炭棒与生物质棒稳态阴燃特性对比

为研究炭与生物质稳态阴燃的特性差异,对不同直径(2~8mm)的炭棒与绝干、空干生物质棒竖直向下的阴燃进行了试验,并编写程序计算了棒状燃料阴燃过程的耗氧速率。结果表明:(1)所制炭棒与生物质棒均能自行调节反应区形状以维持稳态阴燃。(2)炭棒的阴燃传播速度约为生物质棒的4.2倍,最高温度比生物质棒高约50℃,反应区长度约为相应生物质棒的3.8倍,燃料消耗速率约为生物质棒的2.4倍。(3)计算和试验烟气轮廓吻合较好,炭棒耗氧速率约为生物质棒的3.4倍。研究结果可为稳态阴燃机理的深入研究及应用中燃料选择提供参考。

Structural survey of metal-covalent organic frameworks and covalent metal-organic frameworks

This review offers an overview of the latest developments in metal-covalent organic framework(MCOF)and covalent metal-organic framework(CMOF)materials,whose construction entails a combination of reversible coordination and covalent bonding adapted from metal-organic frameworks(MOFs)and covalent organic frameworks(COFs),respectively.With an emphasis on the MCOF and CMOF structures,this review surveys their building blocks and topologies.Specifically,the frameworks are classified based on the dimensions of their components(building blocks),namely,discrete building blocks and one-dimensional infinite building blocks.For the first category,the materials are further divided into collections of two-and three-dimensional networks based on their topologies.For the second category,the recently emerging MCOFs with woven structures are covered.Finally,the state-of-the-art in MCOF and CMOF chemistry has been laid out for promising avenues in future developments.

Tracking the phase transformation and microstructural evolution of Sn anode using operando synchrotron X-ray energy-dispersive diffraction and X-ray tomography

Tin(Sn)holds great promise as an anode material for next-generation lithium(Li)ion batteries but suffers from massive volume change and poor cycling performance.To clarify the dynamic chemical and microstructural evolution of Sn anode during lithiation and delithiation,synchrotron X-ray energydispersive diffraction and X-ray tomography are simultaneously employed during Li/Sn cell operation.The intermediate Li-Sn alloy phases during de/lithiation are identified,and their dynamic phase transformation is unraveled which is further correlated with the volume variation of the Sn at particle-and electrode-level.Moreover,we find that the Sn particle expansion/shrinkage induced particle displacement is anisotropic:the displacement perpendicular to the electrode surface(z-axis)is more pronounced compared to the directions(x-and y-axis)along the electrode surface.This anisotropic particle displacement leads to an anisotropic volume variation at the electrode level and eventually generates a net electrode expansion towards the separator after cycling,which could be one of the root causes of mechanical detachment and delamination of electrodes during long-term operation.The unraveled chemical evolution of Li-Sn and deep insights into the microstructural evolution of Sn anode provided here could guide future design and engineering of Sn and other alloy anodes for high energy density Li-and Na-ion batteries.

Insights into the adsorption performance and mechanism of Cr(Ⅵ)onto porous nanocomposite prepared from gossans and modified coal interface:Steric,energetic,and thermodynamic parameters interpretations

Herein,iron oxide/hydroxides deposits(gossans)were utilized,for the first time,in the fabrication of magnetite nanoparticles(MNPs)to load modified coal(MC).The as-synthesized MNPs@MC composite was characterized via different techniques and utilized for the Cr(Ⅵ)remediation.Experimental studies supported by theoretical treatment were applied to offer a new overview of the Cr(Ⅵ)adsorption geometry and mechanism at 25-45℃.Experimental results suggested that the Cr(Ⅵ)uptake was mainly governed by adsorption-reduction coupled mechanism.The Langmuir model fitted well the Cr(Ⅵ)adsorption data with maximum adsorption capacities extended from 115.24 to 129.63 mg·g^(-1).Theoretical calculations indicated that Cr(Ⅵ)ions were adsorbed on the MNPs@MC following the theory of the advanced monolayer statistical model.The number of ions removed per site ranged from 1.88 to1.23 suggesting the involvement of vertical geometry and multi-ionic mechanism at all temperatures.The increment of the active sites density and the adsorption capacity at saturation with improving temperature reflected an endothermic process.Energetically,the Cr(Ⅵ)adsorption was controlled by physical forces as the adsorption energies were less than 40 kJ·mol^(-1).The calculated free enthalpy,entropy.and internal energy explained the spontaneous nature and the viability of Cr(Ⅵ)adsorption on the MNPs@MC adsorbent.These results offer a new approach in utilizing the iron-rich deposits as gossans in the preparation of magnetic and low-cost adsorbents for wastewater remediation.

