编者按:《氢冶金专刊》

双碳战略正在推动传统冶金行业进行转型升级,冶金行业的高质量和低碳化改革势在必行。氢气作为21世纪的清洁能源,其具有从源头上实现低碳冶金的潜力,目前全球冶金工业已经将“氢冶金”作为未来发展的目标。近年来,以钢铁为代表的传统冶金工艺在富氢冶炼以及氢冶金新工艺方面均得到了快速发展,标志着冶金工业在低碳转型的道路上正在飞速前进。为庆祝北京科技大学成立70周年和加快冶金行业在低碳发展方向的脚步,《矿物冶金与材料学报（英文版）》期刊特此出版“氢冶金”专刊。来自包括德国马普所、日本九州大学在内的世界顶尖大学或研究院所的专家学者受邀分享了他们在“氢冶金”研究方面的进展和展望。专刊共收录了12篇论文,包括1篇等离子氢冶金综述及11篇研究论文。所有论文主要围绕传统炼铁流程富氢冶炼、氢基直接还原炼铁以及等离子氢冶金三个方向。其中,包括高炉富氢冶炼后铁矿石和焦炭的行为变化研究、流化床富氢冶炼物理化学研究、富氢直接还原过程球团矿的还原机理研究以及等离子氢冶金新工艺在铁冶炼中的应用。专刊收录论文覆盖范围全面,从传统冶金工艺的创新到富氢冶金新工艺的开发,涉及了目前氢冶金方面较为热点的研究方向。本专刊客座主编希望通过本期论文,为从事“氢冶金”研究方向的学者们提供一个全面交流的机会,以促进“氢冶金”工艺及技术的发展,早日完成碳中和的伟大目标。我们衷心感谢所有作者和审稿人对本期专刊的奉献和大力支持。     

A molecular cryptography model based on structures of DNA self-assembly

With the progress of DNA computing, DNA- based cryptography becomes an emerging interdisciplinary research field. In this paper, we present a novel DNA cryptography that takes advantage of DNA self assembled structure. Making use of the toehold strands recognition and strand displacement, the bit-wise exclusive-or （XOR） operation is carried out to fulfill the information encryption and decryption in the form of a one-time-pad. The security of this system mainly comes from the physical isolation and specificity of DNA molecules. The system is con- structed by using complex DNA self-assembly, in which technique of fluorescent detection is utilized to implement the signal processing. In the proposed DNA cryptography, the XOR operation at each bit is carried out individually, thus the encryption and decryption process could be con- ducted in a massive, parallel way. This work may dem- onstrate that DNA cryptography has the great potential applications in the field of inRwmation security.     

Plant microremains provide direct evidence for the functions of stone knives from the Lajia site,northwestern China

A large number of stone knives have been recovered from Neolithic archaeological sites in East Asia. However, direct evidence regarding the functions of the stone knives has been scarce, and hence, their functions have remained controversial. In this study, we recovered and analysed ancient starch grains and phytoliths from residues adhering to stone knives excavated from the Lajia site, Qinghai Province, northwest China, thus providing direct evidence for the functions of the knives. Our anal- yses were based on the following： （1） an assemblage of 278 identifiable starch grains, representing grains from the stems of foxtail millet （Setaria italica） and broomcorn millet （Panicum miliaceum） （65.1% of the total） and the stems of Hordeum and Triticum species （3.6 % of the total）, and （2） an assemblage of 361 identifiable phytoliths, the majority of which were from the stems and leaves of plants such as Panicoideae and related taxa （96 % of the total）. Our study demonstrates that one of the functions of the stone knives was the harvesting crops. In addition, a few starch grains from food legumes and roots （3.4 % of the total） indicate that the stone knives were also likely used to process, peel and cut some foods.     

用光谱法研究异鼠李素与牛血清白蛋白的相互作用及几种金属离子对反应的影响

用紫外光谱法、 荧光光谱法研究异鼠李素与牛血清白 蛋白的相互作用机理及几种金属离子与异鼠李素和牛血清白蛋白之间的相互作用, 并探讨了几种金属离子与异鼠李素结合的类型, 阐明了它们的结合产物对牛血清白蛋白的作用机理. 实验结果表明, 异鼠李素与牛血清白蛋白主要是凭借静电引力作用结合, 异鼠李素主要以静态猝灭方式使牛血清白蛋白荧光强度减弱. 金属离子的介入影响了异鼠李素与牛血清白蛋白 的结合, 降低了其结合能力.     

