Monte Carlo study on abnormal growth of Goss grains in Fe-3%Si steel induced by second-phase particles

The selective abnormal growth of Goss grains in magnetic sheets of Fe-3%Si （grade Hi-B） induced by second-phase particles （AlN and MnS） was studied using a modified Monte Carlo Ports model. The starting microstructures for the simulations were generated from electron backscatter diffraction （EBSD） orientation imaging maps of recrystallized samples. In the simulation, second-phase particles were assumed to be randomly distributed in the initial microstructures and the Zener drag effect of particles on Goss grain boundaries was assumed to be selectively invalid because of the unique properties of Goss grain boundaries. The simulation results suggest that normal growth of the matrix grains stagnates because of the pinning effect of particles on their boundaries. During the onset of abnormal grain growth, some Goss grains with concave boundaries in the initial microstructure grow fast abnormally and other Goss grains with convex boundaries shrink and eventually disappear.

Numerical study on fatigue damage properties of cavitation erosion for rigid metal materials

Cavitation erosion is an especially destructive and complex phenomenon. To understand its basic mechanism, the fatigue process of materials during cavitation erosion was investigated by numerical simulation technology. The loading spectrum used was generated by a spark-discharged electrode. Initiation crack life and true stress amplitude was used to explain the cavitation failure period and damage mechanism. The computational results indicated that the components of different materials exhibited various fatigue lives under the same external conditions. When the groove depth was extended, the initiation crack life decreased rapidly, while the true stress amplitude was increased simultaneously. This gave an important explanation to the accelerating material loss rate during cavitation erosion. However, when the groove depth was fixed and the length varied, the fatigue life became complex, more fluctuant than that happened in depth. The results also indicate that the fatigue effect of cavitation plays an important role in contributing to the formation and propagation of characteristic pits.

MSCTA联合术中超声在小肾癌后腹腔镜肾部分切除手术中的应用价值

目的探讨多层螺旋CT血管成像(MSCTA)联合术中超声在小肾癌后腹腔镜肾部分切除术(LPN)中的应用价值。方法选择影像学显示肿瘤直径≤4.0 cm的小肾癌患者55例,其均采用后腹腔镜肾部分切除术。根据术中是否行超声,将其分为超声组(28例)和非超声组(27例)。左肾肿瘤33例,右肾肿瘤22例;肿瘤直径为1.5～5.0 cm,平均3.0 cm。比较两组手术时间、出血量、术中热缺血时间、微小癌灶发现率、术后漏尿、切缘阳性率及肾小球滤过率(GFR)功能。结果超声组手术时间少于非超声组(P <0.05),超声组术中出血量少于非超声组(P <0.05);超声组术中热缺血时间少于非超声组(P <0.05);中转开放手术例数超声组少于非超声组(P <0.05)。微小病灶检出例数:超声组1例;非超声组0例;术后漏尿例数:超声组0例,非超声组1例。切缘阳性率:超声组为0.0%,非超声组为3.7%。超声组术前、术后患肾GFR分别为(55.1±7.2)和(53.1±7.7)ml/min(P>0.05),非超声组术前、术后患肾GFR分别为(55.8±7.0)和(50.4±6.5)ml/min(P>0.05)。结论术中超声可快速准确的定位肿瘤组织,尽可能的保留肾单位、减少切缘阳性率,有利于术后患肾功能的恢复。

Polyurethane foam-supported three-dimensional interconnected graphene nanosheets network encapsulated in polydimethylsiloxane to achieve significant thermal conductivity enhancement