The NMR core analyzing tomograph:a multi-functional tool for non-destructive testing of building materials

NMR is becoming increasingly popular for the investigation of building materials as it is a non-invasive technology that does not require any sample preparation nor causes damage to the material.Depending on the specific application it can offer insights into properties like porosity and spatial saturation degree as well as pore structure.Moreover it enables the determination of moisture transport properties and the(re-)distribution of internal moisture into different reservoirs or chemical phases upon damage and curing.However,as yet most investigations were carried out using devices originally either designed for geophysical applications or the analysis of rather homogeneous small scale(<10 mL)samples.This paper describes the capabilities of an NMR tomograph,which has been specifically optimized for the investigation of larger,heterogeneous building material samples(diameters of up to 72 mm,length of up to 700 mm)with a high flexibility due to interchangeable coils allowing for a high SNR and short echo times(50-80 ms).

论中国早寒武世原牙形类和牙形状化石--分类评述和地层意义

原牙形类和牙形状化石是早寒武世微小骨骼化石中非常特征的一个类群。自二十世纪70年代以来,这些齿状的微型磷质骨片化石在中国下寒武统含小壳化石地层中被大量发现,据统计已描述有25属52种。通过文中的评述和讨论,证实其中的一些属种是次异名或属于无效的分类名称,还有一些在归属上尚存在疑问。通过对原牙形类和牙形状化石定义的讨论,将先前指定为原牙形类的13个属进行了分类评述。表明其中的5个属是次异名,还有2个属是未知的节肢动物。其它的12个牙形状化石属中也有5个属是次异名,它们不仅显示了有多种动物亲缘的牙形状形态,而且大多属于绝灭生物,只有Beshtashella和Paraformitchella(=Beshtashella)被指定为软体动物。文中还简要地讨论了大多数属的时空分布,包括3个阶段的原牙形类地层分布,这不仅具有划分对比地层的意义,而且还反映了原牙形类的演化趋势。

早寒武世疑难化石Rhombocorniculum的刺壁微细结构及形态功能分析

通过研究陕南早寒武世疑难化石Rhombocorniculum cancellatum,首次发现其骨片主要由左型和右型两类刺体组成,两类刺体在样品中数量相近,指示它们为某类两侧对称的动物所有,研究发现其刺壁主要由中空的纤状管体组成,纤管的壁由微晶磷灰石组成,相邻纤管之间相互共壁;横断面观察呈多孔状,管孔在刺体基部断面直径较大,向顶端变小,纵断面可见纤管的延伸方向与刺体纵轴一致,刺壁微细结构及刺体的表面装饰皆不同于原牙形刺化石,难以解释为动物的捕食器官(刺),而可能为某类后生动物躯体表面的、起着防御功能的外骨骼。

Closed-loop hydrometallurgical treatment of end-of-life lithium ion batteries: Towards zero-waste process and metal recycling in advanced batteries

This work presents an enhanced hydrometallurgical process for recycling lithium ion batteries. First, endof-life batteries were processed in a physical pre-treatment plant to obtain a representative electrode material. The resulting leachate was purified forth by iron-precipitation, liquid–liquid extractions, and an innovative Li–Na separation, in order to obtain valuable products. These products include high-grade graphite, cobalt oxide(Co3O4, purity 83%), cobalt oxalate(CoC2O4, purity 96%), nickel oxide(Ni O, purity89%), and lithium carbonate(Li2CO3, purity 99.8%). The recovery rate was quantitative for graphite, between 80% and 85% for cobalt depending on the nature of the recovery method, 90% for nickel, and 72%for lithium. Secondary streams were also valorized to obtain sodium sulfate(Na2SO4, purity 96%), and MnCoFe2O4 magnetic nano-sorbents according to the zero-waste concept. In order to close the loop, recycled Co3O4 and NiO were used as conversion-type anode materials for advanced lithium ion batteries showing promising performances.

