The ligand ttd(ttd=1,4,8,9-Tetraaza-triphenylene-2,3-dicarbonitrile) and a novel spin crossover complex [Fe(ttd)2(NCS)2]·H2O were synthesized, and charac terized by elemental analysis, IR, MS, and UV-vis spectros...The ligand ttd(ttd=1,4,8,9-Tetraaza-triphenylene-2,3-dicarbonitrile) and a novel spin crossover complex [Fe(ttd)2(NCS)2]·H2O were synthesized, and charac terized by elemental analysis, IR, MS, and UV-vis spectroscopy. The temperature dependence of magnetic susceptibility shows that there are a little break betwe en 150～190K and an unusual step transition with a 50K width between 190～240K. Compared with the other complexes with the resemble structure, it can be found t hat the influence of ligand is very notable.展开更多
A belt of low Al-Trondhjemite-Tonalite-Diorite (TTD) series has been recognized along the Northern Qinling Orogenic Belt (NQOB), which is dated as 430―399 Ma and charac-teristic of positive εNd(t ) values. Geochemic...A belt of low Al-Trondhjemite-Tonalite-Diorite (TTD) series has been recognized along the Northern Qinling Orogenic Belt (NQOB), which is dated as 430―399 Ma and charac-teristic of positive εNd(t ) values. Geochemical features and trace elements simulation indicate that the TTD series was probably originated from differently partial melting of tholeiitic rocks from the Erlangping group. Thermodynamic analysis on the residue phases of the partial melting pro- cesses suggests that the TTD series may represent a dynamic process of temperature-increasing and pressure-decreasing, indicating an extension and thinning process of a thickened crust.展开更多
技术变革的本质是一种创新扩散过程。正在发生的数字革命,从技术变革到产业变革、传播变革再到社会变革,有一个隐性化到显性化的过程,存在着一定的时间差,对这一时间差的洞察与把握不足,往往是数字化变革与转型走向失败的最大陷阱。在...技术变革的本质是一种创新扩散过程。正在发生的数字革命,从技术变革到产业变革、传播变革再到社会变革,有一个隐性化到显性化的过程,存在着一定的时间差,对这一时间差的洞察与把握不足,往往是数字化变革与转型走向失败的最大陷阱。在互联网和智能化浪潮席卷全球的当下,本文提出“技术时差”(Technical Time Difference)概念,用以衡量技术变革从隐性阶段过渡到产业与传播显性变革之间的时间落差。这一概念基于30多年互联网商业化发展的经验和实证,作为简化和概略的认知和分析框架,直观地揭示数字技术演进中生产方式与传播方式的代际落差对社会、经济和文化的影响。研究从技术的本质出发,结合互联网不同发展阶段的实践,解析“技术时差”的形成机理、表现形式及其在互联网传播革命中的具体实证,提出以“技术时差”作为衡量互联网战略的核心工具,助力互联网创业、数字化转型、媒体融合、主流媒体系统性变革乃至大国科技博弈,以期进一步提升战略效能,推动形成正确的行动方案。其中,零时差战略是互联网和智能化战略成功的基本前提,而一次时差、多次时差则是各种数字战略与举措失败的共同原因。如何形成智能时代的零时差战略,将是面向未来的关键所在。展开更多
文摘The ligand ttd(ttd=1,4,8,9-Tetraaza-triphenylene-2,3-dicarbonitrile) and a novel spin crossover complex [Fe(ttd)2(NCS)2]·H2O were synthesized, and charac terized by elemental analysis, IR, MS, and UV-vis spectroscopy. The temperature dependence of magnetic susceptibility shows that there are a little break betwe en 150～190K and an unusual step transition with a 50K width between 190～240K. Compared with the other complexes with the resemble structure, it can be found t hat the influence of ligand is very notable.
基金supported by the National Natural Science Foundation of China(Grant No.40372032)the Research Fund for the Doctoral Program of Higher Education of the Ministry of Education,and Analyzing Foundation of Peking University
文摘A belt of low Al-Trondhjemite-Tonalite-Diorite (TTD) series has been recognized along the Northern Qinling Orogenic Belt (NQOB), which is dated as 430―399 Ma and charac-teristic of positive εNd(t ) values. Geochemical features and trace elements simulation indicate that the TTD series was probably originated from differently partial melting of tholeiitic rocks from the Erlangping group. Thermodynamic analysis on the residue phases of the partial melting pro- cesses suggests that the TTD series may represent a dynamic process of temperature-increasing and pressure-decreasing, indicating an extension and thinning process of a thickened crust.
文摘技术变革的本质是一种创新扩散过程。正在发生的数字革命,从技术变革到产业变革、传播变革再到社会变革,有一个隐性化到显性化的过程,存在着一定的时间差,对这一时间差的洞察与把握不足,往往是数字化变革与转型走向失败的最大陷阱。在互联网和智能化浪潮席卷全球的当下,本文提出“技术时差”(Technical Time Difference)概念,用以衡量技术变革从隐性阶段过渡到产业与传播显性变革之间的时间落差。这一概念基于30多年互联网商业化发展的经验和实证,作为简化和概略的认知和分析框架,直观地揭示数字技术演进中生产方式与传播方式的代际落差对社会、经济和文化的影响。研究从技术的本质出发,结合互联网不同发展阶段的实践,解析“技术时差”的形成机理、表现形式及其在互联网传播革命中的具体实证,提出以“技术时差”作为衡量互联网战略的核心工具,助力互联网创业、数字化转型、媒体融合、主流媒体系统性变革乃至大国科技博弈,以期进一步提升战略效能,推动形成正确的行动方案。其中,零时差战略是互联网和智能化战略成功的基本前提,而一次时差、多次时差则是各种数字战略与举措失败的共同原因。如何形成智能时代的零时差战略,将是面向未来的关键所在。
