多通道控制／检测操纵台

本操纵台可以对６４个通道或号位的综合参数，如温度、压力、温度、物位、流量等刊物民检测，它具有两种功能；（１）对６４个地点的进行自动巡回控制／检测；（２）可随意对任意地的参数进行优化控制／检测。     

Two-Dimensional Equalization/Detection for Patterned Media Storage

Although patterned media storage (PMS) is a promising candidate for ultrahigh-capacity magnetic data storage, as the capacity of PMS increases, the bit error rate (BER) performance of the system is degraded by increased two-dimensional intersymbol interference (2D-ISI), which results from intertrack interference (ITI), intersymbol interference (ISI), and noise. To improve the system performance under these adverse effects and to increase the capacity, in this paper, we propose to use and/or devise two-dimensional equalization/detection techniques: iterative decision feedback detection (IDFD) and two-dimensional generalized partial response equalization, which is optimized in minimum mean square error (MMSE), followed by one-dimensional Viterbi algorithm (2D-GPR/1D-VA). We evaluate the performance of the proposed methods by using numerical experiments under different amounts of 2D-ISI and noise. Simulation results suggest that under high storage density, the performance of the IDFD is improved by using more iterations and that under the same computational load, 2D-GPR/1D-VA performs better than IDFD. 2D-GPR/1D-VA, therefore, is a good candidate for ultrahigh-capacity PMS.     

Low Detection Limit Circularly Polarized Light Detection Realized by Constructing Chiral Perovskite/Si Heterostructures

Chiral perovskites have been demonstrated as promising candidates for direct circularly polarized light (CPL) detection due to their intrinsic chirality and excellent charge transport ability. However, chiral perovskite-based CPL detectors with both high distinguishability of left- and right-handed optical signals and low detection limit remain unexplored. Here, a heterostructure, (R-MPA)₂MAPb₂I₇/Si (MPA = methylphenethylamine, MA = methylammonium) is constructed, to achieve high-sensitive and low-limit CPL detection. The heterostructures with high crystalline quality and sharp interface exhibit a strong built-in electric field and a suppressed dark current, not only improving the separation and transport of the photogenerated carriers but also laying a foundation for weak CPL signals detection. Consequently, the heterostructure-based CPL detector obtains a high anisotropy factor up to 0.34 with a remarkably low CPL detection limit of 890 nW cm⁻² under the self-driven mode. As a pioneering study, this work paves the way for designing high-sensitive CPL detectors that simultaneously have great distinguishing capability and low detection limit of CPL.     

Al/Au Bilayer Thermometer for Third Sound Detection

We present results from an experiment to develop bilayer metallic films of Al and Au as superconducting transition edge thermometers for the detection of third sound waves in thin superfluid ⁴He films. We compare transition edge data for such an Al/Au thermometer to that for a pure Zn thermometer and document its utility for third sound detection.     

浅谈能力验证在检测/校准中的应用

能力验证在实验室认可、法定计量检定机构考核、质量管理等多个方面都有广泛的应用,本文介绍了进行能力验证的目的、作用及其在检测/校准中如何具体实施,同时分析了能力验证结果的判断。     

整合纸基微流控检测芯片的食药纸包装

目的探索纸质食品、药品包装与纸基微流控检测芯片的整合方法与规律。方法在传统纸质食品或药品包装的内表面,通过喷蜡打印的方法,整合具有特定生物化学检测作用的纸基微流控芯片,并探索微流体在包装内表面构成的纸基微流控芯片中的运用规律。结果通过喷蜡打印,成功地将纸基微流控芯片整合在了传统纸质食药包装的内表面,经过测试可以完成液体pH检测等基础生物化学检测应用。结论将纸基微流控芯片与食药纸质包装相结合,为食品、药品的实时和现场自我检测提供了新的思路和手段,该方法不仅成本低廉、易于操作,且检测精度高。     

Electrochemical Immunosensor for Detection of Atrazine Based on Polyaniline/Graphene

