Flexible Transparent Reduced Graphene Oxide Sensor Coupled with Organic Dye Molecules for Rapid Dual‐Mode Ammonia Gas Detection

Flexible chemical sensors utilizing chemically sensitive nanomaterials are of great interest for wearable sensing applications. However, obtaining high performance flexible chemical sensors with high sensitivity, fast response, transparency, stability, and workability at ambient conditions is still challenging. Herein, a newly designed flexible and transparent chemical sensor of reduced graphene oxide (R‐GO) coupled with organic dye molecules (bromophenol blue) is introduced. This device has promising properties such as high mechanical flexibility (>5000 bending cycles with a bending radius of 0.95 cm) and optical transparency (>60% in the visible region). Furthermore, stacking the water‐trapping dye layer on R‐GO enables a higher response as well as workability in a large relative humidity range (up to 80%), and dual‐mode detection capabilities of colorimetric and electrical sensing for NH₃ gas (5–40 ppm). These advantageous attributes of the flexible and transparent R‐GO sensor coupled with organic dye molecules provide great potential for real‐time monitoring of toxic gas/vapor in future practical chemical sensing at room conditions in wearable electronics.     

Ultrabroadband Optical Superchirality in a 3D Stacked‐Patch Plasmonic Metamaterial Designed by Two‐Step Glancing Angle Deposition

Low‐cost and large‐scale fabrication of 3D chiral metamaterials is highly desired for potential applications such as nanophotonics devices and chiral biosensors. One of the promising fabrication methods is to use glancing angle deposition (GLAD) of metal on self‐assembled dielectric microsphere array. However, structural handedness varies locally due to long‐range disorder of the array and therefore large‐scale realization of the same handedness is impossible. Here, using symmetry considerations a two‐step GLAD process is proposed to eliminate this longstanding problem. In the proposed scheme, the unavoidable long‐range disorder gives rise to microscale domains of the same handedness but of slightly different structural geometries and ultimately contributes to a broad‐band response. Experimentally, a record‐breaking superchiral response of circular dichroism signal of ≈11° is demonstrated and an average polarization rotation angle of 27° in the visible region on ≈1 cm² sample is observed. Computer‐aided geometric reconstruction with experimental parameters unambiguously reveal the presence of strong structural anisotropy and chirality in the prepared stacked‐patch plasmonic chiral metamaterial; microscopic spectral analyses combined with full‐wave electromagnetic simulations coherently provide deeper insights into the measured circular dichroism and optical activity. The observed chiroptical response can also be flexibly controlled by adjusting the deposition parameters for various potential applications.     

夏盐11井区剩余油分布特征与挖潜对策研究

针对新疆油田夏盐11井区层内、层间非均质性强,产量持续下降,注水开发后油藏剩余油分布规律不清楚,持续稳产能力较差的问题,利用数值模拟、油藏工程方法及动态监测资料开展了非均质性强油藏不同类型剩余油分布规律研究,明确了下步挖潜对策。研究结果表明：夏盐11井区剩余油挖潜潜力区可分为3种,Ⅰ类为注采井网不完善控制型剩余油,剩余油饱和度高,平均大于45%,油层厚度不小于4.5 m,主要发育水下分流河道,挖潜对策为储层改造提高低渗区域的物性;Ⅱ类为井间滞留型剩余油,剩余油饱和度较高,平均为20%～45%,油层厚度为3.0～4.5 m,主要发育河口坝,挖潜对策为油水井补孔、完善注采井网;Ⅲ类为水淹程度较高型剩余油,剩余油饱和度较低,平均小于20%,油层厚度不超过2 m,剩余油分布零散,挖潜对策为老井补孔和水井分注,同时进行注水井调剖,对低产井进行重复压裂、补孔。该研究可为同类型非均质性油藏开发提供参考。     

载体及反应条件对Pt/BaKL沸石催化剂芳构化性能的影响

研究了γ-Al_2O_3或SiO_2载体,以及反应条件对Pt/BaKL沸石催化剂芳构化性能的影响。发现经过碱化或负载Sn的γ-Al_2O_3作为载体,能够较好地保持该催化剂在正己烷芳构化反应中的高活性和高选择性,并有益于改善Pt/BaKL沸石催化剂的抗硫性能。     

A kind of synthetic nanopillar arrays for studying single biomolecule

The anodic aluminum oxide (AAO) template with ordered pores was firstly fabricated in oxalic acid solutions using two-step anodization method. Then, a layer of polymethylmethacrylate (PMMA) was uniformly laid on one surface of the AAO template by a Spin-Coater, then baked and cooled them, after that, the H3PO4 solution was utilized to dissolve the residual aluminum and barrier layer, as the result, the functional nanopillar arrays were achieved. Finally, the morphology of the functional PMMA nanopillars was examined with the Scanning Electron Microscope (SEM) and the properties were discussed. The functional nanopillar arrays could be applied to the micro and nano-scale devices as the sensors for the biological, chemical and single molecular detection.     

Transmission Electron Microscopy and the Science of Carbon Nanomaterials

Carbon is a unique and versatile element that is capable of forming different architectures at nanoscale. The element has become a key component in nanoscience and nanotechnology. Transmission electron microscopy (TEM) acts as “our eyes” enabling us not only to reveal the morphology, but also to provide structural, chemical and electronic information of nanocarbon on the atomic level. In fact, except for fullerene, nearly all types of carbon nanomaterials were discovered by TEM, such as carbon nanotubes, carbon nanocones, and graphene‐like nanocarbon. It cannot be imagined what nanoscience and nanotechnology would be without the contributions of TEM. Herein, the “interaction” between TEM and the science of carbon nanomaterials is reviewed and it is demonstrated for some selected examples that TEM provides a dramatic driving force for the development of nanocarbon science.     

A study of the influence of lanthanum fluoride on the tribological properties of bonded solid film lubricants and its mechanism of function

The influence of lanthanum fluoride (LaF₃) on the characteristics of phenolepoxy-bonded MoS₂ dry films was investigated. The functional mechanism was specifically studied using several analytical means. The results showed that the wear life of dry films containing a certain amount of LaF₃ was considerably increased over that of the films without LaF₃. However, the effect of LaF₃ on the friction coefficient of the dry films was shown to be negligible. It was found that the addition of LaF₃ is effective in reducing the oxidation tendency of MoS₂ in the films during the friction process. The reason for this is investigated by the authors.     

A novel complex network-based deep learning method for characterizing gas-liquid two-phase flow

Gas-liquid two-phase flow widely exits in production and transportation of petroleum industry.Characterizing gas-liquid flow and measuring flow parameters repre...     

松花江流域水利建设成就与展望

松花江是我国七大江河之一， 流经内蒙古、黑龙江、吉林和辽宁省， 流域面积５５６８ 万ｋｍ ２， 文中从流域规划、防洪体系建设、水土流失治理、生态环境保护、农田水利建设和城市水利建设等诸方面介绍了建国５０ 年来的重要成就和主要经验， 并对存在的问题进行了讨论， 提出了嫩江干流控制性枢纽工程的建设将成为下世纪初松花江流域水利建设的重点。     

AC600二次侧非能动应急堆芯余热排出系统实验装置及研究计划

ＡＣ６００二次侧非能动应急堆芯余热排出系统实验装置是一座大型非能动安全系统实验研究装置，在设计上，它以热工水力模拟理论及模拟准则为依据，在保持原型系统主要热工水力现象和过程的前提下，对系统进行了必要的简化，本文介绍了该实验装置回路，电气，仪表及测控系统的设计原则和设计结果，以及第一阶段研究计划和内容，最后，根据调试和运行结果总结了设计特点和经验。