Expert consensus on pediatric orthodontic therapies of malocclusions in children

Malocclusion,identified by the World Health Organization(WHO)as one of three major oral diseases,profoundly impacts the dental-maxillofacial functions,facial esthetics,and long-term development of~260 million children in China.Beyond its physical manifestations,malocclusion also significantly influences the psycho-social well-being of these children.Timely intervention in malocclusion can foster an environment conducive to dental-maxillofacial development and substantially decrease the incidence of malocclusion or reduce the severity and complexity of malocclusion in the permanent dentition,by mitigating the negative impact of abnormal environmental influences on the growth.Early orthodontic treatment encompasses accurate identification and treatment of dental and maxillofacial morphological and functional abnormalities during various stages of dental-maxillofacial development,ranging from fetal stages to the early permanent dentition phase.From an economic and societal standpoint,the urgency for effective early orthodontic treatments for malocclusions in childhood cannot be overstated,underlining its profound practical and social importance.This consensus paper discusses the characteristics and the detrimental effects of malocclusion in children,emphasizing critical need for early treatment.It elaborates on corresponding core principles and fundamental approaches in early orthodontics,proposing comprehensive guidance for preventive and interceptive orthodontic treatment,serving as a reference for clinicians engaged in early orthodontic treatment.

Stratification in central Bohai Sea and how it has shaped hypoxic events in summer

In the last 10 years(2012-2021),five hypoxic events have been observed in summer in the central Bohai Sea(CBS).Frequent and persistent hypoxia will have an impact on the ecosystem of the CBS.In this paper,historical sea temperature(ST),salinity(SAL),density(Den),and dissolved oxygen(DO)concentration data from three stations in the CBS are analyzed via the linear regression method,and the correlations between the stratification factors(ST,SAL,and Den)and DO concentration are determined.The thresholds of the stratification factors at the three stations in June in the year in which hypoxia occurred were determined and applied to survey data from 29 stations in late May to early June in 2022 in the CBS;this assessment found that the data from 19 stations indicated that hypoxia was about to occur.In August,the survey data showed that 14 out of the 29 stations indicated hypoxic conditions,of which 12 were from the predicted 19 stations,meaning that the estimation accuracy reached 63%.The same approach was applied to data from June 2023.The data for August from a bottom-type online monitoring system in the CBS verified the occurrence of hypoxic events around Sta.M2.The results show that the strength of the seawater stratification plays a leading role in hypoxic events in the summer in the CBS,and the thresholds of the stratification factors can be used to predict the occurrence of hypoxic events.

Deciphering TADF Mechanisms in Metal-Free Organic Emitters BrA-HBI:Utilizing Optimally Tuned Range-Separated Functionals for Insight

Metal-free organic emitters,characterized by their thermally activated delayed fluorescence(TADF)properties,offer considerable promise for the creation of highly efficient organic light-emitting diodes(OLEDs).Recently,Shao et al.presented a novel excited state intramolecular proton transfer(ESIPT)system BrA-HBI,demonstrating an emission quantum yield of up to 50%[Adv.Funct.Mater.32,2201256(2022)].However,many open issues cannot be answered solely by experimental means only and require detailed theoretical investigations.For instance,what causes the activation of TADF from the Keto^(*) tautomer and leads to fluorescence quenching in the Enol^(*)form?Herein,we provide a theoretical investigation on the TADF mechanism of the BrA-HBI molecule by optimally tuned range-separated functionals.Our findings reveal that ESIPT occurs in the BrA-HBI molecule.Moreover,we have disclosed the reason for the fluorescence quenching of the Enol^(*)form and determined that the T_(2)state plays a dominant role in the TADF phenomenon.In addition,double hybrid density functionals method was utilized to verify the reliability of optimally tuned range separation functionals on the calculation of the TADF mechanism in BrA-HBI.These findings not only provide a theoretical reference for development of highly efficient organic light-emitting diodes,but also demonstrate the effectiveness of the optimally tuned range-separated functionals in predicting the luminescence properties of TADF molecules.

