Phase sensitivity with a coherent beam and twin beams via intensity difference detection

We focus on the Mach–Zehnder interferometer(MZI) with the input of a coherent beam and one of the bright entangled twin beams with an external power reference beam employed for measurement. The results show that the phase sensitivity can reach sub-Heisenberg limit and approach quantum Cramer–Rao bound by changing the squeezing parameters and the photon number of the coherent beam, under the phase-matching condition. The absence of the external power reference beam will degrade the performance of the phase sensitivity. Meanwhile, this scheme shows good robustness against the losses of the photon detectors. We present a detailed discussion about the phase sensitivities when the inputs are two coherent beams, or a coherent beam plus a single-mode squeezed vacuum beam based on the MZI. This scenario can be applied in the field of phase precision measurements and other optical sensors.

AVA:An automated and AI-driven intelligent visual analytics framework

With the incredible growth of the scale and complexity of datasets,creating proper visualizations for users becomes more and more challenging in large datasets.Though several visualization recommendation systems have been proposed,so far,the lack of practical engineering inputs is still a major concern regarding the usage of visualization recommendations in the industry.In this paper,we proposed AVA,an open-sourced web-based framework for Automated Visual Analytics.AVA contains both empiric-driven and insight-driven visualization recommendation methods to meet the demands of creating aesthetic visualizations and understanding expressible insights respectively.The code is available at https://github.com/antvis/AVA.

Dust transport information and paleoclimatic changes revealed by the loess in Ranwu,south-eastern Xizang

The loess accumulation process has great potential to record patterns of atmospheric circulation change,paleoclimate,and paleoenvironmental evolution.South-eastern Xizang is a climatically sensitive region and here,we analyze a loess profile at Ranwu in order to explore the processes and interactions of dust transport and paleoclimate evolution in the region.Based on parametric grain size end-member analysis,optically stimulated luminescence(OSL)dating,and environmental proxies we show that the Ranwu loess profile comprises five end members(EMs).EM1 represents the fine silt fraction transported by high-altitude westerly winds over long distances;EM2 represents the medium silt fraction accumulated by glacier winds;EM3 is the coarse silt fraction transported by local dust storms under the action of strong glacier winds;EM4 represents the very fine sand fraction transported by strong local dust storms,different wind strengths controls the relative proportion of EM3 and EM4 over time.EM5 is the coarse sand fraction formed from the product of strong weathering of gravels.OSL dating shows loess sedimentation at Ranwu started around 11.16 ka.The prevailing climate was generally warm and wet between 11.6 and 4.2 ka,with four cooling events at 10.50,9.18,7.85,and 6.37 ka.Extensive paleosol development between 8.2 and 4.2 ka,a change to dry and cold climate conditions was favorable for loess formation after 4.2 ka.The palaeoenvironmental changes and abrupt climate events recorded in the Ranwu loess sequence are consistent with Holocene global environmental changes.

Coupling magnetic particles with flocculants to enhance demulsification and separation of waste cutting emulsion for engineering applications

Magnetic particles were coupled with a flocculant to enhance the demulsification and separation of waste cutting emulsions.The optimal magnetic particle size and critical magnetic field conditions were investigated to achieve large-scale engineering application of magnetic demulsification separation for waste cutting emulsion treatment.The micro-scale magnetic particles were found to show comparable effects to nano-scale magnetic particles on enhancing the demulsification and separation of cutting emulsions,which are beneficial for broadening the selectivity of low-cost magnetic particles.The critical magnetic separation region was determined to be an area 40 mm from the magnetic field source.Compared to the flocculant demulsification,the magnetic demulsification separation exhibited a significant advantage in accelerating flocs-water separation by decreasing the separation time of flocs from 180-240 min to less than 15 min,compressing the flocs by reducing the floc volume ratio from 60%-90%to lower than 20%,and showing excellent adaptability to the variable properties of waste cutting emulsions.Coupled with the design of the magnetic disk separator,continuous demulsification separation of the waste cutting emulsion was achieved at 1.0 t/hr for at least 10 hr to obtain clear effluent with 81%chemical oxygen demand removal and 89%turbidity reduction.This study demonstrates the feasibility of applying magnetic demulsification separation to large-scale continuous treatment of waste emulsion.Moreover,it addresses the flocs-water separation problems that occur in practical flocculant demulsification engineering applications.

