Palladium‐Catalyzed Dearomative Cyclocarbonylation by CN Bond Activation

A fundamentally novel approach to bioactive quinolizinones is based on the palladium‐catalyzed intramolecular cyclocarbonylation of allylamines. [Pd(Xantphos)I₂], which features a very large bite angle, has been found to facilitate the rapid carbonylation of azaarene‐substituted allylamines into bioactive quinolizinones in good to excellent yields. This transformation represents the first dearomative carbonylation and is proposed to proceed by palladium‐catalyzed C? N bond activation, dearomatization, CO insertion, and a Heck reaction.     

In Vivo Endoscopic Tissue Identification by Rapid Evaporative Ionization Mass Spectrometry (REIMS)

Gastrointestinal cancers are a leading cause of mortality, accounting for 23 % of cancer‐related deaths worldwide. In order to improve outcomes from these cancers, novel tissue characterization methods are needed to facilitate accurate diagnosis. Rapid evaporative ionization mass spectrometry (REIMS) is a technique developed for the in vivo classification of human tissue through mass spectrometric analysis of aerosols released during electrosurgical dissection. This ionization technique was further developed by utilizing surface induced dissociation and was integrated with an endoscopic polypectomy snare to allow in vivo analysis of the gastrointestinal tract. We tested the classification performance of this novel endoscopic REIMS method in vivo. It was shown to be capable of differentiating between healthy layers of the intestinal wall, cancer, and adenomatous polyps based on the REIMS fingerprint of each tissue type in vivo.     

NiSe Nanowire Film Supported on Nickel Foam: An Efficient and Stable 3D Bifunctional Electrode for Full Water Splitting

Active and stable electrocatalysts made from earth‐abundant elements are key to water splitting for hydrogen production through electrolysis. The growth of NiSe nanowire film on nickel foam (NiSe/NF) in situ by hydrothermal treatment of NF using NaHSe as Se source is presented. When used as a 3D oxygen evolution electrode, the NiSe/NF exhibits high activity with an overpotential of 270 mV required to achieve 20 mA cm^?2 and strong durability in 1.0 M KOH, and the NiOOH species formed at the NiSe surface serves as the actual catalytic site. The system is also highly efficient for catalyzing the hydrogen evolution reaction in basic media. This bifunctional electrode enables a high‐performance alkaline water electrolyzer with 10 mA cm^?2 at a cell voltage of 1.63 V.     

Cobalt‐Catalyzed Allylation of Heterobicyclic Alkenes: Ligand‐Induced Divergent Reactivities

The allylation of heterobicyclic alkenes is presented for the first time. By using an inexpensive cobalt salt as the catalyst and easy‐to‐handle potassium allyltrifluoroborate as the reagent, an unprecedented formal hydroallylation of the bicyclic alkenes is realized in high efficiency. When a chiral cobalt/bis(phosphine) complex is used instead, the alternative ring‐opening products can be obtained in high yield and excellent enantioselectivity.     

Realizing both High Energy and High Power Densities by Twisting Three Carbon‐Nanotube‐Based Hybrid Fibers

Energy storage devices, such as lithium‐ion batteries and supercapacitors, are required for the modern electronics. However, the intrinsic characteristics of low power densities in batteries and low energy densities in supercapacitors have limited their applications. How to simultaneously realize high energy and power densities in one device remains a challenge. Herein a fiber‐shaped hybrid energy‐storage device (FESD) formed by twisting three carbon nanotube hybrid fibers demonstrates both high energy and power densities. For the FESD, the energy density (50 mWh cm^?3 or 90 Wh kg^?1) many times higher than for other forms of supercapacitors and approximately 3 times that of thin‐film batteries; the power density (1 W cm^?3 or 5970 W kg^?1) is approximately 140 times of thin‐film lithium‐ion battery. The FESD is flexible, weaveable and wearable, which offers promising advantages in the modern electronics.     