In this study,a novel layer-by-layer polyaniline/graphene(PANi/Gr)structure for electrochemical detection of atrazine was developed.Gr film was synthesized by thermal chemical vapor deposition(CVD)method and transferred onto the PANi-predeposited microelectrode.The properties of PANi/Gr film were thoroughly investigated by high-resolution transmission electron microscopy and Raman techniques.The most attractive feature of this system is a suitable microenvironment,which could provide an amplification of the conductive signal,thus may contribute to enhancing electron transfer and subsequently improve the sensitivity in electrochemical measurements.With low detection limit(～43×10~(-12)g/L),acceptable stability and good reproducibility,the proposed electrochemical immunosensor could be advantageously extended for multiplexed detection of other agents of environmental pollution.     

微囊藻毒素-LR HPLC/ESI-MS法检测与前处理条件优化

通过对前处理过程中关键环节进行单因素不同水平比较,选择出固相萃取柱、浓缩方式、氮气流量、水浴温度、质谱参数等因素的最优实验方案,建立一种简便省时及回收效果最佳的前处理流程。采用固相萃取液相色谱-电喷雾串联四极杆质谱法(HPLC/ESI-MS)检测微囊藻毒素-LR(MC-LR),选用0.2%甲酸甲醇溶液-0.2%甲酸水溶液梯度洗脱、选用HLB小柱、普通氮吹仪浓缩(氮气流量1.5 L/min、水浴温度38℃)平均回收率为89.3%。质谱优化结果表明:当定量离子质荷比995.8135锥孔电压49,碰撞能量54;995.8375.1锥孔电压49,碰撞能量50,MCYST-LR灵敏度高且响应值最大。所建立优化的前处理、检测方法,具有准确度高、灵敏度高、回收率高、分离效果更好的优点,可用于分析水体中痕量MCYST-LR。     

基于紫外/可见光谱技术的李子硬度无损检测

目的探究采用紫外/可见光谱技术结合化学计量学预测李子硬度的可行性。方法以“红”李子和“青”李子为研究对象,采用光谱采集系统获取李子样本的平均光谱;采用标准正态变换对原始光谱数据进行预处理,并利用连续投影算法(SPA)和竞争性自适应重加权算法(CARS)从全光谱的1024个波长中分别提取2个(513.04 nm和636.72 nm)和10个(230.01,244.67,274.71,287.66,290.90,300.59,311.78,423.08,515.39,631.31 nm)特征波长;分别建立基于全光谱和提取的特征波长预测李子硬度的误差反向传播(BP)网络模型。结果将采用SPA和CARS特征波长选择方法提取的特征变量作为BP网络输入,明显提升了BP网络模型的运行效率,且SPA-BP网络模型具有相对较好的李子硬度预测能力(rp=0.695,预测样本集均方根误差为1.610 kg/cm2)。结论采用紫外/可见光谱技术结合特征波长提取方法可实现李子硬度的快速无损检测。     

紫外/可见光谱技术无损检测苹果的挤压损伤

目的 通过紫外/可见光谱技术结合模式识别算法,建立挤压损伤苹果的Fisher识别模型、K最近邻（KNN）识别模型和偏最小二乘判别分析（PLS-DA）识别模型。方法 以挤压损伤苹果和无损苹果为研究对象,采用光谱仪采集2种苹果的光谱反射率,综合比较不同光谱预处理方法（二阶微分（SD）、标准正态变换（SNV）和多元散射校正（MSC））对各模型识别效果的影响,并利用主成分分析方法（PCA）对预处理后的光谱数据进行降维,并提取能反映损伤苹果的特征光谱。结果 采用主成分分析法选择了累计贡献率超过99%的前7个主成分（P1—P7）作为特征光谱数据,有效地实现了光谱数据的降维;二阶微分对光谱反射率预处理的效果最好;3种判别模型均能满足实际要求,且SD+Fisher和SD+PLS-DA识别模型对校正集和预测集样本的总正确识别率均高达100%。结论 研究结果有助于实现挤压损伤苹果的快速识别。     

