1310 nm Source Spectral-Domain Optical Coherence Tomography for Chinese Pigment and Jadeite Research

Optical Coherence Tomography (OCT) technique is a nondestructive optical detection technology based on low-coherence interferometer and it has become an attractive cultural heritage research method. A 1310 nm source spectral-domain optical coherence tomography (SD-OCT) system based on optical fiber Michelson interferometer and optical spectrum analyzer is proposed and demonstrated for Chinese cultural heritage research. The cross-section OCT images of Chinese pigment samples and jadeite samples can provide a lot of valuable microstructure information for the Chinese cultural heritage research and identification works.

Variation of culturable bacteria along depth in the East Rongbuk ice core,Mt.Everest

Ice melt water from a 22.27 m ice core which was drilled from the East Rongbuk Glacier, Mt. Everest was incubation in two incubation ways： plate melt water directly and enrichment melt water prior plate, respectively. The abundance of cultivable bacteria ranged from 0-295 CFU mL-I to 0--1720 CFU mL-1 in two incubations with a total of 1385 isolates obtained. Comparing to direct cultivation, enrichment cultivation recovered more bacteria. Pigment-producing bacteria accounted for an average of 84.9% of total isolates. Such high percentage suggested that pigment production may be an adaptive physiological feature for the bacteria in ice core to cope with strong ultraviolet radiation on the glacier. The abundances of cultivable bacteria and pigment-producing isolates varied synchronously along depth： higher abundance in the middle and lower at the top and bottom. It indicated that the middle part of the ice core was hospitable for the microbial survival. Based on the physiological properties of the colonies, eighty-nine isolates were selected for phylogenetic analysis. Obtained 16S rRNA gene sequences fell into four groups： Firmicutes, Alpha-Proteobacteria, Gamma-Proteobacteria, and Actinobacteria, with the Firmicutes being dominant. Microbial compositions derived from direct and enrichment cultivations were not overlapped. We suggest that it is a better way to explorethe culturable microbial diversity in ice core by combining the approaches of both direct and enrichment cultivation.

Improved EEMD-based standardization method for developing long tree-ring chronologies

Long tree-ring chronologies can be developed by overlapping data from living trees with data from fossil trees through cross-dating.However,low-frequency climate signals are lost when standardizing tree-ring series due to the"segment length curse".To alleviate the segment length curse and thus improve the standardization method for developing long tree-ring chronologies,here we first calculated a mean value for all the tree ring series by overlapping all of the tree ring series.The growth trend of the mean tree ring width(i.e.,cumulated average growth trend of all the series)was determined using ensemble empirical mode decomposition.Then the chronology was developed by dividing the mean value by the growth trend of the mean value.Our improved method alleviated the problem of trend distortion.Long-term signals were better preserved using the improved method than in previous detrending methods.The chronologies developed using the improved method were better correlated with climate than those developed using conservative methods.The improved standardization method alleviates trend distortion and retains more of the low-frequency climate signals.

STRESS FIELD ANALYSIS OF EXTRA-HEIGHT FORGING DIE USING FINITE ELEMENT METHOD

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Planning a road weather information system with GIS

The road weather information system （RWIS）, which collects and monitors weather and pavement surface conditions, has been proven effective to support winter road maintenance by improving safety, mobility, and effi- ciency. Although the geographic information systems are being widely applied for facility siting, traditional practices of sitting RWIS stations still heavily rely on the experi- ences of maintenance and operation personnel, which is time-consuming and subjective. This study develops a linear model to determine the optimal RWlS locations subject to three selection criteria： weather, traffic condition, and distance to existing RWIS sites, while considering practical constraints to satisfy specific requirements of various agencies （e.g., different weights of weather/traffic factors, various available budgets, etc.）.