Directed meta‐Selective Bromination of Arenes with Ruthenium Catalysts

A Ru‐catalyzed direct C? H activation/meta‐bromination of arenes bearing pyridyl, pyrimidyl, and pyrazolyl directing groups has been developed. A series of bromo aryl pyridines and pyrimidines have been synthesized, and further coupling reactions have also been demonstrated for a number of representative functionalized arenes. Preliminary mechanistic studies have revealed that this reaction may proceed through radical‐mediated bromination when NBS is utilized as the bromine source. This type of transformation has opened up a new direction for the radical non‐ipso functionalization of metal with regard to future C? H activation development that would allow the remote functionalization of aromatic systems.     

岩土工程中的位移反分析法

从弹性力学的位移基本方程出发，讨论了平面应变情况下的各类反演问题，扩展了文［１］的结果，并研制出相应的软件，最后给出的算例表明了算法的可行性及计算精度。     

应用分区非线性变分原理的杂交薄壳单元

本文讨论了高次杂交壳体元在材料非线性分析中的应用，为了更精确估计单元内各部分应力的不同影响，本文应用了分区非线性变分原理推导出杂交壳元在应力增量下应用初始应力法的失衡节点力，这使得高次杂交元在非线性分析中的优点得以充分的发挥，从而大大提高了计算精度。     

Raman spectroscopic detection for liquid and solid targets using a spatial heterodyne spectrometer

Spatial heterodyne Raman spectroscopy (SHRS) is a new type of effective method for the analysis of structure and composition of liquid and solid targets with the characteristics of no moving parts, high spectral resolution, high optical throughput and large field of view. The technique is very suitable for detecting the targets from long distances or under the conditions with ambient light, which is essential for the exploration of planetary surface. In order to have a better understanding of the ability of SHRS for the detection of liquid and solid targets, a breadboard was designed, built and calibrated. Signal to noise was estimated at different integration time or laser power for carbon tetrachloride. Pure materials or materials contained in bottles were both tested. The mixture of organic liquids or inorganic solids were tested. In order to test the detection ability for natural targets, some composition‐unknown rocks and pebbles were tested. The results have shown that SHRS can meet the requirements for the detection of weak Raman signal scattered from artificial or natural targets. Standoff detection of sulfur from 5‐m or 10‐m distance without using any telescope or collimation optics was also tried to test the high optical throughput of SHRS. The potential feasibility of standoff detection has been proved. Copyright © 2015 John Wiley & Sons, Ltd.     

Modeling red coral (Corallium rubrum) and African snail (Helixia aspersa) shell pigments: Raman spectroscopy versus DFT studies

Pigments from red coral (Corallium rubrum) and African snail (Helixia aspersa) shell were studied non‐invasively using Raman spectroscopy with 1064‐nm laser beam. The two observed bands because of organic pigments confined in biomineralized CaCO₃ matrix at about 1500 and 1100 cm⁻¹ were assigned to ν(CC) and ν(C―C), respectively. Both signals originate from polyene(s) of largely unknown structure, containing several conjugated CC bonds. The small peak at 1016 cm⁻¹ in the Raman spectrum of coral pigment was assigned to in‐plane ―CH₃ rocking or structural deformation of polyene chain because of spatial confinement in the mineral matrix. The organic pigments in red coral and snail shell were present in inorganic matrix containing aragonite (shell) and calcite (coral). In addition, using Raman spectroscopy, it was observed that aragonite was replaced by calcite as result of healing damaged parts of snail shell. This is an important finding which indicates a great potential of nondestructive Raman spectroscopy instead of X‐ray technique, as a diagnostic tool in environmental studies. To support analysis of the observed Raman spectra detailed calculations using density functional theory (DFT with B3LYP and BLYP density functionals) on structure and vibrations of model all‐trans polyenes were undertaken. DFT calculated CC and C―C stretching frequencies for all‐trans polyenes containing from 2 to 14 CC units were compared with the observed ν(CC) and ν(C―C) band positions of the studied coral and shell. Individual correction factors were used to better match theoretical wavenumbers with observed band positions in red coral and African snail. It was concluded that all‐trans polyene pigments of red coral and dark parts of African snail shell contain 11–12 and 14 CC double bond units, respectively. However, Raman spectroscopy cannot produce any clear information on the presence and nature of the end‐chain substituents in the studied pigments. Copyright © 2016 John Wiley & Sons, Ltd.