Towards carbon neutrality of calcium carbide-based acetylene production with sustainable biomass resources

Acetylene is produced from the reaction between calcium carbide(CaC_(2))and water,while the production of CaC_(2) generates significant amount of carbon dioxide not only because it is an energy-intensive process but also the raw material for CaC_(2) synthesis is from coal.Here,a comprehensive biomass-to-acetylene process was constructed that integrated several units including biomass pyrolysis,oxygen-thermal CaC_(2) fabrication and calcium looping.For comparison,a coal-to-acetylene process was also established by using coal as feedstock.The carbon efficiency,energy efficiency and environmental impacts of the bio-based calcium carbide acetylene(BCCA)and coal-based calcium carbide acetylene(CCCA)processes were systematically analyzed.Moreover,the environmental impacts were further evaluated by applying thermal integration at system level and energy substitution in CaC_(2) furnace.Even though the BCCA process showed lower carbon efficiency and energy efficiency than that of the CCCA process,life cycle assessment demonstrated the BCCA(1.873 kgCO_(2eq) kg-prod^(-1))a lower carbon footprint process which is 0.366 kgCO_(2eq) kg-prod^(-1) lower compared to the CCCA process.With sustainable energy(biomass power)substitution in CaC_(2) furnace,an even lower GWP value of 1.377 kgCO_(2eq) kg-prod^(-1) can be achieved in BCCA process.This work performed a systematic analysis on integrating biomass into industrial acetylene production,and revealed the positive role of biomass as raw material(carbon)and energy supplier.

A thermodynamic view on the in-situ carbon dioxide reduction by biomass-derived hydrogen during calcium carbonate decomposition

In the carbonate industry,deep decarbonization strategies are necessary to effectively remediate CO_(2).These strategies mainly include both sustainable energy supplies and the conversion of CO_(2)in downstream processes.This study developed a coupled process of biomass chemical looping H2 production and reductive calcination of CaCO_(3).Firstly,a mass and energy balance of the coupled process was established in Aspen Plus.Following this,process optimization and energy integration were implemented to provide optimized operation conditions.Lastly,a life cycle assessment was carried out to assess the carbon footprint of the coupled process.Results reveal that the decomposition temperature of CaCO_(3)in an H_(2)atmosphere can be reduced to 780℃(generally around 900℃),and the conversion of CO_(2)from CaCO_(3)decomposition reached 81.33%with an H2:CO ratio of 2.49 in gaseous products.By optimizing systemic energy through heat integration,an energy efficiency of 86.30%was achieved.Additionally,the carbon footprint analysis revealed that the process with energy integration had a low global warming potential(GWP)of-2.624 kg·kg^(-1)(CO_(2)/CaO).Conclusively,this work performed a systematic analysis of introducing biomass-derived H_(2)into CaCO_(3)calcination and demonstrated the positive role of reductive calcination using green H_(2)in mitigating CO_(2)emissions within the carbonate industry.

可循环利用的生物质基环氧树脂类玻璃高分子材料的研究进展

类玻璃高分子材料(Vitrimer)是一种具有独特功能的新兴材料,基于生物质资源制备的生物质基环氧树脂Vitrimer材料不仅具有良好的力学性能和耐溶剂性,而且具有可循环利用特性(重塑再加工、化学溶解回收、自修复),有望解决传统环氧树脂热固性材料难以可持续循环利用的问题。文中综述了近年来不同生物质资源制备的生物质基环氧树脂以及不同动态化学键构筑的生物质基环氧树脂Vitrimer材料性能的研究进展,展望了生物质基环氧树脂Vitrimer材料未来可能的发展方向,对实现环氧树脂材料的循环利用和可持续发展有重要意义。

超声斑点追踪成像技术评价主动脉瓣狭窄患者左心房功能的临床研究

目的应用超声斑点追踪成像(STI)技术评价主动脉瓣狭窄(AS)患者左心房功能,早期预测肺循环障碍及肺水肿的发生。方法选取30例AS患者(AS组)及30例健康志愿者(对照组)作为研究对象。采用超声诊断仪分别取心尖四腔、五腔及心底短轴切面图测量。记录主动脉瓣口面积(Aa)、主动脉瓣口血流峰速(Av)、左心室射血分数(LVEF)法、二尖瓣口血流E峰/A峰(E/A)、左心房收缩末期容积(LAVS)、左心房舒张末期容积(LAVD)、左心房P容积(LAVp)、左心房主动射血分数(LAAEF)及左心房被动射血分数(LAPEF)。应用Q-LAB软件分析左心室收缩期左心房峰值变形率、左心室舒张早期左心房峰值变形率及左室舒张晚期左心房峰值变形率。结果①AS组较对照组Aa减小,Av增大,E/A减小,LVEF减小(P<0.05);②两组LAVD、LAVp、LAVS、LAPEF比较,差异无统计学意义(P>0.05),AS组较对照组LAAEF减低(P<0.05);③AS组较对照组左心室收缩期左心房峰值变形率、左心室舒张早期左心房峰值变形率、左心室舒张晚期左心房峰值变形率降低。结论AS患者应用STI技术测量各指标有变化。STI技术能早期发现AS患者左心房功能受损,有利于预测肺循环及肺水肿的发生,延缓右心衰、改善预后。

