机架间冷却水对UF340表面组织均匀性的影响研究

利用热轧试验及全流程跟踪研究了机架间冷却水开闭对UF340表面组织均匀性的影响。结果表明:机架间冷却水对热轧卷沿板宽方向的组织均匀性有一定影响,且部分会遗传至成品组织;机架间冷却水全开时,成品距边部1/4处表面晶粒存在少量未再结晶组织,而后部机架间冷却水冷却关闭后,由于热轧时再结晶较充分,成品组织沿板宽方向一致性较好,成品表面为细小的完全再结晶组织,有利于材料表面鲜映性的提升;UF340的细小均匀的组织特性使其涂漆变形后的波纹度仅为0.169μm,表面鲜映性(DOI)值达到92,满足主机厂免中涂表面质量要求。

Sysmex UF5000尿沉渣分析仪鉴别血尿来源的临床应用评估

目的 评估Sysmex UF5000尿沉渣分析仪(UF5000)鉴别血尿来源的准确性。方法 选取241例血尿标本,比较UF5000和人工镜检判断红细胞形态信息的一致性。以临床诊断作为金标准,评估UF5000鉴别血尿来源的准确性和符合率。结果 UF5000和人工镜检在判断红细胞形态信息方面的一致性一般(Kappa值=0.389)。以临床诊断作为金标准,UF5000和临床诊断的一致性(Kappa值=0.474)明显低于人工镜检和临床诊断的一致性(Kappa值=0.71 1),但UF5000判断为混合性和非肾小球源性血尿的符合率高于人工镜检。结论 UF5000可有效排除肾小球源性血尿,但目前鉴别血尿来源的准确性较低,各实验室可根据实际情况调整光源参数以提高仪器鉴别的准确性。

High performance photodegradation resistant PVA@TiO_(2)/carboxyl-PES self-healing reactive ultrafiltration membrane

The occurrence of ultrafiltration(UF)membrane fouling frequently hampers the sustainable advancement of UF technology.Reactive self-cleaning UF membranes can effectively alleviate the problem of membrane fouling.Nevertheless,the self-cleaning process may accelerate membrane aging.Addressing these concerns,we present an innovative design concept for composite self-healing materials based on self-cleaning UF membranes.To begin,TiO_(2)nanoparticles were incorporated into the polymer molecular structure via molecular design,resulting in the synthesis of TiO_(2)/carboxyl-polyether sulfone(PES)hybrid materials.Subsequently,the nonsolvent-induced phase inversion technique was employed to prepare a novel of UF membrane.Lastly,a polyvinyl alcohol(PVA)hydrogel coating was applied to the hybrid UF membrane surface to create PVA@TiO_(2)/carboxyl-PES self-healing reactive UF membranes.By establishing a covalent bond,the TiO_(2)nanoparticles were effectively and uniformly dispersed within the UF membrane,leading to exceptional self-cleaning properties.Furthermore,the water-absorbing and swelling properties of PVA hydrogel,along with its capacity to form hydrogen bonds with water molecules,resulted in UF membranes with improved hydrophilicity and active self-healing abilities.The results demonstrated that the water contact angle of PVA@5%TiO_(2)/carboxyl-PES UF membrane was 43.1°.Following a 1-h exposure to simulated solar exposure,the water flux recovery ratio increased from 48.16%to 81.03%.Moreover,even after undergoing five cycles of 12-h simulated sunlight exposure,the UF membranes exhibited a consistent retention rate of over 97%,thus fully demonstrating their exceptional self-cleaning,antifouling,and selfhealing capabilities.We anticipate that the self-healing reactive UF membrane system will serve as a pioneering and comprehensive solution for the self-cleaning antifouling challenges encountered in UF membranes while also effectively mitigating the aging effects of reactive UF membranes.

