Defective Nickel-Iron Layered Double Hydroxide for Enhanced Photocatalytic NO Oxidation with Significant Alleviation of NO2 Production

Photocatalysis offers a sustainable means for the oxidative removal of low concentrations of NOx(NO,NO2,N2O,N2O5,etc.)from the atmosphere.Layered double hydroxides(LDHs)are promising candidate photocatalysts owing to their unique layered and tunable chemical structures and abundant surface hydroxide(OH)moieties,which are hydroxyl radical(OH)precursors.However,the practical applications of LDHs are limited by their poor charge-separation ability and insufficient active sites.Herein,we developed a facile N_(2)H_(4)-driven etching approach to introduce dual Ni^(2+)and OHvacancies(Niv and OHv,respectively)into NiFe-LDH nanosheets(hereafter referred to as NiFe-LDH-et)to facilitate improved charge-carrier separation and active Lewis acidic site(Fe^(3+)and Ni^(2+)exposed at OHv)formation.In contrast to inert pristine LDH,NiFe-LDH-et actively removed NO under visible-light illumination.Specifically,Ni_(76)Fe_(24)-LDH-et etched with 1.50 mmol·L^(-1)N_(2)H_(4)solution removed 32.8%of the NO in continuously flowing air(NO feed concentration:500 parts per billion(ppb))under visible-light illumination,thereby outperforming most reported catalysts.Experimental and theoretical data revealed that the dual vacancies promoted the production of reactive oxygen species(O_(2)·^(-)andOH)and the adsorption of NO on the LDH.In situ spectroscopy demonstrated that NO was preferentially adsorbed at Lewis acidic sites,particularly exposed Fe^(3+)sites,converted into NO+,and subsequently oxidized to NO3without the notable formation of the more toxic intermediate NO2,thereby alleviating risks associated with its production and emission.

Diagnostic capability of peripapillary retinal nerve fiber layer parameters in time-domain versus spectral-domain optical coherence tomography for assessing glaucoma in high myopia

AIM： To evaluate and compare the diagnostic capabilities of peripapillary retinal nerve fiber layer（p-RNFL） parameters of Spectralis optical coherence tomography（OCT） versus Stratus OCT to detect glaucoma in patients with high myopia. METHODS： This is a retrospective, cross-sectional study. Sixty highly myopic eyes of 60 patients were enrolled, with 30 eyes in the glaucoma group and 30 eyes in the control group. All eyes received peripapillary imaging of the optic disc using Stratus and Spectralis OCT. Areas under the receiver operating characteristic curve（AUROC） and the sensitivity at specificity of 〉80% and 〉95% for p-RNFL parameters obtained using the two devices to diagnose glaucoma were analysed and compared. RESULTS： In Spectralis OCT, p-RNFL thickness parameters with the largest AUROC were the temporal-inferior sector（0.974） and the inferior quadrant（0.951）, whereas in Stratus OCT, the best parameters were the 7-o＇clock sector（0.918） and the inferior quadrant（0.918）. Compared to the Stratus OCT parameters, the Spectralis OCT parameters demonstrated generally higher AUROC; however, the difference was not statistically significant. CONCLUSION： The best p-RNFL parameters for diagnosing glaucoma in patients with high myopia were the temporal-inferior sector on Spectralis OCT and the 7-o＇clock sector on Stratus OCT. There were no significant differences between the AUROCs for Spectralis OCT and Stratus OCT, which suggest that the glaucoma diagnostic capabilities of these two devices in patients with high myopia are similar.