Polyurethane(PU)foams are widely used in thermal management materials due to their good flexibility.However,their low thermal conductivity limits the efficiency.To address this issue,we developed a new method to produce tannic acid(TA)-modified graphene nanosheets(GTs)-encapsulated PU(PU@GT)foams using the soft template microstructure and a facile layer-by-layer(L-B-L)assembly method.The resulting PU@GT scaffolds have ordered and tightly stacked GTs layers that act as three-dimensional(3D)highly interconnected thermal networks.These networks are further infiltrated with polydimethylsiloxane(PDMS).The through-plane thermal conductivity of the polymer composite reaches 1.58 W·m^(−1)·K^(−1) at a low filler loading of 7.9 wt.%,which is 1115%higher than that of the polymer matrix.Moreover,the mechanical property of the composite is~2 times higher than that of the polymer matrix while preserving good flexibility of the polymer matrix owing to the retention of the PU foam template and the construction of a stable 3D graphene network.This work presents a facile and scalable production approach to fabricate lightweight PU@GT/PDMS polymer composites with excellent thermal and mechanical performance,which implies a promising future in thermal management systems of electronic devices.

Conductive photo-thermal responsive bifunctional hydrogel system with self-actuating and self-monitoring abilities

Despite enormous efforts in actuators,most researches are only limited to various actuation behaviors and demonstrations of soft materials.It has not yet been reported to capture and monitor its movement status in an invisible environment.Therefore,it is of great significance to develop a self-sensing and self-actuating dual-function hydrogel actuator system to realize real-time monitoring.Here,we report a bifunctional hydrogel system with self-actuating and self-monitoring abilities,which combines the functions of photothermal actuation and electrical resistance sensing into a single material.The bilayer tough conductive hydrogel synthesized by unconventional complementary concentration recombination and cryogenic freezing technique presents a dense conductive network and high-porosity structure,achieving high toughness at 190.3 kPa of tensile strength,high stretchability(164.3%strain),and the toughness dramatically(1,471.4 kJ·m^(−3)).The working mechanism of the monitoring and self-sensing system is accomplished through the integrated monitoring device of surface temperature–bending angle–electron current,to solve the problem of not apperceiving actuator motion state when encountering obstacles in an invisible environment.We demonstrated for the first time a photothermal actuator’s motion of a football player and goalkeeper to finish the penalty and a soft actuator hand,which can achieve the action of sticking to grab and release under photo-thermal actuation.When connected to the control closed circuit,the actuator realized closed-loop monitoring and sensing feedback.The development of bifunctional hydrogel systems may bring new opportunities and ideas in the fields of material science,circuit technology,sensors,and mechanical engineering.

Template-mediated strategy to regulate hierarchically nitrogen-sulfur co-doped porous carbon as superior anode material for lithium capacity

Considering its rapid lithiation/delithiation process and robust capacitive energy storage,hierarchical porous carbon is regarded as a promising candidate for lithium-ion batteries(LIBs).However,it remains a great challenge to construct a porous structure and prevent structure stacking for carbon-based materials.Herein,a templatemediated approach is developed to synthesize hierarchical nitrogen-sulfur co-doped porous carbon(NSPC)using low-cost asphalt precursors.The strategy for synthesis uses g-C_(3)N_(4) and NaHCO_(3) as gaseous templates and NaCl as a solid template,which causes the formation of hierarchical porous carbon with a high specific surface area.The resultant porous structure and nitrogen-doping process can prevent the aggregation of nanosheets,maintain the structural stability upon cycling,and achieve rate-capable lithium storage.Serving as a LIBs anode,reversible specific capacities of the NSPC24 electrode reach 788 and 280 mAh·g^(-1) at 0.1 and 1 A·g^(-1),respectively.Furthermore,its specific capacity remains at 830 mAh·g^(-1) after 115 cycles at 0.1 A·g^(-1).Even after 500 cycles,high specific capacities of 727 mAh·g^(-1) at 0.5 A·g^(-1) and 624 mAh·g^(-1) at 1 A·g^(-1) are achieved,demonstrating excellent cycling performance.The gas-solid bifunctional template-mediated approach can guide the design of porous materials very well,meanwhile realizing the high value-added utilization of asphalt.

