Cationic Polyelectrolyte Amplified Bead Array for DNA Detection with Zeptomole Sensitivity and Single Nucleotide Polymorphism Selectivity

A highly sensitive strand specific DNA assay, which consists of a peptide nucleic acid (PNA) probe, a cationic conjugated polymer ( PFVP ), and self‐assembled polystyrene beads in microwell arrays on silicon chip, is reported. PFVP , as an efficient signal amplifier and signal reporter, has been specially designed and synthesized to be compatible with commercial confocal microscopes for sensing on solid substrates. The assay operates on the net increase in negative charge at the PNA surface that occurs upon single‐stranded DNA hybridization, which subsequently allows complex formation with the positively charged PFVP to favor energy transfer between the polymer and Cy5‐labeled target. With maximized surface contact provided by bead arrays and signal amplification provided by PFVP , this assay allows detection of ～300 copies of Cy5‐labeled DNA using a commercial confocal microscope. In addition, the same strategy is also extended for label‐free DNA detection with a detection sensitivity of 150 attomole. Excellent discrimination against single nucleotide polymorphism (SNP) is also demonstrated for both Cy5‐labeled and label‐free target detection. This study indicates that cationic conjugated polymers have great potential to be incorporated into the widely used microarray technology for simplified process with improved detection sensitivity.     

Spontaneous and Directional Transportation of Gas Bubbles on Superhydrophobic Cones

Understanding the behavior of gas bubbles in aqueous media and realizing their spontaneous and directional manipulation are of vital importance in both scientific research and industrial applications, owing to their significant influences on many processes, such as waste water treatment, gas evolution reactions, and the recovery of valuable minerals. However, the behaviors of gas bubbles in aqueous media are mainly dominated by the buoyant force, which greatly impedes gas bubble transportation to any other direction except upward. Consequently, the spontaneous and directional transportation of gas bubbles in aqueous media is still identified as a big issue. Here, superhydrophobic copper cones have been successfully fabricated by integrating low‐surface‐tension chemical coatings with conical morphology. The generated superhydrophobic copper cones are capable of transporting gas bubbles from their tip to the base spontaneously and directionally underwater, even when they are vertically fixed with tips pointing up. The present study will inspire people to develop novel strategies to achieve efficient manipulation of gas bubbles in practical applications.     

GaiaWorld: A Novel Blockchain System Based on Competitive PoS Consensus Mechanism

The birth of blockchain has promoted the development of electronic currencies such as Bitcoin and Ethereum. Blockchain builds a financial system based on cryptology instead of credit, which allows parties to complete the transaction on their own without the need for credible third-party intermediaries. So far, the application scenario of blockchain is mainly confined to the peer-to-peer electronic financial system, which obviously does not fully utilize the potential of blockchain.
In this paper, we introduce GaiaWorld, a new system for decentralized application. To solve the problem of resource waste and mismatch between nodes and computing power in traditional PoW mechanism, GaiaWorld introduces a new consensus mechanism called CPoS, which can improve productivity and liquidity of blockchain system. GaiaWorld constructs a new architecture based on forging committee and forging group systems, which can establish a decentralized, free and stable internet trust system, and can be utilized in multiple application scenarios and construct efficient and reliable content delivery systems.     

Influence of Carbon Forms and Doped Elements in the Electrodes for the Production of Fullerenes

Production of fullereries using electrodes made of four kinds of pure carbon bearing materials and artificial graphite doped with seven kinds of elements such as B, Y, La, Gd, Ce, Pr and Nd have been examined. The yields of fullerenes were in a range between 12-20% of the soot produced for all pure carbon electrodes, even though the vaporization rate of amorphous carbon electrodes was about ten times higher than that of the natural graphite electrodes. However, for the doped graphite electrodes, the yield of fullerenes was less than 5%. From the above results it is concluded that fullerenes can be effectively produced with the pure carbon electrodes made of any form of carbon bearing materials used in this study and there is little material dependence on the yield of fullerences. Furthermore, the experiments using the artificaial graphite electrodes doped with metal elements suggests that the purity of the carbon electrodes affects the yeld of fullerenes greatly.     