Effects of virtual agents on interaction efficiency and environmental immersion in MR environments

Background Physical entity interactions in mixed reality(MR)environments aim to harness human capabilities in manipulating physical objects,thereby enhancing virtual environment(VEs)functionality.In MR,a common strategy is to use virtual agents as substitutes for physical entities,balancing interaction efficiency with environmental immersion.However,the impact of virtual agent size and form on interaction performance remains unclear.Methods Two experiments were conducted to explore how virtual agent size and form affect interaction performance,immersion,and preference in MR environments.The first experiment assessed five virtual agent sizes(25%,50%,75%,100%,and 125%of physical size).The second experiment tested four types of frames(no frame,consistent frame,half frame,and surrounding frame)across all agent sizes.Participants,utilizing a head mounted display,performed tasks involving moving cups,typing words,and using a mouse.They completed questionnaires assessing aspects such as the virtual environment effects,interaction effects,collision concerns,and preferences.Results Results from the first experiment revealed that agents matching physical object size produced the best overall performance.The second experiment demonstrated that consistent framing notably enhances interaction accuracy and speed but reduces immersion.To balance efficiency and immersion,frameless agents matching physical object sizes were deemed optimal.Conclusions Virtual agents matching physical entity sizes enhance user experience and interaction performance.Conversely,familiar frames from 2D interfaces detrimentally affect interaction and immersion in virtual spaces.This study provides valuable insights for the future development of MR systems.

Preparation and Performance of Pueraria lobata Root Powder/Polylactic Acid Composite Films

Petroleum-based materials,such as plastic,are characterized by adverse environmental pollution;as a result,researchers have sought alternative degradable plastics that are environmentally friendly,such as polylactic acid(PLA).PLA has shown great potential to replace petroleum-based plastics.In this study,seven different samples of unmodified Pueraria lobata root powder(PRP)with different contents(i.e.,0,5,10,15,20,25,and 30 wt%)and three different modified PRPs(i.e.,treated with NaOH,NaOH-KH-550,and Formic)were used to reinforce polylactic acid(PLA)via solution casting process.These prepared PRP/PLA composite films were characterized using SEM,FTIR,UV-visible spectra analysis,TG,DSC,weight loss measurement(wt%),and mechanical measurements.The results showed that the PRP modified with KH-550(PRPK)intensified the interaction in the interface region between the PRP and the PLA matrix,thus increasing the tensile strength(54.5 MPa),elongation at break(2.8%),and Young’s modulus(3310 MPa)of the PRPK/PLA biofilms.Contact angle measurement showed that the PRP treatments contributed to the hydrophobicity of films.The transparency of PRP-10/PLA film atλ_(800)was 11.09%,and its UVA and UVB transmittance were 3.28 and 1.16,respectively.After blending PLA with PRP,the PRP/PLA composite films exhibited excellent biodegradability.In summary,PRPK improved the mechanical properties of PLA and prevented the films from ultraviolet light,suggesting that PRPK-5/PLA film could be used as packaging materials.

Identification of key genes and biological pathways in lung adenocarcinoma by integrated bioinformatics analysis

