First acceptance testing of multiple A10 absolute gravimeters in China and analysis of the comparison results

Three A10 absolute gravimeters(AGs) were first acquired in China by the Hubei Earthquake Agency under the Belt and Road Seismic Monitoring Network Project. Although AG measuring and testing technique is not new, the purchase and simultaneous testing of 3 A10 absolute gravimeters is unprecedented in China. This study conducted the first acceptance testing of the AGs at 3 locations(the Jiufengshan Gravity Observation Station, the Global Navigation Satellite System Observation Station in Wuhan, and the Jiugongshan Observation Station in Xianning). The results were compared using a method based on expert validation, and the acceptance testing scheme was formulated by referring to the Technical Regulations for Tectonic Environment Monitoring Networks in China and Specifications for Gravimetry Control. Based on the repeatability, precision, and consistency of the measured g values, the results from each instrument were evaluated using the air pressure precision test. Comparing the instrument reference values, the final test results can identify the indicator parameters for 3 A10 AGs, the effects of the surrounding environment, and the related parameters on measurement precision. The precision of A10-059, A10-058, and A10-057 exceeded 0.78 μGal, 0.79 μGal, and 0.42 μGal, respectively.This testing scheme can be used as a reference for conducting acceptance testing of AGs in the future and obtaining absolute gravimetric measurements.

Exploiting the Direct Link in IRS Assisted NOMA Networks with Hardware Impairments

Hardware impairments(HI)are always present in low-cost wireless devices.This paper investigates the outage behaviors of intelligent reflecting surface(IRS)assisted non-orthogonal multiple access(NOMA)networks by taking into account the impact of HI.Specifically,we derive the approximate and asymptotic expressions of the outage probability for the IRS-NOMA-HI networks.Based on the asymptotic results,the diversity orders under perfect self-interference cancellation and imperfect self-interference cancellation scenarios are obtained to evaluate the performance of the considered network.In addition,the system throughput of IRS-NOMA-HI is discussed in delay-limited mode.The obtained results are provided to verify the accuracy of the theoretical analyses and reveal that:1)The outage performance and system throughput for IRS-NOMA-HI outperforms that of the IRS-assisted orthogonal multiple access-HI(IRS-OMA-HI)networks;2)The number of IRS elements,the pass loss factors,the Rician factors,and the value of HI are pivotal to enhancing the performance of IRS-NOMAHI networks;and 3)It is recommended that effective methods of reducing HI should be used to ensure system performance,in addition to self-interference cancellation techniques.

Abnormal characteristics and effectiveness evaluation of the micro-seismic signal before the Debao MS4.8 earthquake

The Debao MS4.8 earthquake occurred in western Guangxi on August 5,2021,near where the Jingxi MS5.2 earthquake occurred in 2019.To study the increasing seismicity in western Guangxi,it is necessary to determine whether there was an anomaly related to the earthquake source near the Pingxiang gravity station,which is located approximately 100 km from the epicenter of the Debao MS4.8 earthquake.In this study,the R-value scoring method was used to analyze the anomaly and evaluate the prediction efficiency of the double frequency(DF)micro-seismic signal vertical displacement(referred to as vertical displacement,VD)and the absolute value of monthly extreme rate(referred to as the monthly rate).Results show that earthquakes larger than MS4.0 in the 350 km range from the Pingxiang station tend to coincide with yearly typhoons,and the VD of micro-seismic signals correspondingly changes from low to high.The Debao MS4.8 earthquake occurred during a gradual VD increase from 0.05×10^(-6)to 0.10×10^(-6)m.When discussing the relationships among R,the rate threshold,and the effective duration of prediction,the rate threshold of the micro-seismic signal converges from 0.00039×10^(-6)to 0.00031×10^(-6)m/month,the effective duration of prediction is approximately 6-10 months,and R also converges from 0.29 to 0.31.By comparing the results of three gPhone gravity stations in Guangxi,we found that the increase of short-term VD before the Debao earthquake was related to the enhancement of the DF micro-seismic signal excited by the typhoon.When the typhoon track was perpendicular to the coastline of China,the possibility of an earthquake occurring was increased.This study provides evidence and reference for the future occurrence period of earthquakes above MS4.0 in western Guangxi.

