Optimization of the N2 generation selectivity in aqueous nitrate reduction using internal circulation micro-electrolysis

The reduction of nitrate using internal circulation micro-electrolysis te chnology(ICE)was investigated.The effect of the reaction time,initial pH,Fe/C ratio,and aeration rate on the nitrate reduction was investigated using a single factor experiment.Based on the results of the single factor experiment,a response surface methodology(RSM)was applied to optimize the N2 generation selectivity.The effects and interactions of three independent variables were estimated using a Box-Behnken design.Using the RSM analysis,a quadratic polynomial model with optimal conditions at pH=8.8,Fe/C=1:1,and an aeration rate of 30 L·min-1 was developed by means of the regre ssion analysis of the experimental data.Using the RSM optimization,the optimal conditions yielded a N2 generation selectivity of 72.0%,which is in good agreement with experimental result(73.2%±0.5%)and falls within the 95%confidence interval(IC:66.8%-77.3%)of the model results.This indicates that the model obtained in this study effectively predicts the N2 generation selectivity for nitrate reduction by the ICE process,thus providing a theoretical basis for process design.

An internal circulation iron-carbon micro-electrolysis reactor for aniline wastewater treatment:Parameter optimization,degradation pathways and mechanism

Aniline is a vital industrial raw material.However,highly-toxic aniline wastewater usually deteriorated effluent quality,posed a threat to human health and ecosystem safety.Therefore,this study reported a novel internal circulation iron-carbon micro-electrolysis(ICE)reactor to treat aniline wastewater.The effects of reaction time,pH,aeration rate and iron-carbon(Fe/C)ratio on the removal rate of aniline and the chemical oxygen demand were investigated using single-factor experiments.This process exhibited high aniline degradation performance of approximately 99.86% under optimal operating conditions(reaction time=20 min,pH=3,aeration rate=0.5 m3·h^(-1),and Fe/C=1:2).Based on the experimental results,the response surface method was applied to optimize the aniline removal rate.The Box–Behnken method was used to obtain the interaction effects of three main factors.The result showed that the reaction time had a dominant effect on the removal rate of aniline.The highest aniline removal rate was obtained at pH of 2,aeration rate of 0.5 m^(3)·h^(-1)and reaction time of 30 min.Under optional experimental conditions,the aniline content of effluent was reduced to 3 mg·L^(-1)and the removal rate was as high as 98.24%,within the 95% confidence interval(97.84%-99.32%)of the predicted values.The solution was treated and the reaction intermediates were identified by high-performance liquid chromatography,ultraviolet-visible spectroscopy,Fourier-transform infrared spectroscopy,gas chromatography-mass spectrometry,and ion chromatography.The main intermediates were phenol,benzoquinone,and carboxylic acid.These were used to propose the potential mechanism of aniline degradation in the ICE reactor.The results obtained in this study provide optimized conditions for the treatment of industrial wastewater containing aniline and can strengthen the understanding of the degradation mechanism of iron-carbon micro-electrolysis.

Structural parameter optimization for novel internal-loop iron–carbon micro-electrolysis reactors using computational fluid dynamics

It is generally recognized that internal-loop reactors are well-developed mass and heat-transfer multiphase flow reactors. However, the internal flow field in the internal-loop reactor is influenced by the structure parameter of the reactor, which has a great effect on the reaction efficiency. In this study, the computational fluid dynamics simulation method was used to determine the influence of reactor structure on flow field, and a volume-offluid model was employed to simulate the gas–liquid, two-phase flow of the internal-loop micro-electrolysis reactor. Hydrodynamic factors were optimized when the height-to-diameter ratio was 4:1, diameter ratio was9:1, draft-tube axial height was 90 mm. Three-dimensional simulations for the water distributor were carried out, and the results suggested that the optimal conditions are as follows: the number of water distribution pipes was four, and an inhomogeneous water distribution was used. According to the results of the simulation,the suitable structure can be used to achieve good fluid mechanical properties, such as the good liquid circulation velocity and gas holdup, which provides a good theoretical foundation for the application of the reactor.

