In‐situ structural characterizations of electrochemical intercalation of graphite compounds

Graphite carbon has been successfully used for the anode materials of secondary ion batteries due to its capability of accommodating ions between graphite layers.The intercalation dynamics intrinsically determine the performance of the batteries.In this review,we summarize recent research progresses of structural characterizations on graphite intercalation in electrochemical devices,especially on the in‐situ study on the intercalations of Li/Na/K ions,AlCl4−and other anions,or solvents.These techniques,including X‐ray,electron microscopy,Raman,neutron scattering,nuclear magnetic resonance,and optical microscopy provide direct information of the reaction dynamics and help to understand the factors affecting the electrochemical performances of metallic ion batteries.

A new strategy for the fabrication of covalent organic framework‐metal‐organic framework hybrids via in‐situ functionalization of ligands for improved hydrogen evolution reaction activity

The development of novel porous materials have attracted significant attention owing to its possible application in several fields.In this study,we designed a novel covalent organic framework‐metal‐organic framework(COF‐MOF)material through an in‐situ ligand self‐assembly method.The in‐situ modified ligands not only act as nucleation sites to form Ti‐MOF,but also as a channel to rapidly transfer photogenerated electrons without introducing additional chemical bonds.The photocatalytic hydrogen production rate achieved over B‐CTF‐Ti‐MOF(1:1)was 1975μmol·g^(–1)·h^(–1) with an apparent quantum efficiency of 4.76%,which is 11.8 times higher than that of the pure CTF‐1.In addition,compared with the sample prepared by separating the ligands(CTF‐1/Ti‐MOF),B‐CTF‐Ti‐MOF shows excellent activity and stability.Finally,a reasonable photocatalytic mechanism was proposed using the results of electrochemical tests and spectral analyses.This study provides a universal method for the construction of highly efficient and stable COF/MOF materials with excellent properties.

In-situ polymerization for PPy/g-C_3N_4 composites with enhanced visible light photocatalytic performance

Polypyrrole‐modified graphitic carbon nitride composites(PPy/g‐C3N4)are fabricated using an in‐situ polymerization method to improve the visible light photocatalytic activity of g‐C3N4.The PPy/g‐C3N4 is applied to the photocatalytic degradation of methylene blue(MB)under visible light irradiation.Various characterization techniques are employed to investigate the relationship between the structural properties and photoactivities of the as‐prepared composites.Results show that the specific surface area of the PPy/g‐C3N4 composites increases upon assembly of the amorphous PPy nanoparticles on the g‐C3N4 surface.Owing to the strong conductivity,the PPy can be used as a transition channel for electrons to move onto the g‐C3N4 surface,thus inhibiting the recombination of photogenerated carriers of g‐C3N4 and improving the photocatalytic performance.The elevated light adsorption of PPy/g‐C3N4 composites is attributed to the strong absorption coefficient of PPy.The composite containing 0.75 wt%PPy exhibits a photocatalytic efficiency that is 3 times higher than that of g‐C3N4 in 2 h.Moreover,the degradation kinetics follow a pseudo‐first‐order model.A detailed photocatalytic mechanism is proposed with·OH and·O2-radicals as the main reactive species.The present work provides new insights into the mechanistic understanding of PPy in PPy/g‐C3N4 composites for environmental applications.

Formation mechanism of highly dispersed semi-embedded ruthenium nanoparticles in porous carbon matrix determined by in situ temperature-programmed infrared spectroscopy

The carbonization process of a sucrose‐RuCl3/SBA‐15composite towards a Ru‐containing ordered mesoporous carbon(Ru‐OMC)catalyst was studied by in situ temperature‐programmed infrared spectroscopy to identify the stabilization role of organic carbon precursors during the formation of highly dispersed Ru nanoparticles.The results show that the formation of metal carbonyl species results in the formation of homogeneously distributed Ru nanoparticles,and the rigid silica support and carbon matrix around the Ru(CO)x complex can significantly avoid the sintering and agglomeration of Ru metal particles during elevated temperature thermal treatment.These results ultimately demonstrate that sucrose plays important roles in the formation of homogeneously distributed Ru nanoparticles in a porous carbon matrix.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Structural change of molybdenum sulfide facilitates the electrocatalytic hydrogen evolution reaction at neutral pH as revealed by in situ Raman spectroscopy

