material

摘要： The hydropower sector is currently experiencing several technological developments.New technologies and practices are emerging to make hydropower more flexible and more sustainable.Novel materials have also been recently developed to increase performance,durability,and reliability;however,no systematic discussions can be found in the literature.Therefore,in this paper,novel materials for hydropower applications are presented,and their performance,advantages,and limitations are discussed.For example,composites can reduce the weight of steel equipment by 50%to 80%,polymers and superhydrophobic materials can reduce head losses by 4%to 20%,and novel bearing materials can reduce bearing wear by 6%.These improvements determine higher efficiencies,longer life span,waste reduction,and maintenance needs,although the initial cost of some materials is not yet competitive with respect to the costs of traditional materials.The novel materials are described here based on the following categories:novel materials for turbines,dams and waterways,bearings,seals,and ocean hydropower.

摘要： A structural search leads to the prediction of a novel alkaline earth nitride BeN_(4)containing a square planar N_(4)^(2-)ring.This compound has a particular chemical bonding pattern giving it potential as a high-energy-density material.The P4/nmm phase of BeN_(4)may be stable under ambient conditions,with a bandgap of 3.72 eV.It is predicted to have high thermodynamic and kinetic stability due to transfer of the outer-shell s electrons of the Be atom to the N_(4)cluster,with the outer-shell 2p orbital accommodating the lone-pair electrons of N_(4)^(2-).The total of sixπelectrons is the most striking feature,indicating that the square planar N_(4)^(2-)exhibits aromaticity.Under ambient conditions,BeN_(4)has a high energy density(3.924 kJ/g relative to Be3N2 and N2 gas),and its synthesis might be possible at pressures above 31.6 GPa.

摘要： Polymeric nitrogen has attracted much attention owing to its possible application as an environmentally safe high-energy-density material.Based on a crystal structure search method accelerated by the use of machine learning and graph theory and on first-principles calculations,we predict a series of metal nitrides with chain-like polynitrogen(P_(21)-AlN_(6),P2_(1)-GaN_(6),P-1-YN_(6),and P_(4)/mnc-TiN_(8)),all of which are estimated to be energetically stable below 40.8 GPa.Phonon calculations and ab initio molecular dynamics simulations at finite temperature suggest that these nitrides are dynamically stable.We find that the nitrogen in these metal nitrides can polymerize into two types of poly-N^(2-)_(4)chains,in which theπelectrons are either extended or localized.Owing to the presence of the polymerized N4 chains,these metal nitrides can store a large amount of chemical energy,which is estimated to range from 4.50 to 2.71 kJ/g.Moreover,these compounds have high detonation pressures and detonation velocities,exceeding those of conventional explosives such as TNT and HMX.

摘要： The ecological and sustainable product is the demand of the present world. But it was not possible to produce an ecological and sustainable product for all sectors as the world requires now. The synthetic material is used to produce flame retardant materials due to the unavailable sustainable ecological flame-retardant material. But different researchers are trying to produce sustainable ecological flame-retardant material. This research found that the Spinach leaves Juice, banana pseudostem sap (SAP) and eggshell powder have flame retardant properties. Different literature shows that the ash also has flame retardant properties. So researcher suggested developing the composite material from the above materials with cotton fibres. It may be more effective as fire-retardant composite materials.

摘要： A series of three-dimensional ordered macroporous(3 DOM)W-TiO_(2)catalysts have been prepared through a facile colloidal crystal template method.The prepared materials characterized in detail exhibited enhanced catalytic activity in aerobic oxidative desulfurization process.The experimental results indicated that the as-prepared materials possessed excellent 3 DOM structure,which is beneficial for the catalytic activity.The sample 3 DOM W-TiO_(2)-20 exhibited the highest activity in ODS process,and the sulfur removal can reach 98%in 6 h.Furthermore,the oxidative product was also analyzed in the reaction process.