A parameterization scheme of vertical mixing due to inertial internal wave breaking in the ocean general circulation model

Based on the theoretical spectral model of inertial internal wave breaking （fine structure） proposed previ- ously, in which the effects of the horizontal Coriolis frequency component f-tilde on a potential isopycnal are taken into account, a parameterization scheme of vertical mixing in the stably stratified interior be- low the surface mixed layer in the ocean general circulation model （OGCM） is put forward preliminarily in this paper. Besides turbulence, the impact of sub-mesoscale oceanic processes （including inertial internal wave breaking product） on oceanic interior mixing is emphasized. We suggest that adding the inertial inter- hal wave breaking mixing scheme （F-scheme for short） put forward in this paper to the turbulence mixing scheme of Canuto et al. （T-scheme for short） in the OGCM, except the region from 15°S to 15°N. The numeri- cal results ofF-scheme by usingWOA09 data and an OGCM （LICOM, LASG/IAP climate system ocean model） over the global ocean are given. A notable improvement in the simulation of salinity and temperature over the global ocean is attained by using T-scheme adding F-scheme, especially in the mid- and high-latitude regions in the simulation of the intermediate water and deep water. We conjecture that the inertial internal wave breaking mixing and inertial forcing of wind might be one of important mechanisms maintaining the ventilation process. The modeling strength of the Atlantic meridional overturning circulation （AMOC） by using T-scheme adding F-scheme may be more reasonable than that by using T-scheme alone, though the physical processes need to be further studied, and the overflow parameterization needs to be incorporated. A shortcoming in F-scheme is that in this paper the error of simulated salinity and temperature by using T-scheme adding F-scheme is larger than that by using T-scheme alone in the subsurface layer.

Influence of external circulation on sludge characteristics during start-up of internal circulation reactor

The start-up of external circulationadded internal circulation(IC) reactor was finished in 26 d, 32 d fewer than that of IC reactor. To evaluate the influence of the added external circulation on the development of granular sludge, the characteristics of the granular sludge taken from the two tested laboratory-scale reactors during start-up were studied. The results show that the added external circulation can enhance biomass granulation, accelerate granule development and improve sludge characteristics. At the end of start-up, the granular size of sludge in external circulation-added IC reactor greatly increases with a size distribution much better than that of sludge in IC reactor. The granular sludge originated from external circulationadded IC reactor contains more extracellular polymers and has a greater settling velocity than that from IC reactor. Methanogenic activity of the granular sludge from the external circulationadded IC reactor started 26 d ago reaches 358.23mL·g -1 ·d -1 , 1.66 and 1.20 times as great as that of the sludge from the IC reactor started 26 d and 58 d ago respectively.

The internal circulations on internal mass transfer rate of a single drop in nonlinear uniaxial extensional flow

The internal flow of a droplet in the nonlinear extensional flow field will exhibit more than two internal circulations with the variation of nonlinear intensity(E).In this paper,the effect of positions and sizes of internal circulations on internal mass transfer rate of a single spherical droplet in a nonlinear extensional flow field is studied and compared with that in a linear extensional flow field.The simulation results show that when E≥0,there are two symmetrical internal circulations in the droplet,which is the same with that in a linear extensional flow.The limit value of mass transfer rate Sh is 15,which is equal to that in a linear extensional flow,no matter how large E is.When E≤-3/7,the number of internal flow circulation of a droplet increase to four and the transfer rate Sh increases.When E=-1,the maximum internal transfer rate Sh equals 30 which is twice of that in a linear extensional flow.The generation of new flow circulations in droplets and the circulation positions will enhance mass transfer when E≤-3/7,which provides a new idea for enhancing the internal mass transfer rate of droplets.

Treating Opaque Beer Wastewater Using a Novel Internal Circulation Membrane Bioreactor

An innovative internal circulation membrane bioreactor（ICMBR）treating traditional opaque beer brewery wastewater was introduced. Beer wastewater from Tianjin Huarun Brewhouse was taken as the influent. The removal efficiency of suspended solid, chemical oxygen demand, total nitrogen and ammonia nitrogen were studied with the changeable hard real time design method, organic loading rate and nutrition elements. The average percentage reduction in chemical oxygen demand achieved 90%. The total nitrogen and ammonia nitrogen were also reduced by 90% and 95%, respectively. The results indicate that the outlet of ICMBR meets the requirements of the environment landscape recycling use.