Metro-Wordle:An Interactive Visualization for Urban Text Distributions Based on Wordle

With the development of cities and the explosion of infonnation,vast amounts of geo-tagged textural data about Points of Interests(POIs)have been generated.Extracting useful information and discovering text spatial distributions from the data are challenging and meaningful.Also,the huge numbers of POIs in modem cities make it important to have efficient approaches to retrieve and choose a destination.This paper provides a visual design combing metro map and wordles to meet the needs.In this visualization,metro lines serve as the divider lines splitting the city into several subareas and the boundaries to constrain wordles within each subarea.The wordles are generated from keywords extracted from the text about POIs(including reviews,descriptions,etc.)and embedded into the subareas based on their geographical locations.By generating intuitive results and providing an interactive visualization to support exploring text distribution patterns,our strategy can guide the users to explore urban spatial characteristics and retrieve a location efficiently.Finally,we implement a visual analysis of the restaurants data in Shanghai,China as a case study to evaluate our strategy.

Characteristics and source apportionment of PM_(2.5) under the dual influence of the Spring Festival and the COVID-19 pandemic in Yuncheng city

Based on the online and membrane sampling data of Yuncheng from January 1st to February 12th,2020,the formation mechanism of haze under the dual influence of Spring Festival and COVID-19 (Corona Virus Disease) was analyzed.Atmospheric capacity,chemical composition,secondary transformation,source apportionment,backward trajectory,pollution space and enterprise distribution were studied.Low wind speed,high humidity and small atmospheric capacity inhibited the diffusion of air pollutants.Four severe pollution processes occurred during the period,and the pollution degree was the highest around the Spring Festival.In light,medium and heavy pollution periods,the proportion of SNA (SO_(4)^(2-),NO_(3)-and NH_(4)^(+)) was 59.6%,56.0%and 54.9%,respectively,which was the largest components of PM_(2.5);the[NO_(3)-]/[SO_(4)^(2-)]ratio was 2.1,1.5 and 1.7,respectively,indicating that coal source had a great influence;the changes of NOR (nitrogen oxidation ratio,0.44,0.45,0.61)and SOR (sulphur oxidation ratio,0.40,0.49,0.65) indicated the accumulation of secondary aerosols with increasing pollution.The coal combustion,motor vehicle,secondary inorganic sources and industrial sources contributed 36.8%,26.59%,11.84%and 8.02%to PM_(2.5)masses,respectively.Backward trajectory showed that the influence from the east was greater during the Spring Festival,and the pollutants from the eastern air mass were higher,which would aggravate the pollution.Meteorological and Spring Festival had a great impact on heavy pollution weather.Although some work could not operate due to the impact of the COVID-19 epidemic,the emission of pollutants did not reduce much.

Enhanced secondary organic aerosol formation during dust episodes by photochemical reactions in the winter in Wuhan

To investigate the effect of frequently occurring mineral dust on the formation of secondary organic aerosol(SOA),106 volatile organic compounds(VOCs),trace gas pollutants and chemical components of PM_(2.5) were measured continuously in January 2021 in Wuhan,Central China.The observation period was divided into two stages that included a haze period and a following dust period,based on the ratio of PM_(2.5) and PM_(10) concentrations.The average ratio of secondary organic carbon(SOC)to elemental carbon(EC)was 1.98 during the dust period,which was higher than that during the haze period(0.69).The contribution of SOA to PM_(2.5) also increased from 2.75% to 8.64%.The analysis of the relationships between the SOA and relative humidity(RH)and the odd oxygen(e.g.,O_(X)=O_(3)+NO_(2))levels suggested that photochemical reactions played a more important role in the enhancement of SOA production during the dust period than the aqueous-phase reactions.The heterogeneous photochemical production of OH radicals in the presence of metal oxides during the dust period was believed to be enhanced.Meanwhile,the ratios of trans-2-butene to cis-2-butene and m-/p-xylene to ethylbenzene(X/E)dropped significantly,confirming that stronger photochemical reactions occurred and SOA precursors formed efficiently.These results verified the laboratory findings that metal oxides in mineral dust could catalyse the oxidation of VOCs and induce higher SOA production.