Selective adsorption of tetracycline by β-CD-immobilized sodium alginate aerogel coupled with ultrafiltration for reclaimed water

In this work,a novel composite material based on β-cyclodextrin-immobilized sodium alginate aerogel(β-CD/NaAlg) was developed utilizing cross-linker of epichlorohydrin and applied as an adsorbent to remove tetracycline antibiotics from reclaimed wastewater.A series of characterizations were utilized to confirm the successful synthesis of the adsorbent and this β-CD/NaAlg presented a three-dimensional network at the nanoscale or microscale.Under optimal conditions(pH=4,t=8 h,β-CD:NaAlg=9,adsorbent dosage = 1.5 g·L-1),the maximum removal rate of β-CD/NaAlg to tetracycline was 70%.The adsorption behavior of tetracycline on β-CD/NaAlg conformed to the Freundlich isotherm model(R2=0.9977) and the pseudo-second-order kinetic model(R^(2)=0.9993).Moreover,the adsorbent still removed 55.3% of tetracycline after five cycles.Specially,the adsorbent was integrated with ultrafiltration to adsorb tetracycline antibiotics from simulated reclaimed wastewater,and the removal rate of tetracycline reached 78.9% within 2 h.The existence of Cr(Ⅵ) had a negligible impact on tetracycline removal,while the presence of humic acid exhibited a promoting effect.The possible adsorption mechanisms were also elucidated through X-ray photoelectron spectroscopy and density functional theory analysis.In summary,β-CD/NaAlg represents an environmentally friendly,efficient,and sustainable adsorbent for removing tetracycline antibiotics from reclaimed water.

基于改进的UFS网络车道线检测算法

为了解决车辆行驶中面对各种复杂环境车道线检测算法精度不高的问题,提出一种基于改进的UFS网络检测算法(Ultra Fast Structure-aware Deep Lane Detection,UFS).首先,采用改进的Gamma校正对待检路面图像进行校正,降低光照、阴影等的影响,以提升夜间图像纹理特征。然后引入非局部神经网络模块(Non-Local Block),充分提取图像全局特征,以提高检测可靠性。最后对改进后的算法使用Tusimple、CULane数据集进行测试。结果表明:改进后的模型在物体遮挡、光照变化、阴影干扰等复杂场景下,提升了对复杂噪声与多元场景的处理能力,车道分割的准确率有所改善,具有较好的鲁棒性。

Fe^(2+)/PMS/UF组合工艺降解PFOA的机制研究

为探究亚铁离子(Fe^(2+))/过氧单硫酸盐(PMS)/超滤(UF)组合工艺对水中全氟辛酸(PFOA)的降解作用,试验通过设置不同条件、定性活性自由基和中间产物来分析组合工艺降解PFOA作用机理。结果表明,体系降解PFOA最佳条件为p H值=3,n(PFOA)∶n(PMS)=1∶200,在此基础上,紫外协同强化方式表现出最佳效果。而当强化体系中腐殖质(HA)共存时,pH值=7的反应条件更优,此时主要以混凝沉淀为主,氧化为辅。EPR结果表明UV/Fe^(2+)/PMS反应体系中同时存在·OH和SO_(4)^(-)·2种活性自由基,SO_(4)^(-)·为主要作用自由基,并通过LC-MS分析得出理想状况下PFOA最终将被矿化为CO_(2)和F^(-)。

NaClO-PAC-UF对二级出水中抗生素抗性基因的去除效能及影响因素

采用次氯酸钠氧化结合粉末活性炭与超滤(NaClO-PAC-UF)组合工艺处理污水厂二级出水,考察NaClO投加量与水样的pH、温度对二级出水中抗生素抗性基因(ARGs)和溶解性有机物(DOC)去除效果的影响。结果表明,氧化阶段向水中添加次氯酸钠氧化剂有效氯浓度8.0 mg/L时去除效果最优,组合工艺对二级出水中不同类型ARGs(tetA、tetC、tetG、sulⅠ、sulⅡ)的去除量为10^(3.25)~10^(3.47)copies/mL,对细胞态和游离态ARGs去除效果明显增强;组合工艺对DOC去除率可达到57.5%,且对于不同分子量有机物的去除率整体都得到提高;升高温度以及降低pH皆能提升组合工艺对ARGs的去除效果。