Influencing Factors of Rural Land Internal Circulation Market in Guangdong Province

The circulation of rural land is helpful to improving the allocation efficiency of land resources,increasing farmers'income and promoting the development of modern agriculture.In this paper,we used the social economy,the main participants and the market environment of rural land circulation to make a qualitative analysis for the factor of rural land internal circulation.With the aid of principal component analysis,grey correlation model,and other methods to make a quantitative analysis for the factor of rural land internal circulation.The results show that the grey correlation degrees of the output value of secondary and tertiary industries as a proportion of GDP,the expenditure on science and education per capita,the expenditure on financial support for agriculture,the proportion of non-agricultural population and the standardization of rural land circulation contracts are 0.8988,0.8382,0.7632 and 0.7576 respectively,indicating that these factors are significantly related to the rural internal land circulation market.

Optimization of the Internal Circulating Fluidized Bed Using Computational Fluid Dynamics Technology

The computational fluid dynamics(CFD)technology is analyzed and calculated utilizing the turbulence model and multiphase flow model to explore the performance of internal circulating fluidized beds(ICFB)based on CFD.The three-dimensional simulation method can study the hydrodynamic properties of the ICFB,and the performance of the fluidized bed is optimized.The fluidization performance of the ICFB is improved through the experimental study of the cross-shaped baffle.Then,through the cross-shaped baffle and funnel-shaped baffle placement,the fluidized bed reaches a coupled optimization.The results show that CFD simulation technology can effectively improve the mass transfer efficiency and performance of sewage treatment.The base gap crossshaped baffle can improve the hydraulic conditions of the fluidized bed and reduce the system energy consumption.The cross-shaped baffle and funnel-shaped baffle can perfect the performance of the reactor and effectively strengthen the treatment in the intense aerobic process of industrial sewage.

Idiopathic steno-occlusive disease with bilateral internal carotid artery occlusion:A Case Report

BACKGROUND Moyamoya disease(MMD)is a rare cause of acute stroke and transient ischemic attacks in children.We described clinical,diagnostic features and follow-ups of a young child with acute stroke.CASE SUMMARY We report a 4-year-old girl with left hemiparesis after an acute ischemic stroke.Her history was also significant for repeated left or right focal motor seizures,generalized tonic-clonic convulsions and transient ischemic attacks.Her magnetic resonance imaging and computed tomography(CT)of the brain and magnetic resonance angiography,CT angiography and venography on the cerebral vessels revealed evidence of bilateral fronto-parietal ischemic infarctions,occlusion of the right and left internal carotid arteries started at its bifurcation and non-visualization of right and left anterior and middle cerebral arteries.There was evidence of progression in angiography manifested as development of collaterals from the basal perforating vessels,increase in the extent of large intracranial arterial stenosis/occlusion and extensive collateral circulation with predominance from the posterior circulation.Physical and neurological evaluation and comprehensive laboratory investigations excluded an obvious comorbid disease or risk factor for the child’s condition.The diagnosis of MMD was highly suggested as a cause of the child’s steno-occlusive condition.She was treated symptomatically with levetiracetam,an antiepileptic medication.Aspirin was prescribed for secondary prevention.Her clinical manifestations were improved during the three years of follow-up.Revascularization surgery was postponed.CONCLUSION Up to our knowledge,this is the first report for MMD in a child in our country.The clinical improvement and the stabilization of the child’s condition over the 3 years of follow-up could be attributed to the rapid and extensive recruitment of collaterals and absence of risk factors or comorbidities.Revascularization surgery is highly recommended.

Influence of the Boundary Forcing on the Internal Variability of a Regional Climate Model

The internal variability of a ten-member ensemble of the regional climate model REMO over Europe is investigated. It is shown that the annual cycle of internal variability behaves differently compared to earlier studies that focused on other regions. To gain better insight into the dependence of the internal variability on the boundary forcing variability, a circulation type classification is performed on the forcing data. It can be shown that especially in the winter season internal variability is dependent on the circulation type included in the boundary forcing, whereas in the summer season the level and pattern of internal variability is rather independent from the circulation type of the driving field. It is concluded that for Europe the internal variability of REMO in winter is governed by circulation patterns related to the North-Atlantic Oscillation, whereas in summer local processes play a bigger role.

