Co and postseismic fault slip models of the 2022 M_(W)6.7 Menyuan earthquake reveal conjugated faulting tectonics at the central section of the Lenglongling fault

The 2022 M_(W)6.7 Menyuan earthquake ruptured the western end of the Tianzhu seismic gap,providing an opportunity to study the regional seismogenic characteristics and seismic hazards.Here we use interferometric synthetic aperture radar(InSAR)and seismic data to study the mainshock rupture,early afterslip and the second largest aftershock of the 2022 Menyuan earthquake sequences.Our modeling results show that the mainshock ruptured the Lenglongling fault and the Tuolaishan fault with a maximum slip of~3 m.Rapid postseismic transient deformation occurred at the center of the Lenglongling fault.Our afterslip modeling reveals that the majority of afterslip occurred in the deeper part of the Lenglongling fault.A high-angle conjugated faulting event is found at the middle section of the Lenglongling fault.We use the stress inversion to investigate the possible triggering mechanism of the conjugated rupture event.The results indicate the maximum principal stress direction is in~222°,forming a~22°angle between the conjugated fault of second largest aftershock and the mainshock.The calculated normal stress changes indicate the region is within a pull-apart stress field,which favors such a conjugated rupturing event.Our study will help understand the rupture behavior of such kind of conjugated fault in other regions.

Rapid report of June 1,2022 M_(W) 5.9 Lushan earthquake,China with geodetic and teleseismic data

Timely response to earthquake characterization can facilitate earthquake emergency rescue and further scientific investigations.On June 1,2022,M_(W) 5.9 earthquake occurred in the southern area of the Longmenshan fault zone.This event also happened at the south end of the Dayi seismic gap and is the largest earthquake that has occurred in this seismic gap since the 1970 M 6.2 event.The slip-distribution model constrained by the seismic waveforms suggests a thrust-dominated faulting mechanism.The main slip occurs at a depth of~14 km,and the cumulative energy is released in the first 6 s.The variations of Coulomb stress caused by the mainshock show a positive change in the southwest area of the Dayi seismic gap,indicating possible activation of future earthquakes.In addition,we emphasize the importance of rapid estimation of deformation for near-field hazard delineation,especially when interferometric radar fails to image coseismic deformation in a high relief terrain.

An enhanced spectral diversity coregistration method for dualpolarimetric Sentinel-1A/B TOPS data

Sentinel-1A/B data are crucial for retrieving numerical information about surface phenomena and processes.Coregistration of terrain observation by progressive scans(TOPS)data is a critical step in its application.TOPS data must be fundamentally co-registered with an accuracy of 0.001 pixels.However,various decorrelation factors due to natural vegetation and seasonal effects affect the coregistration accuracy of TOPS data.This paper proposed an enhanced spectral diversity coregistration method for dual-polarimetric(PolESD)Sentinel-1A/B TOPS data.The PolESD method suppresses speckle noise based on a unified non-local framework in dual-pol Synthetic Aperture Radar(SAR),and extracts the phase of the optimal polarization channel from the denoised polarimetric interferometric coherency matrix.Compared with the traditional ESD method developed for single-polarization data,the PolESD method can obtain more accurate coherence and phase and get more pixels for azimuth-offset estimation.In bare areas covered with low vegetation,the number of pixels selected by PolESD is more than the Boxcar method.It can also correct misregistration more effectively and eliminate phase jumps in the burst edge.Therefore,PolESD will help improve the application of TOPS data in low-coherence scenarios.

Inhibitory Effects of Propolis Water Extract on the Proliferation of Cervical Cancer Cells

[Objectives]To investigate the effects of propolis extract on HeLa cells to provide theoretical guidance for facilitating clinical treatment.[Methods]The effects of propolis on inflammation,and proliferation were analyzed based on the levels of DNA transcriptional regulation and mRNA and protein expression levels.[Results]Propolis water extract(PWE)could inhibit the cell proliferation and production of DNA damage in a dosedependent manner.Moreover,the propolis water extract could significantly downregulate the expression of iNOS-Luc,PTGS-2-Luc,and IL-8-Luc,and that it was related to the expression of the NF-κB family protein.After the induction of HeLa cells by propolis,the expression of the cell cycle inhibitor gene p21 was increased,while that of the cell proliferation gene Ki67 was decreased.[Conclusions]Propolis water extract could significantly inhibit the cell proliferation and production of DNA damage,suggesting propolis as a potential candidate for the development of adjunctive therapy against cervical cancer.