掺杂浓度对ZnO:Ag纳米棒结构和光致发光性能的影响

本文利用水热生长法在掺铝氧化锌(AZO)种子层上以Ag掺杂制备出ZnO:Ag纳米棒,采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和光致发光谱(PL)对所制备样品的晶体结构、表面形貌以及光致发光性能进行了分析。结果表明,随着Ag掺杂比例的增加,ZnO:Ag纳米棒的晶格常数先增大后减小。近紫外发光峰都发生蓝移,在Zn:Ag = 1:0.03时,近紫外发光峰的强度最强,不但出现了明显的“蓝移”,而且Ag离子的掺入也使深能级发光加强。经分析得出在一定的范围内,随着Ag掺杂比例增加,ZnO:Ag纳米棒的近紫外光的强度有明显的增强。

Large-Scale Membrane Bioreactors for Industrial Wastewater Treatment in China:Technical and Economic Features,Driving Forces,and Perspectives

Membrane bioreactors(MBRs)have been and will continue playing an important role in industrial wastewater treatment and reuse in China.The sustainable development of MBR technology in its mature-application stage requires reciprocal interactions between engineering and research participants.Thus,in this study,a total of 182 large-scale MBR projects treating industrial wastewater(with individual treatment capacities5000 m3d1)commissioned and under construction from 2003 to 2019 were analyzed comprehensively.Fast growth of the cumulative treatment capacity was observed,with extension to diverse industries,and the super large-scale was enhanced recently.The treatment processes,pollutant removal efficiencies,and actual operational parameters were summarized regarding the particularity of industrial wastewater compared to municipal wastewater.Economic features including the total investment costs of the projects,their total footprint,and their operational energy consumption were analyzed as well.A vigorous MBR market has formed in China with the fast development of membrane elements and engineering suppliers,continuously increasing official oriented projects,and responsive and innovative business modes.MBR technology has been mostly applied in specific economic zones and water-deficient areas,but its widespread use all over China is foreseeable considering the vast future market for industrial wastewater treatment and recycling.The policy–economy and market–technology driving forces revealed that MBR is consistent with the national development demand.According to the survey and analysis,prospective development in both engineering and research aspects of MBR is proposed to maintain its competitive edge.

Far-field coseismic gravity changes related to the 2015 MW7.8 Nepal(Gorkha)earthquake observed by superconducting gravimeters in Chinese mainland

Using data from five SGs at four stations in Chinese mainland,obvious permanent gravity changes caused by the 2015 MW7.8 Nepal(Gorkha)earthquake were detected.We analyzed the gravity effects from ground vertical deformation(VD)using co-site continuous GPS(cGPS)data collocated at the Lijiang and the Wuhan station,and hydrological effects using GLDAS models and groundwater level records.After removing these effects,SG observations before and after the earthquake revealed obvious permanent gravity changes:−3.0μGal,7.3μGal and 8.0μGal at Lhasa,Lijiang and Wuhan station,respectively.We found that the gravity changes cannot be explained by the results of dislocation theory.

Comparison of noise-levels between superconducting gravimeter and gPhone gravimeter

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Gravity variation in the Tibet area before the Nepal Ms8.1 earthquake

This research utilized two periods of gravity monitoring results from 2010 to 2013 from the Continental Tectonics Environmental Monitoring Network of China, analyzed the corre- lation between gravity variation in the Tibet area and the Nepal Ms8.1 earthquake, and investigated the gravity variation mechanism in combination with the crust vertical movement and horizontal strain field observed by Global Positioning System （GPS）. The research results indicated that （1） the gravity variation exhibited apparent characteristics of a positive anomaly and high gradient zone in the Himalayan frontier. This observation is consistent with the existing recognition of the gravity anomaly and occurrence regularity of a strong earthquake; （2） the gravity variation exhibited apparent consistence with the spacious distribution of the vertical movement and the horizontal deformation field in that area. The crustal vertical movement was not the direct cause leading to the gravity vari- ation. It is assumed that the crust stress-strain accumulation in the Qinghai-Tibetan Plateau and its adjacent areas is the important factor that resulted in the variation of gravity.

