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1.
Ke Li Yingfeng Li Xinyu Wang Mengkui Cui Bolin An Jiahua Pu Jintao Liu Boyang Zhang Guijun Ma Chao Zhong 《国家科学评论(英文版)》2021,8(8)
Marine diatoms construct their hierarchically ordered, three-dimensional (3D) external structures called frustules through precise biomineralization processes. Recapitulating the remarkable architectures and functions of diatom frustules in artificial materials is a major challenge that has important technological implications for hierarchically ordered composites. Here, we report the construction of highly ordered, mineralized composites based on fabrication of complex self-supporting porous structures—made of genetically engineered amyloid fusion proteins and the natural polysaccharide chitin—and performing in situ multiscale protein-mediated mineralization with diverse inorganic materials, including SiO2, TiO2 and Ga2O3. Subsequently, using sugar cubes as templates, we demonstrate that 3D fabricated porous structures can become colonized by engineered bacteria and can be functionalized with highly photoreactive minerals, thereby enabling co-localization of the photocatalytic units with a bacteria-based hydrogenase reaction for a successful semi-solid artificial photosynthesis system for hydrogen evolution. Our study thus highlights the power of coupling genetically engineered proteins and polysaccharides with biofabrication techniques to generate hierarchically organized mineralized porous structures inspired by nature. 相似文献
2.
A control model of binocular vergence eye movements is presented. The control model can reduce blind areas caused by the double cameras in motion platform. In order to validate the model performance, an experimental platform and its control system based on TMS320LF2407 are designed. The control system has its compacted configuration and high reliability. The simulation and experimental results show that the control system can realize binocular vergence movements. Compared with the conventional moving double cameras system, this new system can considerably reduce blind areas. 相似文献
3.
Supported by the National Basic Research Program 《中国科学院院刊(英文版)》2008,22(1):54-54
The CAS Dalian Institute of Chemical Physics （DICP） and BP Group will join efforts to set up an Energy Innovation Laboratory （BP-DICP ElL） at DICP. The agreement for the new initiative was signed by DICP Director ZHANG Tao and BP Group Vice President Tony Meggs on 5 December, 2007 in Dalian. 相似文献
4.
对 1962年以来采集的表层土壤和深层土壤样品进行培养实验,以研究退耕还林 40年来土壤氮的动态变化以及植被恢复对土壤氮库矿质化的影响.供试土样在专门设计的矿质化培养系统中,以温度 30℃、通气并保持土壤湿度的条件下培养 30d,以 2mol LKCl溶液浸提培养土并测定其氮含量.结果表明,土壤矿质氮及全氮含量均在造林的头 2 0年迅速下降,在 2 0年的林木生长过程中,生物吸收积累了土壤中约 80 %-90 %的有效氮,表明耕地中施入的氮对树木早期生长有着重要作用;树龄达 40年时,土壤原有矿质氮的 5 0 %-80 %已返还土壤.这一结果表明,森林地被已成为土壤营养的重要来源,并且森林生态系统提供的这种有机质可成为可持续利用的土壤氮资源. 相似文献
5.
采用室内恒温控湿好气培养法,研究了掺混不同C/N比有机物料土壤中有机氮的矿化进程,及有机碳源添加对其的影响。培养 30周的结果表明:掺混大豆粉的土壤有机氮的矿化速率最快,在第 30d时达到最大;掺混玉米秸粉土壤有机氮的矿化速率最慢;有机碳源的添加明显抑制了有机氮的矿化进程,但这种抑制作用只是暂时的,最终将以有机氮的矿化分解为发展总趋势。 相似文献
6.