UV-PAC-UF对二级出水中抗生素抗性基因的去除效能及影响因素

针对污水处理厂二级出水中的抗生素抗性基因(Antibiotic Resistance Genes,ARGs)进行深入研究。采用紫外线(Ultraviolet,UV)结合粉末活性炭(Powdered Activated Carbon,PAC)与超滤(Ultrafiltration,UF)组合工艺对二级出水中的ARGs和有机物进行去除,评价其去除效能并对其影响因素进行分析。结果表明,ARGs经过UV氧化失活后,经过PAC吸附与UF膜的过滤能够得到更为有效的去除;在UV最佳紫外线剂量(40 mJ/cm^(2))条件下,组合工艺对二级出水中不同类型ARGs(tetA、tetC、tetG、sulI、sulII)的去除量为102.72~103.08 copies/mL,对ARGs去除效果明显增强;浊度和pH值的降低能够使组合工艺更有效的去除二级出水中的ARGs;且组合工艺对各类有机物去除率更高,从而加强对ARGs的去除效果。

UF5000检测酵母样真菌筛查真菌性尿路感染的应用评价

目的:评估UF5000检测尿液中酵母样真菌(yeast-like cells,YLC)结果的准确性,并研究该参数能否用于筛查真菌性尿路感染。方法:选取318例疑似尿路感染患者的尿液标本,分别进行UF5000检测和细菌、真菌培养,显微镜镜检记录尿液中是否存在酵母菌。分别以镜下见到酵母菌和培养出真菌作为金标准,ROC曲线分析进行准确性评估。根据是否培养出真菌,以及真菌菌落生长的数量对尿液标本进行分组,非参数检验用于比较不同组间YLC水平的差异。结果:UF5000检测YLC真阳性的曲线下面积(Area under curve,AUC)为0.863,最佳cut off值2.80/μL。UF5000检测YLC预测真菌性尿路感染的AUC为0.913,最佳cutoff值8.95/μL。均有良好的敏感性(95.45%~97.37%)和阴性预测值(98.62%~98.73%)。组间比较显示真菌组YLC水平明显高于阴性组和细菌组(P值均为0.000),而真菌组内亚组仅≥105CFU/mL组YLC水平与105CFU/mL组差异有统计学意义(P=0.027)。结论:选取2.8/μL作为YLC的阳性标准,比厂家提供的6.0/μL更适用于本实验室的临床工作。选取8.95/μL作为最佳cutoff值时,UF5000检测的YLC结果可有效地筛查真菌性尿路感染。

Towards superior permeability and antifouling performance of sulfonated polyethersulfone ultrafiltration membranes modified with sulfopropyl methacrylate functionalized SBA-15

A non-solvent induced phase separation(NIPS)process was used to fabricate a series of sulfonated polyethersulfone(SPES)membranes blending with different concentrations of SBA-15-g-PSPA with the applications in the ultrafiltration(UF)process.SBA-15 was modified with 3-methacrylate-propyltrime thoxysilane(MPS)to form SBA-15-g-MPS.It was further modified with the charge tailorable polymer chains by reacting with 3-sulfopropyl methacrylate potassium salt.The nanoparticles were uniformly dispersed and finger-like channels were developed within the membrane.The adding of surface modified SBA-15-g-PSPA nanoparticles has significantly improved membrane water permeability,hydrophilicity,and antifouling properties.The pure water fluxes of the composite SPES membranes were significantly higher than the pristine SPES membrane.For the membrane containing 5%(mass)of SBA-15-g-PSPA(MSSPA5),the pure water flux was increased dramatically to 402.15 L
m^(-2)·h^(-1),which is ~1.5 times that of MSSPA0(268.0 L
m^(-2)·h^(-1)).The high flux rate was achieved with 3%(mass)of SBA-15 nanoparticles with retained high rejection ratio 98%for natural organic matter.The results indicate that the fashioned composite membrane comprising SBA-15-g-PSPA nanoparticles have a promising future in ultrafiltration applications.