Atomic layer deposition of TiO_(2) on carbon-nanotubes membrane for capacitive deionization removal of chromium from water

Chromium(Cr)is a common heavy metal that has severe impacts on the ecosystem and human health.Capacitive deionization(CDI)is an environment-friendly and energy-efficient electrochemical purification technology to remove Cr from polluted water.The performance of CDI systems relies primarily on the properties of electrodes.Carbon-nanotubes(CNTs)membranes are promising candidates in creating advanced CDI electrodes and processes.However,the low electrosorption capacity and high hydrophobicity of CNTs greatly impede their applications in water systems.In this study,we employ atomic layer deposition(ALD)to deposit TiO_(2) nanoparticulates on CNTs membranes for preparing electrodes with hydrophilicity.The TiO_(2)-deposited CNTs membranes display preferable electrosorption performance and reusability in CDI processes after only 20 ALD cycles deposition.The total Cr and Cr(VI)removal efficiencies are significantly improved to 92.1%and 93.3%,respectively.This work demonstrates that ALD is a highly controllable and simple method to produce advanced CDI electrodes,and broadens the application of metal oxide/carbon composites in the electrochemical processes.

Recent advances in the detection and removal of heavy metal ions using functionalized layered double hydroxides:a review

Heavy metal pollution is one of the most severe environmental problems,possessing high ecotoxicity and health risk.Therefore,it is important to develop effective methods and corresponding materials for the detection and removal of heavy metals.Recent studies reveal the great potential of layered double hydroxides(LDHs)in detecting and removing heavy metals owing to their designable structure and tunable surface composition.In this review,we majorly discuss the recently adopted detection and removal of heavy metal ions based on LDHs.This review starts with an introduction of the structural characteristics and functionalization of LDHs.Then,the sensing tactics and mechanisms are introduced regarding LDHbased heavy metal ion detection.Based on the type of interaction,the removal of heavy metal ions with LDHs is summarized into two categories:reversible adsorption and irreversible mineralization.This review ends with a discussion on the challenges and future trends of LDH-based detectors and adsorbents for heavy metal ions.

MODIFIED LAYER REMOVAL METHOD FOR MEASUREMENT OF RESIDUAL STRESS DISTRIBUTION IN THICK PRE-STRETCHED ALUMINUM PLATE

The integrated structure parts are widely used in aircraft. The distortion caused by residual stresses in thick pre-stretched aluminum plates during machining integrated parts is a common and serious problem. To predict and control the machining distortion, the residual stress distribution in the thick plate must be measured firstly. The modified removal method for measuring residual stress in thick pre-stretched aluminum plates is proposed and the stress-strain relation matrix is deduced by elasticity theory. The residual stress distribution in specimen of 7050T7451 plate is measured by using the method, and measurement results are analyzed and compared with data obtained by other methods. The method is effective to measure the residual stress.

Initial residual stress experiment and simulation of thin-walled parts for layer removal method

Thin-walled parts have low stiffness characteristic. Initial residual stress of thin-walled blanks is an important influence factor on machining stability. The present work is to verify the feasibility of an initial residual stress measurement of layer removal method. According to initial residual stress experiment for casting ZL205 A aluminum alloy tapered thin-walled blank by a common method,namely hole-drilling method,three finite element models with initial residual stress are established to simulate the layer removal method in ABAQUS and ANSYS software. By analyzing the results of simulation and experiments,the cutting residual stress inlayer removal process has a significant effect on measurement results. Reducing cutting residual stress is helpful to improve accuracy of layer removal method.

Modified Layer-Removal Method for Measurement of Residual Stress in Pre-stretched Aluminium Alloy Plate

Residual stress is one of the factors affecting the machining deformation of monolithic structure parts in the aviation industry. Thus, the studies on machining deformation rules induced by residual stresses largely depend on correctly and efficiently measuring the residual stresses of workpieccs. A modified layer-removal method is proposed to measure residual stress by analysing the characteristics of a traditional, layer-removal method. The coefficients of strain release are then deduced according to the simulation results using the finite element method （FEM）. Moreover, the residual stress in a 7075T651 aluminium alloy plate is measured using the proposed method, and the results are then analyzed and compared with the data obtained by the traditional methods. The analysis indicates that the modified layer-removal method is effective and practical for measuring the residual stress distribution in pre-stretched aluminium alloy plates.