社会互动对中国城镇家庭校外教育支出的影响研究——基于CFPS2018截面数据

随着校外教育支出在家庭收入中所占比例的日益攀高,教育焦虑正在日益成为困扰中国城镇家庭的普遍问题,家庭间的社会互动则在其间发挥着重要作用。本文利用2018年中国家庭追踪调查(CFPS)截面数据,从家庭间的社会互动角度出发,研究其对家庭校外教育支出的影响及其路径。研究结果表明:家庭间的社会互动对于家庭校外教育支出具有显著的正向促进作用,且其影响路径有内生社会互动效应和外生社会互动效应两种。论文进一步讨论了社会互动和家庭校外教育支出间关系的家庭收入异质性和地区异质性。最后论文对当前我国的校外教育监管和校内教育发展提出了若干政策思路。

Environmentally Tough and Stretchable MXene Organohydrogel with Exceptionally Enhanced Electromagnetic Interference Shielding Performances

Conductive hydrogels have potential applications in shielding electromagnetic(EM)radiation interference in deformable and wearable electronic devices,but usually suffer from poor environmental stability and stretching-induced shielding performance degradation.Although organohydrogels can improve the environmental stability of materials,their development is at the expense of reducing electrical conductivity and thus weakening EM interference shielding ability.Here,a MXene organohydrogel is prepared which is composed of MXene network for electron conduction,binary solvent channels for ion conduction,and abundant solvent-polymer-MXene interfaces for EM wave scattering.This organohydrogel possesses excellent anti-drying ability,low-temperature tolerance,stretchability,shape adaptability,adhesion and rapid self-healing ability.Two effective strategies have been proposed to solve the problems of current organohydrogel shielding materials.By reasonably controlling the MXene content and the glycerol-water ratio in the gel,MXene organohydrogel can exhibit exceptionally enhanced EM interference shielding performances compared to MXene hydrogel due to the increased physical cross-linking density of the gel.Moreover,MXene organohydrogel shows attractive stretching-enhanced interference effectiveness,caused by the connection and parallel arrangement of MXene nanosheets.This well-designed MXene organohydrogel has potential applications in shielding EM interference in deformable and wearable electronic devices.

Review of the SBAS InSAR Time-series algorithms, applications, and challenges

In the past 30 years,the small baseline subset(SBAS)InSAR time-series technique has emerged as an essential tool for measuring slow surface displacement and estimating geophysical parameters.Because of its ability to monitor large-scale deformation with millimeter accuracy,the SBAS method has been widely used in various geodetic fields,such as ground subsidence,landslides,and seismic activity.The obtained long-term time-series cumulative deformation is vital for studying the deformation mecha-nism.This article reviews the algorithms,applications,and challenges of the SBAS method.First,we recall the fundamental principle and analyze the shortcomings of the traditional SBAS algorithm,which provides a basic framework for the following improved time series methods.Second,we classify the current improved SBAS techniques from different perspectives:solving the ill-posed equation,increasing the density of high-coherence points,improving the accuracy of monitoring deformation and measuring the multi-dimensional deformation.Third,we summarize the application of the SBAS method in monitoring ground subsidence,permafrost degradation,glacier movement,volcanic activity,landslides,and seismic activity.Finally,we discuss the difficulties faced by the SBAS method and explore its future development direction.

Effects of variation in food resources on foraging habitat use by wintering Hooded Cranes(Grus monacha)

