Recent Advances in the Rapid Detection and Performance Evaluation Methods of Detergent Additives for Gasoline

Although detergent additives for gasoline have been widely commercialized,their formulas are often kept confidential and there is still no standardized method for quickly detecting the main active ingredients and evaluating their effectiveness,which makes their regulation difficult.An overview of the current state of the development and application of detergent additives for gasoline in China and other regions,as well as a review of the rapid detection and performance evaluation methods available for analyzing detergent additives are given herein.The review focuses on the convenience,cost,efficiency,and feasibility of on-site detection and the evaluation of various methods,and also looks into future research directions,such as detecting and evaluating detergent additives in ethanol gasoline and with advanced engine technologies.

Improved RF power performance of InAlN/GaN HEMT by optimizing rapid thermal annealing process for high-performance low-voltage terminal applications

Improved radio-frequency(RF)power performance of InAlN/GaN high electron mobility transistor(HEMT)is achieved by optimizing the rapid thermal annealing(RTA)process for high-performance low-voltage terminal applications.By optimizing the RTA temperature and time,the optimal annealing condition is found to enable low parasitic resistance and thus a high-performance device.Besides,compared with the non-optimized RTA HEMT,the optimized one demonstrates smoother ohmic metal surface morphology and better heterojunction quality including the less degraded heterojunction sheet resistance and clearer heterojunction interfaces as well as negligible material out-diffusion from the barrier to the channel and buffer.Benefiting from the lowered parasitic resistance,improved maximum output current density of 2279 mA·mm^(-1)and higher peak extrinsic transconductance of 526 mS·mm^(-1)are obtained for the optimized RTA HEMT.In addition,due to the superior heterojunction quality,the optimized HEMT shows reduced off-state leakage current of 7×10^(-3)mA·mm^(-1)and suppressed current collapse of only 4%,compared with those of 1×10^(-1)mA·mm^(-1)and 15%for the non-optimized one.At 8 GHz and V_(DS)of 6 V,a significantly improved power-added efficiency of 62%and output power density of 0.71 W·mm^(-1)are achieved for the optimized HEMT,as the result of the improvement in output current,knee voltage,off-state leakage current,and current collapse,which reveals the tremendous advantage of the optimized RTA HEMT in high-performance low-voltage terminal applications.

Green design horizon, hand-painted rendering performance techniques to explore

Green design horizon, explore the hand-painted rendering performance techniques,from conception to take as, composition distribution, global and local processing, local expansion method, the performance of rendering and other aspects of analysis and propose countermeasures. Accumulation of professional material for designers and nutrients at the same time, raise awareness of the environment, space and natural understanding, To improve the aesthetic horizon, hand-painted rendering green design and students ability to innovate education is of great significance.

Effect of Rapid Quenching on Microstructures and Electrochemical Performances of La_2Mg(Ni_(0.85)Co_(0.15))_9M_(0.1)(M=B, Cr) Hydrogen Storage Alloys

The La-Mg-Ni-system （PuNi3-type） La2Mg （Ni0.85 Co0.15 ）9M0.1 （ M = B, Cr） hydrogen storage etectrode alloys were prepared by casting and rapid quenching. The electrochemical performances and microstructures of the as-cast and quenched alloys were determined and measured. The effects of rapid quenching on the microstructures and electrochemical properties of the alloys were investigated in detail. The obtained results show that the alloys are composed of the （La, Mg） Ni3 phase （PuNi3-type structure） and the LaNi5 phase, as well as the small amount of the LaNi2 phase. A trace of the Ni2B phase exists in the as-cast alloy containing boron, and the Ni2B phase in the alloy nearly disappears after rapid quenching. The relative amount of each phase in the alloys depends on the quenching rate. The rapid quenching technique can greatly improve the electrochemical performance of the alloy, and the effect of rapid quenching on the activation performances of the alloys is minor. Rapid quenching enhances the cycle stability of the alloy, and the cycle life of the alloy increases with the increase of the quenching rate.