基于CANoe的UDS诊断网络层测试方法

在UDS诊断协议栈设计过程中,网络层设计是否满足要求,影响数据传输的实时性,对诊断测试结果有很大影响。为了验证网络层数据传输实时性是否满足要求,在CANoe软件的基础上设计了UDS诊断网络层自动化测试平台。经整车厂实际项目验证,设计的网络层自动化测试平台满足测试要求,通过了测试认证,得到了整车厂的认可。

去除凋落物和草毡层对寒温带典型森林土壤活性有机碳的短期影响

[目的]探究去除凋落物和草毡层对寒温带森林土壤活性有机碳的影响,为我国寒温带森林土壤碳循环的研究提供科学参考。[方法]以大兴安岭北部3种典型森林(白桦林、樟子松林和兴安落叶松林)为研究对象,在3种林型中设置对照、去除凋落物、去除草毡层以及去除凋落物和草毡层4种处理,于2021年9月对各处理不同土层(0—10 cm和10—20 cm)土壤进行取样,研究其土壤活性有机碳组分及其影响因子。[结果]在0—10 cm土层,与对照相比,去除凋落物后土壤可溶性有机碳和易氧化有机碳含量在白桦林和樟子松林中无显著变化,而在兴安落叶松林中显著降低了25.49%和39.40%;土壤微生物量碳含量在白桦林和兴安落叶松林中显著降低了19.26%和18.86%,而在樟子松林中无显著变化。去除草毡层后土壤可溶性有机碳和易氧化有机碳含量在白桦林和樟子松林中显著降低了16.08%,60.69%和17.38%,17.33%,而在兴安落叶松林中的变化不显著;土壤微生物量碳含量在3种林型中显著降低了19.47%~42.02%。同时去除凋落物和草毡层后3种林型土壤微生物量碳和易氧化有机碳含量极显著降低了22.03%~27.01%和52.22%~57.01%;土壤可溶性有机碳含量降低了11.25%~22.18%,其中白桦林和樟子松林达显著水平;在10—20 cm土层,不同去除处理对3种林型土壤可溶性有机碳和微生物量碳含量均无显著影响,白桦林和樟子松林土壤易氧化有机碳含量分别在去除草毡层以及同时去除凋落物和草毡层后显著降低,而兴安落叶松林土壤易氧化有机碳含量无明显变化。3种林型土壤活性有机碳各组分与土壤总有机碳、全氮、含水量呈显著正相关,与土壤pH则呈显著负相关。[结论]去除凋落物和草毡层降低了土壤活性有机碳含量,凋落物和草毡层的存在有利于土壤活性有机碳的形成与累积。

榆树林油田CCUS采油工程方案优化设计与实践

大庆榆树林油田扶杨油层属低孔、特低渗透储层,针对以往开发过程中存在注水困难、压裂有效期短、水驱开发难以有效动用的问题,开展CO_(2)驱油技术现场试验。从经济性、技术适应性、配套工艺成熟性等角度对采油工程方案进行综合评价,优选出单、双管分层注入工艺、高气液比举升工艺、注采两端个性化防腐工艺及物理化学组合解冻堵工艺等CCUS采油工程技术。结果表明:试验区投产初期及目前生产情况均达到了油藏预测指标;采出井平均泵效及检泵周期与外围油田平均水平相持平,注气井与采出井腐蚀速率小于行业指标;实现CO_(2)有效埋存108.9×10^(4) t,比水驱预测采出程度提高采收率4.39百分点,取得较好的驱油开发效果。研究成果为CCUS示范区的高效建设提供了技术支撑,开辟了大庆油田外围难采储量有效动用的新途径。