钠离子电池低温电解质的研究进展与挑战

钠离子电池因资源丰富、成本低廉、安全性高及环境友好等优势,在低速电动汽车、大型储能系统等领域备受关注。电解质作为电池的重要组成部分之一,承担着在正负极间传输离子的作用,对电池的循环寿命、倍率、安全性及自放电等性能具有重要影响。然而,在低温环境下,由于离子电导率下降、电解质与正负极兼容性变差、去溶剂化能升高、电极/电解质界面性质变差等问题,使得钠离子电池难以发挥理想的性能。本文总结了近年来对低温电解质的钠离子溶剂化结构及电极/电解质界面的新认识,并对基于氢键网络破坏、弱溶剂化、快速反应动力学及阴离子干预的低温电解质设计策略进行了系统分析。最后,提出深入理解电解质的钠离子溶剂化结构、电极/电解质界面性质与电解质低温性能之间的关系是未来从电解质角度提升钠离子电池低温性能的关键。

多团队系统研究述评与展望

多团队系统(Multiteam System,MTS)是指两个及两个以上团队基于共同目标,相互合作的现象。MTS的出现将团队研究领域从单一团队运行机制拓展到多团队协助机制,成为实践界和学术界关注的重要议题。首先,本文基于国内外相关文献概括了MTS的特征,阐述了MTS与子团队之间的关系。其次,本研究基于社会身份、资源、社会网络理论视角,总结MTS的双刃剑效应。最后,针对MTS研究的理论局限性,提出关于新的理论研究方向,探究不同理论间的联结点,并进一步探讨数字化转型背景下MTS的发展机遇。

SD-RLK28 positively regulates pollen hydration on stigmas as a PCP-Bβ receptor in Arabidopsis thaliana

Pollen hydration on dry stigmas is strictly regulated by pollen–stigma interactions in Brassicaceae. Although several related molecular events have been described, the molecular mechanism underlying pollen hydration remains elusive. Multiple B-class pollen coat proteins(PCP-Bs) are involved in pollen hydration. Here, by analyzing the interactions of two PCP-Bs with three Arabidopsis thaliana stigmas strongly expressing S-domain receptor kinase(SD-RLK), we determined that SD-RLK28 directly interacts with PCP-Bβ. We investigated pollen hydration, pollen germination, pollen tube growth, and stigma receptivity in the sd-rlk28 and pcp-bβ mutants. PCP-Bβ acts in the pollen to regulate pollen hydration on stigmas. Loss of SD-RLK28 had no effect on pollen viability, and sd-rlk28 plants had normal life cycles without obvious defects. However,pollen hydration on sd-rlk28 stigmas was impaired and pollen tube growth in sd-rlk28 pistils was delayed. The defect in pollen hydration on sd-rlk28 stigmas was independent of changes in reactive oxygen species levels in stigmas. These results indicate that SD-RLK28 functions in the stigma as a PCP-Bβ receptor to positively regulate pollen hydration on dry stigmas.

Estimating the annual runoff frequency distribution based on climatic conditions and catchment characteristics:A case study across China