Background:The ideal habitat use of waterbirds can be considered to be fixed,but current habitat use depends on environmental conditions,especially those of food characteristics,considered crucial to their use of habitats.Understanding how waterbirds respond to variation in food availability at degraded wetland sites and change their habitat use patterns over spatial and temporal scales should direct future conservation planning.The objectives of this study were to identify these spatial-temporal foraging habitat use patterns of Hooded Cranes(Grus monacha)and their relationship with food characteristics in the severely degraded wetlands of the Shengjin and Caizi lakes along with the Yangtze River floodplain.Methods:We investigated the changes in food characteristics,relative abundance and density of Hooded Cranes in various habitat types across three winter periods from November 2012 to April 2013.We examined the effect of these winter periods and habitat types on the pattern of use by the cranes and explored the relationship between these patterns and food characteristics using linear regression.Results:The food characteristics and habitat use clearly changed over spatial-temporal scales.In the early and mid-winter periods,the most abundant,accessible and frequented food resources were found in paddy fields,while in the late period the more abundant food were available in meadows,which then replaced the paddy fields.There were fewer effects of winter periods,habitat types and their interactions on habitat use patterns except for the effect of habitat types on the relative abundance,determined as a function of food abundance,but independent of food depth and sediment permeability.Conclusions:In response to the degradation and loss of lake wetlands,the cranes shifted their habitat use patterns by making tradeoffs between food abundance and accessibility over spatial-temporal scales that facilitated their survival in the mosaic of these lake wetlands.

Foraging behavior of the Greater White-fronted Goose(Anser albifrons) wintering at Shengjin Lake: diet shifts and habitat use

Background: The habitat use and foraging behaviors of waterbirds are closely related to the distribution and abundance of their food resources. Reductions in food supply can cause waterbirds to shift their habitats and adjust their foraging behaviors to meet their nutritional requirements and increase fitness. Seasonal withdraw of the water levels in the river-connected lakes in the middle and lower Yangtze River floodplain provides abundant food resources for the wintering Greater White-fronted Goose(Anser albifrons). Sedge(Carex) meadows are critical foraging habitats for herbivorous waterbirds in the hydro-fluctuation belt, which changes with hydrological conditions and climate. This study aimed to examine the behavioral responses of the Greater White-fronted Goose to temporal-spatial changes of food availability in the Sedge meadows.Methods: Fields surveys were carried out at Shengjin Lake from November 2017 to April 2018. According to the phenology of Shengjin Lake, we divided the wintering season into three periods. The food density, minimum temperature, food items, grass height, and number of foraging geese were surveyed, and samples of the foraging behavior were collected. We analyzed the relationship of the foraging behavior and habitat use relative to the food resources, using correlation and linear regression analyses.Results: Along with the temporal-spatial variation and exploitation of food resources, the food abundance and items varied widely among the foraging sites. Over the whole wintering period, the foraging habitat with the highest utilization rate was the meadows, followed by the paddy fields, and then mudflats. Furthermore, the utilization of the meadows showed a bimodal distribution trend, while the paddy fields showed a unimodal trend, and a decreasing trend was seen in the mudflats over the whole wintering period. The results of the generalized linear model showed that the foraging rate was related to the food density and grass height, with a linearly increasing trend during the winter.Conclusions: With the change of food resources in the three habitats, the habitats used by the Greater White-fronted Geese shifted from meadows in the hydro-fluctuation belt to the paddy fields, and then back to the meadows. The time budget for foraging activities increased correspondingly, and there was an increase in the foraging rate to compensate for food shortages.

Correlation between radiologic features on contrastenhanced CT and pathological tumor grades in pancreatic neuroendocrine neoplasms

Contrast-enhanced computed tomography(CT)contributes to the increasing detection of pancreatic neuroendocrine neoplasms(PNENs).Nevertheless,its value for differentiating pathological tumor grades is not well recognized.In this report,we have conducted a retrospective study on the relationship between the 2017 World Health Organization(WHO)classification and CT imaging features in 94 patients.Most of the investigated features eventually provided statistically significant indicators for discerning PNENs G3 from PNENs G1/G2,including tumor size,shape,margin,heterogeneity,intratumoral blood vessels,vascular invasion,enhancement pattern in both contrast phases,enhancement degree in both phases,tumor-to-pancreas contrast ratio in both phases,common bile duct dilatation,lymph node metastases,and liver metastases.Ill-defined tumor margin was an independent predictor for PNENs G3 with the highest area under the curve(AUC)of 0.906 in the multivariable logistic regression and receiver operating characteristic curve analysis.The portal enhancement ratio(PER)was shown the highest AUC of 0.855 in terms of quantitative features.Our data suggest that the traditional contrastenhanced CT still plays a vital role in differentiation of tumor grades and heterogeneity analysis prior to treatment.