Environment and COVID-19 incidence: A critical review

The coronavirus disease 2019(COVID-19)pandemic is an unprecedented worldwide health crisis.Many previous research studies have found and investigated its links with one or some natural or human environmental factors.However,a review on the relationship between COVID-19 incidence and both the natural and human environment is still lacking.This review summarizes the inter-correlation between COVID-19 incidence and environmental factors.Based on keyword searching,we reviewed 100 relevant peer-reviewed articles and other research literature published since January 2020.This review is focused on three main findings.One,we found that individual environmental factors have impacts on COVID-19 incidence,but with spatial heterogeneity and uncertainty.Two,environmental factors exert interactive effects on COVID-19 incidence.In particular,the interactions of natural factors can affect COVID-19 transmission in micro-and macro-ways by impacting SARS-CoV-2 survival,as well as human mobility and behaviors.Three,the impact of COVID-19 incidence on the environment lies in the fact that COVID-19-induced lockdowns caused air quality improvement,wildlife shifts and socio-economic depression.The additional value of this review is that we recommend future research perspectives and adaptation strategies regarding the interactions of the environment and COVID-19.Future research should be extended to cover both the effects of the environment on the COVID-19 pandemic and COVID-19-induced impacts on the environment.Future adaptation strategies should focus on sustainable environmental and public policy responses.

Impact of environmental factors on gastric cancer:A review of the scientific evidence,human prevention and adaptation

Globally,gastric cancer(GC) ranks fifth in prevalence and third in fatalities,and shows a distinct geographical distribution in morbidity and mortality.Such a spatial pattern indicates that environmental factors could be an important contributor to GC.We reviewed a total of 135 relevant peer-reviewed articles and other literature published 1936-2019 to investigate the scientific evidence concerning the effects of environmental factors on GC worldwide.Environmental factors affect GC from the aspects of water,soil,air,radiation,and geology.Risk factors identified include water type,water pollution,water hardness,soil type,soil pollution,soil element content,climate change,air pollution,radiation,altitude,latitude,topography,and lithology;and most of them have an adverse impact on GC.Furthermore,we found that their effects followed five common rules:(1) the leading environmental factors that affect GC incidence and mortality vary by region,(2) the same environmental factors may have different effects on GC in different regions,(3) some different environmental factors have similar effects on GC in essence,(4) different environmental factors often interact to have combined or synergistic effects on GC,and(5)environmental factors can affect human factors to have an impact on GC.Environmental factors have a great impact on GC.Human beings may prevent GC by controlling carcinogenic factors,screening high-risk populations and providing symptomatic and rehabilitative treatments.Furthermore,adaptation measures are recommended to reduce GC risk on private and public levels.Future studies should transcend existing empirical studies to develop causal relationship models and focus on vulnerable population analysis.

On-chip short-wave infrared multispectral detector based on integrated Fabry–Perot microcavities array

We demonstrate an ultra-compact short-wave infrared[SWIR]multispectral detector chip by monolithically integrating the narrowband Fabry–Perot microcavities array with the In Ga As detector focal plane array.A 16-channel SWIR multispectral detector has been fabricated for demonstration.Sixteen different narrowband response spectra are acquired on a 64×64 pixels detector chip by four times combinatorial etching processes.The peak of the response spectra varies from1450 to 1666 nm with full width at half-maximum of 24 nm on average.The size of the SWIR multispectral detection system is remarkably reduced to a 2 mm^(2) detector chip.

Coupled Tamm plasmon polaritons induced narrow bandpass filter with ultra-wide stopband

Narrow bandpass filters(NBPFs)play important roles in optics,such as quantum communication,spectrometer,and wavelength division multiplexing.However,the stopband and restraint ability of traditional NBPFs is limited.In this article,a coupled Tamm plasmon polaritons(TPPs)induced transmission theory has been proposed to design high-efficiency NBPFs with ultra-wide deep stopbands.An NBPF at 1.55 μm has been experimentally demonstrated with full width at half maximum(FWHM)of 10 nm and stopband ranging from 0.2 to 25 μm which is 62 times wider than that of traditional ones.Furthermore,the restraint depth of the stopband reaches 0.03%,which is only 1/20 of a traditional filter with the same FWHM.Its advantage in restraining ambient light over traditional ones has also been demonstrated with an InGaAs infrared detector.It provides a very powerful way to capture specific narrowband optical signals from ultra-wide strong ambient light,especially useful for daytime quantum communications.