对云南元阳县大坪大型金多金属矿床矿脉地质特征、流体包裹体和稳定同位素的研究表明，矿区内大量的矿脉是叠加成矿的产物，空间上具有并置、侧列（现）、再现等复杂关系，成矿可分石英．黄铁矿（主要形成金矿化）和石英．方铅矿（主要形成铜铅银矿化，并叠加有金矿化）两个阶段共7个亚阶段。石英-黄铁矿阶段流体包裹体以个体小，数量多。杂乱分布为特征，以二相气液包裹体为主，均一温度变化区间为165℃～393℃，平均258℃；流体密度为0．648—0．7984g／cm^3，盐度变化为13，72％～18．96％NaCleqv，平均17．13％NaCleqv，捕获压力为64MPa左右。流体为含CO2的NaCl-H2O体系，在成分上相对富集Na^＋、Cl^-、CH4和N2、NO3^-等组分，从早到晚，具有Na^＋、Ca^2＋、SO4^2-略有升高，而K^＋有所降低的趋势。石英方铅矿阶段流体包裹体大小混杂，杂乱分布或呈线性排列，以CO2包裹体为主，并有二相气液和少量单相包裹体。均一温度177℃～372℃，平均284℃，流体密度为0，7413～O．9518g／cm^3，盐度变化为10．86％～21．26％NaCleqv，平均14．16％NaCleqv，捕获压力为60MPa左右。流体属为NaCl-H2O-CO2体系，在成分上以相对富集Na^＋、K^＋、SO4^2-为特征，部分脉体的流体包裹体中还含有一定量的Ca^2＋、Mg^2＋等离子。矿区不同（亚）阶段矿石氧同位组成总体变化较小（2.65‰～6.0‰），氢同位素组成变化较大（-120％～-40‰），其中石英-黄铁矿阶段H、O同位素组成变化均较小，以岩浆源为主，而石英．方铅矿阶段氢同位素组成变化较大，表明有新的流体加入，但也以深源流体为主；石英-方铅矿阶段一个铁白云石的δ^13C值为-4．81％o，而石英．黄铁矿阶段晚期方解石碳同位素组成变化为-2．79‰～-4.34‰，平均-3．75‰。不同矿脉黄铁矿、方铅矿的硫同位素组成变化范围为0．3‰-4.4‰，其中石英-黄铁矿阶段为0.3‰～4．4‰，石英-方铅矿阶段为0.5～4.3‰，总体上与深源（地幔）碳、硫同位素组成基本一致。综合对比研究认为，大坪金多金属矿床为源于深部的多源成矿热液在同一容矿空间充填的结果，叠加成矿作用与区内长期的岩浆活动密切相关。矿床为中-高温热液硫化物．石英薄脉型金多金属矿床。 相似文献
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狼山造山带位于华北地台北缘西段,它经历了新太古代和古元古代结晶基底形成与变形、中元古代被动陆缘裂陷槽裂解→沉积→闭合、新元古代晚期开始的活动陆缘、海西期-中生代以来的挤压造山并伴有大量中酸性岩浆侵入的漫长构造演化与发展过程.该造山带有丰富的锌、铅、铜、铁、金等矿产资源,矿床（化）类型、矿床规模与时空分布规律都与其成矿地质背景、构造演化有密切的耦合关系,在不同构造演化阶段有不同的矿床形成：在新太古代主要形成了海底火山环境热水沉积条带状铁矿、在中元古代主要形成了与被动陆缘裂解过程相关的海底喷流-沉积铅锌铜铁硫化物矿床、而在海西期-中生代以来挤压造山过程中的岩浆热液活动,既形成了中小型的斑岩型铜金矿床、又对中元古代等先成的喷流-沉积矿床产生了明显的改造和叠加成矿作用.东升庙、炭窑口和霍各乞矿床的部分铜矿是造山过程中叠加成矿的结果. 相似文献
8.
旱地土壤氮素矿化的动力学研究 总被引：1，自引：0，他引：1
傅会芳 《中国科学院研究生院学报》1996,(2)
通过对有机质、全氮、Ｃ／Ｎ比差异较大的１０种土壤进行盆栽和培养试验，用对数方程、指数方程和幂函数方程对土壤氮素矿化过程进行模拟．结果表明：幂函数模型能很好地描述土壤Ｎ素矿化过程；建立了土壤氮素矿化的一级动力学模式，求出了不同模型中的参数；最后探讨了影响土壤氮素矿化动力学模型系数的土壤因子． 相似文献
9.
铧厂沟金矿床成矿期次划分 总被引：2，自引：0，他引：2
通过对铧厂沟金矿床矿区地质、矿床地质以及矿石类型、矿石矿物、矿石组构的研究，认为铧厂沟金矿床的形成至少经历了基性火成岩和凝灰质绢云千枚岩的退化蚀变作用期，构造热液矿化蚀变作用期和表生氧化作用期的三个主成矿演化期。 相似文献
10.
Herein, a wide-spectrum (∼678 nm) responsive Bi8(CrO4)O11 photocatalyst with a theoretical solar spectrum efficiency of 42.0% was successfully constructed. Bi8(CrO4)O11 showed highly efficient and stable photocatalytic water oxidation activity with a notable apparent quantum efficiency of 2.87% (420 nm), superior to many reported wide-spectrum driven photocatalysts. Most remarkably, its strong oxidation ability also enables the simultaneous degradation and complete mineralization for phenol, and its excellent performance is about 23.0 and 2.9 times higher than CdS and P25-TiO2, respectively. Its high activity is ascribed to the giant internal electric field induced by its large crystal dipole, which accelerates the rapid separation of photogenerated electron–hole pairs. Briefly, the discovery of wide-spectrum bismuth chromate and the mechanism of exponentially enhanced photocatalytic performance by increasing the crystal dipole throw light on improving solar energy conversion. 相似文献