Evaluation of a Rapid Diagnostic Test, Boson Biotech SARS CoV-2 Ag, for the Detection of SARS-CoV-2 in Gabon

1) Background: Rapid and acurate diagnostic testing for case identification, quarantine, and contact tracing is essential for managing the COVID 19 pandemic. Rapid antigen detection tests are available, however, it is important to evaluate their performances before use. We tested a rapid antigen detection of SARS-CoV-2, based on the immunochromatography (Boson Biotech SARS-CoV-2 Ag Test (Xiamen Boson Biotech Co., Ltd., China)) and the results were compared with the real time reverse transcriptase-Polymerase chain reaction (RT-PCR) (Gold standard) results;2) Methods: From November 2021 to December 2021, samples were collected from symptomatic patients and asymptomatic individuals referred for testing in a hospital during the second pandemic wave in Gabon. All these participants attending “CTA Angondjé”, a field hospital set up as part of the management of COVID-19 in Gabon. Two nasopharyngeal swabs were collected in all the patients, one for Ag test and the other for RT-PCR;3) Results: A total of 300 samples were collected from 189 symptomatic and 111 asymptomatic individuals. The sensitivity and specificity of the antigen test were 82.5% [95%CI 73.8 - 89.3] and 97.9 % [95%CI 92.2 - 98.2] respectively, and the diagnostic accuracy was 84.4% (95% CI: 79.8 - 88.3%). The antigen test was more likely to be positive for samples with RT-PCR Ct values ≤ 32, with a sensitivity of 89.8%;4) Conclusions: The Boson Biotech SARS-CoV-2 Ag Test has good sensitivity and can detect SARS-CoV-2 infection, especially among symptomatic individuals with low viral load. This test could be incorporated into efficient testing algorithms as an alternative to PCR to decrease diagnostic delays and curb viral transmission.

Performance improvement of CdS/Cu(In,Ga)Se_2 solar cells after rapid thermal annealing

In this paper, we investigated the effect of rapid thermal annealing （RTA） on solar cell performance. An opto-electric conversion efficiency of 11.75% （Voc = 0.64 V, Jsc = 25.88 mA/cm2, FF=72.08%） was obtained under AM 1.5G when the cell was annealed at 300℃ for 30 s. The annealed solar cell showed an average absolute efficiency 1.5% higher than that of the as-deposited one. For the microstructure analysis and the physical phase confirmation, X-ray diffraction （XRD）, Raman spectra, front surface reflection （FSR）, internal quantum efficiency （IQE）, and X-ray photoelectron spectroscopy （XPS） were respectively applied to distinguish the causes inducing the efficiency variation. All experimental results implied that the RTA eliminated recombination centers at the p-n junction, reduced the surface optical losses, enhanced the blue response of the CdS buffer layer, and improved the ohmic contact between Mo and Cu（In, Ga）Se2 （CIGS） layers. This leaded to the improved performance of CIGS solar cell.

Integrated Performance Measures for Bus Rapid Transit System and Traffic Signal Systems Using Trajectory Data

Bus rapid transit (BRT) systems have been implemented in many cities over the past two decades. Widespread adoption of General Transit Feed Specification (GTFS), the deployment of high-fidelity bus GPS data tracking, and anonymized high-fidelity connected vehicle data from private vehicles have provided new opportunities for performance measures that can be used by both transit agencies and traffic signal system operators. This paper describes the use of trajectory-based data to develop performance measures for a BRT system in Indianapolis, Indiana. Over 3 million data records during the 3-month period between March and May 2022 are analyzed to develop visualizations and performance metrics. A methodology to estimate the average delay and schedule adherence is presented along a route comprised of 74 signals and 28 bus stations. Additionally, this research demonstrates how these performance measures can be used to evaluate dedicated and non-dedicated bus lanes with general traffic. Travel times and reliability of buses are compared with nearly 30 million private vehicle trips. Results show that median travel time for buses on dedicated bi-directional lanes is within one minute of general traffic and during peak periods the buses are often faster. Schedule adherence was observed to be more challenging, with approximately 3% of buses arriving within 1 minute on average during the 5AM hour and 5% of buses arriving 6 - 9 minutes late during the 5PM hour. The framework and performance measures presented in this research provide agencies and transportation professionals with tools to identify opportunities for adjustments and to justify investment decisions.