Estimation of the annual runoff frequency distribution is an essential basis for water resource management.This study proposes a framework for estimating the annual runoff frequency distribution across252 catchments in China based on climatic conditions and catchment characteristics from 1956 to 2000.The Budyko land-specific parameter n,which intergrates influences other than the mean climate conditions,is firstly estimated based on easily ascertainable catchment characteristics without the requirementsof having long-term runoff observations.Second,the annual runoff statistical parameters,namely,the mean value and standard deviation(STD),are derived based on the Budyko rainfall-runoffmodel with the central moment method.Finally,the annual runoff on any recurrence interval is obtainedby the Pearson-Ill frequency function.Results show that the parameter n can be estimated fromthe catchment average slope,longitude,and climatic seasonality index.The estimated statistical parametersof annual runoff have acceptable agreement with observed values(mean value:R^(2)-0.94,STD:R^(2)-0.91,and both relative errors<10%).In addition,estimated annual runoff at each catchment fortypical wet and dry years(25%and 75%ranked percentiles)coincides well with observed values,with R^(2) of 0.92-0.93 and relative erors less than 10%.This result indicates the robustness of this framework forestimating the annual runoff frequency distribution,which provides a simple and effective tool forungauged orpoorlygauged catchments.

Nitric oxide removal from flue gas coupled with the Fe^(II)EDTA regeneration by ultraviolet irradiation

During wet complexation denitrification of flue gas,Fe^(II)EDTA regeneration,also known as reducing Fe^(II)IEDTA and Fe^(II)EDTA-nitric oxide(NO)to Fe^(II)EDTA,is crucial.In this paper,ultraviolet(UV)light was used for the first time to reduce Fe^(II)EDTA-NO.The experimental result demonstrated that Fe^(II)EDTA-NO reduction rate increased with UV power increasing,elevated temperature,and initial Fe^(II)EDTA-NO concentration decreasing.Fe^(II)EDTA-NO reduction rate increased first and then decreased as pH value increased(2.0e10.0).Fe^(II)EDTA-NO reduction with UV irradiation presented a first order reaction with respect to Fe^(II)EDTA-NO.Compared with other Fe^(II)EDTA regeneration methods,Fe^(II)EDTA regeneration with UV show more superiority through comprehensive consideration of regeneration rate and procedure.Subsequently,NO absorption experiment by Fe^(II)EDTA solution with UV irradiation confirmed that UV can significantly promote the NO removal performance of Fe^(II)EDTA.Appropriate oxygen concentration(3%(vol))and acidic environment(pH=4)was favorable for NO removal.With UV power increasing as well as temperature decreasing,NO removal efficiency rose.In addition,the mechanism research indicates that NO from flue gas is mostly converted to NO_(2)-,NO_(3)-,NH_(4)^(+),N_(2),and N_(2)O with Fe^(II)EDTA absorption liquid with UV irradiation.UV strengthens NO removal in Fe^(II)EDTA absorption liquid by forming a synergistic effect of oxidationereductionecomplexation.Finally,compared with NO removal methods with Fe^(II)EDTA,Fe^(II)EDTA combined UV system shows prominent technology advantage in terms of economy and secondary pollution.

一株新的砷还原菌分离鉴定及其对天然矿物臭葱石的溶解作用

【目的】探究江汉平原土著砷还原微生物如何介导臭葱石的溶解和释放过程,以及硝酸盐和硫酸盐对该过程的影响。【方法】采集江汉平原高砷沉积物,利用多轮传代富集方法筛选出一株兼性厌氧砷还原菌;克隆其16S rRNA基因、砷还原酶基因(arsC)、硫代硫酸盐还原酶基因(phsA)、硝酸盐还原酶基因(nar)以获得其分类地位;分析该细菌的As(V)、NO3^–、Fe(III)、S2O32–还原功能;利用microcosm技术分析该菌株催化臭葱石中不可溶砷和铁的溶解和释放作用及硝酸盐和硫酸盐对此过程的影响;采用X-射线衍射(XRD)和扫描电镜(SEM)等方法对细菌作用前后的矿物表面形貌进行分析。【结果】16S rRNA基因测序结果表明该细菌为柠檬酸杆菌属(Citrobacter sp.),故命名为Citrobacter sp.A11;在Citrobacter sp.A11作用下,0.45 mmol/L As(V)在4 d内被还原成As(III),2.0 mmol/L S2O3^2–在6 d内被还原成S2^–,1.0 mmol/L Fe(III)在3 d内被还原成Fe(II),140.0 mg/L NO3^–在28 h内被还原成NO2^–;经过28 d该细菌的催化作用使得体系中不可溶砷和铁的释放量分别为33.68μmol/L、51.93μmol/L;硫酸根的加入使得砷和铁的释放量分别增长了41.04%和34.30%,硝酸根的加入则使砷和铁释放量分别降低了35.07%和53.46%。XRD、SEM-EDS分析表明,细菌作用后的臭葱石表面形貌发生明显改变,并出现细小且分散的溶解性颗粒。【结论】本次研究从江汉平原高砷沉积物中富集分离得到一株兼性厌氧砷还原细菌Citrobacter sp.A11,能有效还原As(V)、S2O3^2–、NO3^–、Fe(III);砷还原细菌Citrobacter sp.A11能显著促进臭葱石中砷和铁的溶解和释放,硫酸根离子的存在会促进细菌介导臭葱石中固态砷、铁的释放,而硝酸根离子的存在则对此过程起明显抑制作用。

