One step from nanofiber to functional hybrid structure: Pd doped ZnO/SnO2 heterojunction nanofibers with hexagonal ZnO columns for enhanced low-temperature hydrogen gas sensing

In this paper, a novel hybrid structure of Pd doped ZnO/SnO₂ heterojunction nanofibers with hexagonal ZnO columns was one step synthesized from electrospun precursor nanofibers. Due to the synergistic effect of hexagonal ZnO, SnO₂ and Pd, the structure exhibited excellent hydrogen (H₂) gas sensing properties. At low-temperature of 120 °C, the response (R_a/R_g) to 100 ppm H₂ gas exceeded 160, the response/recovery time was only 20 s and 6 s respectively and the limit of detection was only 0.5 ppm. Meanwhile, it also had good selectivity for H₂ gas and excellent linearity. In addition, the materials were characterized by XRD, FESEM, HRTEM, XPS, and the synthesis mechanism and gas sensing mechanism were proposed.     

Phase and microstructure evolution of Sc2O3–CeO2 –ZrO2ceramics in Na2SO4 + V2O5 molten salts

In this study, the destabilization resistance of Sc₂O₃ and CeO₂ co-stabilized ZrO₂ (SCZ) ceramics was tested in Na₂SO₄ + V₂O₅ molten salts at 750°C–1100 °C. The phase structure and microstructure evolution of the samples during the hot corrosion testing were analyzed with X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), energy dispersive X-ray spectrum (EDS), and X-ray photoelectron spectroscopy (XPS). Results showed that the destabilization of SCZ ceramics at 750 °C was the result of the chemical reaction with V₂O₅ to produce m-ZrO₂ and CeVO₄, and little ScVO₄ was detected in the Sc₂O₃-rich SCZ ceramics. The primary corrosion products at 900 °C and 1100 °C were CeO₂ and m-ZrO₂ due to the mineralization effect. The Sc₂O₃-rich SCZ ceramics exhibited excellent degradation resistance and phase stability owing to the enhanced bond strength and the decreased size misfit between Zr⁴⁺ and Sc³⁺. The destabilization mechanism of SCZ ceramic under hot corrosion was also discussed.     

Processing Modflow在地下水位预测中的应用

数值模拟软件逐渐成为预测地下水演化更普遍的工具,并且广泛应用于地下水动态变化研究.以乌苏市平原区为例,结合区域水文地质条件及钻井资料,利用Processing Modflow建立三维水流数值模拟模型,并对该模型进行平面流场拟合,验证出模拟值基本符合2018年实测地下水位,通过模型模拟2018—2027年不同条件地下水位变化趋势,结果显示,2027年现状条件下比用水总量条件下浅埋深面积减少了550km2.     

Recent Development of Photothermal Agents (PTAs) Based on Small Organic Molecular Dyes

Photothermal therapy (PTT) has attracted great attention due to its noninvasive and effective use against cancer. Various photothermal agents (PTAs) including organic and inorganic PTAs have been developed in the last decades. Organic PTAs based on small-molecule dyes exhibit great potential for future clinical applications considering their good biocompatibility and easy chemical modification or functionalization. In this review, we discuss the recent progress of organic PTAs based on small-molecule dyes for enhanced PTT. We summarize the strategies to improve the light penetration of PTAs, methods to enhance their photothermal conversion efficiency, how to optimize PTAs’ delivery into deep tumors, and how to resist photobleaching under repeated laser irradiation. We hope that this review can rouse the interest of researchers in the field of PTAs based on small-molecule dyes and help them to fabricate next-generation PTAs for noninvasive cancer therapy.     

非晶态PdCuSi的内耗和DSC研究

用葛摆测量了ａ－ＰｄＣｕＳｉ合金的内耗－温度曲线，证明在该合金的Ｔｇ和Ｔｘ温度附近有两个内耗峰Ｐ１和Ｐ２．Ｐ２峰是与非晶晶化有关的内耗峰，而Ｐ１峰可能是弛豫型的内耗峰．分析了倒扭摆和Ｃｏｌｌｅｔｔｅ摆的灵敏度，阐述了这两种摆不适用于测量ａ—ＰｄＣｕＳｉ类合金的内耗峰．     

