A method to interpret fracture aperture of rock slope using adaptive shape and unmanned aerial vehicle multi-angle nap-of-the-object photogrammetry

The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods are inadequate for collecting data on high-steep rock slopes in complex mountainous regions.This study establishes a high-resolution three-dimensional model of a rock slope using unmanned aerial vehicle(UAV)multi-angle nap-of-the-object photogrammetry to obtain edge feature points of fractures.Fracture opening morphology is characterized using coordinate projection and transformation.Fracture central axis is determined using vertical measuring lines,allowing for the interpretation of aperture of adaptive fracture shape.The feasibility and reliability of the new method are verified at a construction site of a railway in southeast Tibet,China.The study shows that the fracture aperture has a significant interval effect and size effect.The optimal sampling length for fractures is approximately 0.5e1 m,and the optimal aperture interpretation results can be achieved when the measuring line spacing is 1%of the sampling length.Tensile fractures in the study area generally have larger apertures than shear fractures,and their tendency to increase with slope height is also greater than that of shear fractures.The aperture of tensile fractures is generally positively correlated with their trace length,while the correlation between the aperture of shear fractures and their trace length appears to be weak.Fractures of different orientations exhibit certain differences in their distribution of aperture,but generally follow the forms of normal,log-normal,and gamma distributions.This study provides essential data support for rock and slope stability evaluation,which is of significant practical importance.

立体定向放疗后原发病灶旁新发快速进展磨玻璃型肺腺癌1例

磨玻璃型肺癌临床常表现为惰性,其接受立体定向放疗(stereotactic body radiation therapy,SBRT)治疗后长期随访的临床研究较少。本文提供1例接受SBRT治疗的磨玻璃型肺癌的成功案例,但随访中发现临近SBRT治疗靶区的肺组织内,新发1例磨玻璃结节。该结节进展迅速,经手术切除证实为肺腺癌,但分子病理结果及基因检测未见明显高危因素和相关驱动基因。新发磨玻璃结节是否与既往SBRT治疗有关,值得进一步研究。本案例提示,SBRT治疗后的随访复查,应警惕靶区及临近肺组织内新发快速进展型肺癌的发生。

Surface Oxygen Injection in Tin Disulfide Nanosheets for Efficient CO_(2) Electroreduction to Formate and Syngas

Surface chemistry modification represents a promising strategy to tailor the adsorption and activation of reaction intermediates for enhancing activity.Herein,we designed a surface oxygen-injection strategy to tune the electronic structure of SnS_(2) nanosheets,which showed effectively enhanced electrocatalytic activity and selectivity of CO_(2) reduction to formate and syngas(CO and H_(2)).The oxygen-injection SnS_(2) nanosheets exhibit a remarkable Faradaic efficiency of 91.6%for carbonaceous products with a current density of 24.1 mA cm^(−2) at−0.9 V vs RHE,including 83.2%for formate production and 16.5%for syngas with the CO/H_(2) ratio of 1:1.By operando X-ray absorption spectroscopy,we unravel the in situ surface oxygen doping into the matrix during reaction,thereby optimizing the Sn local electronic states.Operando synchrotron radiation infrared spectroscopy along with theoretical calculations further reveals that the surface oxygen doping facilitated the CO_(2) activation and enhanced the affinity for HCOO*species.This result demonstrates the potential strategy of surface oxygen injection for the rational design of advanced catalysts for CO_(2) electroreduction.

Diffractive photonic applications mediated by laser reduced graphene oxides

Modification of reduced graphene oxide in a controllable manner provides a promising material platform for producinggraphene based devices. Its fusion with direct laser writing methods has enabled cost-effective and scalable production for advanced applications based on tailored optical and electronic properties in the conductivity, the fluorescence and the refractive index during the reduction process. This mini-review summarizes the state-of-the-art status of the mechanisms of reduction of graphene oxides by direct laser writing techniques as well as appealing optical diffractive applications including planar lenses, information storage and holographic displays. Owing to its versatility and up-scalability, the laser reduction method holds enormous potentials for graphene based diffractive photonic devices with diverse functionalities.

Metrology Challenges in 3D NAND Flash Technical Development and Manufacturing

3D NAND technical development and manufacturing face many challenges to scale down their devices,and metrology stands out as much more difficult at each turn.Unlike planar NAND,3D NAND has a three-dimensional vertical structure with high-aspect ratio.Obviously top-down images is not enough for process control,instead inner structure control becomes much more important than before,e.g.channel hole profiles.Besides,multi-layers,special materials and YMTC unique X-Tacking technology also bring other metrology challenges:high wafer bow,stress induced overlay,opaque film measurement.Technical development can adopt some destructive methodology(TEM,etch-back SEM),while manufacturing can only use nondestructive method.These drive some new metrology development,including X-Ray,mass measure and Mid-IR spectroscopy.As 3D NAND suppliers move to>150 layers devices,the existing metrology tools will be pushed to the limits.Still,the metrology must innovate.