Satellite Communications Integration with Terrestrial Networks

In this paper we evaluate the feasibility of seamless and efficient integration of terrestrial communication systems with satellite networks. This aspect is considered by standardisation bodies such as ETSI [1], 5 G-PPP [2] and 3 GPP [3]. A comprehensive system is designed and implemented in an emulation prototype, including standard 3 GPP LTE core network functionality [4] with its different layers: networking, data forwarding, control, management and monitoring and is validated through performance measurements. This work is a technical feasibility study of extending terrestrial communication systems with satellite networks as backhaul, increasing the energy efficiency, network robustness during natural disasters as well as being an alternative for peak-time data forwarding of the terrestrial communication services. Due to its global coverage property, terrestrial-satellite integration provides an obvious extension of communication services towards isolated and remote areas and an alternative for rural or highly distributed/highly mobile enterprise networks.

Electrocatalytic hydrogen peroxide formation on mesoporous non-metal nitrogen-doped carbon catalyst

Direct electrochemical formation of hydrogen peroxide(H2O2) from pure O2 and H2on cheap metal-free earth abundant catalysts has emerged as the highest atom-efficient and environmentally friendly reaction pathway and is therefore of great interest from an academic and industrial point of view. Very recently,novel metal-free mesoporous nitrogen-doped carbon catalysts have attracted large attention due to the unique reactivity and selectivity for the electrochemical hydrogen peroxide formation [1–3]. In this work,we provide deeper insights into the electrocatalytic activity, selectivity and durability of novel metal-free mesoporous nitrogen-doped carbon catalyst for the peroxide formation with a particular emphasis on the influence of experimental reaction parameters such as p H value and electrode potential for three different electrolytes. We used two independent approaches for the investigation of electrochemical hydrogen peroxide formation, namely rotating ring-disk electrode(RRDE) technique and photometric UV–VIS technique. Our electrochemical and photometric results clearly revealed a considerable peroxide formation activity as well as high catalyst durability for the metal-free nitrogen-doped carbon catalyst material in both acidic as well as neutral medium at the same electrode potential under ambient temperature and pressure. In addition, the obtained electrochemical reactivity and selectivity indicate that the mechanisms for the electrochemical formation and decomposition of peroxide are strongly dependent on the p H value and electrode potential.

Tracing manufacturing processes using blockchain-based token compositions

Supply chain traceability is one of the most promising use cases to benefit from characteristics of blockchain,such as decentralization,immutability and transparency,not required to build prior trust relationships among entities.A plethora of supply chain traceability solutions based on blockchain has been proposed recently.However,current systems are limited to tracing simple goods that have not been part of the manufacturing process.We recommend a method that allows for the traceability of manufactured goods,including their components.Products are represented using non-fungible digital tokens that are created on a blockchain for each batch of manufactured products.To create a link between a product and the components that are needed to produce it,we propose“token recipes”that define the amount of tokenized goods required for minting a new token.As input tokens are automatically and transparently consumed when creating a product token,the physical process of producing a new item out of existing components is projected onto the ledger.This ultimately leads to the complete traceability of goods,including the origin of inputs.Evaluating the performance of the system,we show that a prototypical implementation for the Ethereum Virtual Machine(EVM)scales linearly with the amount of the input and goods tracked.

Analysis of drop deformation dynamics in turbulent flow

Drop breakage and coalescence influence the particle formation in liquid–liquid dispersions.In order to reduce the influencing factors of the whole dispersion process,single drops where coalescence processes can be neglected were analyzed in this work.Drops passing the turbulent vicinity of a single stirrer blade were investigated by high-speed imaging.In order to gain a statistically relevant amount of drops passing the area of interest and corresponding breakage events,at least 1600 droplets were considered for each parameter set of this work.A specially developed fully automatic image analysis based on Matlab&#174;was used for the evaluation of the resulting high amount of image data.This allowed the elimination of the time-consuming manual analysis and furthermore,allowed the objective evaluation of the drops' behavior.Different deformation parameters were considered in order to describe the drop deformation dynamics properly.Regarding the ratio of both main particle axes(θaxes),which was therefore approximated through an ellipse,allowed the determination of very small deviations from the spherical shape.The perimeter of the particle(θperi) was used for the description of highly deformed shapes.In this work the results of a higher viscosity paraffin oil(ηd= 127 m Pa·s) and a low viscosity solvent(petroleum,ηd= 1.7 m Pa·s) are presented with and without the addition of SDS to the continuous water phase.All results show that the experimentally determined oscillation but also deformation times underlie a wide spreading.Drop deformations significantly increased not only with increasing droplet viscosity,but also with decreasing interfacial tension.Highly deformed particles of one droplet species were more likely to break than more or less spherical particles.As droplet fragmentation results from a variety of different macro-scale deformed particles,it is not assumed that a critical deformation value must be reached for the fragmentation process to occur.Especially for highly deformed particles thin particle filaments are assumed to induce the breakage process and,therefore,be responsible for the separation of drops.