补气活血法应用于冠心病治疗的教学评价

目的分析中医补气活血法运用于冠状动脉粥样硬化性心脏病治疗中的教学评价情况。方法选择2021年9月—2022年9月滨州医学院烟台附属医院的实习生12人作为研究对象,分为对照组与观察组,对照组运用冠状动脉粥样硬化性心脏病传统教学模式,观察组运用中医补气活血法进行冠状动脉粥样硬化性心脏病教学,比较两组最终理论成绩以及对教学模式的满意度。结果观察组实习生最终的理论成绩高于对照组(P<0.05)。观察组对教学模式的总满意度为100.00%(6/6),高于对照组的50.00%(3/6)(P<0.05)。因此观察组应用的教学模式更容易受到实习生喜欢。结论在冠状动脉粥样硬化性心脏病治疗的教学中采取中医补气活血法,教学效果较好,受到了实习生的喜爱,且教学满意度较高,能有效提高实习生理论成绩。

Solids flow characteristics and circulation rate in an internally circulating fluidized bed

Internally circulating fluidized beds(ICFBs)enable effective control of the reactions and heat distribution in reactors.The ICFB contains two or more connected fluidized regions with different gas velocities to promote controlled solid circulation.The control of solid circulation rate(G_(0))is a critical factor.We recorded single particle trajectories by tracing a fluorescent particle,based on which particle flow behaviors were analyzed in different regions.G_(0)was obtained for a wide range of operating parameters.An increase in gas velocity in the down-and upflow beds shortened the particle circulation time in both beds and G_(0)increased significantly.As the static bed height increased,the differential pressure on both sides of the circulation port increased,which resulted in an increase in the solid circulation rate.As the orifice area increased,the flow resistance through the orifice decreased and thus the solid circulation rate increased.G_(0)increased with the decrease in particle size.The gas velocity in the upflowing bed and orifice area was the most important parameter to control the solid circulation rate.G_(0)was compared with the experimental measurements in literature and predictions using the correlation based on Bernoulli’s equation,and they agreed well.

中国锂矿的多旋回深循环内外生一体化成矿理论及其找矿应用

中国锂资源的分布具有卤水型与硬岩型相伴相随、若即若离的特点。“多旋回深循环内外生一体化”成锂理论,在多年三稀金属矿产找矿实践和理论研究的基础上不断丰富完善。中国锂矿的形成与“多旋回”构造运动密切相关,从前寒武纪到新生代均有成矿潜力,可构成一个完整的多旋回成矿谱系。锂的“深循环”,一是锂深度参与成岩成矿的物质循环;二是需要一个“圈闭”的构造背景将锂“捕获”以避免其过度分散,锂从开始加入到岩浆与最终定位的深度之差,是硬岩型锂矿成矿的关键之一,压差越大越有利于伟晶岩型锂矿的形成。大量锂矿实例显示锂的物质循环是“内外生一体化”的统一过程,高海拔地区(山上)的含锂地质体(花岗岩类甚至直接就是含锂矿床)经风化剥蚀之后,可能成为沉积型锂矿的物质来源之一;而富含锂的沉积岩经过埋藏、变质、深熔也可以形成含锂的岩浆岩、伟晶岩。我国西部塔里木盆地、四川盆地、扎布耶盆地及东部的江汉盆地、吉泰盆地、周田盆地等大小不一的盆地均含锂,而其周边造山带中也不同程度发育硬岩型锂矿,这就为区域找矿指明了方向。“多旋回深循环内外生一体化”成锂理论是三稀矿产成矿理论的重要组成部分,为我国锂矿找矿工作提供了指导和借鉴,在甲基卡、可尔因、阿尔金、幕阜山等锂矿矿集区的找矿实践中发挥了积极作用。

内循环与外循环互动:中美双循环路径的差异

构建新发展格局需要宏观大历史的比较视野。作为大国经济,中国发展的主线是以国内大循环促进国际大循环,美国发展的主线是以国际大循环促进国内大循环。当前,中美两国历史上第一次但可能不是最后一次,都站在了以国内大循环为主体的历史关口,都对国际大循环产生着重要乃至决定性的影响。作为负责任的全球利益攸关者,世界大国携手构建人类命运共同体乃是正途。

