Continuous-flow electrosynthesis of urea and oxalic acid by CO_(2)-nitrate reduction and glycerol oxidation

Urea and oxalic acid are critical component in various chemical manufacturing industries.However,achieving simultaneous generation of urea and oxalic acid in a continuous-flow electrolyzer is a challenge.Herein,we report a continuous-flow electrolyzer equipped with 9-square centime-ter-effective area gas diffusion electrodes(GDE)which can simultaneously catalyze the glycerol oxidation reaction in the anode region and the reduction reaction of CO_(2) and nitrate in the cathode region,producing oxalic acid and urea at both the anode and cathode,respectively.The current density at low cell voltage(0.9 V)remained above 18.7 mA cm^(-2) for 10 consecutive electrolysis cycles(120 h in total),and the Faraday efficiency of oxalic acid(67.1%) and urea(70.9%)did not decay.Experimental and theoretical studies show that in terms of the formation of C-N bond at the cathode,Pd-sites can provide protons for the hydrogenation process of CO_(2) and NO_(3)^(-),Cu-sites can promote the generation of *COOH and Bi-sites can stabilize *COOH.In addition,in terms of glycerol oxidation,the introduction of Cu and Bi into Pd metallene promotes the oxidation of hydroxyl groups and the cleavage of C-C bond in glycerol molecules,respectively.

Recent advances in design of hydrogen evolution reaction electrocatalysts at high current density:A review

The electrolysis of water powered by renewable energy sources offers a promising method of"green hydrogen"production,which is considered to be at the heart of future carbon-neutral energy systems.In the past decades,researchers have reported a number of hydrogen evolution reaction(HER)electrocatalysts with activity comparable to that of commercial Pt/C,but most of them are tested within a small current density range,typically no more than 500 mA cm^(-2).To realize the industrial application of hydrogen production from water electrolysis,it is essential to develop high-efficiency HER electrocatalysts at high current density(HCD≥500 mA cm^(-2)).Nevertheless,it remains challenging and significant to rational design HCD electrocatalysts for HER.In this paper,the design strategy of HCD electrocatalysts is discussed,and some HCD electrocatalysts for HER are reviewed in seven categories(alloy,metal oxide,metal hydroxide,metal sulfide/selenide,metal nitride,metal phosphide and other derived electrocatalysts).At the end of this article,we also pro-pose some viewpoints and prospects for the future development and research directions of HCD electrocatalysts for HER.

Enhancing photo-generated carriers transfer of K-C_(3)N_(4)/UiO-66-NH_(2) with Er doping for efficient photocatalytic oxidation of furfural to furoic acid

Biomass-derived platform molecules,such as furfural,are abundant and renewable feedstock for valuable chemical production.It is critical to synthesize highly efficient photocatalysts for selective oxidation under visible light.The Er@K-C_(3)N_(4)/UiO-66-NH_(2) catalyst was synthesized using a straight-forward hydrothermal technique,and exhibited exceptional efficiency in the photocatalytic oxidation of furfural to furoic acid.The catalyst was thoroughly characterized,confirming the effective adjustment of the band gap energy of Er@K-C_(3)N_(4)/UiO-66-NH_(2).Upon the optimized reaction conditions,the conversion rate of furfural reached 89.3%,with a corresponding yield of furoic acid at 79.8%.The primary reactive oxygen species was identified as·O_(2)^(-) from ESR spectra and scavenger tests.The incorporation of Er and K into the catalyst enhanced the photogenerated carriers transfer rate,hence increasing the separating efficiency of photogenerated electron-hole pairs.This study expands the potential applications of rare earth element doped g-C_(3)N_(4) in the photocatalytic selective oxidation of furfurans.

Clinical and experimental investigations into the immune modulatory effects of Qianjinba polysaccharides on a rheumatoid arthritis mouse model:in vivo and in vitro studies

