真空冷喷涂LiNi_(0.33)Co_(0.33)Mn_(0.33)O_2涂层颗粒沉积行为研究

真空冷喷涂是一种基于室温及真空条件下超细陶瓷粉末粒子的撞击破碎实现涂层沉积的方法。目前,真空冷喷涂技术已经在微电子器件,金属防护以及新能源领域展现了良好的应用前景。本研究将目光转向锂离子电池,基于真空冷喷涂技术,在氧化铝基体上制备了锂离子电池LiNi_(0.33)Co_(0.33)Mn_(0.33)O_2(NMC)三元材料正极涂层,使用扫面电子显微镜(SEM)观察了NMC涂层的表面及截面微观形貌,使用X射线衍射(XRD)对涂层的相结构进行了测试,使用3D激光显微镜表征了涂层的表面粗糙度,系统研究了载气流量、喷涂距离、喷涂次数等沉积条件对NMC涂层微观形貌及粒子沉积行为的影响。结果表明,在真空冷喷涂NMC涂层中可以观察到明显颗粒破碎沉积现象,涂层结构致密。NMC粉末颗粒沉积方式受气流量、喷涂距离、喷涂次数等沉积条件的影响,载气流量的提高会提高粒子撞击速度,从而提高涂层沉积速率,但过高的气流量会导致粒子发生冲蚀,在涂层表面留下凹坑,致使涂层粗糙度增大。喷涂距离过大会导致NMC颗粒撞击速度减小,粒子破碎不充分,涂层呈现出类似团聚粉末堆积的疏松结构。喷涂次数影响涂层厚度,在合适的沉积参数条件下,可以通过调整喷涂次数实现涂层厚度的线性调控。

Analysis of differentially expressed genes in Verruca vulgaris vs.adjacent normal skin by RNA-sequencing

Introduction:Verruca vulgaris is one of the most common low-risk HPV infections and is characterized by excessive proliferation of keratinocytes.Currently,very little genetic information is available regarding verruca vulgaris in the Chinese population.This study aimed to obtain comprehensive transcript information of verruca vulgaris by RNA sequencing.Methods:High-throughput sequencing was performed on three fresh verruca vulgaris samples and adjacent normal skin on the Illumina sequencing platform.The transcriptomes were analyzed using bioinformatics and the differentially expressed genes(DEGs)were verified by immunohistochemistry.Verruca vulgaris exhibited a unique molecular signature.Results:In total,1,643 DEGs were identified in verruca vulgaris compared to normal skin.The functions of the DEGs were studies by Gene Ontology(GO)enrichment,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis,DEGs Reactome analysis,disease annotation function,and STRING protein-protein interaction(PPI)network analysis.The results revealed 595 GO terms associated with the cell cycle,signal transduction,immune system,signaling molecules,and interaction.The Reactome analysis revealed enrichment in reversible hydration of carbon dioxide and BMP signaling,while the disease annotation function revealed that the enriched DEGs are involved in keratosis disorders.The STRING PPI network showed that the edges with the highest density mainly included the 2′-5′oligoadenylate synthase(OAS)family-related proteins.Furthermore,the M-code analysis found ISG15,IRF7,and OASL were scored as significant modules and their high expression compared to the control was verified by immunohistochemistry.Conclusion:These findings contribute to the genetic information of verruca vulgaris in the Chinese population,revealing that interferon-stimulated genes may play essential roles in verruca vulgaris.

Waste to treasure:Reutilization of fluid catalytic cracking coke block as photothermal conversion material for water evaporation

This study aims to analyze the coking process and propose an effective method for the reutilization of fluid catalytic cracking(FCC)coke block.Herein,we analyzed the basic characteristics and chemical composition of FCC coke blocks.The results showed that the main components were carbon,oxygen,and aluminum,accounting for 60.8%,26.6%,and 11.5%,respectively.Under the conventional catalytic cracking reaction temperature from 500°C to 600°C,the formation of the first aromatic hydrocarbon was particularly important for the formation of coke.The condensation of oil-gas-entrained catalyst particles and their heavy components was the physical cause of coking,while the dehydrogenation condensation reaction of oil-gas heavy components was the chemical factor.In addition,the membrane prepared by powdered coke had excellent photothermal conversion ability,which could be heated to more than 110°C within 360 s under two fixed light intensities.The evaporation rate of photothermal water was 5.89 kg m 2 h−1,which has great industrial application potential.These works provide a novel and effective method of separation membrane for the reutilization of FCC coke blocks.

A new method of enhancing reliability for transmission expansion planning

The reliability plays a significant role in power systems and it is an important objective or constraint in transmission expansion planning.Firstly,a DC optimization model was proposed to calculate the maximum arrival power at each load point.Compared to the network flow method,DC model is closer to the actual power flow and it is able to obtain more realistic reliability assessment results.Furthermore,a novel sensitivity index(SI)was also proposed to choose the most effective line so as to enhance the nodal and/or system reliability.The Monte Carlo simulation is used to simulate the system components state.This improved reliability evaluation method and SI can be used for transmission expansion planning or maintenance scheduling.Tests are performed using 6-bus system derived from the Garver’s system and the IEEE 10-machine 39-bus system.The results show the effectiveness of the method.

