Enzyme-free and DNA-based universal platform for the construction of various logic devices based on graphene oxide and G-quadruplex

In the fields of biocomputing and biomolecular, DNA molecules are applicable to be regarded as data of logical computing platform that uses elaborate logic gates to perform a variety of tasks. Graphene oxide (GO) is a type of novel nanomaterial, which brings new research focus to materials science and biosensors due to its special selectivity and excellent quenching ability. G-quadruplex as a unique DNA structure stimulates the intelligent application of DNA assembly on the strength of its exceptional binding activity. In this paper, we report a universal logic device assisted with GO and G-quadruplex under an enzyme-free condition. Integrated with the quenching ability of GO to the TAMRA (fluorophore, Carboxytetramethylrhodamine) and the enhancement of fluorescence intensity produced by the peculiar binding of G-quadruplex to the NMM (N-methylmesoporphyrin IX), a series of basic binary logic gates (AND. OR. INHIBIT. XOR) have been designed and verified through biological experiments. Given the modularity and programmability of this strategy, two advanced logic gates (half adder and half subtractor) were realized on the basis of the same work platform. The fluorescence signals generated from different input combinations possessed satisfactory results, which provided proof of feasibility. We believe that the proposed universal logical platform that operates at the nanoscale is expected to be utilized for future applications in molecular computing as well as disease diagnosis.     

Biosurfactant trehalose lipid‐enhanced ultrasound‐assisted micellar extraction and determination of the main antioxidant compounds from functional plant tea

Hydrosoluble trehalose lipid (a biosurfactant) was employed for the first time as a green extraction solution to extract the main antioxidant compounds (geniposidic acid, chlorogenic acid, caffeic acid, and rutin) from functional plant tea (Eucommia ulmoides leaves). Single‐factor tests and response surface methodology were employed to optimize the extraction conditions for ultrasound‐assisted micellar extraction combined with ultra‐high‐performance liquid chromatography in succession. A Box‐Behnken design (three‐level, three‐factorial) was used to determine the effects of extraction solvent concentration (1–5 mg/mL), extraction solvent volume (5–15 mL), and extraction time (20–40 min) at a uniform ultrasonic power and temperature. In consequence, the best analyte extraction yields could be attained when the trehalose lipid solution concentration was prepared at 3 mg/mL, the trehalose lipid solution volume was 10 mL and the extraction time was set to 35 min. In addition, the recoveries of the antioxidants from Eucommia ulmoides leaves analyzed by this analytical method ranged from 98.2 to 102%. These results indicated that biosurfactant‐enhanced ultrasound‐assisted micellar extraction coupled with a simple ultra‐high‐performance liquid chromatography method could be effectively applied in the extraction and analysis of antioxidants from Eucommia ulmoides leaf samples.     

Wearable Multiparameter Platform Based on AlGaN/GaN High‐electron‐mobility Transistors for Real‐time Monitoring of pH and Potassium Ions in Sweat

Biosensors based on field‐effect transistor (FET) structures have attracted considerable attention because they offer rapid, inexpensive parallel sensing and ultrasensitive label‐free detection. However, long‐term repeatable detection cannot be performed, and Ag/AgCl reference electrode design is complicated, which has hindered FET biosensors from becoming truly wearable health‐monitoring platforms. In this paper, we propose a novel wearable detection platform based on AlGaN/GaN high‐electron‐mobility transistors (HEMTs). In this platform, a sweatband was used to continuously collect sweat, and a pH detecting unit and a potassium ion detecting unit were formed by modifying different sensitive films to realize the long‐term stable and repeatable detection of pH and potassium ions. Experimental data show that the wearable detection platform based on AlGaN/GaN HEMTs has good sensitivity (pH 3–7 sensitivity is 45.72 μA/pH; pH 7.4–9 sensitivity is 51.073 μA/pH; and K⁺ sensitivity is 4.94 μA/lgα_K⁺), stability (28 days) and repeatability (the relative standard deviation (RSD) of pH 3–7 sensitivity is 2.6 %, the RSD of pH 7.4–9 sensitivity is 2.1 %, and the RSD of K⁺ sensitivity is 7.3 %). Our newly proposed wearable platform has excellent potential for predictive analytics and personalized medical treatment.     