Qianjinba is derived from the dried root of a legume vine and is known for its plant polysaccharide,which has demonstrated anti-inflammatory,analgesic,and neuroprotective properties.Despite these known effects,its immunomodulatory potential remains underexplored.This study aimed to investigate the immunoregulatory effects of Qianjinba polysaccharide(QJBDT)in a murine model of rheumatoid arthritis(RA)and elucidate its mechanism of action in inhibiting the disease.To assess the immunomodulatory effects,RAW264.7 macrophage cells were stimulated with bacterial lipopolysaccharide(LPS)and subsequently treated with varying concentrations of QJBDT or total glucoside of paeonic acid(TGP).Cell proliferation and the expression levels of mitogen-activated protein kinase p38 and nuclear factor NF-κB proteins were evaluated.Following the successful modeling of RA in mice,different doses of QJBDT and TGP were administered via intragastric administration once daily for 21 d.Mice were divided into normal,model,QJBDT low-,medium-,and high-dose groups,along with a positive control group(TGP group),each comprising 10 mice.Organ coefficients were calculated,immune indexes in blood cells were determined,and alterations in T helper cell 17(Th17)and regulatory T cells(Treg)were analyzed using flow cytometry.Compared to the normal group,cell proliferation rates significantly increased across all groups(P<0.05).Elevated expressions of p38 and NF-κB proteins were observed in the model group,QJBDT low-and medium-dose groups(P<0.05).Various systemic immune inflammation indexes,including systemic immune inflammation index(SII),total inflammation systemic index(AISI),and systemic inflammation response index(SIRI),platelet-to-lymphocyte ratio(PLR),neutrophil-to-lymphocyte ratio(NLR),monocyte-to-lymphocyte ratio(MLR),showed increments(P<0.05).Additionally,body weight and organ coefficients of the thymus,spleen,and liver decreased in both the model and low-dose groups(P<0.05).Moreover,Th17 levels increased while Treg levels decreased across all groups(P<0.05),resulting in a heightened Th17 to Treg ratio in the model and low-dose groups(P<0.05).Notably,the QJBDT medium-dose,high-dose,and positive control groups demonstrated significant inhibitory effects on cell proliferation compared to the model group(P<0.05),along with reduced expression levels of p38 and NF-κB(P<0.05).Furthermore,various immune indicators from routine blood tests exhibited different degrees of decrease(P<0.05),while immune indices displayed increases(P<0.05).The low-,medium-,and high-dose groups of QJBDT,as well as the positive control group,showed decreased Th17 levels,elevated Treg levels,and diminished Th17 to Treg ratios(P<0.05).Additionally,there was no statistically significant difference in efficacy between the QJBDT high-dose and TGP groups(P>0.05).In conclusion,this study demonstrated that QJBDT exerted potent immunomodulatory effects on RA in mice in a dose-dependent manner.Its mechanism of action might involve the inhibition of NF-κB activation by suppressing the p38 MAPK signaling pathway.

Quantifying the Effects of Near-Surface Viscosity on Seismic Acquisition Geometry: A case study from Chepaizi Exploration Area, Junggar Basin (NW China)

The Chepaizi Exploration Area,Junggar Basin(NW China)holds substantial importance for seismic exploration endeavors,yet it poses notable challenges due to the intricate nature of its subsurface and near-surface conditions.To address these challenges,we introduce a novel and comprehensive workflow tailored to evaluate and optimize seismic acquisition geometries while considering the impacts of near-surface viscosity.By integrating geological knowledge,historical seismic data,and subsurface modeling,we conduct simulations employing the visco-acoustic wave equation and reverse-time migration to produce detailed subsurface images.The quality of these images is quantitatively evaluated using a local similarity metric,a pivotal tool for evaluating the accuracy of seismic imaging.The culmination of this workflow results in an automated optimization strategy for acquisition geometries that enhances subsurface exploration.Our proposed methodology underscores the importance of incorporating near-surface viscosity effects in seismic imaging,offering a robust framework for improving the accuracy of subsurface imaging.Herein,we aim to contribute to the advancement of seismic imaging methodologies by providing valuable insights for achieving high-quality seismic exploration outcomes in regions characterized by complex subsurface and near-surface conditions.

Why the abnormal phenomena of D-band center theory exist?A new BASED theory for surface catalysis and chemistry

Since the D-band center theory was proposed,it has been widely used in the fields of surface chemistry by almost all researchers,due to its easy understanding,convenient operation and relative accuracy.However,with the continuous development of material systems and modification strategies,researchers have gradually found that D-band center theory is usually effective for large metal particle systems,but for small metal particle systems or semiconductors,such as single atom systems,the opposite conclusion to the D-band center theory is often obtained.To solve the issue above,here we propose a bonding and anti-bonding orbitals stable electron intensity difference(BASED)theory for surface chemistry.The newly-proposed BASED theory can not only successfully explain the abnormal phenomena of D-band center theory,but also exhibits a higher accuracy for prediction of adsorption energy and bond length of intermediates on active sites.Importantly,a new phenomenon of the spin transition state in the adsorption process is observed based on the BASED theory,where the active center atom usually yields an unstable high spin transition state to enhance its adsorption capability in the adsorption process of intermediates when their distance is about 2.5Å.In short,the BASED theory can be considered as a general principle to understand catalytic mechanism of intermediates on surfaces.