An Approach to Field Test Scheme of Main Fan Performance for the Special Type Mine Fan-House

The field tot of performance of mine main fan is going to become an independance requirement of coal mlue progressively and to be taken seriously. According to the fan-house with air gate closed to the fan inlet, this paper analyses the influence of the rapid changing air flow field upon field test and puts forward a reasonable test scheme.

ELECTRODE PERFORMANCES OF MELT-SPINNED AB_2 TYPE Zr-BASED HYDROGEN STORAGE ALLOYS

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国内外食品快速检测方法评价技术研究

相比于国外成熟的快速检测方法评价技术体系,我国的评价技术体系发展滞后且有较多问题,严重制约了快检行业的发展。本文主要从验证方法、性能指标、测试要求等方面对各个评价技术体系做了对比分析。同时梳理了国内不同监管部门的评价技术体系发展与侧重,以期为我国食品快速检测方法确认政策和技术研究提供良好的借鉴,引导食品快速检测方法及产品的评价标准进一步规范,形成完善的科学评价方法和评价技术体系,促进我国食品安全及快速检测行业的健康发展。

水性环氧树脂-聚丙烯纤维改性水泥基快速修补砂浆性能研究

为改善机场道面修补砂浆脆性大和粘结性能差等问题,本文利用水性环氧树脂(WER)、聚丙烯(PP)纤维和硫铝酸盐水泥(SAC)制备出一种快速修补砂浆,并对其工作性能、力学性能、阻尼性能和耐硫酸盐腐蚀性能进行研究。结果表明,PP纤维和WER可显著提高快速修补砂浆韧性和粘结性能,使得快速修补砂浆2 h抗压、抗折强度和粘结强度分别达到22.3,5.1和3.7MPa,满足民用机场规范要求,同时可改善快速修补砂浆的阻尼性能和抗硫酸盐侵蚀性能。

基于在线柱切换液相色谱技术的红霉素软膏含量测定研究

目的建立在线柱切换高效液相色谱法测定红霉素软膏中主药含量的方法,为相关制剂的质量控制提供有效手段。方法样品经80℃提取后直接进样,柱切换系统下,采用C_(18)(50 mm×2.1 mm,5μm)色谱柱初步分离,2.5 min后转入C_(18)(150 mm×2.1 mm,5μm)柱进行分析,流速0.2 mL·min^(-1),柱温35℃。结果红霉素在1~100μg·mL^(-1)范围内线性关系良好(r=0.9994);平均加样回收率大于96.9%;日内和日间精密度小于1.29%(n=6)。结论本研究改进样品提取方法,并通过在线柱切换完成目标组分的净化和富集,该方法操作简单、准确灵敏、稳定性好,可用于红霉素软膏的含量测定。

超高效液相色谱-四极杆-飞行时间高分辨质谱用于化妆品中15种前列腺素类似物的快速筛查和测定

建立了超高效液相色谱-四极杆-飞行时间高分辨质谱(UPLC-Q-TOF MS)快速筛查和测定化妆品中15种前列腺素类似物的方法。样品以饱和氯化钠作为分散剂(蜡质类样品以四氢呋喃分散),经乙腈提取,离心取上清液过滤后,采用Poroshell 120 EC-C_(18)柱(150 mm×3.0 mm,2.7μm)分离,以5 mmol/L甲酸铵(含0.1%甲酸)-乙腈为流动相梯度洗脱。在ESI正离子模式下,采用Targeted MS/MS模式采集15种前列腺素类似物的质谱信息,构建筛查数据库进行快速筛查,确证后的目标物通过外标法定量。结果表明,15种前列腺素类似物的线性关系良好,相关系数(r^(2))均大于0.99;检出限为0.3~17.6μg/g,定量下限为1.1~58.8μg/g。在低、中、高3个加标水平下,水剂、膏霜、乳类、粉类、凝胶5类化妆品基质的回收率为70.1%~134%,相对标准偏差不大于7.5%。该方法简单高效、准确度好,可用于化妆品中前列腺素类似物的定性确证和定量分析,为化妆品风险识别提供技术支撑。