Molybdenum sulfides are promising electrocatalysts for the hydrogen evolution reaction(HER).Sand Mo‐related species have been proposed as the active site for forming adsorbed hydrogen to initiate the HER;however,the nature of the interaction between Mo centers and S ligands is unclear.Further,the development of cost‐effective water‐splitting systems using neutral water as a proton source for H2evolution is highly desirable,whereas the mechanism of the HER at neutral pH is rarely discussed.Here,the structural change in the Mo?Mo and S?S species in a synthesized molybdenum sulfide was monitored at neutral pH using in situ electrochemical Raman spectroscopy.Analysis of the potential dependent Raman spectra revealed that the band assigned to a terminal S?S species emerged along with synchronized changes in the frequency of the Mo?Mo,Mo3?μ3S,and Mo?S vibrational bands.This indicates that Mo?Mo bonds and terminal S?S ligands play synergistic roles in facilitating hydrogen evolution,likely via the internal reorganization of trinuclear Mo3?thio species.The nature and role of metal‐ligand interactions in the HER revealed in this study demonstrated a mechanism that is distinct from those reported previously in which the S or Mo sites function independently.

Heterostructuring 2D TiO_(2) nanosheets in situ grown on Ti_(3)C_(2)T_(x) MXene to improve the electrocatalytic nitrogen reduction

In this study,TiO_(2) nanosheets(NSs)grown in situ on extremely conductive Ti_(3)C_(2)T_(x) MXene to form TiO_(2)/Ti_(3)C_(2)T_(x) MXene composites with abundant active sites are proposed to effectively achieve elec‐trocatalytic NH_(3) synthesis.Electron transfer can be promoted by Ti_(3)C_(2)T_(x) MXene with high conduc‐tivity.Meanwhile,the TiO_(2) NSs in‐situ formation can not only avoid Ti_(3)C_(2)T_(x) MXene microstacking but also enhance the surface specific area of Ti_(3)C_(2)T_(x) MXene.The TiO_(2)/Ti_(3)C_(2)T_(x) MXene catalyst reach‐es a high Faradaic efϐiciency(FE)of 44.68%at−0.75 V vs.RHE and a large NH3 yield of 44.17µg h^(-1) mg^(-1)cat.at−0.95 V,with strong electrochemical durability.15N isotopic labeling experiments imply that the N in the produced NH3 originated from the N2 of the electrolyte.DFT calculations were conducted to determine the possible NRR reaction pathways for TiO_(2)/Ti_(3)C_(2)T_(x) MXene composites.MXene catalysts combined with other materials have been rationally designed for efficient ammonia production under ambient conditions。

Identification of active sites for hydrogenation over Ru/SBA-15 using in situ Fourier-transform infrared spectroscopy

The active sites for hydrogenation over Ru/SBA‐15catalysts were identified using in situ Fourier‐transform infrared spectroscopy.The amount of active sites was proportional to the interfacial circumference of the Ru particles.In contrast,the rate of hydrogen spillover from Ru to the support was inversely proportional to the size of the Ru metal particles.Consequently,a catalyst with small Ru metal particles has a high rate of hydrogen spillover but a low density of active sites,whereas one with large Ru particles has a low rate of hydrogen spillover but a high density of active sites.The formation of these active sites is probably an intermediate step in hydrogen spillover.