基于荷电状态一致性的电池组双层动态均衡方法

针对储能系统中电池组充放电过程中能量利用率以及系统运行安全性较低的问题,提出考虑SOC一致性的电池组双层动态均衡方法。首先,采用耦合电感与Flyback变换器搭建均衡系统双层架构,建立电池组端电压、均衡电流及占空比间的关联特性。为提高电池组的供能可靠性,系统引入故障切除功能,通过改变开关阵列导通状态实现故障电池组的快速切除;其次,考虑增补电池组剩余容量较大问题,利用传统最值法改进的双层极值法,以荷电状态(stage of charge,SOC)作为均衡目标变量,对增补电池组进行快速放电均衡;最后,设计充放电及静置均衡实验,对比传统最值法,分析常态及故障切除后电路的均衡速度与均衡效率。结果表明,提出的双层均衡方法可以将均衡速度提升约10%,且故障切除后电路的均衡效率最高可达95%以上。

基于胡麻油工作液电火花成形加工可行性研究

传统的电火花工作液煤油或碳氢矿物油等,存在加工效率低、表面质量差且环境污染和资源消耗等问题。而绿色可持续制造也是当今发展的主要趋势。因此文章提出利用植物油胡麻油为工作液在电火花成形加工中的实验研究,旨在实现绿色可持续电火花加工。研究响应参数电流、脉冲宽度和间隙电压对材料去除率,表面粗糙度值,表面质量的影响规律。实验结果表明,胡麻油在电火花加工过程中表现出显著的性能优势。胡麻油为工作液时,材料去除率显著提高,可获得更好的加工表面,表面裂纹明显减少,重铸层厚度更薄。说明胡麻油具有代替传统工作液的潜质,有望进一步促进绿色电火花加工技术的发展和应用。

深翻耕-起高垄对镉污染酸紫泥田修复效果的研究

通过大田配对试验,研究了常规耕作和深翻耕—起高垄耕作对土壤—作物的降Cd效果。结果表明:与常规耕作相比,深翻耕—起高垄处理的油菜生物量、Cd富集量和植株Cd的移除率分别提高了22%~39%、28%~180%和56%,后茬水稻茎叶、根的Cd含量和富集系数也分别提高了28%~57%、27%~50%,糙米Cd含量显著降低了42%。此外,深翻耕—起高垄处理0~30 cm土壤中的总Cd含量降低了11%~56%,15~30 cm土壤二乙烯三胺五乙酸提取态Cd(DTPA-Cd)含量也显著降低了59%。糙米Cd含量与土壤DTPA-Cd含量、植株Cd富集转运系数呈显著相关。水田旱作季应用深翻耕—起高垄耕作措施,可能通过提高油菜Cd的移除率,降低了土壤总Cd、Cd生物有效性和水稻Cd转运,从而降低糙米Cd含量。

激光清洗技术在半潜式平台分层除漆中的应用

应用1064 nm纳秒脉冲光纤激光器对半潜式平台零部件分层除漆进行研究,探究不同激光工艺参数对分层除漆效果的影响。结果表明,填充间距对分层除漆效果影响显著,除漆参数存在最佳匹配,最佳参数可实现漆层以底漆、中涂漆、面漆之间层次距离约1 cm,以破损点为中心清理出清晰的台阶结构,且激光清洗后基材无烧蚀和氧化变色,表面等级可达Sa2.5。激光除漆前后基材表面粗糙度均在20μm左右。对激光除漆过程进行温升检测,发现除漆过程基材温升为60~65℃,此温升不会改变基材组织结构。因此,激光用于半潜式平台分层除漆是可行的。所作研究为激光清洗在海洋工程领域的应用提供基础。

适合延长油田低渗透储层分层注水井的有机酸解堵体系

为了解决延长油田低渗透储层分层注水井注入压力升高以及注水量下降的问题,以复合有机酸FH-S为主体酸液,结合黏土稳定剂、缓蚀剂和助排剂等主要处理剂,研制了一套适合延长油田低渗透储层分层注水井的有机酸解堵体系,室内对其基本性能和岩心驱替解堵性能进行了评价。结果表明:有机酸解堵体系具有良好的溶蚀性能、缓蚀性能和较强的铁离子稳定能力,降低表面张力和界面张力的效果也较好,体系与地层水的配伍性较好,不会出现浑浊和沉淀;另外,在天然岩心被注入水污染后挤入2 PV有机酸解堵体系,能够有效解除堵塞污染,岩心驱替压力明显降低,岩心渗透率恢复值可以达到100%以上,解堵效果较好。现场应用结果表明:目标注水区块5口注水井采取有机酸解堵体系施工措施后,注入压力显著降低,日注水量明显增大,并且措施的有效期较长,取得了良好的现场施工效果。