石墨烯改性硅基负极材料的研究进展

随着电动汽车的快速发展,对锂离子电池的负极材料有了越来越高的要求。目前商用锂离子电池的负极材料还是以石墨为主,但是石墨负极的理论比容量较低(为372 mAh/g),严重限制了锂离子电池的能量密度。硅的理论比容量高达4200 mAh/g,被认为是最有前途的锂离子电池负极材料之一。然而,硅负极材料在锂化的过程中会伴随着巨大的体积膨胀效应,导致电极材料破裂和粉碎,从而大幅度降低电池的循环稳定性,并且硅的电导率不理想,也限制了其倍率性能和循环性能。用石墨烯对硅负极材料进行改性,有望缓解其电极材料的体积膨胀以及导电性差的难题。本文重点阐述了石墨烯对于硅基负极材料的性能提升机理,期望对未来石墨烯改性硅基负极材料的制备和研究提供思路。

Amorphous Sn modified nitrogen-doped porous carbon nanosheets with rapid capacitive mechanism for highcapacity and fast-charging lithium-ion batteries

Sn-based materials are considered as a kind of potential anode materials for lithium-ion batteries(LIBs)owing to their high theoretical capacity.However,their use is limited by large volume expansion deriving from the lithiation/delithiation process.In this work,amorphous Sn modified nitrogen-doped porous carbon nanosheets(ASnNPCNs)are obtained.The synergistic effect of amorphous Sn and high edge-nitrogendoped level porous carbon nanosheets provides ASn-NPCNs with multiple advantages containing abundant defect sites,high specific surface area(214.9 m^(2)·g^(−1)),and rich hierarchical pores,which can promote the lithium-ion storage.Serving as the LIB anode,the as-prepared ASn-NPCNs-750 electrode exhibits an ultrahigh capacity of 1643 mAh·g^(−1) at 0.1 A·g^(−1),ultrafast rate performance of 490 mAh·g^(−1) at 10 A·g^(−1),and superior long-term cycling performance of 988 mAh·g^(−1) at 1 A·g^(−1) after 2000 cycles with a capacity retention of 98.9%.Furthermore,the in-depth electrochemical kinetic test confirms that the ultrahigh-capacity and fast-charging performance of the ASn-NPCNs750 electrode is ascribed to the rapid capacitive mechanism.These impressive results indicate that ASn-NPCNs-750 can be a potential anode material for high-capacity and fast-charging LIBs.

舌鳞状细胞癌相关长链非编码RNA的筛选与分析

[目的]获得舌鳞状细胞癌组织与正常舌组织中差异表达的长链非编码RNA,并进行功能注释和参与的生理过程进行初步分析。[方法]利用GEO数据库中GES13601的原始芯片数据,采用affymatrix软件套件对芯片数据进行重新均一化和标准化,并筛选差异表达的长链非编码RNA,查找其参与的生理过程。[结果]舌鳞状细胞癌组织与正常舌组织差异表达的基因个数为5 613个。其中在癌组织中上调的为2 951个,下调的共2 662个。从中筛选到长链非编码RNA 38个,上调19个,下调19个。其中的某些参与涉及肌肉、淋巴生长和癌细胞发送等生理过程,但是大部分的功能未知,尚需进一步研究。[结论]筛选到舌鳞状细胞癌相关的38个长链非编码RNA,为寻找早期舌鳞状细胞癌标志物提供了新的参考。

Tumor-suppressor microRNA-139-5p restrains bladder cancer cell line ECV-304 properties via targeting Connexin 43