服务业开放、数字化赋能与国际循环质量提升

服务业高水平对外开放及数字赋能,是我国进一步提升国际循环质量和水平的重要内容,也是构建新发展格局的有力抓手。自改革开放以来,我国服务业开放已历经45年,但服务贸易发展不均衡不充分的特征依旧明显。从生产成本,贸易成本,贸易方式、贸易对象和贸易主体等层面,对我国服务贸易开放发展进行数字化赋能,现阶段仍存在政策性壁垒较高等问题。从全球价值链分工的视角看,继续逐步降低服务要素流动的政策性成本,能够从全球价值链分工地位、全球价值链参与的安全性与稳定性以及国际经贸规则制定中的话语权等方面,提升我国的国际循环质量。此外,数字技术的发展同样能够以独立或者与服务业开放互动的形式促进我国国际循环质量的提升。

五措并举提升大型仪器设备共享成效的探索

大型仪器设备是高校提高教学科研水平和人才培养质量的重要条件,是反映学校的综合实力和办学水平的重要指标。随着高等教育的发展,高校大型仪器设备的类型和数量在不断增加,由此也带来了重复购置、利用率低等问题。通过加大大型仪器设备信息化共享、加强大型仪器设备人员队伍建设、建立健全大型仪器设备共享机制、探索大型仪器全成本核算管理、强化大型仪器设备制度集成创新,形成以内循环为主、区域化为辅的共享模式,全面提升大型仪器设备共享实效。

“专业—技术—产业”双循环创新创业模式的生成机制及推进路径——在应用型高校中建设国家级创新创业学院的系统思考

专业是创新创业的基础,创新创业是专业的应用,专业教育与创新创业教育密不可分、互相促进。基于专业应用的高品质创新创业是面向产业需求和服务于产业发展的产业化创新创业,这种创新创业需要以专业技术作为中介。因此,构建以“专业—技术”为主线的校内循环体系和以“技术—产业”为主线的校外循环体系,是打破学校与产业壁垒、推动创新创业产业化的必然要求。在应用型高校中建设国家级创新创业学院强化示范引领,需要构建“专业—技术—产业”双循环创业模式,通过机制创新与路径优化,培育创新创业教育良好生态,推动创新创业教育高质量发展。

长江中游城市群交通一体化建设存在的问题与推进建议

交通一体化能促进生产要素高效流动与整合,有力推动区域经济与社会一体化发展和经济内循环顺利实现。长江中游城市群在交通一体化方面取得很大进展,不仅建立完备的由铁路、公路、地铁、航空、水运等运输方式组成的综合交通运输网络,而且在交通管理与服务方面实现一定程度的信息化与智能化。但长江中游城市群交通一体化建设存在政府与市场配合度不高,缺乏统一的跨区域整体规划和协调机制,各种交通方式互联互通效率低下,智能交通建设落后等困难与问题。可以通过提高政府一体化建设积极性与市场参与度,破除行政壁垒,建立一体化管理协调机制,发展多式联运促进互联互通,增强交通管理与服务的信息化和智能化建设等,进一步推进长江中游城市群交通一体化建设,以服务区域经济内循环和城市群的整体发展。

我国跨境电商服务行业发展趋势研究

近年来,跨境电商服务行业受到了广泛关注。新时期,企业成本结构发生了较大变化、行业合规化趋势愈演愈烈,供需关系也发生了深刻变革。跨境服务商通过跨地区、多平台的形式不断拓宽业务范围,提升服务价值内涵,巩固自身竞争地位。此外,当前TikTok平台的流行和语言障碍的破除为跨境服务商提供了新的发展机遇。相关服务商依托专业资源为跨境卖家创造和传递价值,探索跨境电商共赢模式。同时,服务商还通过创新的技术和服务,为卖家提供更高效、更便捷的服务,帮助卖家降低成本、提高效率。综上,服务商在跨境电子商务领域中扮演着越来越重要的角色,为卖家提供了更多的机会和更好的服务。