检索结果-南通市图书馆

疯狂英语(初中天地) 2024年第4期 12-17页

作者： ernst Stuhlinger

1970年，赞比亚修女就给美国国家航空航天局写了一封信：“目前地球上还有这么多小孩子吃不上饭，你们怎么舍得为远在火星的项目花费数十亿美元？”本文节选自美国国家航空航天局的科学家写给她的回信。我相信，致力于太空计划有助于缓...

1970年，赞比亚修女就给美国国家航空航天局写了一封信：“目前地球上还有这么多小孩子吃不上饭，你们怎么舍得为远在火星的项目花费数十亿美元？”本文节选自美国国家航空航天局的科学家写给她的回信。我相信，致力于太空计划有助于缓解乃至最终解决地球上诸如贫困与饥饿这样的严峻问题。饥饿问题的根本在于两个方面：食物生产与食物分配。通过农业、畜牧业、远洋渔业以及其他大规模生产方式进行食物生产在世界某些地区行之有效，但在其他许多地区效率极其低下。

关键词：

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

为什么要探索太空(节选)

疯狂英语（初中天地） 2024年第4期 11-17页

作者： ernst Stuhlinger 不详

1970年,赞比亚修女就给美国国家航空航天局写了一封信:“目前地球上还有这么多小孩子吃不上饭,你们怎么舍得为远在火星的项目花费数十亿美元?”本文节选自美国国家航空航天局的科学家写给她的回信。

关键词：美国国家航空航天局一封信太空赞比亚科学家

挖掘应用型高校和双元制教育对不同社会背景人才培养的潜力

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

应用型高等教育研究 2024年第2期9卷 40-46页

作者： ernst Deuer 陈颖(翻译) 巴登-符腾堡州拉文斯堡双元制大学德国拉文斯堡88212 奥斯纳布吕克应用科学大学

随着专业人才短缺问题的加剧,亟需在各个层面上更有效地开发和利用潜在受教育群体的学习机会。从教育公平的角度来看,现在比以往任何时候都更需要基于学生的实际表现和潜力来促进不同社会背景群体的发展。在此过程中,高等教育系统,尤其... 详细信息

随着专业人才短缺问题的加剧,亟需在各个层面上更有效地开发和利用潜在受教育群体的学习机会。从教育公平的角度来看,现在比以往任何时候都更需要基于学生的实际表现和潜力来促进不同社会背景群体的发展。在此过程中,高等教育系统,尤其是应用型和双元制教育发挥着重要作用。

关键词：教育资源大学入学教育公平

CONJUGATE-SYMPLECTICITY OF LINEAR MULTISTEP METHODS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2008年第5期26卷 657-659页

作者： ernst Hairer Section de Mathématiques Univ.de Genève

For the numerical treatment of Hamiltonian differential equations, symplectic integrators are the most suitable choice, and methods that are conjugate to a symplectic integrator share the same good long-time behavior. This note characterizes linear multistep methods whose underlying one-step method is conjugate to a symplectic integrator. The bounded- hess of parasitic solution components is not addressed.

关键词： Linear multistep method Underlying one-step method Conjugate-symplecticity,Symmetry.

Insensitive high explosives:Ⅳ. Nitroguanidine-Initiation & detonation

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2019年第4期15卷 467-487页

作者： ernst-Christian Koch Lutradyn-Energetic Materials

This paper reviews the detonative properties of low bulk density(LBD),high bulk density(HBD)Nitroguanidine(NGu)(1),CAS-No:[556-88-7]and 82 explosive formulations based on NGu reported in the public *** rank the performance of those formulations they are compared with 15 reference compositions containing both standard high explosives such as octogen(HMX)(2),hexogen(RDX)(3),pentaerythritol tetranitrate(PETN)(4),2,4,6-trinitrotoluene(TNT)(5)as well as insensitive high explosives such as 3-nitro-1,2,4-triazolone(NTO)(6),1,3,5-triamino-2,4,6-trinitrobenzene(TATB)(7),1,1-diamino-2,2-dinitroethylene(FOX-7)(8)and N-Guanylurea dinitramide(FOX 12)(9).NGu based formulations are superior to those based on FOX-12 or TATB and are a close match with FOX-7 based explosives,the latter just having higher Gurney Energies(-10%)and slightly higher detonation pressure(+2%).NGu based explosives even reach up to 78% of the detonation pressure,82% Gurney energy and up to 95% of detonation velocity of ***-NGu dissolves in many melt cast eutectics forming dense charges thereby eliminating the need for costly High Bulk Density *** based formulations are at the rock bottom of sensitiveness among all the above-mentioned explosives which contributes to the safety of these *** review gives 132 references to the public *** a review on the synthesis spectroscopy and sensitiveness of Nitroguanidine see Ref.[1].

