护作用;网络药理学预测了潜在的药物-疾病共同靶点后,GO富集分析预测荜茇可能影响多种生物过程,如脂质代谢和炎症反应。KEGG富集分析提示TNF和AGE-RAGE信号通路可能参与其中,分子对接预测芝麻素与胡椒碱等可能是荜茇抗炎和抗菌作用的主要成分。此外,荜茇的血清药物化学揭示了入血成分中有23种原型成分和17种代谢物。本研究整合了血清药物化学和网络药理学,为荜茇在胃溃疡治疗中的药效物质研究提供了实验依据。

The overexpression of Rps14 in Lgr5+progenitor cells promotes hair cell regeneration in the postnatal mouse cochlea

Sensory hair cells(HCs)in the cochlea cannot regenerate spontaneously in adult mammals after being damaged by external or genetic factors.However,several genes and signaling pathways are reported to induce cochlear HC regeneration at the early neonatal stage.Rps14 encodes a ribosomal protein that is involved in the regulation of cell differentiation and proliferation in mammals.However,its roles in the cochlea have not been reported in vivo.Here,we specifically overexpressed Rps14 in Lgr5+progenitor cells in the newborn mouse cochlea and found that Rps14 conditional overexpression(cOE)mice had significantly increased the ectopic HCs,including inner and outer HCs.We further explored the source of these ectopic HCs and found no EdU+supporting cells observed in the Rps14 cOE mice.The lineage tracing results,on the other hand,revealed that Rps14 cOE mice had significantly more tdTomato+HCs in their cochleae than control mice.These results indicated that regenerated HCs by cOE of Rps14 are most likely derived from inducing the direct trans-differentiation of Lgr5+progenitor cells into HCs.Moreover,real-time qPCR results suggested that the transcription factor genes Atoh1 and Gfi1,which are important in regulating HC differentiation,were upregulated in the cochlear basilar membrane of Rps14 cOE mice.In summary,this study provides in vivo evidence that,in the postnatal mouse cochlea,Rps14 is a potential gene that can promote the spontaneous trans-differentiation of Lgr5+progenitor cells into HCs.This gene may one day be exploited as a therapeutic target for treating hearing loss.

Somatic Embryogenesis Receptor Kinases Control Root Development Mainly via Brassinosteroid-Independent Actions in Arabidopsis thaliana

Brassinosteroids （BRs）, a group of plant steroidal hormones, play critical roles in many aspects of plant growth and development. Previous studies showed that BRI1-mediated BR signaling regulates cell division and differentiation during Arabidopsis root development via interplaying with auxin and other phytohormones. Arabidopsis somatic embryogenesis receptor-like kinases （SERKs）, as co-receptors of BRI1, were found to play a fundamental role in an early activation step of BR signaling pathway. Here we report a novel function of SERKs in regulating Arabidopsis root development. Genetic analyses indicated that SERKs control root growth mainly via a BR-independent pathway. Although BR signaling pathway is completely disrupted in the serkl bakl bkkl triple mutant, the root growth of the triple mutant is much severely damaged than the BR deficiency or signaling null mutants. More detailed analyses indicated that the triple mutant exhibited drastically reduced expression of a number of genes critical to polar auxin transport, cell cycle, endodermis development and root meristem differentiation, which were not observed in null BR biosynthesis mutant cpd and null BR signaling mutant bril-701.

Role of Wnt and Notch signaling in regulating hair cell regeneration in the cochlea

Sensory hair cells in the inner ear are responsible for sound recognition. Damage to hair cells in adult mammals causes permanent hearing impairment because these cells cannot regenerate. By contrast, newborn mammals possess limited regenerative capacity because of the active participation of various signaling pathways, including Wnt and Notch signaling. The Wnt and Notch pathways are highly sophisticated and conserved signaling pathways that control multiple cellular events necessary for the formation of sensory hair cells. Both signaling pathways allow resident supporting cells to regenerate hair cells in the neonatal cochlea. In this regard, Wnt and Notch signaling has gained increased research attention in hair cell regeneration. This review presents the current understanding of the Wnt and Notch signaling pathways in the auditory portion of the inner ear and discusses the possibilities of controlling these pathways with the hair cell fate determiner Atohl to regulate hair cell regeneration in the mammalian cochlea.

Research progress on large-area perovskite thin films and solar modules

Organometal halide perovskites have exhibited a bright future as photovoltaic semiconductor in next generation solar cells due to their unique and promising physicochemical properties.Over the past few years,we have witnessed a tremendous progress of efficiency record evolution of perovskite solar cells(PSCs).Up to now,the highest efficiency record of PSCs has reached 22.1%;however,it was achieved at a very small device area of<0.1 cm^(2).With the device area increasing to mini-module scale,the efficiency record dropped dramatically.The inherent causes are mainly ascribed to inadequate quality control of large-area perovskite thin films and insufficient optimization of solar module design.In current stage of PSCs research and development,to overcome these two obstacles is in urgent need before this new technology could realize scale-up industrialization.Herein,we present an overview of recently developed strategies for preparing large-area perovskite thin films and perovskite solar modules(PSMs).At last,cost analysis and future application directions of PSMs have also been discussed.