杆弹侵彻钢纤维混凝土实验研究

采用DOP实验方法,进行了35CrMnSiA杆弹对不同钢纤维体积含量的钢纤维混凝土的侵彻实验.分别研究了杆弹着速和钢纤维体积含量对钢纤维混凝土杭侵彻性能的影响.实验表明,随着弹速增加,不同钢纤维含量的钢纤维混凝土侵彻深度都会增加,但钢纤维混凝土中弹体便深增加较素混凝土缓慢;而钢纤维能增强混凝土的抗侵彻性能,且随钢纤维体...     

深水钢悬链线立管触地区疲劳实验系统设计

深水钢悬链线立管(steel catenary riser, SCR)触地区易发生疲劳破坏, 且疲劳寿命预测问题是 目前理论计算与数值分析的难点, 通过实验能更好地促进理论和数值研究. 因此在相关理论 研究基础上, 设计一套SCR触地区疲劳实验系统, 模拟实际工作状况, 考虑张力、弯曲、内 外压与管土相互作用等因素的变化组合. 该实验系统为以后开展深水立管疲劳实验、研究SCR 触地区疲劳破坏机理以及准确预测SCR触地区的疲劳寿命奠定基础.     

一种基于数独的新试验设计

通过研究数独方的构成与设计,建立了一种基于数独的新试验设计,给出了这种设计的数学模型与统计分析。该设计能安排单因素的n个水平,并能在行、列、块3个方向控制变异性。     

基于虚拟仪器技术的多路水声信号同步采集及处理平台设计

本文介绍了虚拟仪器技术在水声信号处理研究中的一个具体应用,利用LabVIEW语言编程,在NI公司高速数据采集硬件平台上实现了高采样率下多通道数据的同步采集、处理、记录功能,并在不使用信号处理机的情况下,利用主控单板机的单核CPU完成了32通道常规波束成形(CBF)的实时计算。同时,本文对非DSP硬件平台的实时信号处理实现方法进行了初步的研究。     

透射光栅的实验标定和衍射效率的理论模拟

透射光栅广泛应用于软X射线能谱测量.为了获得用于惯性约束聚变研究的透射光栅的各级衍射效率及其他参数,在北京同步辐射源上200—1600 eV能量范围内对其进行了标定,获得了透射光栅衍射效率的实验结果.扩展了透射光栅衍射效率的计算方法,提出了7边准梯形截面衍射效率计算模型.分析拟合了实验数据,理论结果与实验结果很好符合.得到了7边准梯形的透射光栅栅线截面结构. 关键词： 透射光栅 衍射效率 实验标定 光栅模型     

纳秒脉冲下聚合物电树枝引发实验方法

 借鉴直流、交流的研究经验,比较了纳秒脉冲条件下几种不同的电树枝老化实验方法。对单针-板电极和多针-板电极在纳秒脉冲下实验结果的一致性进行考察,结果表明,多针-板电极系统可以在提高实验效率的同时保证结果的准确性。采用步进法和累加法进行了不同频率下聚苯乙烯电树枝引发实验,结果表明:两种方法得到的纳秒脉冲下聚苯乙烯电树枝引发电压-频率特性基本一致,在50~500 Hz范围内,引发电压随频率的升高而降低;在500~800 Hz范围内,引发电压随频率的升高而增加。最后讨论了对于不同脉冲功率装置中绝缘材料老化试验设计的方法。     

某光电雷达稳定平台关键部件转板的动态特性分析

 转板是光电雷达稳定平台的关键元件之一。为了更好地设计和分析某光电雷达稳定平台的转板,运用Pro E软件对其进行三维实体建模,合理简化后,进入Ansys软件界面建立有限元模型。应用有限元理论和Ansys软件对其进行动态特性分析,得到了转板前八阶模态的固有频率和振型,以及要求范围内的谐响应。对比了不同方法划分网格的网格质量,采取不同材料得到了不同模态。分析结果表明：设计的转板在关心的频段0~50 Hz,2 000 Hz~8 000 Hz内不发生共振,符合设计要求。