MicroRNA-regulated viral vectors for gene therapy

Safe and effective gene therapy approaches require targeted tissue-specific transfer of a therapeutic transgene.Besides traditional approaches, such as transcriptional and transductional targeting, micro RNA-dependent posttranscriptional suppression of transgene expression has been emerging as powerful new technology to increase the specificity of vector-mediated transgene expression. Micro RNAs are small non-coding RNAs and often expressed in a tissue-, lineage-, activation- or differentiation-specific pattern. They typically regulate gene expression by binding to imperfectly complementary sequences in the 3' untranslated region(UTR) of the m RNA. To control exogenous transgene expression, tandem repeats of artificial micro RNA target sites are usually incorporated into the 3' UTR of the transgene expression cassette, leading to subsequent degradation of transgene m RNA in cel s expressing the corresponding micro RNA. This targeting strategy, first shown for lentiviral vectors in antigen presenting cells, has now been used for tissue-specific expression of vector-encoded therapeutic transgenes, to reduce immune response against the transgene, to control virus tropism for oncolytic virotherapy, to increase safety of live attenuated virus vaccines and to identify and select cell subsets for pluripotent stem cell therapies, respectively. This review provides an introduction into the technical mechanism underlying micro RNA-regulation, highlights new developments in this field and gives an overview of applications of micro RNA-regulated viral vectors for cardiac, suicide gene cancer and hematopoietic stem cell therapy, as well as for treatment of neurological and eye diseases.

Spent coffee ground as source for hydrocarbon fuels

The conversion of triglycerides(coffee oil) obtained from spent coffee ground to produce hydrocarbon fuel(diesel) was studied. In more detail, a catalytic hydrodeoxygenation of the coffee oil was performed applying polymethylhydrosiloxane(PMHS) as cheap reductant under mild reaction conditions. However, along with the hydrocarbons significant amounts of PMHS-waste are generated, since only～1.7% of the PMHS is required for the reduction process. Based on that, in a subsequent depolymerization step the PMHS-waste was converted to methyltrifluorosilane and difluoromethylsilane, which can be applied as building blocks for the production of new silicones, with boron trifluoride diethyl etherate(BF_3OEt_2) as depolymerization reagent.

针对60GHz无线连接的集成远端光接入单元的设计

远端光接入点的设计是将光载无线通信（Radio-Over-Fiber,RoF）,60GHz无线（片上带宽10~20GHz）和光纤到户（FTTH）服务集成在一起。器件在磷化铟的芯片上集成了若干可调无线电频率的发射器和光学接收器。可以在1 500到1 570nm波长范围的4个带宽内同时工作。设计芯片是在两个晶圆厂的多项目晶圆（Multi-project Wafer,MPW）的框架下进行。通过专用的设计工具和工艺设计工具包（Process Design Kits,PDKs）,充分利用了通用集成技术和标准的结构单元（Building Blocks,BBs）带来的便利。

在不同的半导体制造技术间高效转换集成光路设计的方法

针对60GHz的光纤到户无线通信应用,我们设计了一种基于磷化铟的远端接入点集成光子芯片[1]。在多项目晶圆的框架下,为了确保芯片能满足截止日期的要求,我们选取了两个不同的晶圆厂流片。在设计过程中,我们仔细检验了设计方法,从需要满足的功能、结构单元的参数,直到准备最后的掩膜设计。针对于不同晶圆厂的,最后的掩膜设计是不同的。但通过在设计环境下使用通用的结构单元（Building Blocks,BBs）,使针对不同晶圆厂之间的设计转换变得容易,从而大大降低了芯片设计所需要的时间。