JaponiconeA induces apoptosis of bortezomib-sensitive and -resistant myeloma cells in vitro and in vivo by targeting IKKβ

Objective:Multiple myeloma(MM)remains incurable with high rates of relapse.New therapeutic drugs are therefore urgently needed to improve the prognosis.JaponiconeA(JA),a natural product isolated from Inula japonica Thunb,has shown good anti-MM potential.A comprehensive study should therefore be conducted to identify both the in vitro and in vivo mechanisms of the anti-MM effects of JA.Methods:CCK8 assays and flow cytometry were used to detect the proliferation,apoptosis,and cell cycle of MM cell lines when treated with JA.In vivo experiments were conducted using subcutaneous xenograft mouse models.We also identified possible targets and the mechanism of JA using RNA-seq and c-Map databases,and identified the specific targets of JA in bortezomib-sensitive and-resistant MM cell lines using CETSA,DARTS,and rescue experiments.Furthermore,JA and bortezomib were used separately or together to characterize their possible synergistic effects.Results:In vitro,JA inhibited proliferation,and induced apoptosis and G2/M phase arrest in MM cell lines,and selectively killed primary CD138+MM cells.In vivo,JA also demonstrated a strong anti-tumor effect with no observable toxicity.In addition,JA showed synergetic effects in combination with bortezomib,and enhanced the anti-tumor effect of bortezomib in bortezomibresistant cells.CETSA and DARTS confirmed direct binding of JA to NF-κB inhibitor kinase beta(IKKβ),and overexpression of IKKβor knockdown of IκBαpartially rescued the apoptosis induced by JA.Conclusions:JA exhibited strong anti-tumor effects in MM.It sensitized myeloma cells to bortezomib and overcame NF-κB-induced drug resistance by inhibiting IKKβ,providing a new treatment strategy for MM patients.

Organising a juvenile ratio monitoring programme for 10 key waterbird species in the Yangtze River floodplain:analysis and proposals

Background:In the face of continued degradation and loss of wetlands in the Yangtze River floodplain(YRF),there is an urgent need to monitor the abundance and distribution of wintering waterbirds.To understand fully observed annual changes,we need to monitor demographic rates to understand factors affecting global population size.Annual reproduction success contributes to dynamic changes in population size and age structure,so an assessment of the juvenile ratio(i.e.first winter birds as a proportion of total number aged)of overwintering waterbirds can be an important indicator of the reproductive success in the preceding breeding season.Methods:During 2016-2019,we sampled juvenile ratios among 10 key waterbird species from the wetlands in the YRF.Based on these data,we here attempt to establish a simple,efficient,focused and reliable juvenile ratio monitoring scheme,to assess consistently and accurately relative annual breeding success and its contribution to the age structure among these waterbird species.Results:We compared juvenile ratio data collected throughout the winter and found that the optimal time for undertaking these samples was in the early stages of arrival for migratory waterbirds reaching their wintering area(early to mid-December).We recommend counting consistently at key points(i.e.those where>1%biogeographical flyway population were counted)at sites of major flyway importance(Poyang Lake,East Dongting Lake,Shengjin Lake,Caizi Lake,Longgan Lake and Chen Lake).Based on this,the error rate of the programme(155 planned points,the count of 10 waterbird species is 826-8955)is less than 5%.Conclusions:We established a juvenile ratio monitoring programme for 10 key waterbird species in the wetlands of the YRF,and discuss the feasibility and necessity of implementing such a future programme,and how to use these data in our monitoring and understanding of the population dynamics of these waterbird populations.

用干涉合成孔径雷达数据和贝叶斯估计提高地震定位来识别活动断层：2004年沙特阿拉伯特布克地震序列

2004年在红海裂谷东侧的沙特阿拉伯西北部特布克城附近,发生了一系列震级≤5.1的浅源地震。由于该地区台站分布稀疏,这些地震不能被很好地定位,这也给确定这些地震与该地区绘制的断层之间的关联带来困难,从而无法提高地震灾害的评估。我们使用来自欧洲空间局(ESA)的环境卫星(Envisat)和资源遥感卫星2(ERS-2)的干涉合成孔径雷达(InSAR)数据来提高发生在2004年6月22日最大震级为MW5.1的地震序列的定位和震源参数。主震在干涉合成孔径雷达数据上显示为一个很小但是较明显的约2.7cm的位移信号,这显示了地震发生的位置,同时也显示地震目录上对地震的定位误差约为3~16km。基于贝叶斯估计,我们采用均匀半空间弹性介质中的有限断层模型来模拟干涉合成孔径雷达数据,发现主震发生在距特布克城东南约70km处,显示为一条正断层。南西倾向的断层,走向大致与红海裂谷平行,我们估计该地震的质心深度约为3.2km。断层模型不确定性在地表的投影显示主震可能发生在该区的一条西倾的正断层上,且该断层与红海平行。结果表明可以用干涉合成孔径雷达数据来提高中等强度地震的定位和识别现在的活动断层。