Interfacial characteristics and mechanical properties of additive manufacturing martensite stainless steel on the Cu-Cr alloy substrate by directed energy deposition

Copper/steel is a typical bimetal functional material,combining the excellent electrical and thermal conductivity of copper alloy and the high strength and hardness of stainless steel.There has been recent interest in manufacturing copper/steel bimetal by directed energy deposition(DED)due to its layer-bylayer method.However,cracks tend to form on the copper/steel interface because of the great difference in thermal expansion coefficient and crystal structure between copper and steel.In this work,interfacial characteristics and mechanical properties of the copper/steel bimetal were studied from one layer to multilayers.The laser power has a great influence on the Cu element distribution of the molten pool,affecting the crack formation dramatically on the solidification stage.Cracks tend to form along columnar grain boundaries because of the Cu-rich liquid films and spherical particles in the cracks.Crack-free and good metallurgical bonding copper/steel interface is formed at a scanning velocity of 800 mm/min and the laser power of 3000 W.The ultimate tensile strength(UTS)and the break elongation(EL)of the vertically combined crack-free copper/steel bimetal are 238.2±4.4 MPa and 20.6±0.7%,respectively.The fracture occurs on the copper side instead of the copper/steel interface,indicating that the bonding strength is higher than that of the Cu-Cr alloy.The UTS of the horizontally combined crack-free copper/steel bimetal is 746.7±22.6 MPa,which is 200%higher than that of the Cu-Cr alloy substrate.The microhardness is 398.6±5.4 HV at the steel side and is 235.3±64.1 HV at the interface,which is400%higher than that of the Cu-Cr alloy substrate.This paper advances the understanding of the interfacial characteristics of heterogeneous materials and provides guidance and reference for the fabrication of multi-material components by DED.

A Review of Self-healing Metals: Fundamentals, Design Principles and Performance

Self-healing metals possess the capability to autonomously repair structural damage during service. While self-healing concepts remain challenging to be realized in metals and metallic systems due to the small atomic volume of the mobile atoms, the slow diffusion unless at high temperatures and the strong isotropic metallic bonds, the scientific interest has increased sharply and promising progress is obtained. This article provides a comprehensive and updated review on the developments and limitations associated with the various modes of potentially healable damage induced in metals and alloys, i.e., stressinduced damage, irradiation-induced damage in bulk materials and contact damage in corrosion protective coatings. The spontaneous intrinsic healing mechanisms not requiring external assistance other than the material operating at the right temperature and an assisted healing mechanism with external intervention are reviewed. Promising strategies to achieve self-healing in metals are identified. Finally, we give some prospects for future research directions in self-healing metals.

Rubicon deficiency exacerbates fasting-induced hepatic steatosis

Objective: Rubicon is an inhibitory interacting protein of the autophagy-related protein Uvrag. We previously showed thatRubicon deficiency promotes autophagic fluxin vivo and that autophagy can degrade lipid droplets. This study aimed to investigate the effects of Rubicon deficiency on fasting-induced hepatic steatosis.Methods: Two-month-old wild-type (WT) andRubicon-deficient mice were subjected to feeding or fasting for 24 hours to induce hepatic steatosis. The distribution of liver lipid droplets was revealed by oil red O staining. Hepatic and plasma triglyceride, non-esterified fatty acid (NEFA), and cholesterol levels were detected using commercially available kits. Real-time reverse transcriptasepolymerase chain reaction was performed to analyze the mRNA expression of genes related to lipid metabolism in the liver. Western blot was conducted to assess autophagy-related protein levels in the liver. The animal experiments were approved by the Institutional Animal Care and Use Committee at Shanghai Jiao Tong University, China.Results: We showed that under fasting conditions,Rubicon-deficient mice had more lipid droplets in the liver than WT controls. Consistent with these results, the hepatic triglyceride, NEFA, and cholesterol levels in fastedRubicon-deficient mice were significantly higher than those of fasted WT controls. The levels ofSREBP-1, a key regulator of lipid synthesis, were significantly lower in livers from fasted WT mice than those of fed WT mice. However, the decrease inSREBP-1 in fasted mice was attenuated byRubicon deficiency. Western blot analysis demonstrated that the fasting-induced increase in autophagic flux was amplified byRubicon deficiency. Finally, we showed thatRubicon deficiency in mice led to elevated plasma triglyceride and NEFA acid levels under fasting conditions.Conclusion: Rubicon deficiency exacerbates fasting-induced hepatic steatosis in mice.

Preparation of Square and Labyrinth-Like TiO_2 Particles for Photo-Degradation of Organic Pollutants

Square and labyrinth-like titanium dioxide particles were successfully synthesized by a simple hydrothermal method with assistant of halloysite nanotubes. The morphology and microstructure of as-prepared photo-catalysts were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The photo-catalytic activity of as-prepared catalysts was evaluated by degradation of organic pollutants（Rhodamine B, methylene blue and methanol） under UV light irradiation.