Layered manganese phosphorus trisulfides for high-performance lithium-ion batteries and the storage mechanism

Although advanced anode materials for the lithium-ion battery have been investigated for decades,a reliable,high-capacity,and durable material that can enable a fast charge remains elusive.Herein,we report that a metal phosphorous trichalcogenide of MnPS_(3)(manganese phosphorus trisulfide),endowed with a unique and layered van der Waals structure,is highly beneficial for the fast insertion/extraction of alkali metal ions and can facilitate changes in the buffer volume during cycles with robust structural stability.The few-layered MnPS_(3)anodes displayed the desirable specific capacity and excellent rate chargeability owing to their good electronic and ionic conductivities.When assembled as a half-cell lithium-ion battery,a high reversible capacity of 380 mA h g^(−1)was maintained by the MnPS_(3)after 3000 cycles at a high current density of 4 A g^(−1),with a capacity retention of close to or above 100%.In full-cell testing,a reversible capacity of 450 mA h g^(−1)after 200 cycles was maintained as well.The results of in-situ TEM revealed that MnPS_(3)nanoflakes maintained a high structural integrity without exhibiting any pulverization after undergoing large volumetric expansion for the insertion of a large number of lithium ions.Their kinetics of lithium-ion diffusion,stable structure,and high pseudocapacitance contributed to their comprehensive performance,for example,a high specific capacity,rapid charge-discharge,and long cyclability.MnPS_(3)is thus an efficient anode for the next generation of batteries with a fast charge/discharge capability.

现制防水技术在混凝土建筑中的应用

混凝土建筑密封防水领域大量采用防水卷材制作防水层,传统防水卷材形变能力较,差易形成空鼓,施工搭接边部位防水能力薄弱,且施工质量受限于施工人员的经验水平,漏水隐患大。提出采用现场施工的方式制得卷材防水层,形成的防水层通过化学和物理的交联作用实现与混凝土基面的满粘效果,克服传统防水卷材存在与基面粘结不牢的问题,实现全密封防水。介绍了现制防水技术的工程应用实例。

Coordination environment of active sites and their effect on catalytic performance of heterogeneous catalysts

The structural complexity of supported metal catalysts,playing significant role in a wide range of chemical technologies,have prevented us from deeply understanding their catalytic mechanisms at atomic level.A fundamental understanding of the nature of active sites and structure–performance relationship of supported metal catalysts from a comprehensive view will open up numerous new opportunities for the development of advanced catalysts to address the global challenges in energy conversion and environmental protection.This review surveys the effects of multiple factors,including the metal size,shape,support,alloy and ligand modifier,on the coordinated environment of active center and further their influence on the catalytic reactions,aiming to provide guidance for the design of industrialized heterogeneous catalysts with extraordinary performance.Subsequently,the key structure characterization techniques in determining the coordination structure of active metal sites,especially the dynamic coordination structure change under the reaction condition,are well summarized.A brief summary is finally provided together with personal perspectives on the further development in the field of heterogeneous metal catalysts.

总体最小二乘法在惯导原位标定中的应用

惯导系统原位标定是提高恒战状态下惯导性能的重要手段。在原位标定输入输出观测数据均含有噪声的情况下,应用传统的最小二乘法进行参数辨识将会得到有偏的结果。因此,为了提高惯导误差参数的标定精度,研究了总体最小二乘法在惯导原位标定数据处理中的应用。首先给出一种16位置标定方案,推导了考虑框架轴、陀螺和加速度计安装误差的惯导系统误差模型,讨论了总体最小二乘法,并分别应用最小二乘法和总体最小二乘法辨识惯导系统的36项误差参数。仿真表明,总体最小二乘法对误差参数的辨识效果优于传统的最小二乘法,满足原位标定精度的要求。

New insight into hydroxyl-mediated NH_3 formation on the Rh-CeO_2 catalyst surface during catalytic reduction of NO by CO

Vibrational IR spectra and light‐off investigations show that NH3forms via the“hydrogen down”reaction of adsorbed CO and NO with hydroxyl groups on a CeO2support during the catalytic reduction of NO by CO.The presence of water in the reaction stream results in a significant increase in NH3selectivity.This result is due to water‐induced hydroxylation promoting NH3formation and the competitive adsorption of H2O and NO at the same sites,which inhibits the reactivity of NO reduction by NH3.