Construction of a novel six-gene signature to predict tumour response to induction chemotherapy and overall survival in locoregionally advanced laryngeal and hypopharyngeal carcinoma

Locoregionally advanced laryngeal and hypopharyngeal cancers(LA-LHCs)are traditionally treated with surgery followed by postoperative radiotherapy,which impairs speech and swallowing functions and reduces the quality of life.^(1,2)The use of induction chemotherapy(IC)as a larynxpreserving approach for LA-LHCs has been verified and refined.^(3)However,the short-term tumor response to IC varies,non-responders usually show poor survival and little benefit.

A joint InSAR-GNSS workfow for correction and selection of interferograms to estimate high-resolution interseismic deformations

Knowledge of the spatial distribution of interseismic deformations is essential to better understand earthquake cycles.The existing methods for improving the reliability of the obtained deformations often rely on visual inspection and prior model corrections that are time-consuming,labor-intensive,and do not consider the spatial distribution of interseismic deformations.Interferometric Synthetic Aperture Radar(InSAR)data provides wide-scale coverage for interseismic deformation monitoring over a wide area.However,the interseismic signal featured as millimeter-scale and long-wave deformations is often contaminated with noise.In the present study,a new workfow to correct the interferometric phase and quantitatively select interferograms is proposed to improve the accuracy of interseismic deformation measurements.Initially,the Generic Atmospheric Correction Online Service(GACOS),Intermittent Code for Atmospheric Noise Depression through Iterative Stacking(I-CANDIS),and plate model are combined to correct the atmospheric screen and long-wave ramp phase.Subsequently,the Pearson’s Correlation Coefcient(PCC)between the interferometric phase and the Global Navigation Satellite System(GNSS)constrained interseismic model as well as the STandard Deviation(STD)of the interferometric phase are introduced as criteria to optimize the selection of interferograms.Finally,the intermittent stacking method is used to generate an average velocity map.A comprehensive test using Sentinel-1 images covering the Haiyuan Fault Zone validate the efectiveness of our workfow in measuring interseismic deformations.This demonstrates that the proposed joint InSAR-GNSS workfow can be extended to study the subtle interseismic deformations of major fault systems in Tibet and worldwide.

The repression of oncoprotein SET by the tumor suppressor p53 reveals a p53-SET-PP2A feedback loop for cancer therapy

The oncoprotein SET is frequently overexpressed in many types of tumors and contributes to malignant initiation and progression through multiple mechanisms,including the hijacking of the tumor suppressors p53 and PP2A.Targeting aberrant SET represents a promising strategy for cancer intervention.However,the mechanism by which endogenous SET is regulated in cancer cells remains largely unknown.Here,we identified the tumor suppressor p53 as a key regulator that transcriptionally repressed the expression of SET in both normal and cancer cells.In addition,p53 stimulated PP2A phosphatase activity via p53-mediated transcriptional repression of SET,whereby SET-mediated inhibition of PP2A was alleviated.Moreover,targeting the interaction between SET and PP2A catalytic subunit(PP2Ac)with FTY720 enhanced stress-induced p53 activation via PP2A-mediated dephosphorylation of p53 on threonine 55(Thr55).Therefore,our findings uncovered a previously unknown p53-SETPP2A regulatory feedback loop.To functionally potentiate this feedback loop,we designed a combined therapeutic strategy by simultaneously administrating a p53 activator and SET antagonist in cancer cells and observed a dramatic synergistic effect on tumor suppression.Our study reveals mechanistic insight into the regulation of the oncoprotein SET and raises a potential strategy for cancer therapy by stimulating the p53-SET-PP2A feedback loop.