Extracorporeal veno-venous ultrafiltration in congestive heart failure:What’s the state of the art?A mini-review

Hospitalizations for heart failure exceed 1 million per year in both the United States and Europe and more than 90%are due to symptoms and signs of fluid overload.Rates of rehospitalizations or emergency department visit at 60 days are remarkable regardless of whether loop diuretics were administered at low vs high doses or by bolus injection vs continuous infusion.Ultrafiltration(UF)has been considered a promising alternative to stepped diuretic therapy and it consists in the mechanical,adjustable removal of iso-tonic plasma water across a semipermeable membrane with the application of hydrostatic pressure gradient generated by a pump.Fluid removal with ultrafiltration presents several advantages such as elimination of higher amount of sodium with less neurohormonal activation.However,the conflicting results from UF studies highlight that patient selection and fluid removal targets are not completely understood.The best way to assess fluid status and therefore establish the fluid removal target is also still a matter of debate.Herein,we provide an up-to-date systematic review about the role of ultrafiltration among patients with fluid overload and its gaps in daily practice.

新型汽车覆盖件钢板性能研究

UF340作为一种新型超细晶高强钢,在汽车外覆盖件的应用上具有替代HC180BD的潜力,研究了UF340力学性能和成形性能。结果表明,在塑性、加工硬化指数和各向异性方面,UF340与HC180BD具有相似的力学性能,与HC180BD相比UF340没有明显的烘烤硬化性,2种材料的成形性能基本一致。通过Keeler模型计算获得UF340的成形极限曲线与成形试验结果存在一定差异,采用线性分段拟合方式获得的成形极限图与试验结果吻合度更高,采用该方法获得的成形极限曲线可为新材料的成形应用提供参考。

微砂载体絮凝预处理缓解超滤膜污染

采用微砂载体絮凝工艺对城市污水厂二级出水进行预处理,考察了该工艺对污水中溶解性有机碳(DOC)、UV_(254)和浊度的去除效果,表征了微砂载体絮凝对污水中溶解性有机物的去除特性,比较了絮体分形维数和絮凝指数(FI)的变化,分析了絮凝预处理对超滤膜比通量和膜阻力的影响。结果表明:微砂载体絮凝能有效去除污水中的大分子腐殖酸和蛋白类有机物,抑制有机物在膜表面的堆积,形成较大分形维数、抗剪切力强的絮体滤饼层;微砂的支撑作用有利于提高滤饼层的渗透性,有效降低膜过滤总阻力,尤其是滤饼层阻力,延缓了超滤膜通量的衰减进程,缓解了膜污染。

预混合和预沉积MIEX-超滤处理含藻水的膜污染控制

为了降低超滤处理含藻水的膜污染,探究了预混合和预沉积磁性离子交换树脂(MIEX)超滤处理含藻水的膜污染控制。对实验过程中的总阻力、可逆阻力及不可逆阻力进行分析,并使用扫描电子显微镜、三维荧光光谱、不可逆污染组分及超滤过滤模型对膜污染机理进行探究。结果表明:在相同投加量下,预沉积MIEX比预混合MIEX膜污染的控制更好,最大预沉积量为235.2 mL/m^(2)时,膜污染控制最好,此时预沉积MIEX的总阻力、可逆阻力和不可逆阻力分别比预混合MIEX的相应值低52.7%、65.7%和50.1%;蛋白质均是造成2种投加方式不可逆阻力的主要原因;随着预混合投加量的增加,滤饼层厚度从4.82 m降低至4.07 m,滤饼层内藻细胞及胞外有机物(EOM)含量降低;在预沉积MIEX中,随着沉积量的增加,沉积层形态发生变化,当沉积量最大时,沉积层拦截较多藻细胞和EOM,形成明显的藻类滤饼层。

基于混凝预处理的超滤净水工艺研究进展

膜污染是超滤工艺大规模运用的主要限制性因素,介绍超滤膜净水工艺膜污染的原理及其污染物。详述基于混凝预处理的三种超滤膜工艺:传统超滤工艺、短流程超滤工艺、一体式絮体-超滤工艺。以短流程超滤工艺为重点,阐述近年来以混凝预处理工艺来缓解超滤净水工艺膜污染的研究成果。总结了滤饼层结构对膜污染的影响,以及混凝预处理缓解超滤膜污染的作用原理,为膜法水处理工艺技术工程应用提供参考。