深基坑支护设计浅探

深基坑支护的设计、施工、监测技术是近10多年来在我国逐渐涉及的技术难题。深基坑的护壁,不仅要求保证基坑内正常作业安全,而且要防止基坑及坑外土体移动,保证基坑附近建筑物、道路、管线的正常运行。各地通过工程实践与科研,在基坑支护理论与技术上都有了进一步的发展,取得了可喜的成绩。     

Corrosion study of resorbable Ca60Mg15Zn25 bulk metallic glasses in physiological fluids

The corrosion activity of amorphous plates of Ca_(60)Mg_(15)Zn_(25)alloy was investigated.The biocompatible elements were selected for the alloy composition.The electrochemical corrosion and immersion tests were carried out in a multi-electrolyte fluid and Ringer's solution.Better corrosion behavior was observed for the samples tested in a multi-electrolyte fluid despite the active dissolution of Ca and Mg in Ringer's solution.The experimental results indicated that reducing concentration of NaCl from 8.6 g/dm~3for Ringer's solution to 5.75 g/dm~3caused the decrease of the corrosion rate.The volume of the hydrogen evolved after 480 min in Ringer's solution(40.1 ml/cm~2)was higher in comparison with that obtained in a multi-electrolyte fluid(24.4 ml/cm~2).The values of opencircuit potential(E_(OCP))for the Ca_(60)Mg_(15)Zn_(25)glass after 1 h incubation in Ringer's solution and a multielectrolyte fluid were determined to be-1553 and-1536 m V vs.a saturated calomel electrode(SCE).The electrochemical measurements indicated a shift of the corrosion current density(j_(corr))from 1062μA/cm~2for the sample tested in Ringer's solution to 788μA/cm~2for the specimen immersed in a multi-electrolyte fluid.The corrosion products analysis was conducted by using the X-ray photoelectron spectroscopy(XPS).The corrosion products were identified to be CaCO_3,Mg(OH)_2,CaO,MgO and Zn O.The mechanism of corrosion process was proposed and described based on the microscopic observations.The X-ray diffraction and Fourier transform infrared spectroscopy(FTIR)also indicated that Ca(OH)_2,CaCO_3,Zn(OH)_2and Ca(Zn(OH)_3)_2·2H_2O mainly formed on the surface of the studied alloy.     

Influences of synthesis methods and modifier addition on the properties of Ni-based catalysts supported on reticulated ceramic foams

A method of synthesizing Ni-based catalysts supported on α-Al₂O₃-based foams was developed. The foams were impregnated with aqueous solutions of metal chlorides under an air atmosphere using an aerosol route. Separate procedures involved calcination to form oxides and drying to obtain chlorides on the foam surface. The synthesized samples were subsequently reduced with hydrogen. With respect to the Ni/Al₂O₃ catalysts, the chloride reduction route enabled the formation of a Ni coating without agglomerates or cracks. Further research included catalyst modification by the addition of Pd, Cu, and Fe. The influences of the additives on the degree of reduction and on the low-temperature reduction effectiveness (533 and 633 K) were examined and compared for the catalysts obtained from oxides and chlorides. Greater degrees of reduction were achieved with chlorides, whereas Pd was the most effective modifier among those investigated. The reduction process was nearly complete at 533 K in the sample that contained 0.1wt% Pd. A lower reduction temperature was utilized, and the calcination step was avoided, which may enhance the economical and technological aspects of the developed catalyst production method.     

Prognosis of residual coal gas capacity made by the ‘Express’ method

An easy, reliable, and inexpensive method, called ‘Express’ method, was described to determine the residual gas capacity of deep mines using results from an air and gas balance. Air and gas balances are common elements of mine management and must be performed periodically. Using the process described here to obtain balance results, it is straightforward to obtain the residual gas capacity, which is an important parameter for decision-making in current mine operations. After a mine is closed, the residual gas capacity becomes a dominant factor used to select methods to protect against gas emissions from the closed underground area or perhaps to provide information for the use of gas reserves. The proposed ‘Express’ method is a much simpler method to obtain the residual gas capacity than other procedures used for this purpose to date.     

网络环境下图书馆电子阅览室安全问题研究

网络环境下的图书馆电子阅览系统是一个比较复杂多变的系统,安全管理受到包括硬件因素、软件因素、人为因素和制度因素等多种因素的影响。电子图书阅览模式不仅能快速地为读者提供最新的图书资讯,更能拓宽读者的阅览面,使读者获得更为全面的阅览资源与接触途径。然而在方便快捷的同时,电子阅览室也如其他事物一样,具有不可避免的缺陷。电子网络环境的繁复性为电子阅览室的安全带来巨大的挑战。本文就我国目前网络环境下的图书馆电子阅览室安全问题做了初步的研究与探讨。