Dynamical Stability of Cantilevered Pipe Conveying Fluid with Inerter-Based Dynamic Vibration Absorber

Cantilevered pipe conveying fluid may become unstable and flutter instability would occur when the velocity of the fluid flow in the pipe exceeds a critical value.In the present study,the theoretical model of a cantilevered fluid-conveying pipe attached by an inerter-based dynamic vibration absorber(IDVA)is proposed and the stability of this dynamical system is explored.Based on linear governing equations of the pipe and the IDVA,the effects of damping coefficient,weight,inerter,location and spring stiffness of the IDVAon the critical flow velocities of the pipe system is examined.It is shown that the stability of the pipe may be significantly affected by the IDVA.In many cases,the stability of the cantilevered pipe can be enhanced by designing the parameter values of the IDVA.By solving nonlinear governing equations of the dynamical system,the nonlinear oscillations of the pipe with IDVA for sufficiently high flow velocity beyond the critical value are determined,showing that the oscillation amplitudes of the pipe can also be suppressed to some extent with a suitable design of the IDVA.

Community Structure and Diversity of Ground Cover Plants in Tianjin Binhai International Airport

By using quadrat sampling method, the community structure and diversity of ground cover plants in the flight area in Tianjin Binhai International Airport were investigated from spring to autumn in 2015. The results showed that 58 plant species were recorded at the airport, belonging to 18 families and 48 genera. Dominant plant species showed seasonal characteristics. Specifically, lxeri chinensis （ Thunb. ） Nakai and Lagopsis supina （ Steph. ） Ik. -Gal. ex Knorr. were the dominant species in spring; Lagopsis supina, Cirsium setosum （Willd.） MB, Plantago asiatica L. , Cynanchum chinense R. Br. and Humulus scandens （I_our.） Merr. were the dominant species in summer; Chloris virgata Sw. and Eleusine indica （L.） Gaertn. were the dominant species in autumn. Quantitative characteris- tics of the dominant species, including the density, frequency, coverage and height, varied in different seasons. In different seasons, changes in the diversity of plant communities in three sampling points were analyzed. The results indicated that plant communities in summer exhibited the highest diversity and the most uni- form distribution. This study provided a theoretical basis for avoidance of bird strike in Tianjin Binhai International Airport.

Evaluation of floating car technologies for travel time estimation

Travel times have been traditionally estimated from data collected by roadway sensors. Recently, new tech- nologies, such as cell phone tracking, license plate matching, automatic vehicle identifications and video detection, are employed for this purpose. In this study, the data collected by TRANSMIT readers, Bluetooth sensors, and INRIX are assessed by comparing each to the ＂ground truth＂ travel times collected by probe vehicles carrying GPS-based naviga- tion devices. Travel times of probe vehicles traveling on the study segment of 1-287 in New Jersey were collected in 2009. Statistical measures, such as standard deviation, average absolute speed error, and speed error bias, were used to make an in-depth analysis. The accuracy of each travel time estimation method is analyzed. The data collected by Bluetooth sensors and the TRANSMIT readers seem more consistent with the ground true data, and slightly outperform the data reported by 1NRIX. This study established a procedure for analyzing the accuracy of floating car data （FCD） collected by different technologies.

盘点气候风险机遇,展望健康繁荣未来

气候变化带来的健康风险与日俱增,煤炭消费及相关碳排放量的反弹,再度敲响了中国气候变化警钟.2022年,中国面临了严峻的气候挑战.极端天气事件发生的频率和强度不断上升,许多地区气温纪录屡创新高,全国平均气温攀升至历史第二高位,同时降水量自2012年以来创新低,南方地区遭遇夏秋连旱,而湖南和东北地区则出现了极端降雨和洪涝灾害.采取及时、充分的措施不仅能减轻气候变化对健康的影响,还将保护基础设施不被极端天气破坏.

Does driving-day-based tradable credit scheme outperform license plate rationing? Examination considering transaction cost

This article models a novel driving-day-based tradable credit scheme (DD-TCS) to alleviate urban traffic congestion. In this model, car-using allowances (in terms of the number of days in a month, termed as "credit") are freely and uniformly allocated to all travellers, who are also allowed to trade them in a market according to his/her travel needs (e.g. driving more or fewer days than the free endowment). As opposed to most studies on TCS, this paper explicitly considers the transaction cost (e.g. infor-mation cost of finding potential traders) in the trading market. To assess the feasibility of DD-TCS, we compare it against the license plate rationing (LPR) scheme, which has been practically implemented in many cities such as Beijing and Chengdu in China. Taking the performance of LPR as a benchmark, we quantify the threshold values of the transaction cost in DD-TCS when the two schemes yield equivalent performance (in terms of the total gener-alized cost). In numerical studies, we also compare the DD-TCS and LPR with the no-action case and the congestion pricing case (representing the theoretical optimum). Results show that both DD-TCS and LPR outperform the no-action case under certain conditions. With small trans-action cost, DD-TCS may achieve a lower system cost that can be very close to the ideal optimum. In addition, parameter analysis shows that DD-TCS performs better than LPR in a wide range of transaction cost, where the threshold values appear to account for a considerable portion of the auto travel time. This implies that DD-TCS will be more appealing than LPR in practice because a transaction cost lower than the extremely large threshold values can be easily achieved for the trading market, e.g. via a mobile platform and modern communication techniques.