Sensitivity of two drug-resistant bacteria to low-temperature air plasma in catheterassociated urinary tract infections under different environments

The high incidence of catheter-associated urinary tract infections,which are dominated by drugresistant bacteria,has attracted an increasing number of researchers interested in solving this public health problem.The purpose of this study was to explore the killing effect of lowtemperature air plasma(LTAP)on extended-spectrum beta-lactamase-producing Escherichia coli and high level gentamycin resistance enterococci under two simulated environments in vitro.The results showed that the survival rate of these two kinds of bacteria decreased to less than20%after being treated by LTAP in different environments for 5 min.A comparison of the LTAP treatments showed that the killing efficacy of the two kinds of bacteria in the early stage(0-1 min)was up to 50%.Moreover,the results of transmission electron microscopy,reactive nitrogen species measurement,and a temperature test indicated that the bactericidal effect of the LTAP treatment on the two kinds of bacteria worked through the destruction of the ribosome and other organelles inside the bacteria,rather than the thermal effect,to achieve sterilization.

High resolution deep imaging of a bright radio quiet QSO at z～3

We have obtained deep J and Ks-band images centered on a bright radio quiet QSO UM 402 （Zem = 2.856） using the IRCS camera and adaptive optics systems that are part of the Subaru Telescope, as well as retrieved WFC3/F140W archive images of this object. A faint galaxy （ink = 23.32 ±0.05 in the Vega magnitude system） that lies ～2.4″north of the QSO sightline has been clearly resolved in all three deep high resolution datasets, and appears as an irregular galaxy with two close components in the Ks-band images （separation ～ 0.31″）. Given the small impact parameter （b = 19.6 kpc, at Zlls = 2.531）, as well as the red color of （J - Ks）vega ～1.6, it might be a candidate galaxy giving rise to the Lyman Limit system absorption at Zabs = 2.531 seen in the QSO spectrum. After carefully subtracting the point spread function from the QSO images, the host galaxy of this bright radio quiet QSO at z ～ 3 was marginally revealed. We placed a lower limit on the host component of mk～ 23.3 according to our analyses.

Strong optical and UV intermediate-width emission lines in the quasar SDSS J232444.80–094600.3:dust-free and intermediate-density gas at the skin of dusty torus?

Emission lines from the broad emission line region （BELR） and the narrow emission line region （NELR） of active galactic nuclei （AGNs） have been extensively studied. However, emission lines are rarely detected between these two regions. We present a detailed analysis of quasar SDSS J232444.80-094600.3 （SDSS J2324-0946）, which is remarkable for its strong intermediate-width emission lines （IELs） with FWHM ≈ 1800 km s^-1. The IEL component is present in different emission lines, including the permitted lines Lyαλ1216, CⅣ λ1549, semiforbidden line C Ⅲ] λ1909, and forbidden lines [OⅢ] ss4959, 5007. With the aid of photo-ionization models, we found that the IELs are produced by gas with a hydrogen density of nH - 10^6.2 -- 10^6.3 cm^-3, a distance from the central ionizing source of R - 35 - 50 pc, a covering factor of - 6%, and a dust-to-gas ratio of ≤ 4% that of the SMC. We suggest that the strong IELs of this quasar are produced by nearly dust-free and intermediate-density gas located at the skin of the dusty torus. Such strong IELs, which serve as a useful diagnostic, can provide an avenue to study the properties of gas between the BELR and the NELR.

Discovery of Balmer broad absorption lines in the quasar LBQS 1206+1052

We report the discovery of Balmer broad absorption lines （BALs） in the quasar LBQS 1206＋1052 and present a detailed analysis of the peculiar absorption line spectrum. Besides the Mg II λλ2796, 2803 doublet, BALs are also detected in the He I＊ multiplet at λλ2946, 3189, 3889 A arising from the metastable helium 2 3 S level, and in Hα and Hβ from the excited hydrogen H I＊ n = 2 level, which are rarely seen in quasar spectra. We identify two components in the BAL troughs of v ～ 2000 km s 1 width： One component shows an identical profile in H I＊, He I＊ and Mg II with its centroid blueshifted by v c ≈ 726 km s-1 . The other component is detected in He I＊ and Mg II with v c ≈ 1412 km s-1 . We estimate the column densities of H I＊, He I＊, and Mg II, and compare them with possible level population mechanisms. Our results favor the scenario that the Balmer BALs originate in a partially ionized region with a column density of N H ～ 10 21 10 22 cm-2 for an electron density of n e ～ 10 6 10 8 cm-3 via Lyα resonant scattering pumping. The harsh conditions needed may help to explain the rarity of Balmer absorption line systems in quasar spectra. With an i-band PSF magnitude of 16.50, LBQS 1206＋1052 is the brightest Balmer-BAL quasar ever reported. Its high brightness and unique spectral properties make LBQS 1206＋1052 a promising candidate for followup high-resolution spectroscopy, multi-band observations, and long-term monitoring.