BACKGROUND The objectives of this study were to identify hub genes and biological pathways involved in lung adenocarcinoma(LUAD)via bioinformatics analysis,and investigate potential therapeutic targets.AIM To determine reliable prognostic biomarkers for early diagnosis and treatment of LUAD.METHODS To identify potential therapeutic targets for LUAD,two microarray datasets derived from the Gene Expression Omnibus(GEO)database were analyzed,GSE3116959 and GSE118370.Differentially expressed genes(DEGs)in LUAD and normal tissues were identified using the GEO2R tool.The Hiplot database was then used to generate a volcanic map of the DEGs.Weighted gene co-expression network analysis was conducted to cluster the genes in GSE116959 and GSE-118370 into different modules,and identify immune genes shared between them.A protein-protein interaction network was established using the Search Tool for the Retrieval of Interacting Genes database,then the CytoNCA and CytoHubba components of Cytoscape software were used to visualize the genes.Hub genes with high scores and co-expression were identified,and the Database for Annotation,Visualization and Integrated Discovery was used to perform enrichment analysis of these genes.The diagnostic and prognostic values of the hub genes were calculated using receiver operating characteristic curves and Kaplan-Meier survival analysis,and gene-set enrichment analysis was conducted.The University of Alabama at Birmingham Cancer data analysis portal was used to analyze relationships between the hub genes and normal specimens,as well as their expression during tumor progression.Lastly,validation of protein expression was conducted on the identified hub genes via the Human Protein Atlas database.RESULTS Three hub genes with high connectivity were identified;cellular retinoic acid binding protein 2(CRABP2),matrix metallopeptidase 12(MMP12),and DNA topoisomerase II alpha(TOP2A).High expression of these genes was associated with a poor LUAD prognosis,and the genes exhibited high diagnostic value.CONCLUSION Expression levels of CRABP2,MMP12,and TOP2A in LUAD were higher than those in normal lung tissue.This observation has diagnostic value,and is linked to poor LUAD prognosis.These genes may be biomarkers and therapeutic targets in LUAD,but further research is warranted to investigate their usefulness in these respects.

两种圈套器改良牵引法辅助内镜黏膜下剥离术治疗上消化道早癌和黏膜下肿瘤的临床对比研究

目的研究体外圈套器改良牵引辅助技术在内镜黏膜下剥离术(ESD)治疗上消化道早癌和黏膜下肿瘤中的应用价值,并对比两种圈套器牵引法的应用效果。方法回顾性分析该院接受ESD治疗的上消化道早癌和黏膜下肿瘤患者72例,A组为传统ESD方法治疗组,B组为粗圈套器圈套牵引组,C组为细圈套器圈套牵引组。比较3组病变直径、手术平均时间、止血夹脱离次数、黏膜下补充注射量、一次完整切除率、并发症和随访情况。结果72例患者均成功完成ESD术,3组病灶直径、术中明显出血和迟发性出血比较,差异均无统计学意义(P>0.05);C组手术平均时间和黏膜下补充注射量明显少于A组,两组比较,差异有统计学意义(P<0.05);C组(100.00%)一次完整切除率高于B组和A组,3组比较,差异有统计学意义(P<0.05);C组组织夹脱离次数少于B组,两组比较,差异有统计学意义(P<0.05)。结论改良圈套器牵引辅助技术能明显缩短操作时间,减少术中黏膜下补充注射量,且具有牵引方向可调节的优点。使用体外细圈套器辅助牵引法,组织夹不易脱离,一次完整切除率高,特别是在上消化道困难ESD术中应用更具优势。

汉防己甲素通过促进HIF-1α降解增强p53缺陷型非小细胞肺癌的放疗敏感性

目的:探讨汉防己甲素(tetrandrine,TET)增强非小细胞肺癌(non-small cell lung cancer,NSCLC)放疗敏感性的作用机制。方法:通过CCK-8法检测H1299和Calu-1细胞活力,并结合克隆形成实验检测在常规或缺氧条件下,TET对NSCLC放疗敏感性的影响。研究TET对NSCLC中由辐射和缺氧诱导的缺氧诱导因子-1α(hypoxia inducible factor-1,HIF-1α)及血管内皮生长因子(vascular endothelial growth factor,VEGF)表达的影响,并敲低HIF-1α基因进一步验证。通过逆转录聚合酶链反应(reverse tran⁃scription-polymerase chain reaction,RT-PCR)、环己酰亚胺(cycloheximide,CHX)追踪及免疫沉淀法检测TET对HIF-1α降解的影响,并探讨p53在TET放疗增敏中的作用。结果:TET可显著增强p53缺陷型NSCLC细胞的放疗敏感性,而对p53野生型的细胞作用不明显。辐射和缺氧暴露后,TET明显抑制HIF-1α及VEGF的表达。TET可通过蛋白泛素化降解系统加速HIF-1α的降解。野生型p53基因转染到H1299细胞中可减弱TET抑制HIF-1α表达的作用。结论:TET通过促进HIF-1α降解抑制HIF-1α通路,使p53缺陷型NSCLC细胞对辐射敏感,而p53在TET诱导的HIF-1α降解中发挥抑制作用。