HSA-MIR-203/MyD88 axis mediates the protective effect of hispidulin on LPS-induced apoptosis in a human renal tubular epithelial line,HK-2

Acute kidney injury(AKI),commonly occurring as complications of sepsis,cardiac surgery,and liver or kidney transplantation,is a critical care syndrome.It is well known that lipopolysaccharide(LPS)shock is a common triggering factor for AKI.This study is aimed to examine the effect of flavonoid compound hispidulin on LPS-induced AKI.For this,renal tubular epithelial cell HK-2 was treated with LPS to establish an in vitro model of AKI.The effect of hispidulin on HK-2 cell viability was examined using CCK-8 assay.Cell apoptosis was determined by TUNEL and flow cytometry.Apoptosis marker proteins were determined by using western blot.The levels of pro-inflammatory cytokines were determined by ELISA assay and qRT-PCR.The translocation of NF-κB was determined by western blot.The effect of MyD88 on the cytoprotective activities of hispidulin was examined by overexpressing MyD88 in HK-2 cells.Our results showed that hispidulin was not able to produce a cytotoxic effect on HK-2 cells at tested concentrations.However,hispidulin could protect HK-2 cells from LPS-induced cell injury.Our results also showed that hispidulin was able to attenuate LPS-induced HK-2 cell apoptosis.In addition,LPS led to an inflammatory response in HK-2 cells,evidenced by NF-κB p65 activation as well as increased expression and release of inflammatory cytokine IL-6 and TNF-α,which could be reversed by pretreatment with hispidulin.Overexpression MyD88 was found to significantly dampen the cytoprotective activities of hispidulin against LPS insult.More importantly,MyD88 was identified as a direct target of hsa-miR-203,and hispidulin was found to regulate the expression of MyD88 via upregulating hsa-miR-203.Our results showed that hispidulin attenuates LPS-induced HK-2 damage via regulating hsa-miR-203/MyD88 axis.

Novel Pattern-Centric Solution for Xtacking^TM AFM Metrology

3D NAND(three-dimensional NAND type)has rapidly become the standard technology for enterprise flash memories,and is also gaining widespread use in other applications.Continued manufacturing process improvements are essential in delivering memory devices with higher I/O performance,higher bit density,and at lower cost.Current 3D NAND technology involves process steps that form array and peripheral CMOS(Complementary Metal-Oxide-Semiconductor)regions side-by-side,resulting in waste of silicon real estate and film stress compromises,and limits the paths of making advanced 3D NAND devices.An innovative architecture was invented to overcome these challenges by connecting two wafers electrically through metal VIAs(Vertical Interconnect Access)[1].Highly accurate and efficient metrology is required to monitor VIA interface due to increased process complexity and precision requirements.With the advanced processing of AFM(Atomic Force Microscopy)images,highly accurate and precise measurements have been achieved.An inline pattern-centric metrology solution that is designed for high volume mass production of high-performance 3D NAND is presented in this paper.

White Light Interference Solution for Novel 3D NAND VIA Dishing Metrology

In traditional 3D NAND design,peripheral circuit accounts for 20-30%of the chip realestate,which reduces the memory density of flash memory.As 3D NAND technology stacks to 128 layers or higher,peripheral circuits may account for more than 50%of the overall chip area.On the contrast,the Xtacking^TM technology arranges array and logic parts on two different wafers,and connects the memory arrays to the logic circuit by metal VIAs(Vertical Interconnect Accesses)to achieve unprecedented high storage density as well as DRAM level I/O speed.As a consequence,it becomes increasingly significant to monitor metal VIAs depth before wafer bonding process as to ensure reliability of array-logic connections.Currently,AFM(Atom Force Microscopy)is the main stream method of VIA depth monitoring.Apparently,AFM wins the battle of precision,however the low throughput limited its usage in mass production.In order to accomplish the requirement of VLSI production,a WLI(White Light Interference)metrology is revisited and a novel WLI method was developed to monitor VIAs depth.Basically there are two major limitations that keep WLI tools from wider use,transparent film impact and diffraction limitation.In this work,the engineering solutions are illustrated and inline dishing measurement is achieved with high accuracy and precision.

Spatiotemporal pulse weaving scalar optical hopfions

Scalar optical hopfions weaved by nested equiphase lines in the shape of a toroidal vortex are theoretically designed and experimentally demonstrated.This category of hopfions manifesting as a spatiotemporally structured pulse propagating in space-time may enable encoding and transferring optical topological information in an additional(temporal)dimension.

Extracellular Signal-Regulated Kinase in Nucleus Accumbens Mediates Propofol Self-Administration in Rats

Abstract Clinical and animal studies have indicated that propofol has potential for abuse, but the specific neurobi- ological mechanism underlying propofol reward is not fully understood. The purpose of this study was to inves- tigate the role of extracellular signal-regulated kinase （ERK） signal transduction pathways in the nucleus accumbens （NAc） in propofol self-administration. We tested the expression of p-ERK in the NAc following the maintenance of propofol self-administration in rats. We also assessed the effect of administration of SCH23390, an antagonist of the D1 dopamine receptor, on the expression of p-ERK in the NAc in propofol self-administering rats, and examined the effects of intra-NAc injection of U0126, an MEK inhibitor, on propofol reinforcement in rats. The results showed that the expression of p-ERK in the NAc increased significantly in rats maintained on propofol, and pre-treatment with SCH23390 inhibited the propofol self- administration and diminished the expression of p-ERK in the NAc. Moreover, intra-NAc injection of U0126 （4 μg/ side） attenuated the propofol self-administration. The data suggest that ERK signal transduction pathways coupledwith D1 dopamine receptors in the NAc may be involved in the maintenance of propofol self-administration and its rewarding effects.