基于多元信息融合的基坑预警分级研究

为保证基坑预警结果的准确性和有效性,在基坑预警准则构建的基础上,利用累计变形判据和变形速率判据实现了多元监测信息融合的基坑预警研究。其中:累计变形判据包含稳定性指标和相对变形指标,即从基坑稳定性和变形安全储备角度实现了基坑长时段预警分析;而变形速率判据包含了绝对量指标和发展趋势指标,即从变形速率的现有变形绝对量及其发展趋势角度实现了基坑短时段预警分析。实例分析表明:不同判据在不同监测项目中的预警等级具有一定的差异,在累计变形判据的预警结果中,得出基坑处于稳定状态,预警等级为Ⅱ级;而在变形速率判据的预警结果中,坑顶变形监测项目的预警等级为Ⅲ级,其余监测项目的预警等级为Ⅱ级;按不利原则,对两类判据的预警结果进行叠加,综合确定基坑预警等级为Ⅲ级,即应采取密切监测措施,切实保证施工安全。     

体相纳米气泡及其研究进展

纳米气泡是直径在1μm以下的气泡,已被证明可以在固液界面、体相中长期稳定存在。基于跨越气液界面的拉普拉斯压强定理,气泡无法保持热力学稳定,将在微秒的尺度上消失。然而,大量试验报道,体相纳米气泡可以长时间稳定存在。目前,关于纳米气泡的产生技术、表征手段和相关的稳定机制已被世界各国的课题组竞相报道。该综述对现有纳米气泡的研究成果,尤其是体相纳米气泡的研究进行总结概述。首先,总结了体相纳米气泡产生和表征的主要方法;其次,介绍了体相纳米气泡的稳定机制;再次,概括了体相纳米气泡的试验应用情况;最后,对体相纳米气泡的进一步研究和应用作出展望。     

基于广义双参数最弱链统计模型分析纤维断裂强度与尺寸的相关性

为探究纤维断裂强度与尺寸之间的相关性,通过一种改进的广义双参数最弱链统计模型分别对不同标距尺寸下聚丙烯腈基碳纤维和黄麻纤维的断裂强度数据进行统一处理. 通过引入指数参量β,表征缺陷实际空间分布与理想均匀空间分布条件的偏离程度,将纤维断裂强度和尺寸作为统计参量,得到的纤维失效函数综合反映纤维断裂强度和尺寸对失效概率的影响,较好地描述了纤维断裂强度和尺寸之间的相关性.     

贮藏温度对筇竹笋采后品质的影响

筇竹笋味甘鲜嫩,笋体脆爽,富含多种营养物质,具有重要的食用、经济和生态价值。筇竹笋采后生命力旺盛,笋体易老化腐烂,难以贮藏,而适当的低温贮藏可有效延缓其木质化进程,延长保鲜期。本文探讨了18、4、0和?18 ℃ 4种贮藏温度对筇竹笋色泽、硬度、失重率、呼吸强度、酶活性、MDA（丙二醛）、木质素及粗纤维的影响。结果表明:采后鲜笋在18 ℃条件下贮藏4 d木质化严重,丧失食用价值;而在4、0和?18 ℃条件下贮藏至第10 d,产品外观品质均保持较好,但由于冻藏（?18 ℃）对笋体细胞造成损伤,解冻后其质地变软,食用品质降低。0 ℃条件下各指标结果优于4 ℃,能更好地保持筇竹笋采后原有品质,延长贮藏时间。本研究为竹笋低温贮藏提供了理论依据。     

甲苯—正庚烷—庚烯-(3)三元系统的气液平衡

测定了庚烯-（3）的蒸气压。用Gillespie型平衡器测定了甲苯—庚烯-（3）、正庚烷—庚烯-（3）二元系及甲苯—正庚烷—庚烯-（3）三元系统的平衡数据,并分别用Spinner及White方法验证了这些数据,计算结果与实验结果是符合的。三元系统气液平衡的数据不论在工程中或是实验工作上都很重要,过去对三元系统气液平衡的研究虽然有一些,但对甲苯—正庚烷—庚烯-（3）三元系统气液平衡至今在文献上尚未有记载。 由于庚烯-（3）的蒸气压数据不见于文献,我们测定了它的蒸气压数据。正庚烷—甲苯二元系统前人已有许多结果发表,我们进行了一些校核,结果与文献记载符合。甲苯—庚烯-（3）二元系统文献上没有,我们倣效了并用Spinner方法及White方法整理。至于正庚烷—庚烯-（3）二元系统,因为此两组分的性质（如沸点、n_D~（20）等）极其接近,分析误差较大,我们将其当作理想溶液处理,误差当在允许误差以内。 三元系统的分析较为繁难,误差也较大,故希望从理论和实验材料找出其规律性,以校核实验数据和推算未知三元系统。本工作利用三个二元系统的数据,用Spinner以及White的方法推算三元系统的气液平衡,与实验数据相比较,是相互符合的。