Residential relocation in response to light rail transit investment:case study of the Hudson–Bergen Light Rail system

It is widely acknowledged that the improved accessibility enabled by investment in public transport services can, under favorable market conditions, impact the local real estate market within the zone of influence of the service＇s stations. The motivation for this study is to establish the nature of two such impacts, specifically the spatial and socio-economic patterns of residential relocations that are driven by the new light rail transit （LRT） service. Using empirical data （n = 1,023） from the Hudson-Bergen Light Rail system in New Jersey （US）, we report findings regarding the impacts of the introduction of the new LRT service. We investigate two linked dimensions; the first is the distinctive socio-economic profile of LRT passengers who self-report having relocated to the new transit corridor due, at least in part, to the new transit service. The second is their proximity （following their resi- dential relocation） to the new LRT line＇ s stations. We present a novel analysis that accounts for endogeneity between these two dimensions of residential relocation. Of light rail passengers who engaged in a residential relocation in the 5 years prior to the survey, two-thirds （69 %） indicate that proximity to the light rail service was a ＇somewhat＇ or ＇very＇ important consideration. Via the multivariate analysis, we demonstrate that small household size, low income, youth （as opposed to older age）, and low car ownership are each positively linked, ceteris paribus, with having engaged in a residential reloca- tion motivated by the new transit service. Finally, higher household income is found to be associated with distance （after relocation） to the nearest transit station, which is consistent with bid-rent theory.

Laboratory and Semi-Field Evaluation on S-Methoprene Formulations Against Anopheles sinensis(Diptera:Culicidae)—Yuxi City,Yunnan Province,China

Summary What is already known about this topic?Anopheles sinensis(An.sinensis)is the predominant malaria vector in China.The impact of S-methoprene on the emergence process of mosquito larvae suggests its potential as a control method for vector mosquitoes.However,the efficacy of S-methoprene in controlling An.sinensis has not yet been demonstrated.What is added by this report?

Graphene reinforced nanoarchitectonics of 3D interconnected magnetic-dielectric frameworks for high-efficient and anti-corrosive microwave absorbers

The combination of high efficiency and environmental stability is vital to promote the commercial appli-cations of microwave absorption(MA)materials,yet remains challenging in the absence of facile routes.Here,we put forward a graphene-reinforced construct approach for one-pot synthesis of 3D intercon-nected magnetic-dielectric frameworks via pre-functionalization and subsequent assembly.Multiple in-teractions among discrete precursors are capable of manipulating the confined growth and interfacial self-assembly.Significant enhancements in MA properties are triggered in a straightforward manner us-ing ultralow feeding fractions of graphene oxide nanosheet.The minimum reflection loss is up to-60.1 dB(99.9999%wave absorption)and the effective absorption bandwidth reaches 5.9 GHz(almost covering the Ku band).Remarkably,based on the optimization by ultralow concentrations of graphene,the as-prepared nanoarchitecture simultaneously integrates strong absorption,broad bandwidth,and low matching thick-ness.The embedded graphene nanosheets serve as high-speed electron transmission channels and hollow resonance cavities,facilitating multimode attenuations and impedance-matching characteristics.Mean-while,the graphene-reinforced framework suppresses the corrosion of magnetic components,whose cor-rosion rate reduces by an order of magnitude.This study provides a simple procedure to boost magnetic-dielectric absorbers for comprehensive MA performances and enhanced corrosion resistance.