脑电双频指数监测在危重症患儿电子支气管镜术中的应用

目的探讨脑电双频指数(BIS)监测应用于儿童重症监护病房(PICU)患儿行电子支气管镜术的临床价值。方法选取河南省儿童医院PICU收治的患有呼吸系统疾病的患儿107例,均符合行电子支气管镜术指征,随机分为对照组(51例)和观察组(56例)。两组患儿在行电子支气管镜术的过程中,均给予心电监护、舒芬太尼联合丙泊酚镇痛镇静。对照组以临床经验判断麻醉深浅程度指导用药;观察组持续行BIS监测,根据BIS监测数值判断麻醉深浅程度并指导用药。记录两组患儿术前、术中及操作结束后的心率(HR)、平均动脉压(MAP)、血氧饱和度(SpO_(2)),比较两组患儿术后苏醒时间及呛咳呕吐等不良反应发生率的情况。结果观察组在T_(1)、T_(2)时间点SpO_(2)明显高于对照组(P <0.05),术后苏醒时间短于对照组,不良反应发生率低于对照组(P <0.05);观察组因低氧血症导致的操作中断、引起二次进镜操作的发生率明显低于对照组(P <0.05),在丙泊酚药物用量上,观察组也少于对照组(P <0.05)。结论在危重症患儿行电子支气管镜术中,BIS监测能够有效监测患儿的麻醉深浅程度,降低不良反应发生率,保障患儿能够安全顺利地完成电子支气管镜术。

Analysis of Eco-Tourism Climate Resources in Xingwen, China Based on the Comfort Index and the Negative Air (Oxygen) Ion

The present work investigates an analysis of Eco-Tourism Climate Resources in Xingwen, China based on the Comfort Index and Negative Air (Oxygen) Ion (“NAI” for short in this article) concentration. The daily temperature, precipitation, wind speed, sunshine hours, and relative humidity data of the Xingwen National Meteorological Station from 1999 to 2018, as well as the NAI data of Feiwu Cave station and Shoushan Lake station in Xingwen of 2018 were used in this study. Based on the analysis of the characteristics of basic meteorological elements, the index of climate comfort of human living environment and the NAI variation in Xingwen, the eco-tourism climate resources in this area were evaluated comprehensively. The results show that: The climate is mild, the precipitation is abundant and the seasonal variation trend of precipitation and heat is similar in the study area. The annual average temperature of this area is 17.8°C, the annual average precipitation is 1096 mm, the annual average precipitation days are 186 days, the annual average relative humidity is 81%, the annual average wind speed is 1.3 m/s, and the annual average sunshine hours are 999 h. The living environment comfort level reaches the “comfort” level for 6 months per year. In addition, the concentration of NAI in Xingwen remains at the highest level 7 throughout the year, and the rate of good air quality is extremely high. Overall, the study area has high-quality ecological climate resources that are conducive to the development of forest recuperation, leisure and vacation and other ecological tourism activities.

Kansuinine J,a new macrocyclic diterpenoid from the roots of Euphorbia kansui

A new macrocyclic diterpenoid,named kansuinine J（1）,was isolated from the roots of Euphorbia kansui.Its structure was characterized on the basis of spectroscopic analysis.