Thermo‐driven photocatalytic CO reduction and H_(2) oxidation over ZnO via regulation of reactant gas adsorption electron transfer behavior

Photothermal catalysis is a widely researched field in which the reaction mechanism is usually investigated based on the photochemical behavior of the catalytic material.Considering that the adsorption of reactants is essential for catalytic reactions to occur,in this study,the synergistic effect of photothermal catalysis is innovatively elucidated in terms of the electron transfer behavior of reactant adsorption.For the H_(2)+O2 or CO+H_(2)reaction systems over a ZnO catalyst,UV irradiation at 25°C or heat without UV irradiation did not cause H_(2)oxidation or CO reduction;only photothermal conditions(100 or 150°C+UV light)initiated the two reactions.This result is related to the electron transfer behavior associated with the adsorption of CO or H_(2)on ZnO,in which H_(2)or CO that lost an electron could be oxidized by O2 or hydroxyls.However,the electron‐accepting CO could be reduced by the electron‐donating H_(2)into CH4 under photothermal conditions.Based on the in‐situ characterization and theoretical calculation results,it was established that the synergistic effect of the photothermal conditions acted on the(002)crystal surface of ZnO to stimulate the growth of zinc vacancies,which resulted in the formation of defect energy levels,adsorption sites,and an adjusted Fermi level.As a result,the electron transfer behavior between adsorbed CO or H_(2)and the crystal surface varied,which further affected the photocatalytic behavior.The results show that the effect of photothermal synergy may not only produce the expected kinetic energy,but more importantly,produce energy that can change the activation mode of the reactant gas.This study provides a new understanding of the CO catalytic oxidation and reduction processes over semiconductor materials.

Preparation of graphene/MgCl_2-supported Ti-based Ziegler-Natta catalysts by the coagglomeration method and their application in ethylene polymerization

We report a facile coagglomeration method for preparing graphene (G)/MgCl2‐supported Ti‐based Ziegler‐Natta catalysts. The effects of graphene feed ratio on catalyst morphology and ethylene polymerization behavior were examined. The synthesized catalyst exhibited very high activity for ethylene polymerization. The resultant polyethylene (PE)/G nanocomposites showed a layered morphology, and the graphene fillers were well dispersed in the PE matrix. In addition, the thermal stability and mechanical properties of PE were significantly enhanced with the introduction of a very small amount of G fillers (0.05 wt%). This work provides a facile approach to the production o fhigh‐performance PE.

惯性导航系统原位标定技术

误差标定及补偿是提高惯性系统使用精度的重要手段。惯导系统原位标定在提高装备机动性和保障效率方面具有明显的优势。综合考虑惯导系统的框架轴、陀螺和加速度计安装误差,详细推导了适合惯导系统原位标定的误差模型。给出了一种16位置标定方案,分离出惯导系统的36项误差系数。经仿真验证,标定精度取得了良好的效果。

急性早幼粒细胞白血病变异易位derins(17；15)患者的联合G显带和间期荧光原位杂交分析

为探讨1例罕见的急性早幼粒细胞白血病插入型变异易位derins(17;15)的白血病细胞的生物学特征,联合应用G显带、间期荧光原位杂交、RT-PCR、基因扫描、基因测序和流式细胞术等对该例变异型易位患者进行了研究。结果表明:G显带所见的derins(17;15)是一种罕见的类型,联合应用间期荧光原位杂交技术、采用位点特异的双色pml/rarα融合探针证实了G显带的结果,间期FISH技术检测出几种信号类型,分子生物学方法证实该例虽具有插入型变异易位,但仍存在完整的pml/rarα基因。该病例经联合化疗达完全缓解,随访1年至今仍完全缓解。结论:t(15;17)变异型插入易位发生率低,其在间期荧光原位杂交中具有多种信号类型,本例应用联合化疗疗效明显。