Background:In our previous paper,we demonstrated that Connexin 43(CX43)was highly expressed in bladder cancer(BC)tissues.But the molecular mechanism about microRNAs(miRNAs)regulation upstream of CX43 in BC has not been well elucidated and remains to be further studied.MicroRNA-139-5p(miR-139-5p)is a tumor suppressor in progression of multifarious cancers including BC.Nevertheless,the underlying mechanisms of CX43/miR-139-5p in tumorigenesis of BC are still not well illustrated.The specific objective of our study was to inquiry the effect of CX43/miR-139-5p on BC progression and its underlying mechanism.Methods:The bioinformatics analysis softwares were applied to predict the miRNAs in the upstream of CX43.First,the expression levels of miR-139-5p in BC tissues(tumor)and paracancer tissues(normal)were investigated using the data from The Cancer Genome Atlas database.Quantitative reverse transcription-polymerase chain reaction(qRT-PCR)was used to detect the mRNA expression level of miR-139-5p in three human BC cell lines 5637,T24,ECV-304 and a human bladder epithelial immortalized cell line SV-HUC-1(normal control).Then si-CX43,si-control,miR-139-5p mimic,and its negative control(NC)were transfected into BC cell line ECV-304.The relationship of miR-139-5p and CX43 was analyzed by dual-luciferase reporter assay.The qRT-PCR and Western blotting were used to test the mRNA and protein expression level of CX43.The proliferation of ECV-304 and T24 cells were examined by cell counting kit-8.The migration and invasion of ECV-304 cells were tested by transwell assay.To determine whether miR-139-5p would affect cell proliferation,migration and invasion by targeting CX43,we executed the rescue assay.The comparison between two groups was analyzed by Student’s t test,and comparisons among multiple samples were performed by oneway analysis of variance and a Bonferroni post hoc test.Results:The expression of miR-139-5p was remarkably down-regulated in BC tissues(tumor vs.normal,2.286±0.017 vs.3.211±0.034,t=11.540,P<0.0001)and cell lines(P<0.01 in all BC cell lines).Besides,we also indicated that over-expression of miR-139-5p reduced the proliferation of ECV-304(P=0.001)and T24 cells(P=0.005).Moreover,miR-139-5p over-expression weakened the invasion(P=0.001)and migration(P=0.001)of ECV-304 cells.Furthermore,the relative luciferase activity of CX43-wild type construct was distinctly lessened by up-regulation of miR-139-5p(miR-139-5p mimic NC vs.miR-139-5p mimic,0.916±0.063 vs.0.356±0.048,t=7.085,P=0.002),nevertheless the activity of CX43-mutant type construct was untouched(miR-139-5p mimic NC vs.miR-139-5p mimic,0.918±0.057 vs.0.878±0.039,t=0.577,P=0.595).Finally,the rescue assay revealed that CX43 deletion enhanced the depressor effect of miR-139-5p on ECV-304 cell proliferation(P<0.01),invasion(P=0.028),and migration(P=0.014).Conclusion:MiR-139-5p,as a tumor-suppressor,repressed cell proliferation,invasion,and migration in BC,which might be achieved by regulating CX43.

{411}<148> Texture in Thin-Gauge Grain-Oriented Silicon Steel

The significant occupancy of {411}〈148〉texture exists in the thin-gauge grain-oriented silicon steel（TGCRGO is defined that thickness of the sheet is〈0.25 mm and the reduction in cold rolling is more than 90%） which has been considered to have obviously effects on the abnormal growth of Goss-oriented grains during the secondary recrystallization process. The microstructures of the TG-CRGO were investigated by X-ray diffraction and electron back-scattered diffraction in this study. It was found that {411}〈148〉〉texture mainly exists in the center layer of hot-rolled as well as normalized plates.With the increase in cold rolling reduction, {411}〈148〉 orientation gradually rotates to a-fiber texture（〈110〉//RD）.Finally, few {411}〈148〉would retain at the boundaries of deformed a-fiber grains（〈110〉//RD） as the reduction in cold rolling reaches 90%. After annealing treatment, a small amount of c-fiber textures（〈111〉//ND） preferably nucleates and recrystallizes between the DBs（deformation bands） at first; then, the {411}〈148〉 recrystallization texture occurs and mainly nucleates at the grains boundaries of the deformed a-fiber grains, and also quite a few {411}〈148〉orientation grains nucleate in the inner of {112}〈110〉grains. But this phenomenon was not observed in the {100}〈011〉deformation grains.With respect to the occurrence of {411}〈148〉recrystallization texture, it is mainly induced by strong a-fiber as well as weak c-fiber textures formed during cold rolling other than originating from {411}〈148〉 regions in hot bands.