Dynamic Volumography of Cylindrical Li-Ion Battery Cells by Watching Its Breath During Cycling

It has been well-documented that the charging of Li-ion battery(LIB)is accompanied by volume expansion,a significant source of their capacity fading and structural failure.However,existing operando techniques for measuring battery expansion either use single-point detection to report the local deformation or are not sensitive enough for hard-pack cylindrical batteries.Here,we propose an optical volumography(OVG)technology,including both apparatus and methodology,to measure the absolute volume of a commercial 18650 cylindrical LIB cell by taking a series of optical images of a rotating battery and reconstructing its 3D surface profile.Charging(discharging)induced volume expansion(shrinkage),i.e.,the“breath,”of multiple battery cells can be quantitatively determined in parallel and in real time.This method has a sensitivity of up to 1×10^(−5)(ΔV/V0)and an accuracy of 0.1μm.In contrast to the overall expansion of a soft-pack pouch battery,hard-pack cylindrical cells exhibit rather small and heterogeneous wrinkle-type deformation during charging,underscoring the value of the sensitivity and spatial resolution of OVG.In addition to mapping the strain distribution,OVG further allows for differentiating the thermal-induced expansion from the reaction-induced expansion and evaluation of the state-of-charge and the state-of-health optically,with promising implications for process optimization,quality control,and energy and thermal management of batteries.

Dual-shot dynamics and ultimate frequency of all-optical magnetic recording on GdFeCo

Although photonics presents the fastest and most energy-efficient method of data transfer,magnetism still offers the cheapest and most natural way to store data.The ultrafast and energy-efficient optical control of magnetism is presently a missing technological link that prevents us from reaching the next evolution in information processing.The discovery of all-optical magnetization reversal in GdFeCo with the help of 100fs laser pulses has further aroused intense interest in this compelling problem.Although the applicability of this approach to high-speed data processing depends vitally on the maximum repetition rate of the switching,the latter remains virtually unknown.Here we experimentally unveil the ultimate frequency of repetitive all-optical magnetization reversal through time-resolved studies of the dual-shot magnetization dynamics in Gd27 Fe63.87 C09.T3.Varying the intensities of the shots and the shotto-shot separation,we reveal the conditions for ultrafast writing and the fastest possible restoration of magnetic bits.It is shown that although magnetic writing launched by the first shot is completed after 100 ps,a reliable rewriting of the bit by the second shot requires separating the shots by at least 300 ps.Using two shots partially overlapping in space and minimally separated by 300 ps,we demonstrate an approach for GHz magnetic writing that can be scaled down to sizes below the diffraction limit.

Construction and investigation of photo-switch property of azobenzene-bridged pillar[5]arene-based[3]rotaxanes

Series of azobenzene-bridged pillar[5]arene-based [3]rotaxanes with different alkyl chain length of guest molecules were constructed by threading-endcapping method with alkylenetriazole as axile and tetrahydrochromene as endcapping group.The encapsulation of pillar[5]arenes were proved by highresolution mass,^(1) H NMR and NOESY spectra.The photo-responsive property were examined by irradiation of the synthesized [3]rotaxanes with 365 nm and blue light LED,which caused trans to cis and cis to trans isomerization,respectively.Irradiation of corresponding model guest compounds without pillar[5]arene encapsulation resulted in near completely trans to cis and cis to trans isomerization,indicating the existence of pillar[5]arenes is the determining factor for the comprised photo isomerization efficiency.

Trend Analysis and Intervention Effect Starting Point Detection of COVID-19 Epidemics Using Recalibrated Time Series Models—Worldwide,2020

Objective:This study aimed to identify a model for short-term coronavirus disease 2019(COVID-19)trend prediction and intervention evaluation.Methods:We compared the autoregressive integrated moving average(ARIMA)model and Holt exponential smoothing(Holt)model on predicting the number of cumulative COVID-19 cases in China.Based on the mean absolute percentage error(MAPE)value,the optimal model was selected and further tested using data from the United States,Italy and Republic of Korea.The intervention effect starting time points and abnormal trend changes were detected by observing the pattern of differences between the predicted and real trends.Results:The recalibrated ARIMA model with a 5-day prediction time span has the best model performance with MAPEs ranged between 2%and 5%.The intervention effects started to show on February 7 in the mainland of China,March 5 in Republic of Korea and April 27 in Italy,but have not been detected in the US as of May 19.Temporary abnormal trends were detected in Korea and Italy,but the overall epidemic trends were stable since the effect starting points.Conclusion:The recalibrated ARIMA model can detect the intervention effects starting points and abnormal trend changes;thus to provide valuable information support for epidemic trend analysis and intervention evaluation.