摘要： CH_(4) storage associated with adsorbed natural gas(ANG)technology is an issue attracting great concern.Following the Advanced Research Project Agency-Energy(ARPA-E)targeted deliverable capacity of 315 cm^(3)·cm^(-3)(STP),hundreds of thousands of materials have been experimentally or theoretically evaluated,while the best results still show a 35% gap from the target.Moreover,recent theoretical research reveals that the target is beyond the possibility that real materials can be designed.To get rid of the awkward situation,we make attempts on investigating the CH_(4) delivery performance under other operation conditions.Methods of raising the discharge temperature(to infinite high)or elevating the storage pressure(to 25 MPa)have been proved to show limited effectiveness.In this work,it is found that the ARPA-E target can be achieved by using a decreasing storage temperature strategy.By taking 280 CoRE(computation-ready,experimental)COFs(covalent organic frameworks)as ANG materials,when reduce the storage temperature to 190.6 K,the highest deliverable capacity can reach 392 cm^(3)·cm^(-3)(STP),and 16.1% CoRE COFs can surpass the target.The target is also achievable when storage at 220 K.Structure performance relationships study shows strong correlation between deliverable capacity and void fraction.Hence,120 hypothetical COFs are generated to ascertain the optimum void fraction.In addition,the performance of 2D-COFs can be greatly enhanced by increasing the interlayer spacings,e.g.CH_(4) deliverable capacity(storage at 190.6 K)of ATFG-COF can be improved from 239 to 411 cm^(3)·cm^(-3)(STP)when interlayer spacing is enlarged to 1.65 nm.

摘要： LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)@Cr_(2)O_(5)composite electrode combines the high rate-capability characteristics of NCA with the stability of Cr_(2)O_(5),playing a synergistic role in improving the cyclic stability,initial discharge capacity and the security of low cut-off voltage(2.0 V).When the mass ratio of Cr_(2)O_(5)in NCA is 45%(mass),the capacity retention rate increases from 58.5% without Cr_(2)O_(5)to 69.3% in the range of 2.0-4.3 V.The initial discharge capacity of NCA@Cr_(2)O_(5)composite material is 211.4 mA·h·g^(-1),its first coulombic efficiency is 94.2%,and the charging capacity remains approximately constant when mixed with 15%(mass)Cr_(2)O_(5).The reason for the improvement of the initial charge-discharge efficiency(ICDE)was explained.Impedance and cyclic voltammetry analysis reveal more detailed reasons of the observed improvements.Compared with NCA cathode material,the NCA@Cr_(2)O_(5)composite material can provide not only additional stable sites and channels for Li^(+)insertion/extraction to make up for the loss of active Li^(+)sites and prevent the accumulation of Li+in the circulation process,but also protect the NCA electrode from the corrosion of the electrolyte decomposition by the Cr_(2)O_(5)nanoparticles adhering to NCA interface.

摘要： The heterogeneous integration of III-V devices with Si-CMOS on a common Si platform has shown great promise in the new generations of electrical and optical systems for novel applications,such as HEMT or LED with integrated control circuitry.For heterogeneous integration,direct wafer bonding(DWB)techniques can overcome the materials and thermal mismatch issues by directly bonding dissimilar materials systems and device structures together.In addition,DWB can perform at wafer-level,which eases the requirements for integration alignment and increases the scalability for volume production.In this paper,a brief review of the different bonding technologies is discussed.After that,three main DWB techniques of single-,double-and multi-bonding are presented with the demonstrations of various heterogeneous integration applications.Meanwhile,the integration challenges,such as micro-defects,surface roughness and bonding yield are discussed in detail.

摘要： The perovskite material has many superb qualities which allow for its remarkable success as solar cells;flexibility is an emerging field for this technology.To encourage commercialization of flexible perovskite solar cells,two main areas are of focus:mitigation of stability issues and adaptation of production to flexible substrates.An in-depth report on stability concerns and solutions follows with a focus on Ruddlesden-Popper perovskites.Roll to roll processing of devices is desired to further reduce costs,so a review of flexible devices and their production methods follows as well.The final focus is on the sustainability of perovskite solar cell devices where recycling methods and holistic environmental impacts of devices are done.