保压取样钻具内岩心温压采集器的研制与应用

在绳索取心钻探过程中,井底温度与压力的实时测量,有助于改进取心工艺,提高岩心采取率;同时岩心在井底的原位测量数据对于了解岩心的物理特性有着重要意义,这一点在海域天然气水合物勘探中尤为明显。本文主要介绍了一种内置于保压取样钻具中的温压采集器的结构及其工作原理。该采集器采用干电池供电,单次工作时间>72 h,能够采集与存储整个取样过程中岩心管内的温度与压力参数,与电脑端连接后就能得到全部数据。通过搭载海洋地质十号钻探船,该采集器完成了一个回次的海试试验,得到了整个绳索取心钻进过程的温度与压力数据。经过分析,收集到的数据与实际取心工艺过程相符,数据平稳可靠。

Tunable catalytic release of nitric oxide via copper‐loaded coatings on titanium nanotubes for regulating biological performance

Severe lesions in vessels need to be treated with implantable interventional devices such as vascular stents,which should be anti‐coagulantion,anti‐proliferation and promoting endothelialisation.Nitric oxide(NO),as a physiological gas signalling molecule,play an important role in revascularisation.Catalysing the release of NO from endogenous do-nors has already been widely favoured to treatment strategy for lesioned vessels.In this work,a series of copper‐loaded coatings(titanium nanotube(TNT)/PDA‐Cu)was fabricated by TNTs combined with polydopamine and ions,which achieve controlled in situ catalytic release of NO.This strategy could effectively immobilised copper ions on TNTs,and promoted the proliferation of endothelial cells and inhibited growth of smooth muscle cells(SMCs)via the performance of NO,as well as restrain the platelet adhesion.With the multiple function,TNT/PDA‐Cu provides a promise approach for promoting endothelialisation,anti‐coagulation and inhibition of SMC proliferation via copper‐loaded coatings on TNTs.

Thermo-mechanical and tribological properties of SU-8/h-BN composite with SN150/perfluoropolyether filler

In this study, SU-8 and its composites are fabricated by blending 10 wt.% hexagonal boron nitride(h-BN) fillers with/without lubricants, such as 10 wt.% base oil(SN150) and 20 wt.% perfluoropolyether(PFPE). The thickness of SU-8 and its composites coating is fabricated in the range ~100–105 μm. Further, SU-8 and its composites are characterized by a 3D optical profilometer, atomic force microscopy, scanning electron microscopy, a thermal gravimetric analyzer, a goniometer, a hardness tester, and an optical microscope. Under a tribology test performed at different normal loads of 2, 4, and 6 N and at a constant sliding speed of 0.28 m/s, the reduction in the initial and steady-state coefficient of friction is obtained to be ~0.08 and ~0.098, respectively, in comparison to SU-8(~0.42 and ~0.75), and the wear resistance is enhanced by more than 103 times that of pure SU-8. Moreover, the thermal stability is improved by ~80–120 ℃, and the hardness and elastic modulus by ~3 and ~2 times that of pure SU-8, respectively. The SU-8 composite reinforced with 10 wt.% h-BN and 20 wt.% PFPE demonstrated the best thermo-mechanical and tribological properties with a nano-textured surface of high hydrophobicity.

伴有ins（8；21）（q22；q22．1q22．3）髓系白血病的荧光原位杂交研究

目的 对1例临床诊断为慢性粒单核细胞白血病患者进行荧光原位杂交（fluorescence in situ hybridization，FISH）研究。方法将患者骨髓细胞24h培养后按常规方法制备染色体，采用R显带技术进行染色体核型分析；采用AML1-ETO双色双融合探针、8号和21号整条染色体涂染探针、8号染色体着丝粒探针和21号染色体亚端粒探针分别进行3种FISH分析；应用逆转录聚合酶链反应（reversetranscription polymerase chain reaction，RT—PCR）检测AML1-ETO融合转录本。结果核型分析显示46，XX，ins（8；21）（q22；q22．1q22．3）[7]／46，XX[3]；FISH分析证实ins（8；21）（q22；q22．1q22．3）；RT-PCR分析检出AML1-ETO融合转录本。结论 按照世界卫生组织分型标准，此例应重新诊断为急性髓系白血病，FISH和RT—PCR在证实ins（8；21）中起重要作用。