Microscopic Approach of Adhesion and Wetting of Liquid Metal on Solid Ionocovalent Oxide Surface

The adhesion and wetting of non-reactive liquid metals with solid ionocovalent oxides are studied on thebasis of the experimental work of adhesion W data obtained with the sessile drop method.An analysis of theexperimental W values of different liquid metals on various solid oxides is first performed to evidence the de-pendence of the work of adhesion of a metal/oxide system on the electron density of the metal and on thethermodynamic stability of the oxide.An electronic model is then proposed to describe the microscopic mech-anism of metal-oxide interactions.Based on the model,the contact angle and the work of adhesion of differentliquid metals on various solid oxides can be interpreted and estimated,and their correlations to the variousphysical quantities of the oxides can be easily deduced.The basic consideration of the model is that the adhe-sion between a metal and an oxide is assured by the electron transfer from the metal into the oxide valenceband which is not completely filled of electrons at high temperatures,and is enhanced when this electron trans-fer at the metal/oxide interface is intensified.The influence of interface defects on the wetting and adhesion issuggested and discussed.

利用红外光谱确定干酪根类型、热成熟度、生烃潜力及其岩石学特性

本文阐述了根据红外光谱确定成熟度和干酪根类型的这一新方法.这种光谱清晰地显示了脂族、羧基以及芳香族化合物的吸收峰,与传统的Krevelen的H/C-O/C图解以及镜质体反射率等方法相类似,利用这些吸收峰可以对干酪根进行分类.干酪根中芳香族C=C谱带向最小波数W_(min)迁移的现象以及干酪根和沥青的芳香度,可以提供更多的有关成熟度方面的信息.从红外光谱中所获得的某些参数也可用来预测生油气潜力.Rock-Eval热解技术与红外光谱结合可以更为有效地将原岩划分为含油(或)含气类型.此外,利用一种新的红外方法,还可以确定其矿物学特性和沉积学特性.用此法在15分钟内可以计算出原始均一化样品中石英、白云石、方解石、高岭石、绿泥石、伊利石、蒙脱石以及黄铁矿的含量.

Wave propagation speeds and source term influences in single and integral porosity shallow water equations

In urban flood modeling,so-called porosity shallow water equations(PSWEs),which conceptually account for unresolved structures, e.g.,buildings, are a promising approach to addressing high CPU times associated with state-of-the-art explicit numerical methods. The PSWE can be formulated with a single porosity term, referred to as the single porosity shallow water model(SP model), which accounts for both the reduced storage in the cell and the reduced conveyance, or with two porosity terms: one accounting for the reduced storage in the cell and another accounting for the reduced conveyance. The latter form is referred to as an integral or anisotropic porosity shallow water model(AP model). The aim of this study was to analyze the differences in wave propagation speeds of the SP model and the AP model and the implications of numerical model results. First, augmented Roe-type solutions were used to assess the influence of the source terms appearing in both models. It is shown that different source terms have different influences on the stability of the models. Second, four computational test cases were presented and the numerical models were compared. It is observed in the eigenvalue-based analysis as well as in the computational test cases that the models converge if the conveyance porosity in the AP model is close to the storage porosity. If the porosity values differ significantly, the AP model yields different wave propagation speeds and numerical fluxes from those of the BP model. In this study, the ratio between the conveyance and storage porosities was determined to be the most significant parameter.

Surface Tension of Molten Silicon Deduced from Wetting Experiments

The accurate measurements of the surface tension for molten silicon are not easy to be carried out.Themajor problem comes from the fact that it is very difficult to avoid the contamination of silicon surface byoxygen arising from experimental atmosphere or from the starting materials.Indirect determination of thisphysical property for liquid silicon is thus of interests.In the present work,wetting experiments have per-formed for molten silicon on very pure and dense glassy carbon substratc at oxygen partial pressures wellbelow and above the saturation limit of oxygen in the liquid metal.Analyses of the wetting results,togetherwith the experimental results reported in the literature for the surface tension values of molten silicon,ena-ble the surface tension of pure and clean liquid silicon to bc deduced.