Studying the urban hierarchical pattern and spatial structure of China using a synthesized gravity model

The Gravity Model(GM), one of the most classic models adopted by the domain of social sciences from physics, has been widely used to study the interactions between social identities. Previous research that has used the Gravity Model to study the interactions among cities have mostly used a single variable, such as population or GDP, to represent a city, which does not provide a comprehensive depiction of a city's influence. This paper develops a Synthesized Gravity Model(SGM) based on the traditional Gravity Model to study the evolution of the hierarchy of the Chinese urban system since the mid-1990 s. Under this model, socioeconomic variables are synthesized and are represented by the Influential Factor, while the Function Distance is derived from a Network Analysis that is based on multiple transportation methods. As an improvement on the GM, the SGM is used to accurately establish and represent the nodal structure of China's urban system, the evolution of its hierarchical structure,and the relationships that exist between the nodal structure and socioeconomic factors. The results based on the SGM indicate that China's national urban system is characterized by the emergence of urban clusters with stronger inter-city interactions since the 1990 s. However, the development among cities within certain urban clusters is not even, although the general pattern indicates a lessening inequality amongst cities. Spatially, while most cities at the top of the hierarchy are located in Eastern China, cities in the center and the west of the country are also gaining higher positions in the hierarchy over time. This paper is dedicated to improving the traditional GM in the applications of urban studies, while the system of Chinese cities is used to validate the SGM.

Investigation of microstructure changes in Al_(2)O_(3)-YSZ coatings and YSZ coatings and their effect on thermal cycle life

Yttria-stabilized zirconia(YSZ)coatings and Al_(2)O_(3)–YSZ coatings were prepared by atmospheric plasma spraying(APS).Their microstructural changes during thermal cycling were investigated via scanning electron microscopy(SEM)equipped with electron backscatter diffraction(EBSD)and X-ray diffraction(XRD).It was found that the microstructure and microstructure changes of the two coatings were different,including crystallinity,grain orientation,phase,and phase transition.These differences are closely related to the thermal cycle life of the coatings.There is a relationship between crystallinity and crack size.Changes in grain orientation are related to microscopic strain and cracks.Phase transition is the direct cause of coating failure.In this study,the relationship between the changes in the coating microstructure and the thermal cycle life is discussed in detail.The failure mechanism of the coating was comprehensively analyzed from a microscopic perspective.

Enhancement of precursor amino acid supplies for improving bacitracin production by activation of branched chain amino acid transporter BrnQ and deletion of its regulator gene lrp in Bacillus licheniformis