The global regulation of c-di-GMP and cAMP in bacteria

Nucleotide second messengers are highly versatile signaling molecules that regulate a variety of key biological processes in bacteria.The best-studied examples are cyclic AMP(cAMP)and bis-(3'-5')-cyclic dimeric guanosine monophosphate(c-di-GMP),which both act as global regulators.Global regulatory frameworks of c-di-GMP and cAMP in bacteria show several parallels but also significant variances.In this review,we llustrate the global regulatory models of the two nucleotide second messengers,compare the different regulatory frameworks between c-di-GMP and cAMP,and discuss the mechanisms and physiological significance of cross-regulation between c-di-GMP and cAMP.c-di-GMP responds to numerous signals de-pendent on a great number of metabolic enzymes,and it regulates various signal transduction pathways through its huge number of effectors with varying activities.In contrast,due to the limited quantity,the cAMP metabolic enzymes and its major effector are regulated at different levels by diverse signals.cAMP performs its global regulatory function primarily by controlling the transcription of a large number of genes via cAMP receptor protein(CRP)in most bacteria.This review can help us understand how bacteria use the two typical nucleotide second messengers to effectively coordinate and integrate various physiological processes,providing theoretical guidelines for future research.

Acoustic Full Waveform Inversion of DAS-VSP Data

INTRODUCTION The optical-fiber distributed acoustic sensing-vertical seismic profiling(DAS-VSP)acquisition system can record seismic data in wells continuously,thus providing several advantages such as dense spatial sampling,high signal-to-noise ratio,high acoustic sensitivity,and broad bandwidth(Ellmauthaler et al.,2021;Spikes et al.,2019).

Dix-Type Multi-Component Scholte Wave Dispersion Inversion without Initial Model

0 INTRODUCTION Scholte wave dispersion curves contain rich information regarding seafloor media and have therefore attracted increasing attention(Wang et al.,2022;Dong et al.,2021;Du et al.,2020).Ocean bottom seismometer(OBS)data are widely used in the study of seafloor medium information(Wang et al.,2024),and contain rich surface wave information.

Propagation and Dispersion Characteristics of Scholte Wave in VTI Media with the Presence of Irregular Seabed

INTRODUCTION Surface waves propagating along the seafloor are general ly called Scholte waves,and were first discovered and studied in the early 1950s(Kugler et al.,2005;Buchen and Ben-Hador,1996).Scholte waves exhibit a dispersion phenomenon,which implies that their velocity varies with frequency.Low-frequency Scholte waves can propagate over long distances on the seabed with little attenuation(Bohlen et al.,2004).The particle mo tion of Scholte waves in a solid medium changes from a retro grade to a prograde ellipse(Klein et al.,2005;McMechan and Yedlin,1981).

Preface of the Special Issue on Symplectic Geometry and Mathematical Physics

Symplectic geometry is a branch of differential geometry and differential topology and has its origins in the Hamiltonian formulation of classical mechanics.In the last few decades,symplectic geometry has experienced enormous progress and has had interactions with many other branches of mathematics,including enumerative geometry,low-dimensional topology,mathematical physics,Hamiltonian dynamics,integrable systems etc..

把握机会窗口期减缓气候变化对中国居民健康影响

随着中国总人口的不断增加以及改革开放以来经济的飞速发展,中国面临来自气候变化的健康威胁也在不断上升.与此同时,中国也处于一个独特的机遇窗口期,如果能够有效应对气候变化带来的健康风险,将造福今后几代人的健康.反之,如果没有及时、充分的应对措施,气候变化对中国居民健康和生命的威胁将与日俱增.为了推动更及时且有利于改善人群健康的气候应对行动,由清华大学牵头建立的柳叶刀倒计时亚洲中心在全球柳叶刀倒计时工作的基础上[1,2],从2020年开始,聚焦气候变化对中国人群健康的影响进行全面且系统的评估[3,4].

以气候行动助力健康老龄化

在中国宣布碳中和目标以及频繁遭受极端气候事件的背景下,2021年以来中国社会对气候变化的关注度持续高涨.与此同时,随着中国人口老龄化趋势愈加明显,气候变化所带来的健康风险问题日益突出.采取健康友好型的气候变化应对策略及碳中和实现路径,将可以有效减少人类(尤其是老年人群)的空气污染暴露情况.这方面的行动不仅有助于改善人类健康和福祉,还能够促进经济社会的高质量发展.