生化-超滤-纳滤组合工艺在餐厨垃圾废水处理中的应用

采用除渣预处理+厌氧反应器+二级AO+外置式超滤+NF(双膜法)组合工艺进行餐厨垃圾废水处理,研究结果表明,当进水COD为72315~78562 mg/L时,NF系统产水COD为264~347 mg/L,对有机物的去除率达到99.5%~99.7%,研究了NF系统压力、温度、pH和运行时间对膜分离性能的影响。NF出水可以达到《污水排入城镇下水道水质标准》(GB/T 31962-2015)标准B等级指标,NF系统浓水用于静脉产业园垃圾焚烧炉飞灰固化。最后,对工程投资、运行费用和经济效益进行了分析和讨论。

脱硫废水预处理系统运行性能分析与优化

为逐步实现脱硫废水零排放处理目标,广东某电厂建设投运一套脱硫废水预处理工艺系统,该系统采用“双碱软化+管式超滤”处理工艺,处理后废水可直接进入后续全厂废水零排处理系统。对脱硫废水预处理系统运行性能进行监测分析,结果显示:双碱软化工艺参数控制较差,主要表现为pH控制不稳定和纯碱加药量不合理,管式超滤浓缩倍率远远不够。通过双碱法软化参数优化试验,结果表明:pH在10.90以上、纯碱加药比达1.1时,出水水质即可满足后续全厂废水零排处理系统进水要求。通过物料平衡分析,管式超滤工艺单元中进水流量、排泥流量和产水流量依次应为9 m^(3)/h、2 m^(3)/h、7 m^(3)/h,可以最大限度地提高浓缩倍率。经过运行性能监测分析和优化研究,提高了脱硫废水预处理系统运行效率,降低了运行成本。

响应面优化超声波预处理辅助酶解法制备金针菇抗氧肽

为获取抗氧性更强的金针菇肽,本试验对超声波预处理辅助酶解法制备金针菇抗氧肽的最佳工艺条件进行了优化。以金针菇肽对2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(ABTS·)的清除率作为指标,对木瓜蛋白酶、胰蛋白酶、中性蛋白酶和碱性蛋白酶进行了筛选,又对等电点沉淀法分离抗氧肽的最适pH进行了优化,然后在确定胰蛋白酶为最佳蛋白酶,6为沉淀抗氧肽的最佳pH的基础上进行单因素试验,再在固定液料比为40:1(mL/g),酶解温度为37℃,酶解pH为8的前提下进行四因素三水平的响应面试验,以探讨超声功率、超声时间、酶添加量、酶解时间对制备工艺的影响。最后通过超滤分离法对抗氧肽进行了分级和活性比较。结果显示:金针菇抗氧肽的最佳制备条件为:超声时间6 min,超声功率296 W,酶添加量为金针菇样品量的1.1%(g/g),酶解时间75 min,在此条件下,金针菇抗氧肽对ABTS·的清除率为(76.63±1.24)%;截留分子质量<3 kDa的肽对ABTS·的清除率最高。说明金针菇肽具有一定的抗氧性,为金针菇抗氧肽的开发提供了依据。

UF膜过滤天然原水阻力特性的研究

黄浦江原水中的溶解性有机物是造成膜过滤阻力的重要因素。投加混凝剂会大大降低膜过滤阻力。使膜过滤阻力最小的最佳混凝剂投加量与去除水中溶解性有机物效果最佳的投加量一致。

基于“超滤——正渗透——膜蒸馏”工艺的中药废水利用研究

本文提出了基于“超滤—正渗透—膜蒸馏”(UF-FO-MD)耦合工艺的中药废水利用研究。通过设计模拟FO有效物质回收实验与UF-FO-MD耦合工艺处理实验,对比2组实验数据,验证该耦合工艺在实际中药废水处理中的应用效果。实验结果表明,经UF-FO-MD耦合工艺处理,实际中药生产废水中的回收效率明显提升。由此说明,该耦合工艺可有效回收中药废水中的有效物质和水资源,可在处理废水的同时,缓解中药生产的用水压力,可提高废水资源化利用的经济可行性,为中药生产废水资源化利用提供了创新方法。