A broad absorption line outflow associated with the broad emission line region in the quasar SDSS J075133.35+134548.3

We report on the discovery of unusual broad absorption lines(BALs)in the bright quasar SDSS J075133.35+134548.3 at z~1,using archival and newly obtained optical and NIR spectroscopic data.The BALs are detected reliably in HeⅠ*λ3889,HeⅠ*λ10830 and tentatively in AlⅢ,MgⅡ.These BALs show complex velocity structures consisting of two major components:a high-velocity component(HV),with a blueshifted velocity range ofΔv_(HV)~9300--3500 km s^(-1),which can be reliably detected in HeⅠ*λ10830,and tentatively in AlⅢand MgⅡ,whereas it is undetectable in HeⅠ*λ3889;and a low-velocity component(LV),withΔv_(LV)~3500--1800 km s^(-1),is only detected in HeⅠ*λ3889 and HeⅠ*λ10830.With the BALs from different ions,the HV outflowing gas can be constrained to have a density of nH~10^(10.3)-10^(11.4) cm^(-3),a column density of NH~10^(21) cm^(-2)and an ionization parameter of U~10^(-1.83)-10^(-1.72);inferring a distance of RHV~0.5 pc from the central continuum source with a monochromatic luminosityλLλ(5100)=7.0×10^(45)erg s^(-1)at 5100 A.This distance is remarkably similar to that of the normal broad line region(BLR)estimated from reverberation experiments,suggesting association of the BLR and the HV BAL outflowing gas.Interestingly,a blueshifted component is also detected in AlⅢand MgⅡbroad emission lines(BELs),and the AlⅢ/MgⅡof such a BEL component can be reproduced by the physical parameters inferred from the HV BAL gas.The LV BAL gas likely has a larger column density,a higher ionization level and hence a smaller distance than the HV BAL gas.Further spectroscopy with a high S/N ratio and broader wavelength coverage is needed to confirm this to shed new light on the possible connection between BALs and BELs.

Polyoxometalates for continuous power generation by atmospheric humidity

Atmospheric humidity is a sustainable low-value energy widely existing in natural environment,which is a promising candidate to solve the noncontinuous and low efficiency of low-value energy power generation.Here the mono-substituted Dawson-type polyoxometalates are constructed to be highly dispersed organic ammonium-polyoxoanion clusters and are assembled into thin films power generators with micropores,working in atmospheric humidity.The optimal polyoxometalates generator with the thickness of 7.2μm and the area of 0.36 cm^(2) produces a voltage of 0.68 V and a current density of 19.5μA·cm^(-2) under simulated natural environment,and works continuously and stably under almost all-natural environments(humidity 10%–90%).The highly dispersed polyoxometalate nanoclusters can form microporous in polyoxometalate films to effectively absorb atmospheric humidity and spontaneously form distribution gradient of water,which is the structural basis of power generation.The continuous power generation may be maintained by the effective adsorption and utilization of H_(2)O,the huge electrostatic field of organic ammonium-polyoxoanion clusters,and the reasonably designed polyoxometalates containing inorganic small ions with high mobility.It is the first humidity generator designed with polyoxometalates,which may provide a new research direction for polyoxometalates in sustainable utilization of low-value energy.

De novo ADGRV1 variant in a patient with ictal asystole provides novel clues for increased risk of SUDEP