Preparation and electromagnetic shielding properties of PET/rGO/SWCNT composite fabric

Graphene oxide(GO)with excellent dispersion ability can assist the dispersion of single-walled carbon nanotube(SWCNT)and promote the formation of uniform and stable GO/SWCNT coating liquid.The highly conductive polyethylene terephthalate/reduced graphene oxide/SWCNT(PET/rGO/SWCNT)electromagnetic shielding composite fabric was successfully prepared by anchoring rGO/SWCNT on PET fabric via dip-coating piror to low-temperature thermal reduction.The results showed that the carboxyl groups and hydroxyl groups formed of hydrophilic-treated PET were conducive to the formation of hydrogen bonds with that of GO,which enhanced the interaction between PET fabric and GO/SWCNT coating;the loading of GO/SWCNT increased with the number of dip-coating,the unit area loading of rGO/SWCNT in the final composite fabric was 2.7 mg/cm^(2) after 10 dip-coating cycles and thermal reduction;the PET/rGO/SWCNT composite fabric had a continuous and dense conductive network,with a conductivity of up to 41.6 S/m and the average electromagnetic interference shielding effectiveness in X-band was 22 dB;the flexible PET/rGO/SWCNT composite fabric was not only easy to process,but also exhibited excellent conductivity and shielding efficiency,showing great potential in the application of electromagnetic shielding fabrics.

Supported Ziegler-Natta catalysts from MgCl_(2)·nROH precursors and its catalytic behaviors for diene copolymerization

Heterogeneous TiCl4/MgCl_(2) type Ziegler-Natta(Z-N)catalysts with unique advantages like low cost,high activity,high stereoregularity and pretty particle morphology,contribute to more than 130 Mt polyolefin large-scale production.However,most researches related with heterogeneous Z-N catalysts focused onα-olefin polymerizations like ethylene,propylene,etc.

Efficient in-situ end-functionalization of polydienes by isothiocyanate via neodymium mediated coordinative chain transfer polymerization system

End-functionalization of polydiene rubbers can not only improve its compatibility with inorganic fillers,but also enhance the overall mechanical properties.Nevertheless,for traditional neodymium(Nd)diene polymerization systems,it is highly challenging to achieve such end-functionalizations,because most of polydienyl chains are capped withη3-allyl-Nd moiety during the end of polymerization,which shows very poor reactivity with nucleophile compounds.We launched a new diene polymerization strategy calling coordinative chain transfer polymerization(CCTP)[1].In such a system,all the polydienyl chains are capped withη1-allyl-Al moieties,which reveal greater reactivity with cyclic esters and epoxide compounds,providing an effective manner to prepare polydiene-polyester amphiphilic block copolymers.Inspired by such findings,we now show herein how such types of chain-ends react with isot-hiocyanate to demonstrate an efficient in-situ manner to access end-functionalized polydienes by using CCTP.

Influence of external nitrogen-containing donors on polymerization behavior of neodymium-based cis-1,4-polybutadiene rubber

Neodymium(Nd)-based catalyst in butadiene(Bd)polymerization has drawn interests due to its availability in affording higher cis-1,4-unit selectivity than transition metal(Ti,Co,Ni,etc.)-based catalysts[1-2].Such outstanding high cis-1,4-unit selecti-vity is hypothetically originated from the presence of 4 f orbitals,that can participate in monomer coordination and thereby govern subsequent enchainment manners.This unique characteristic also renders the active species highly susceptible to Lewis bases,and may impact the overall selectivity as well as polyme-rization behavior after coordination.Nevertheless,it is still a virgin area in such a field,and the influence of Lewis bases on Nd-based diene polymerizations is still a black box.Based on this consideration,how nitrogen-containing donors(D)impacts the overall behaviors of Nd-mediated Bd polymerizations is disclosed.

青岛红卍字会附设慈济院初探

青岛红卍字会附设慈济院是民间慈善机构附属的行慈机构，内部机构完备，基金来源渠道多样，进行永久性慈业，涵盖了专门性救济、慈善教育、慈善治疗、慈善救济等慈善活动，客观促进了青岛慈善救助事业的发展。

基于EVA模型的企业价值评估

随着互联网行业的快速发展,我国网民数量也在同步增加,该行业对我国民众生活及资本市场的影响正逐渐扩大。因此,对互联网公司进行估值研究显得尤为重要。本文选取网易公司作为研究对象,通过EVA模型对网易公司进行企业价值评估,并将评估值与公司市场价值进行比较,验证模型的有效性,同时提出相应的建议。