超高效液相色谱质谱法快速测定血浆中6种蘑菇毒素

目的 建立超高效液相色谱质谱法快速测定血浆中异绒白乳菇醛、α-鹅膏毒肽、β-鹅膏毒肽、γ-鹅膏毒肽、二羟鬼笔毒肽和羧基二羟鬼笔毒肽的含量。方法 取血浆样本,以1∶3的比例加入乙腈,旋涡混匀1min后,以10 000转/min、4℃离心3min。吸取上清液,以0.03%氨水和乙腈进行超高效液相分离,在电喷雾正离子模式下进行多反应监测检测。结果 一次进样4min即可实现血浆中异绒白乳菇醛、α-鹅膏毒肽、β-鹅膏毒肽、γ-鹅膏毒肽、二羟鬼笔毒肽和羧基二羟鬼笔毒肽的分离检测。血浆中6种蘑菇毒素的线性范围为40~500μg/L,检出限分别为10.0μg/L、10.0μg/L、10.0μg/L、6.0μg/L、6.0μg/L和6.0μg/L(S/N=3),相对标准偏差为0.60%~1.90%(n=11),回收率为90.8%~127.0%。结论 本方法可实现血浆中包括异绒白乳菇醛在内的6种蘑菇毒素的快速同时测定,操作简单,结果准确,为中毒患者的蘑菇毒素快速确证提供技术平台。

基于快速康复理念的线上线下整体优化干预在伴肌少症老年全髋关节置换术患者中的应用效果

目的探讨基于快速康复理念的线上线下整体优化干预在伴肌少症老年全髋关节置换术(THA)患者中的应用效果。方法选取2021年4月—2023年4月收治的104例伴肌少症老年THA,根据干预方法不同分为对照组、观察组,各52例。对照组予以常规围手术期干预,在此基础上,观察组予以基于快速康复理念的线上线下整体优化干预。对比2组住院情况、不良事件发生率、依从性、视觉模拟评分法(VAS)、简易躯体执行能力测试量表(SPPB)、髋关节伤残和骨关节炎问卷(HOOS)、Harris髋关节功能及Barthel指数评分。结果观察组首次下床时间、首次排便时间、住院时间均短于对照组(P<0.01);观察组术后3 d、术后7 d VAS评分均低于对照组(P<0.05);观察组不良事件总发生率3.85%(2/52)低于对照组17.31%(9/52)(P<0.05);观察组总依从度96.15%(50/52)高于对照组78.85%(41/52)(P<0.01);术后1个月、3个月观察组SPPB、HOOS及Harris、Barthel指数评分均较对照组高(P<0.05)。结论基于快速康复理念的线上线下整体优化干预应用于伴肌少症老年THA患者中,可降低患者术后疼痛感,减少不良事件,提升依从性,促进髋关节及躯体功能好转,有助于患者预后恢复。

高烈度区快速施工跨线桥基础隔震性能研究

为适应高烈度区跨线桥快速施工的需要,提出基础隔震跨线桥的设计理念。以某2×25m高速公路跨线桥为工程背景,将铅芯橡胶支座作为基础隔震装置进行研究。采用Midas/Civil建立桥梁动力分析模型,选取7条时程曲线作为地震动输入,对跨线桥进行顺桥向和横桥向时程分析,对比采用基础隔震体系前后跨线桥抗震性能的变化,并分析弹性挡块对跨线桥地震位移的控制效果。结果表明:基础隔震跨线桥将主梁与中墩作为整体预制安装,最大限度地减少了现场作业时间,理论上可作为跨线桥快速施工的一种方式;相比于常规结构体系,基础隔震体系既能降低中墩地震内力,又能减小梁端支座位移,可显著提升跨线桥在顺桥向和横桥向的抗震性能;弹性挡块可有效控制基础隔震跨线桥的地震位移,但使得桥墩的地震内力明显增大,设计时应注意二者的平衡,合理选择弹性挡块的力学参数。