层状双金属氢氧化物(LDH)去除磷酸盐的性能研究

我国水体特别是湖泊的富营养化与氮磷营养盐的超标排放有关.如果集中式污水处理厂的除磷效果不理想,将易引发尾水总磷超标,因此对污水处理厂二级处理过程的效能挖潜是当下污水处理厂提标改造的重点.层状双金属氢氧化物(LDH)是新型纳米吸附剂,可实现水体中磷元素的高效去除.研究中采用共沉淀法制备Mg/Al层状双金属氢氧化物(Mg/Al-LDH)及其煅烧产物(Mg/Al-LDO),通过扫描电子显微镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、红外光谱(FTIR)和Zeta电位等方法表征其组成和微观形貌,借助吸附动力学和吸附等温线探究Mg/Al-LDH和Mg/Al-LDO对磷酸盐的吸附特点和作用机理.结果表明:①当磷酸盐的初始质量浓度为10 mg/L(以P计)时,Mg/Al-LDH和Mg/Al-LDO对磷酸盐的吸附在2 h内快速增加并完成90%的吸附率,且它们的拟二级动力学模型(R^(2)值均大于0.999)比拟一级动力学模型能更好地模拟磷酸盐吸附过程,因而可以认为Mg/Al-LDH和Mg/Al-LDO的除磷过程主要通过化学吸附或化学键合来实现.②由于Mg/Al-LDH和Mg/Al-LDO的等温吸附数据更符合Langmuir等温吸附模型(R^(2)值均大于0.994),说明溶液中的磷酸根应以单分子层方式吸附在Mg/Al-LDH或Mg/Al-LDO上,它们在298 K下的最大饱和吸附量分别为84.5和122.7 mg/g.③Mg/Al-LDO在pH为3.0~11.0范围内具有的界面正电性,以及吸附磷酸盐后部分恢复原有层状结构的能力,使得Mg/Al-LDO在宽pH范围内具有比Mg/Al-LDH更强的脱磷能力.研究显示,Mg/Al-LDH和Mg/Al-LDO可实现含磷水样的高效快速去除,从而为今后市政污水处理技术的革新提供新思路.

人乳头瘤病毒检查、液基薄层细胞检测联合阴道镜检查在早期宫颈病变筛查中的意义

目的探讨人乳头瘤病毒检查、液基薄层细胞检测联合阴道镜检查在早期宫颈病变筛查中的运用效果。方法选取110例疑似宫颈病变患者为研究对象,均接受人乳头瘤病毒检查、液基薄层细胞检测与阴道镜检查,以病理诊断结果为金标准,比较人乳头瘤病毒检查、液基薄层细胞检测及阴道镜检查与联合检查的阳性检出情况,以及单独检查与联合检查的诊断效能。结果病理诊断确诊低度鳞状上皮内病变24例、高度鳞状上皮内病变33例与宫颈癌12例;联合检查的阳性检出率为98.55%,高于人乳头瘤病毒检查、液基薄层细胞检测及阴道镜检查的84.06%、62.32%、86.96%(P<0.05);联合检查的准确率、敏感度、特异度、阳性预测值与阴性预测值高于人乳头瘤病毒检查、液基薄层细胞检测及阴道镜检查(P<0.05)。结论在早期宫颈病变诊断中运用人乳头瘤病毒检查、液基薄层细胞检测联合阴道镜检查,能够明显提高阳性检出率,且具有较高的诊断效能,值得推广。