Exosomal microRNA-588 from M2 polarized macrophages contributes to cisplatin resistance of gastric cancer cells

BACKGROUND Gastric cancer is a prevalent malignant cancer with a high incidence and significantly affects the health of modern people globally.Cisplatin(DDP)is one of the most common and effective chemotherapies for patients with gastric cancer,but DDP resistance remains a severe clinical challenge.AIM To explore the function of M2 polarized macrophages-derived exosomal microRNA(miR)-588 in the modulation of DDP resistance of gastric cancer cells.METHODS M2 polarized macrophages were isolated and identified by specific markers using flow cytometry analysis.The exosomes from M2 macrophages were identified by transmission electron microscopy and related markers.The uptake of the PKH67-labelled M2 macrophages-derived exosomes was detected in SGC7901 cells.The function and mechanism of exosomal miR-588 from M2 macrophages in the modulation of DDP resistance of gastric cancer cells was analyzed by CCK-8 assay,apoptosis analysis,colony formation assay,Western blot analysis,qPCR analysis,and luciferase reporter assay in SGC7901 and SGC7901/DDP cells,and by tumorigenicity analysis in nude mice.RESULTS M2 polarized macrophages were isolated from mouse bone marrow stimulated with interleukin(IL)-13 and IL-4.Co-cultivation of gastric cancer cells with M2 polarized macrophages promoted DDP resistance.M2 polarized macrophagesderived exosomes could transfer in gastric cancer cells to enhance DDP resistance.Exosomal miR-588 from M2 macrophages contributed to DDP resistance of gastric cancer cells.miR-588 promoted DDP-resistant gastric cancer cell growth in vivo.miR-588 was able to target cylindromatosis(CYLD)in gastric cancer cells.The depletion of CYLD reversed miR-588 inhibition-regulated cell proliferation and apoptosis of gastric cancer cells exposed to DDP.CONCLUSION In conclusion,we uncovered that exosomal miR-588 from M2 macrophages contributes to DDP resistance of gastric cancer cells by partly targeting CYLD.miR-588 may be applied as a potential therapeutic target for the treatment of gastric cancer.

Secular trend analysis of lung cancer incidence in Sihui city,China between 1987 and 2011

Background:With industrial and economic development in recent decades in South China,cancer incidence may have changed due to the changing lifestyle and environment.However,the trends of lung cancer and the roles of smoking and other environmental risk factors in the development of lung cancer in rural areas of South China remain unclear.The purpose of this study was to explore the lung cancer incidence trends and the possible causes of these trends.Methods:Joinpoint regression analysis and the age-period-cohort(APC) model were used to analyze the lung cancer incidence trends in Sihui,Guangdong province,China between 1987 and 2011,and explore the possible causes of these trends.Results:A total of 2,397 lung cancer patients were involved in this study.A 3-fold increase in the incidence of lung cancer in both sexes was observed over the 25-year period.Joinpoint regression analysis showed that while the incidence continued to increase steadily in females during the entire period,a sharp acceleration was observed in males starting in 2005.The full APC model was selected to describe age,period,and birth cohort effects on lung cancer incidence trends in Sihui.The age cohorts in both sexes showed a continuously significant increase in the relative risk(RR)of lung cancer,with a peak in the eldest age group(80-84 years).The RR of lung cancer showed a fluctuating curve in both sexes.The birth cohorts identified an increased trend in both males and females;however,males had a plateau in the youngest cohorts who were born during 1955-1969.Conclusions:Increasing trends of the incidence of lung cancer in Sihui were dominated by the effects of age and birth cohorts.Social aging,smoking,and environmental changes may play important roles in such trends.