Investigation on the Cracking Mechanism of Melt Growth Alumina/Aluminum Titanate Ceramics Prepared by Laser Directed Energy Deposition

Oxide melt growth ceramics(OMGCs)exhibit excellent performance and microstructure stability near their melt-ing point and are expected to become a new structural material for long-term stable service in extremely high-temperature water-oxygen environments.Owing to its unique advantages of high efficiency,flexible manufac-turing,and near-net shaping,laser directed energy deposition(LDED)has become a promising technology for the rapid preparation of high-performance OMGCs.However,owing to the limited understanding of the crack-ing mechanism,the severe cracking problem that hinders OMGCs-LDED towards engineering applications has not been resolved.Alumina/aluminum titanate(Al_(2)O_(3)/Al_(x)Ti_(y)O_(z),A/AT)ceramics are prepared using an LDED system and their cracking characteristics are investigated.Subsequently,numerical simulations are conducted to reveal the dominant factors and influencing mechanisms of the cracking behavior.The results demonstrate that the cracking nucleation process is mainly controlled by solidification defects,whereas the cracking propagation process is determined primarily by both the microstructure and stress level.This study provides a theoretical basis for the development of appropriate cracking suppression methods for OMGCs-LDED.

氧化石墨烯负载无纺布复合膜的制备及光热转换性能

氧化石墨烯(GO)是一种性能良好的光热转换材料,广泛用于海水淡化、光电转换和太阳能利用等领域。为了测试GO负载无纺布膜(GO膜)和聚乙烯醇-氧化石墨烯无纺布复合膜(PVA-GO复合膜)的光热水蒸发特性,通过改进Hummers方法制备GO,选取了纤维素和聚酯类型的无纺布,通过浸泡-超声法制得GO膜和PVA-GO复合膜。运用紫外-可见-近红外光谱仪分析了GO膜和PVA-GO复合膜的吸光性能,并通过电子天平测量GO膜和PVA-GO复合膜的蒸发水量。由于PVA具有亲水性,能增大膜的吸水性,因而PVA加入会使蒸发水量增大。通过SEM分析GO膜和PVA-GO复合膜表面特征,发现无添加PVA的GO膜是纤维丝状结构,且纤维清晰可见。加入PVA后,纤维被PVA包裹,说明膜对光的吸收能力增强。当加入6wt%PVA时,无纺布纤维被PVA完全包裹。当用氙灯对两种膜进行水蒸发实验时,GO膜的蒸发速率达到了1.67 kg/(m^(2)·h),PVA-GO复合膜的蒸发速率达到了1.85 kg/(m^(2)·h)。此外,GO膜中出现GO层状结构,在紫外-可见-近红外光谱分析中表现出较好的吸光能力,在光热蒸发实验中表现出较好的光热转换能力。PVA-GO复合膜在PVA质量浓度为4wt%时有较好的光热转换性能和吸光性。

Short fixation with a 3‐rod technique for posterior hemivertebra resection in children younger than 5 years old

Importance Congenital hemivertebra is commonly treated with posterior hemivertebra resection with bilateral transpedicular fixation.However,implant‐related complications are common in children younger than 5 years old who undergo this surgical procedure.Objective To present the preliminary clinical and radiological outcomes of children younger than 5 years old treated by posterior hemivertebra resection and 3‐rod fixation technique.Methods From January 2016 to December 2017,14 consecutive patients of congenital scoliosis with 16 hemivertebrae were retrospectively reviewed,including 5 girls and 9 boys,aged between 25 and 55 months old(average,37.6 months).All patients underwent posterior hemivertebra resection with short fixation with bilateral pedicle screws and a convex lamina hook.Surgical complications and corrective outcomes were assessed based on the clinical charts and spinal radiographs with a minimum 24‐month follow‐up.Results The mean Cobb angle of the main curve was 38.4°before surgery,8.5°after surgery,and 8.7°at final follow‐up.In the compensatory cranial curve,the preoperative Cobb angle of 16.8°was corrected to 8.1°postoperatively and was 10.3°at final follow‐up.In the compensatory caudal curve,the preoperative Cobb angle of 15.9°improved to 5.3°postoperatively and was 7.8°at final follow‐up.The segmental kyphosis was corrected from 13.5°to 0.5°and was 1.1°at final follow‐up.There were no crankshaft phenomena,no proximal kyphosis,and no complications related to the instrumentation.Interpretation Posterior hemivertebra resection with instrumentation with bilateral pedicle screws and a convex lamina hook can achieve rigid fixation and deformity correction.

Preparation and properties of substrate PVA-GO composite membrane for solar photothermal conversion

Solar thermal desalination(STD)is a promising and sustainable technology for extracting clean water resources.Whereas recent studies to improve STD performance primarily focus on interfacial solar evaporation,a non-traditional bottom heating method was designed in this study.Herein,we prepared the polyvinyl alcohol/graphene oxide(PVA-GO)composite membrane and adhered to the bottom of a beaker using crystallized PVA.The GO was loaded on a non-woven fabric and different concentrations of PVA were compared for their effect on the evaporation efficiency.The results showed that the addition of PVA increased the evaporation rate.The surface characteristic of GO membrane without PVA was a fibrous filamentous structure as observed by SEM,whereby the fibers were clearly visible.When the PVA concentration reached 6%,the non-woven fiber was completely wrapped by PVA.Under the action of a fixed light intensity,the photothermal conversion rates of GO,2%PVA-GO,4%PVA-GO and 6%PVA-GO membrane device could reach 39.93%,42.61%,45.10%and 47.00%,respectively,and the evaporation rates were 0.83,0.88,0.94 and 0.98 kg$m-2$h-1,respectively.In addition,the PVA-GO composite membrane showed an excellent stability,which has significance for industrial application.