低温养护对环氧树脂基砂浆早期性能的影响及机理

环氧树脂基砂浆是一种快速修补材料,为研究低温养护条件对环氧树脂基砂浆工作性能及早期力学性能的影响,构建了全过程低温环境,分别进行了抗压强度、抗折强度、流动度、凝结时间以及内部温度测试,分析了环氧树脂基砂浆的微观结构。结果表明:环氧树脂基砂浆性能受养护温度影响较大,当养护温度为0℃时,流动度仅为112 mm,但随着温度升高流动度增长较快;低温养护使得砂浆内部热效应减弱,延缓了凝结时间;早期强度也损失显著,0℃时,砂浆养护1 d才形成强度,说明低温环境大大减慢了体系的固化速度。微观分析表明低温养护导致砂浆内部结构疏松,裂缝及孔隙增多,说明固化反应不完全,从而降低了砂浆的性能。当养护温度为20℃时,砂浆内部结构较为致密,宏观结构也表现出较高强度。

考虑实测信息的既有规则建筑状态识别与抗震性能快速评估

城市既有建筑(群)的地震安全性评价面临高效分析、快速评估、定量判定的多重技术发展需求。考虑长期服役过程中的结构性能演化现象,既有建筑安全性评价需要结构本身和当地地震动等一系列实测数据与信息,以标定结构真实服役状态,保证结构抗震性能评估结果的准确性,并兼顾结构抗震性能分析的时效性。本文基于等效非线性单自由度模型,结合作者近年来在数据驱动型状态评估指标方面的研究成果,提出了以既有建筑实测模态频率和阻尼比映射结构宏观服役状态,结合当地实测地震动数据集,快速评估该目标建筑抗震安全性的方法。阐述了基于动力测试和HAZUS技术手册的既有结构等效非线性单自由度模型的建立过程,提出了两类结构状态评价指标,结合多元工程性能参数,建立了等效模型变形状态与不同抗震性能水准之间的直接联系。以四川省珙县当地一栋高层规则框架结构和2019至2022年间10次实测地震动为例,对该建筑在当地近期实际地震动作用下的抗震安全性进行评估。

微热压成形石墨件的快速碳化工艺

针对石墨件在碳化过程中易开裂的问题,基于多材料组装技术原理,提出在石墨粉末微热压成形过程中构造烧蚀性二维有机物网络以形成排气通道、避免开裂的方法。研究了碳化速率、石墨件径向尺寸及网络结构、分布方式对石墨件成形质量和力学性能的影响。结果表明:较快的碳化速率会加剧有机物热解,开裂的现象越明显,较大径向尺寸的石墨件气体逸出阻力越大;提高有机物网络密集度有助于改善排气效果,但对石墨件力学性能产生不利影响;在有机物网络沿成形高度方向的布置中,当间距为10 mm时,石墨件不出现裂纹。采用优化的工艺制备的石墨件结构完整,经过浸渍增强后其抗压强度达到15.8 MPa,Z轴导热系数仅为1.894 W/(m·K),综合性能与水玻璃型砂相当,在铸造行业有广泛应用前景。

基于全自动免疫磁珠净化技术快速测定中药材中4种黄曲霉毒素

基于全自动免疫磁珠净化前处理技术,建立了适用于多种中药材基质中4种黄曲霉毒素的快速测定方法。中药材中的黄曲霉毒素经乙腈-水(9∶1)提取后,采用免疫磁珠自动富集净化后,由0.5%乙酸甲醇洗脱后定容;经Inertsil ODS-3 C18柱(250 mm×4.6 mm,5µm)分离,以乙腈-甲醇-水为流动相等度洗脱,采用高效液相色谱-荧光检测器(HPLC-FLD)测定。以5种易污染黄曲霉毒素的中药材基质进行方法学验证。结果表明该方法的线性关系良好,相关系数(r^(2))均达到0.9999;检出限为0.06~0.2µg·kg^(-1),定量下限为0.12~0.40µg·kg^(-1);不同基质中的平均回收率为71.9%~116%,相对标准偏差为0.10%~6.9%;在18 min内可完成24批样品的净化,比免疫亲和柱法的检测效率提高近85%。该方法快速、准确,通用性强,可用于多种中药材中4种黄曲霉毒素的批量快速测定。