Background Various cardiac and autonomic manifestations are frequently reported during seizures.Among the seizure-related arrhythmia,ictal tachycardia is the most common,followed by ictal bradycardia,with ictal asystole being the rarest.The occurrence of ictal asystole may obscure the clinical presentation and delay the diagnosis,representing a life-threatening presentation of epilepsy,with an elevated risk of sudden unexpected death in epilepsy patients(SUDEP).These cardiac abnormalities are being increasingly recognized as the key to elucidating the mechanisms of SUDEP.Case presentation We present a 35-year-old man with a history of focal-onset seizures with impaired consciousness since his mid-20 s.He developed different types of seizures for 2 years,described as tonic seizure and atonic seizure(drop attack).During such clinical events,he suffered from falls and cardiac arrest.However,thorough cardiac electrophysiology and imaging workup failed to reveal a cardiac etiology.Subsequent video electroencephalograph(EEG)monitoring was performed,and ictal bradycardia and ictal asystole were discovered.A cardiac pacemaker was implanted,and at 3-year follow-up,the patient did not suffer more atonic seizures,or falls.Genetic tests discovered a de novo variant of Adhesion G Protein-Coupled Receptor V1(ADGRV1),which may provide a clue for the patient’s ictal asystole and the increased risk of SUDEP.Conclusions Considering the important impact of ictal bradycardia and asystole on the morbidity and potential mortality of epileptic patients,it is important to simultaneously utilize EEG and electrocardiogram to confirm the diagnosis.This case report highlights the link between the de novo variant of ADGRV1 and the ictal bradycardia/asystole phenotype and implicates the importance of genetic testing in adult epilepsy patients.

The histone methyltransferase SUVR2 promotes DSB repair via chromatin remodeling and liquidliquid phase separation

Maintaining genomic integrity and stability is particularly important for stem cells,which are at the top of the cell lineage origin.Here,we discovered that the plant-specific histone methyltransferase SUVR2 maintains the genome integrity of the root tip stem cells through chromatin remodeling and liquid-liquid phase separation(LLPS)when facing DNA double-strand breaks(DSBs).The histone methyltransferase SUVR2(MtSUVR2)has histone methyltransferase activity and catalyzes the conversion of histone H3 lysine 9 monomethylation(H3K9me1)to H3K9me2/3 in vitro and in Medicago truncatula.Under DNA damage,the proportion of heterochromatin decreased and the level of DSB damage marker y-H2AX increased in suvr2 mutants,indicating that MtSUVR2 promotes the compaction of the chromatin structure through H3K9 methylation modification to protect DNA from damage.Interestingly,MtSUVR2 was induced by DSBs to phase separate and form droplets to localize at the damage sites,and this was confirmed by immunofluorescence and fluorescence recovery after photobleaching experiments.The IDR1 and lowcomplexity domain regions of MtSUVR2 determined its phase separation in the nucleus,whereas the IDR2 region determined the interaction with the homologous recombinase MtRAD51.Furthermore,we found that MtSUVR2 drove the phase separation of MtRAD51 to form"DNA repair bodies,"which could enhance the stability of MtRAD51 proteins to facilitate error-free homologous recombination repair of stem cells.Taken together,our study reveals that chromatin remodeling-associated proteins participate in DNA repair through LLPS.

The bright star survey telescope for the planetary transit survey in Antarctica

Transiting extrasolar planets(exoplanets),especially those orbiting bright stars, are desired for study of the diversity of planetary compositions, internal structures and atmospheres beyond our solar system. Dome A at Antarctica is a promising site for planetary transit surveys,where the continuous darkness and the large clear-sky fraction in the winter months greatly enhance the detection efficiency. The Chinese Small Telescope ARray and the Antarctic Survey Telescopes are the first facilities that have been operated at Dome A for use in exoplanet surveys. To increase the sky coverage, a low-temperature-resistant wide-field robotic telescope, named the bright star survey telescope(BSST), has been developed to join the ongoing planetary transit survey in Antarctica. The BSST has an aperture size of 300 mm and is equipped with a largeframe 4K×4K CCD camera to receive starlight from a 3.°4×3.°4 field of view. The BSST was operated at Lijiang observatory in April and May 2015 for a test run.Photometric precision of 3.5 mmag was achieved for stars with V～11 mag using 75 s exposures. The transiting events of two Jupiter-size exoplanets, HAT-P-3b and HATP-12 b, were observed on May 10 and May 20, 2015,respectively.

A tri-vanadium-capped Keggin phosphomolybdate: synthesis, characterization, photocatalytic and bifunctional electrocatalytic properties

A purely inorganic tri-vanadium-capped Keggin phosphomolybdate[Na_(3)PMo_(12)V_(3)O_(43)]·4H_(2)O(compound 1)has been synthesized by hydrothermal means and characterized via powder X-ray diffraction,infrared spectrum,thermogravimetric analysis,single-crystal X-ray diffraction,scanning electron microscope,ultraviolet–visible absorption spectroscopy,ultraviolet–visible diffuse reflection spectra as well as electrochemical cyclic voltammetry tests.The structure analysis displays that compound 1 is a symmetric tri-vanadium-capped cluster through six half occupancy{VO_(5)}units.Compound 1 remains a purely inorganic Keggin phosphomolybdate,which presents electrocatalytic properties for the oxidization of ascorbic acid and reduction of H_(2)O_(2).At the same time,it possesses high-efficiency degradation capability for typical methylene blue,Rhodamine B and methyl orange dyes under ultraviolet light.