关键词： Cook-off Detonation Insensitive munitions Nitroguanidine Shock sensitvity

Special materials in pyrotechnics Ⅶ: Pyrotechnics used in thermal batteries

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2019年第3期15卷 254-263页

作者： ernst-Christian Koch Lutradyn Energetic Materials Science & Technology

Thermal batteries are unique direct current(DC) electrical power sources with long shelf live, high reliability and higher power density than classical alkaline batteries. This paper gives a brief overview into the working principle of thermal batteries and reviews the properties of zirconium/barium chromate(Zr/BaCrO4) pyrolant previously used as first fire and iron/potassium perchlorate(Fe/KClO4) pyrolant(Heat), commonly applied as heating pellet in thermal batteries and its hazard properties. The review gives 64 references to the public domain. CAS-Nos. Zr: [7440-67-7], BaCrO4: [10294-40-3], Fe: [7439-89-6], KClO4: [7778-74-7], Viton: [9011-17-0].CAS-Nos. Zr: [7440-67-7], BaCrO4: [10294-40-3], Fe: [7439-89-6], KClO4: [7778-74-7], Viton: [9011-17-0].

关键词： Barium chromate Heat-powder Iron Lithium Molten salt Potassium perchlorate Pyrotechnics Thermal battery Zirconium

Using coalgebras and the Giry monad for interpreting game logics a tutorial

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2017年第6期11卷 948-970页

作者： ernst-Erich DOBERKAT Math++ Software Bochum 44879 Germany

The stochastic interpretation of Parikh＇s game logic should not follow the usual pattern of Kripke models, which in turn are based on the Kleisli morphisms for the Giry monad, rather, a specific and more general approach to proba- bilistic nondeterminism is required. We outline this approach together with its probabilistic and measure theoretic basis, in- troducing in a leisurely pace the Giry monad and its Kleisli morphisms together with important techniques for manipu- lating them. Proof establishing specific techniques are given, and pointers to the extant literature are provided. After working through this tutorial, the reader should find it easier to follow the original literature in this and related areas, and it should be possible for her or him to appreciate measure theoretic arguments for original work in the areas of Markov transition systems, and stochastic effectivity func- tions.

关键词： coalgebras modal logics monads Giry monad,upper closed monad composition of monads game logics

Superlubricity on the nanometer scale

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2014年第2期2卷 106-113页

作者： ernst MEYER Enrico GNECCO Department of Physics University of BaselKlingelbergstr.824056 BaselSwitzerland IMDEA Nanociencia Campus Universitario de CantoblancoCalle Faraday 928049 MadridSpain

The transition from atomic stick-slip to continuous sliding has been observed in a number of *** extended contacts are moved in different directions,so-called structural lubricity is observed when the two surface lattices are ***,a“superlubric”state of motion can be achieved if the normal force is reduced below a certain threshold,the temperature is increased,or the contact is actuated *** processes have been partially demonstrated using atomic force microscopy,and they can be theoretically understood by proper modifications of the Prandtl−Tomlinson model.

关键词： structural lubricity dynamic superlubricity atomic force microscopy friction force microscopy themolubricity Prandtl−Tomlinson model

Review of Late Jurassic-early Miocene sedimentation and plate-tectonic evolution of northern California:illuminating example of an accretionary margin

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal Of Geochemistry 2015年第2期34卷 123-142页

作者： W.G.ernst Department of Geological & Environmental Sciences Stanford University

Production of voluminous igneous arc rocks,high-pressure/low-temperature(HP/LT) metamafic rocks,westward relative migration of the Klamath Mountains province,and U-Pb ages of deposition,sediment sources,and spatial locations of Jurassic and younger,detrital zirconbearing clastic rocks constrain geologic development of the northern California continental edge as follows:(1) At~ 175 Ma,transpressive plate underflow began to generate an Andean-type Klamath-Sierran arc along the margin.(2)Oceanic crustal rocks were metamorphosed under HP/LT conditions in an inboard,east-inclined subduction zone from~ 170-155 *** for the Red Ant blueschists,such Ethologies remained stored at depth;most HP/LT mafic tectonic blocks returned surfaceward only during mid- and Late Cretaceous time,chiefly entrained in circulating,buoyant Franciscan mud-matrix melange.(3) By ~ 165 Ma and continuing to ~ 150-140 Ma,erosion supplied volcanogenic debris to proximal Mariposa-Galice ± Myrtle overlap strata.(4) At ~ 140,immediately prior to the onset of paired Franciscan and Great Valley Group(GVG) +Hornbrook deposition,the Klamath salient was deformed and displaced ~ 100-150 km westward relative to the Sierran arc,stranding pre-existing oceanic crust on the south as the Coast Range Ophiolite(CRO).(5) After the end-ofJurassic seaward step-out of the Farallon-North American convergent plate junction,terrigineous debris began to be deposited in the outboard Franciscan trench and intervening Great Valley forearc.(6) Voluminous sedimentation and accretion of Franciscan Eastern + Central belts and GVG detritus took place during paroxysmal igneous activity and rapid,nearly orthogonal plate convergence at^125-80 Ma.(7) Sierran arc volcanism-plutonism ceased by^80 Ma in northern California,signaling a transition to shallow,nearly subhorizontal eastward plate underflow attending Laramide orogeny far to the east.(8) Presently exposed Paleogenelower Miocene Franciscan Coastal Belt sedimentary strata were

关键词：板块构造早中新世加利福尼亚州晚侏罗世增生保证金 U-Pb年龄地层沉积