我国老年人数字融入困境反思

数字融入既是行动和过程,又是一种状态和目标。数字媒体技术为生活质量的提高带来极大的正向反馈,而纵观当下人口老龄化趋势,老年群体已成为巨大“数字浪潮”中的弱势群体,数字融入过程更明显地体现为被动接受,具有较少的主动性。本文以积极老龄化新发展理念为背景,针对我国老年人数字融入现状,通过回顾数字融入与数字鸿沟的概念,分析问题成因、可介入路径,并结合后疫情时代现实视角,总结现实困境,提出创新之路与若干思考。

家庭农场采纳数字技术影响因素研究

本文利用扎根理论,对实地调研结果和有关文献进行编码,构建“数字技术认知-数字技术知识获取-数字技术采纳决策”故事线,将家庭农场采纳数字技术的影响因素对应这三个阶段。研究表明:政府和数字技术供给方对数字技术宣传的全面性和真实性是在数字认知阶段的重要影响因素;在数字技术知识获取阶段,农户个人禀赋、财政投入、培训质量、优质人才数量和数字技术的易用性等因素影响着农户获取数字技术知识的效果;在数字技术采纳决策阶段,影响因素有自然环境、基础设施、个体偏好、农场资源禀赋、数字技术成熟度、使用保障、示范作用等。探究家庭农场采纳数字技术的影响因素,以助力农业现代化发展。

孵化基地与科技型小微企业融合发展研究

在移动互联网时代,创新管理成为科技型企业推动区域经济和社会发展的核心。新型孵化基地建设是激发小微企业参与创新、实现创业的有效平台,也是科技型小微企业生存与发展的摇篮。本文从科技型小微企业的特点和孵化基地的内涵导入,提出孵化基地孵化科技型小微企业的机制和模式,并提出孵化基地和科技型小微企业融合协调发展建议。

新零售企业融资风险控制研究

近年来,新零售模式发展迅速,企业在飞快发展的同时,因高额负债与轻资产的模式带来一定的风险,也因此加大新零售企业在取得融资以及管理融资方面上的难度。并且,由于新零售模式具有快速成长、大量投入、受市场影响较大等独特特征,比传统企业有着较低的融资风险。因此,对新零售企业的融资风险进行精确度量,采取合理有效的应对措施,就显得尤为重要。

净矿出让模式与用地要素保障问题探析

净矿出让是我国矿产资源有偿使用过程中的一项重大制度创新。从2019年全国试点以来,各地积极探索创新工作体制机制、优化行政审批流程、做好矿业权用地用林等要素保障、强化全过程信用监管、完善矿业权所在地群众收入分配方式,成为落实和深化国家“放管服”改革的重要举措,又是服务矿产资源管理的具体抓手。本文通过政策梳理和问题分析,总结净矿出让流程,分析当前用地要素保障问题,提出优化矿产处置、用地保障与监督管理建议。认为“净矿”出让制度模式是理清市场与政府公共服务的边界;应推进各类规划、政策的融合与衔接,统筹矿业权选址与布局;应兼顾各方利益,助力乡村振兴;兼顾矿产、土地资源全周期的综合利用与保护模式。探索和推进采矿权净矿出让制度改革,建立采矿权、土地使用权明晰的产权制度,以维护全民所有资源资产权益,处理好自然资源资产的合理利用与保护的各种矛盾和问题。

“公司+农户”型股份合作社权利制衡思考

“公司+农户”型股份合作社中社员与股东共存,利润和盈余共存,股份合作社应主要按公司化模式运营,股东应享有按股分红的权利和主导决策的权利。为保障社员利益,制衡大股东权利,应由社员按照一人一票的原则,选举至少一名社员理事和监事。社员应享有按交易量返还盈余的权利及通过社员代表参与决策的权利。利润主要归股东所有,盈余主要归社员所有。

谈灾害会计

近年来,随着人类对环境资源的过度开发利用,可能会导致自然灾害渐渐频发,因此有必要将经济发展、灾害管理与会计研究结合在一起作为研究灾害会计的基础。国外对于灾害会计早期的研究主要集中于政府间对灾害应急方面的管理,以及对灾害的法规制度以及灾害的保险;国内对于灾害会计研究较晚,还存在着法律法规不完善,缺乏统一的标准等问题,因此需要继续健全相关法律法规,制定相对统一的标准。

“三权分置”下农村土地经营权流转法律规制

随着我国乡村振兴战略的深入发展,农村土地经营权流转中暴露出一系列问题,因而对农村土地经营权流转进行法律规制尤为必要。在现行法律秩序下,通过健全相关法律制度、强化流转全过程监管、提升法律规范意识等举措,不断激发农村土地经营权的内生动力,释放农村基本经营制度的持久活力,进一步优化农村土地权利与资源合理配置,为乡村振兴取得决定性进展、农业农村现代化基本实现提供坚实的法律与制度保障。