摘要： Compositions and methods o f use thereof in sandcasting Compositions useful for foundry processes such as green sandcasting are provided.The present disclosure includes compositions useful in sandeasting,preparation of such compositions,and methods of use thereof.The compositions herein include binder compositions and green sand compositions that may be used to prepare a sand mold for casting.The compositions may comprise ball clay,bentonite,and a carbonaceous material.The ball day may comprise from about 15%to about 35%alumina by weight with respect to the total weight of the ball clay and/or from about 30%to about 60%silica by weight with respect to the total weight of the ball day.In some aspects,the ball clay may have a loss on ignition(LOI)ranging from about 12%to about 50%.

摘要： Quality standards of polygraphic production are raising at the market.Hereupon a role of the surface of paper quality becomes more important and its ability of image reproduction.Particularly color reproduction quality is highly required.Samples of paper with different surface texture and structure were taken to investigation.Techniques of an estimation of properties of a surface of materials are presented.By results of work it is possible to track character of dependence between indicators of quality of a surface and a material color rendition.In this work presents investigation of microgeometry of paper and influence of this factor on color coverage area of printing system.

摘要： 本发明特别涉及一种采用Materials Studio软件模拟二氧化硅包覆氟化钙的方法，包括如下步骤：1)利用软件对待计算的初始模型进行构建，得到二氧化硅‑氟化钙分子结构数据文件；2)利用软件中的Forcite模块对初始模型进行结构优化；3)利用软件中的Forcite模块对模型进行分子动力学运算；4)对动力学处理后的模型进行动力学分析；5)对二氧化硅‑氟化钙分子结构的界面距离及能量进行计算，获得距离与能量参数；6)通过计算得到二氧化硅‑氟化钙之间的吸附能。本发明通过计算机对实验过程中工序复杂的二氧化硅包覆氟化钙进行了模拟，且从原子层面进行了详细分析，帮助实验者分析模拟包覆的结果，有效地缩短了试验周期，节约了实验成本，避免了大量实验，保证了实验者的安全性。

摘要： 本发明特别涉及一种在大规模集群中调度MaterialsStudio并行计算的方法。该在大规模集群中调度MaterialsStudio并行计算的方法通过openPBS作业调度软件，openmpi等工具使MaterialsStudio在Linux集群中实现作业的并行计算。本发明通过相关配置，使用openPBS作业调度软件能实现在大规模Linux集群中对MaterialsStudio作业进行统一调度；对用户来说，只需要用qsub命令提交作业，计算和存储都在集群中，方便；对集群管理员，能够达到对使用该软件用户可见可管可控的目的，省心。

摘要： 本发明涉及一种基于materials studio的聚乳酸复合体系玻璃化转变温度预测方法，包括以下步骤：S1）基于蒙特卡洛方法搭建聚乳酸体系无定型晶胞模型；S2）对所构建的无定型晶胞模型进行几何优化和退火模拟，得到能量最低构型；S3）对得到的能量最低构型进行动力学计算，得到聚乳酸体系的降温模拟初始平衡构型；S4）对平衡构型进行降温模拟，得到各个降温温阶下的密度和自由体积分数，线性拟合密度‑温度关系得到玻璃化转变温度预测值，依据自由体积分数分析聚乳酸体系的玻璃化转变温度变化趋势。该方法有利于便捷、准确地预测聚乳酸复合体系的玻璃化转变温度，降低实验成本，缩短研发周期。

摘要： 本发明涉及一种基于materials studio的聚乳酸复合体系玻璃化转变温度预测方法，包括以下步骤：S1）基于蒙特卡洛方法搭建聚乳酸体系无定型晶胞模型；S2）对所构建的无定型晶胞模型进行几何优化和退火模拟，得到能量最低构型；S3）对得到的能量最低构型进行动力学计算，得到聚乳酸体系的降温模拟初始平衡构型；S4）对平衡构型进行降温模拟，得到各个降温温阶下的密度和自由体积分数，线性拟合密度‑温度关系得到玻璃化转变温度预测值，依据自由体积分数分析聚乳酸体系的玻璃化转变温度变化趋势。该方法有利于便捷、准确地预测聚乳酸复合体系的玻璃化转变温度，降低实验成本，缩短研发周期。