基于A位元素置换策略合成新型MAX相材料Ti3ZnC2

MAX相材料是一类兼具金属和陶瓷特性的三元层状材料, 在高温导电、耐磨、耐腐蚀和耐辐照损伤等方面性能优异。目前已经合成出的MAX相材料已有70余种, 但A位元素一直局限在ⅢA和ⅣA主族元素, 如Al、Si、Ga等, 而以副族元素占据A位的MAX相鲜有报道。本研究以Ti₃AlC₂为前驱体, 利用熔盐中的A位置换反应, 制备出了A位为Zn元素的全新MAX相材料Ti₃ZnC₂。结合X射线衍射、扫描电子显微镜和透射电子显微镜等分析手段对Ti₃ZnC₂的成分和结构进行了确认, 并通过密度泛函理论对Ti₃ZnC₂的结构稳定性和晶格参数进行了确定。进一步通过热力学计算对Fe、Co、Ni、Cu等几种元素的A位置换反应进行了预测, 发现采用这几种元素的氧化物进行置换反应在热力学上也都具有可行性。本研究所提出的元素置换策略是在保持MAX相六方层状晶体结构的基础上, 利用Al、Zn在高温下形成共晶产物实现Zn原子向A层内的迁移, 而熔盐介质的存在促进了反应动力学。本方法巧妙地避免了MAX相传统合成过程中竞争相的形成, 如M-A合金相, 因此可以用于探索更多未知的MAX相材料。     

光纤水听器阵列在黄浦江航道监测中的应用

详细介绍了布设于黄浦江上游航道的光纤水听器阵列及其工作原理。通过光纤水听器阵列采集过往船只的声信号,结合能量阈值与特征强线谱,实现了对过往船只数量的统计。实验结果表明,船只流量监测功能已基本实现。此外,通过集成其他参量的传感器,扩展了水听器阵列的功能,实现对航道多参量(水温、水位以及淤泥厚度)实时监测。     

Microporous Carbon and Carbon/Metal Composite Materials Derived from Bio-Benzoxazine-Linked Precursor for CO2 Capture and Energy Storage Applications

There is currently a pursuit of synthetic approaches for designing porous carbon materials with selective CO₂ capture and/or excellent energy storage performance that significantly impacts the environment and the sustainable development of circular economy. In this study we prepared a new bio-based benzoxazine (AP-BZ) in high yield through Mannich condensation of apigenin, a naturally occurring phenol, with 4-bromoaniline and paraformaldehyde. We then prepared a PA-BZ porous organic polymer (POP) through Sonogashira coupling of AP-BZ with 1,3,6,8-tetraethynylpyrene (P-T) in the presence of Pd(PPh₃)₄. In situ Fourier transform infrared spectroscopy and differential scanning calorimetry revealed details of the thermal polymerization of the oxazine rings in the AP-BZ monomer and in the PA-BZ POP. Next, we prepared a microporous carbon/metal composite (PCMC) in three steps: Sonogashira coupling of AP-BZ with P-T in the presence of a zeolitic imidazolate framework (ZIF-67) as a directing hard template, affording a PA-BZ POP/ZIF-67 composite; etching in acetic acid; and pyrolysis of the resulting PA-BZ POP/metal composite at 500 °C. Powder X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller (BET) measurements revealed the properties of the as-prepared PCMC. The PCMC material exhibited outstanding thermal stability (T_d10 = 660 °C and char yield = 75 wt%), a high BET surface area (1110 m² g^–1), high CO₂ adsorption (5.40 mmol g^–1 at 273 K), excellent capacitance (735 F g^–1), and a capacitance retention of up to 95% after 2000 galvanostatic charge–discharge (GCD) cycles; these characteristics were excellent when compared with those of the corresponding microporous carbon (MPC) prepared through pyrolysis of the PA-BZ POP precursors with a ZIF-67 template at 500 °C.     

基于AHP—DEA模型的鱼雷方案评价研究

将层次分析法（AHP）与数据包络法（DEA）有机结合,构建了AHP—DEA的鱼雷方案评价模型,首先通过AHP法计算各鱼雷方案在评价因素中的相对权重,然后根据DEA法的原理将鱼雷方案作为决策单元、各方案的相对权重作为产出建立优化模型,通过计算模型的相对效率值,求出鱼雷方案可能性大小的顺序,并以实例阐述该模型在鱼雷方案评价中的具体运用。     

硅烷交联聚乙烯电力电缆绝缘料基础树脂的性能

利用拉伸试验、红外光谱、凝胶渗透色谱、差示扫描量热、热延伸试验等方法,对几种硅烷交联聚乙烯电力电缆绝缘料用LDPE基础树脂的性能以及LDPE和LLDPE与硅烷的接枝交联性能进行了研究。结果表明,乙烯基硅烷对LLDPE的相对接枝率比对LDPE高,LLDPE和LDPE共混物的硅烷接枝能力高于纯LDPE,LLDPE和LDPE的共混物宜用作硅烷交联聚乙烯电力电缆绝缘料的基础树脂。