Bacitracin,a new type of cyclic peptide antibiotic,is widely used as the feed additive in feed industry.Branched chain amino acids(BCAAs)are the key precursors for bacitracin synthesis.In this research,soybean meal was served as the raw material to supply precursor amino acids for bacitracin synthesis,and enhanced production of bacitracin was attempted by engineering BCAA transporter BrnQ and its regulator Lrp in the bacitracin industrial production strain Bacillus licheniformis DW2.Firstly,our results confirmed that Lrp negatively affected bacitracin synthesis in DW2,and deletion of lrp improved intracellular BCAA accumulations,as well as the expression level of BCAA transporter BrnQ,which further led to a 14.71%increase of bacitracin yield,compared with that of DW2.On the contrary,overexpression of Lrp decreased bacitracin yield by 12.28%.Secondly,it was suggested that BrnQ acted as a BCAA importer in DW2,and overexpression of BrnQ enhanced the intracellular BCAA accumulations and 10.43%of bacitracin yield.While,the bacitracin yield decreased by 18.27%in the brnQ deletion strain DW2△brnQ.Finally,BrnQ was further overexpressed in lrp deletion strain DW2△lrp,and bacitracin yield produced by the final strain DW2△lrp::BrnQ was 965.34 U/mL,increased by 22.42%compared with that of DW2(788.48 U/mL).Collectively,this research confirmed that Lrp affected bacitracin synthesis via regulating the expression of BCAA transporter BrnQ and BCAA distributions,and provided a promising strain for industrial production of bacitracin.

Antimony smelting process generating solid wastes and dust:Characterization and leaching behaviors

A large amount of solid waste has been produced by the antimony smelting process in the＂World Capital of Antimony＂, Xikuangshan area in China. This study comprehensively investigated the physical and chemical characteristics of the various solid wastes, as well as the leaching behavior of the solid wastes, which included water-quenched slag,arsenic-alkali residue, desulfurized slag and blast furnace dust. These four types of waste were enriched in a variety of heavy metals and metalloids and more specifically with As and Sb levels up to 8.6 × 104 and 3.16 × 105mg/kg, respectively, in arsenic-alkali residue. For desulfurized slag and water-quenched slag, the leaching concentration of Sb significantly exceeded the acceptable limits during the leaching tests using the toxicity characteristic leaching procedure and the synthetic precipitation leaching procedure. In addition, As leaching in arsenic-alkali residue was extraordinarily hazardous, being three orders of magnitude higher than the regulatory level of As. According to the results of the extraction tests, all the tested wastes were classified as hazardous waste.

Hybrid MARTE statecharts

The specification of modeling and analysis of real-time and embedded systems （MARTE） is an extension of the unified modeling language （UML） in the domain of real-time and embedded systems. Even though MARTE time model offers a support to describe both discrete and dense clocks, the biggest effort has been put so far on the specifi- cation and analysis of discrete MARTE models. To address hybrid real-time and embedded systems, we propose to ex- tend statecharts using both MARTE and the theory of hybrid automata. We call this extension hybrid MARTE statecharts. It provides an improvement over the hybrid automata in that： the logical time variables and the chronometric time vari- ables are unified. The formal syntax and semantics of hybrid MARTE statecharts are given based on labeled transition sys- tems and live transition systems. As a case study, we model the behavior of a train control system with hybrid MARTE statecharts to demonstrate the benefit.

Through-polymer,via technology-enabled,flexible,lightweight,and integrated devices for implantable neural probes

In implantable electrophysiological recording systems,the headstage typically comprises neural probes that interface with brain tissue and integrated circuit chips for signal processing.While advancements in MEMS and CMOS technology have significantly improved these components,their interconnection still relies on conventional printed circuit boards and sophisticated adapters.This conventional approach adds considerable weight and volume to the package,especially for high channel count systems.To address this issue,we developed a through-polymer via(TPV)method inspired by the through-silicon via(TSV)technique in advanced three-dimensional packaging.This innovation enables the vertical integration of flexible probes,amplifier chips,and PCBs,realizing a flexible,lightweight,and integrated device(FLID).The total weight of the FLIDis only 25%that of its conventional counterparts relying on adapters,which significantly increased the activity levels of animals wearing the FLIDs to nearly match the levels of control animals without implants.Furthermore,by incorporating a platinum-iridium alloy as the top layer material for electrical contact,the FLID realizes exceptional electrical performance,enabling in vivo measurements of both local field potentials and individual neuron action potentials.These findings showcase the potential of FLIDs in scaling up implantable neural recording systems and mark a significant advancement in the field of neurotechnology.