碳纳米管/聚苯胺化学修饰电极的制备及其对抗坏血酸的检测

通过恒电压沉积法将纳米金属镍沉积于石墨电极表面, 经化学气相沉积法在石墨电极表面原位生长出碳纳米管(CNTs), 通过电化学聚合法在CNTs表面原位聚合聚苯胺, 从而获得化学修饰电极。采用扫描电子显微镜对所得电极形貌结构进行表征, 并研究CNTs与PNAI复合电极对抗坏血酸(AA)的检测效果。研究结果表明: 制备的CNTs都能均匀地生长在石墨电极表面, 纳米中空管状结构都保持完好; PANI均匀地包覆在CNTs管壁上, 复合材料呈现出典型的三维网状结构。所制备的CNTs/PANI修饰电极对AA具有良好的电化学响应, 其中管径较小CNTs的修饰电极对AA的电化学响应更强: 具有更宽的检测范围和更低的检出限。其检测线性范围为1.0×10^-6~4.5×10^-4 mol/L, 检出限为1.0×10^-7 mol/L (S/N = 3)。且具有良好的稳定性、重复性和可靠性。     

Biobased Agents for Single-Particle Detection with Optoacoustics (Small 29/2023)

Optoacoustic (OA, photoacoustic) imaging synergistically combines rich optical contrast with the resolution of ultrasound within light-scattering biological tissues. Contrast agents have become essential to boost deep-tissue OA sensitivity and fully exploit the capabilities of state-of-the-art OA imaging systems, thus facilitating the clinical translation of this modality. Inorganic particles with sizes of several microns can also be individually localized and tracked, thus enabling new applications in drug delivery, microrobotics, or super-resolution imaging. However, significant concerns have been raised regarding the low bio-degradability and potential toxic effects of inorganic particles. Bio-based, biodegradable nano- and microcapsules consisting of an aqueous core with clinically-approved indocyanine green (ICG) and a cross-linked casein shell obtained in an inverse emulsion approach are introduced. The feasibility to provide contrast-enhanced in vivo OA imaging with nanocapsules as well as localizing and tracking individual larger microcapsules of 4–5 µm is demonstrated. All components of the developed capsules are safe for human use and the inverse emulsion approach is known to be compatible with a variety of shell materials and payloads. Hence, the enhanced OA imaging performance can be exploited in multiple biomedical studies and can open a route to clinical approval of agents detectable at a single-particle level.     

1600/3000t/h型斗轮堆取料机油缸支座开裂原因的检测分析

某厂1600/3000t/h型斗轮堆取料机运行多年后,油缸支座反复出现开裂的缺陷,造成斗轮机臂架晃动增大,影响设备的安全。通过测试找出了该部位开裂的根本原因,由于着地力过大造成支座受力增大和俯仰油缸故障造成油缸左右侧受力方向相反造成的。用户根据测试结果及建议,制定了针对性的整改方案,整改结束后重新进行了油缸支座的应力、着地力和油缸压力测试,检测结果均符合了设计要求,为用户彻底解决了油缸支座问题。     

相似异物的透/反射光谱成像检测新方法

针对复杂背景中相似异物检测难题,提出了一种利用透/反射光谱成像的相似异物检测方法.该方法利用异物与背景不同的透/反射特性差异,根据差异建立不同的成像模式,在不同的成像模式下优选最佳光照波长以区分背景中的异物,以此构建透/反射光谱成像检测系统.以棉花中的白色丝状异物作为实验对象,利用最佳波长透/反射成像系统获取异物图像特征,采用二值化自适应阈值图像处理从背景中提取异物.实验结果表明,在反射光照系数0.74及透射光照系数0.83条件下,该方法对相似异物的检测率达到91%.这一方法为目前相似异物检测提供一条切实可行的新思路.