面向运动目标探测的分时型红外偏振成像系统

为了提高传统分时旋型红外偏振成像的速度,设计了适用于中波红外热像仪的检偏器组件,将红外热像仪改装成中波红外偏振成像装置,用于获取目标场景的红外偏振信息。该装置通过电机以900 r/min速度匀速驱动红外偏振片旋转,采集不同偏振方向的红外强度图像。利用单像元非均匀性差分图像校正方法对红外图像中的冷反射进行扣除,利用迭代排序方式对校正后的红外强度图像进行处理,结合构建的斯托克斯矢量模型,计算连续相邻的三幅红外强度图像的红外偏振度和偏振角,保证与红外强度图像有相同的成像帧频。实验结果表明,该装置能够稳定输出待测目标的红外偏振度和偏振角图像,输出红外偏振图像的帧频为45 frame/s,满足对变化场景实时红外偏振探测的需求。

Effects of applying lactic acid bacteria to the fermentation on a mixture of corn steep liquor and air-dried rice straw

This study was to determine the fermentation quality of a mixture of corn steep liquor(CSL)(178 g/kg wet basis) and air-dried rice straw(356 g/kg wet basis) after being treated with inoculants of different types of lactic acid bacteria(LAB). The treatments included the addition of no LAB additive(control),which was deionized water; homo-fermentative LAB alone(^(ho)LAB), which was Lactobacillus plantarum alone), and a mixture of homo-fermentative and hetero-fermentative LAB(^(he+ho)LAB), which were L. plantarum, Lactobacillus casei, and Lactobacillus buchneri. The results showed that the inoculation of the mixture of CSL and air-dried rice straw with ^(he+ho)LAB significantly increased the concentration of acetic acid and lactic acid compared with the control(P < 0.05). The addition of ^(he+ho)LAB effectively inhibited the growth of yeast in the silage. The concentration of total lactic acid bacteria in the ^(he+ho)LAB-treated silage was significant higher than those obtained in other groups(P < 0.05). The duration of the aerobic stability of the silages increased from 56 h to >372 h. The control group was the first to spoil, whereas the silage treated with ^(he+ho)LAB remained stable throughout the 372 h period of monitoring. The results demonstrated that the ^(he+ho)LAB could effectively improve the fermentation quality and aerobic stability of the silage.

Effect of different levels of corn steep liquor addition on fermentation characteristics and aerobic stability of fresh rice straw silage

The object of this study was to determine the proper mixing ratio of fresh rice straw to corn steep liquor(CSL) to obtain a high protein content silage feed. The following experimental silages were generated: the control(C1), composed of fresh rice straw without CSL additive, mixed with CSL in the ratios of 4:1(C4),3:1(C3) and 2:1(C2). Lactic acid bacteria(LAB) inoculant was applied at the rate of 50 mL/kg(fresh basis)of forage to achieve a final application rate of 1 x 10~6 cfu/g of fresh matter(FM). Duplicate silos for each treatment were opened after 0,3, 7,10,20,30,45 and 60 d for microbiological and chemical analysis. The results showed that the addition of CSL significantly increased crude protein(CP) contents, and decreased neutral detergent fiber(NDF) and acid detergent fiber(ADF) contents of treatments after 60 d of ensiling(P < 0.05). The lactic acid contents in C4 and C3 were significantly higher than that in C1(P <0.05). In summary, mixing fresh rice straw with CSL at addition levels of 4:1(C4) and 3:1(C3) can improve the fermentation quality and nutrient composition of fresh rice straw silage. However, a large proportion of CSL(C3) had a negative impact on the aerobic stability of fresh rice straw.

数据科学与化学交叉视域下的重金属危废物相分析

我国重金属危险废物(重金属危废)产生量全球第一,高达数千万吨/年,环境危害性极强,一旦控制不当将引发重大环境安全事故,其处理处置一直是环境领域的世界难题。目前,基于物相调控的资源化是解决该难题最具潜力的方案。然而,重金属危废来源广,物相种类多样、结构多变,导致难以发展共性的资源化技术。本文以《国家危险废物名录》中所列危废为研究对象,在数据科学和化学交叉视域下系统深入地分析重金属危废的物相组成特征,归纳出重金属危废中的共性物相,并构建了全行业重金属危废中重金属元素与物相的映射图谱。在此基础上,本文介绍了两种重金属赋存分布的定量分析方法,明确了典型重金属危废中的赋存物相,最后展望了重金属危废物相新认知在推动处理处置技术革新方面的广阔前景。