Experimental research on oil fi lm thickness and its microwave scattering during emulsifi cation

Synthetic Aperture Radar(SAR) plays a major role in identifying oil spills on the sea surface.However,obtaining information of oil spill thickness(volume) is still a challenge.Emulsification is an important process affecting the thickness and normalized radar cross section(NRCS) of oil film.Experiments of crude oil emulsification with C-band fully-polarized scatterometer were conducted combining airborne hyperspectral imaging spectrometer and 3 D laser scanner observation data,to provide experimental parameters and method to support accurate remote sensing monitoring on marine oil spill.It is further proved that through quantitative homogeneous emulsified oil spill experiments,to a certain extent,the NRCS of oil film increased during the emulsification process of crude oil.The backscattering mechanism of crude oil emulsification was explored using a semi-empirical model(SEM);the change of oil film NRCS was modulated by its dielectric constant and surface roughness,in which the dielectric constant showed a dominant effect.The relationship between thickness and NRCS of oil film was studied under two experimental conditions.The differences of NRCS between oil film and adjacent seawater(Δσ~0) and the damping ratio(DR) were found to have a linear relationship with oil thickness,which were best in the vertical polarization mode(VV) at 45° incident angle during the quantitative crude oil homogeneous emulsification process.In the natural emulsification process of continuous oil spill in which oil film was mixed with both crude oil and emulsified oil,an empirical equation of oil film thickness is preliminarily established.The Δσ~0,DR,and the empirical equation of oil film thickness were applied to the marine continuous oil spill incident on a 19-3 oil platform with spaceborne SAR image and successfully explained the distribution of the relative thickness of the oil film.

耳内镜在听骨链探查及重建中的应用

目的研究耳内镜在听骨链探查及重建中的应用效果。方法回顾性分析2019年2月-2021年5月该院64例(64耳)听骨链探查鼓室成形术患者的临床资料。耳内镜组采用耳内镜手术,显微镜组采用显微镜手术。结果在病变范围未超过鼓窦的患者中,耳内镜组术中出血量少于显微镜组,手术时间和住院时间短于显微镜组,疼痛评分和不良反应率低于显微镜组,差异均有统计学意义(P<0.05);术后6个月,耳内镜组鼓膜愈合率为93.3%(28/30),显微镜组鼓膜愈合率为91.2%(31/34),两组患者均能获得较高的鼓膜愈合率以及纯音听阈均值(PTA)的改善,但组间比较,差异无统计学意义(P>0.05)。术后在听骨链重建的患者中,耳内镜组人工听骨植入患者气骨导间距(A-B gap)缩小程度大于显微镜组,差异有统计学意义(P<0.05)。结论在病变未超过鼓窦的患者中,选择耳内镜手术优势较多,具有临床实用价值。

Mid-infrared atmospheric transmittance at 5100 m-altitude Ali Observatory

Ali in Tibet,5100 m above sea level,is one of the most suitable locations in the world for infrared spectral observations.The atmospheric transmittances at Ali Observatory and Mauna Kea Observatory were calculated by MODTRAN using radiosonde data.The results were 0.848 and 0.789 respectively which indicated better conditions at Ali Observatory.A self-made instrument with a 320×256-pixel HgCdTe infrared focal plane array and a 7.5-cm diameter telescope was utilized for the actual measurements.Without the help of standard stars,the on-site and real-time atmospheric transmittance can be obtained as 0.831 by fitting the relation between the measured atmospheric radiation intensity and the zenith angle based on radiation transfer equations.This paper firstly reports the atmospheric transmittance in the M'band(4.605–4.755μm)at the 5100 m-altitude Ali observatory by actual measurement.It shows that the high-altitude Ali observatory with sufficiently low water vapor content is suitable for observation in the mid-infrared bands.

A new oil spill detection algorithm based on Dempster-Shafer evidence theory

Features of oil spills and look-alikes in polarimetric synthetic aperture radar(SAR)images always play an important role in oil spill detection.Many oil spill detection algorithms have been implemented based on these features.Although environmental factors such as wind speed are important to distinguish oil spills and look-alikes,some oil spill detection algorithms do not consider the environmental factors.To distinguish oil spills and look-alikes more accurately based on environmental factors and image features,a new oil spill detection algorithm based on Dempster-Shafer evidence theory was proposed.The process of oil spill detection taking account of environmental factors was modeled using the subjective Bayesian model.The Faster-region convolutional neural networks(RCNN)model was used for oil spill detection based on the convolution features.The detection results of the two models were fused at decision level using Dempster-Shafer evidence theory.The establishment and test of the proposed algorithm were completed based on our oil spill and look-alike sample database that contains 1798 image samples and environmental information records related to the image samples.The analysis and evaluation of the proposed algorithm shows a good ability to detect oil spills at a higher detection rate,with an identifi cation rate greater than 75%and a false alarm rate lower than 19%from experiments.A total of 12 oil spill SAR images were collected for the validation and evaluation of the proposed algorithm.The evaluation result shows that the proposed algorithm has a good performance on detecting oil spills with an overall detection rate greater than 70%.

Growth of high quality InSb thin films on GaAs substrates by molecular beam epitaxy method with AlInSb/GaSb as compound buffer layers

A series of In Sb thin films were grown on Ga As substrates by molecular beam epitaxy(MBE).Ga Sb/Al In Sb is used as a compound buffer layer to release the strain caused by the lattice mismatch between the substrate and the epitaxial layer,so as to reduce the system defects.At the same time,the influence of different interface structures of Al In Sb on the surface morphology of buffer layer is explored.The propagation mechanism of defects with the growth of buffer layer is compared and analyzed.The relationship between the quality of In Sb thin films and the structure of buffer layer is summarized.Finally,the growth of high quality In Sb thin films is realized.

Experimental study of C-band microwave scattering characteristics during the emulsification process of oil spills

In this study,oil spill experiments were performed in a water tank to determine changes in the surface scattering characteristics during the emulsification of oil spills.A C-band fully-polarimetric microwave scatterometer and a vector network analyzer were used to observe films of the following oils:crude oil with an asphalt content below3%that is prone to emulsification(type A),fresh crude oil extracted from an oilfield(type B),and industrial crude oil that was dehydrated and purified(type C).The difference in the backscatter results between the emulsified oil film and the calm water surface under C-band microwaves and the influence of the emulsification of the oil film on the backscatter were analyzed in detail.The results demonstrate that under a low-wind and no-waves condition(the maximum wave height was below than 3 mm),the emulsification of crude oil could modulated the backscatter through changes in the surface roughness and the dielectric constant,where the surface roughness had the dominant effect.The surface backscatters of the type B oil were greater than that of the type C oil in both the emulsified and non-emulsified states.In the non-emulsified state,the average differences in the backscatter between the type B and C oils were 2.19 dB,2.63 dB,and 2.21 dB for the polarization modes of VV,HH,and HV/VH,respectively.Smaller corresponding average differences of 0.98 dB,1.49 dB,and 1.5 dB were found for the emulsified state with a 20%moisture constant for the oil film.The results demonstrated that the surface roughness of the different oil films could vary due to the differences in the oil compositions and the oil film properties,which in turn affect the backscatter of the oil film surface.

High material quality growth of AlInAsSb thin films on GaSb substrate by molecular beam epitaxy

In this paper, high material quality Al_(0.4) In_(0.6) AsSb quaternary alloy on GaSb substrates is demonstrated. The quality of these epilayers is assessed using a high-resolution x-ray diffraction, Fourier transform infrared(FTIR) spectrometer,and atomic force microscope(AFM). The x-ray diffraction exhibits high order satellite peaks with a measured period of 31.06 ?(theoretical value is 30.48 ?), the mismatch between the GaSb substrate and AlInAsSb achieves-162 arcsec,and the root-mean square(RMS) roughness for typical material growths has achieved around 1.6 ? over an area of 10 μm×10 μm. At room temperature, the photoluminescence(PL) spectrum shows a cutoff wavelength of 1.617 μm.