搜索结果: 1-15 共查到“理学 rings”相关记录156条 . 查询时间(0.171 秒)
Swirling around the planet’s equator, the rings of Saturn are a dead giveaway that the planet is spinning at a tilt. The belted giant rotates at a 26.7-degree angle relative to the plane in which it o...
MIT chemists have devised a new chemical reaction that allows them to synthesize a phosphorus-containing ring, using a catalyst to add phosphorus to simple organic compounds called alkenes.
Tree rings and Iceland's Laki volcano eruption:A closer look at climate（图）
Tree rings Iceland Laki volcano eruption A closer look climate
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2021/2/5
By reading between the lines of tree rings, U.S. National Science Foundation-funded researchers at the University of Arizona reconstructed what happened in Alaska the year the Laki Volc...
Penn Physicists Discover Why Drying Liquid Crystal Drops Leave Unusual “Coffee Rings”（图）
Penn Physicists Drying Liquid Crystal Drops Coffee Rings
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2017/7/21
In previous papers, University of Pennsylvania physicists investigated the “coffee ring effect,” the ring-shaped stain of particles left after drops of coffee evaporate. In one paper, they learned how...
Rings around young star suggest planet formation in progress
Rings around young star planet formati progress
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2016/12/27
Rice University astronomers and their colleagues have for the first time mapped gases in three dark rings around a distant star. The rings mark spaces where planets are thought to have formed from dus...
UMD Physicists Discover “Smoke Rings” Made of Laser Light（图）
UMD Physicists Smoke Rings Laser Light
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2016/9/29
Most basic physics textbooks describe laser light in fairly simple terms: a beam travels directly from one point to another and, unless it strikes a mirror or other reflective surface, will continue t...
Vortex rings may aid cell delivery,cell-free protein production
Vortex rings cell delivery cell-free protein production
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2016/8/23
Some of the world’s most important discoveries – penicillin, vulcanized rubber and Velcro, to name a few – were made by accident. In fact, it’s been said that upward of half of all scientific discover...
N-body simulations of cohesion in dense planetary rings:A study of cohesion parameters
Planetary rings Saturn, Rings Tides, Solid body Ices, Mechanical properties Collisional physics
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2015/12/25
We present results from a large suite of simulations of Saturn’s dense A and B rings using a new model of particle sticking in local simulations (Perrine, R.P., Richardson, D.C., Scheeres, D.J. [2011]...
A numerical model of cohesion in planetary rings
Planetary rings Saturn, Rings Rotational dynamics Tides, Solid body Ices, Mechanical properties Collisional physics
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2015/12/25
We present a numerical method that incorporates particle sticking in simulations using the N-body code pkdgrav to study motions in a local rotating frame, such as a patch of a planetary ring. Particle...
AN ANALYTIC PARAMETERIZATION OF SELF-GRAVITY WAKES IN SATURN’S RINGS, WITH APPLICATION TO OCCULTATIONS AND PROPELLERS
planets and satellites individual (Saturn)–planets and satellites rings
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2015/12/25
We have developed a semianalytic method of parameterizing N-body simulations of self-gravity wakes in Saturn’s rings, describing their photometric properties by means of only six numbers: three optica...
EQUIVARIANT FLOW EQUIVALENCE FOR SHIFTS OF FINITE TYPE,BY MATRIX EQUIVALENCE OVER GROUP RINGS
EQUIVARIANT FLOW EQUIVALENCE SHIFTS OF FINITE TYPE MATRIX EQUIVALENCE OVER GROUP RINGS
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2015/9/29
Let G be a finite group. We classify G-equivariant flow equivalence of nontrivial irreducible shifts of finite type interms of (i) elementary equivalence of matrices over ZG and (ii) the conjugacy cla...
Oxygen isotopes as a valuable tool for measuring annual growth in tropical trees that lack distinct annual rings
tropical tree with non-distinct annual rings cellulose oxygen isotopes fractionation model Styrax tonkinensis Ficus semicordata var. semicordata
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2017/4/11
Some trees from tropical areas lack visually detectable and consistent annual growth rings. As such, we have measured
the radial variation of cellulose oxygen isotopes in trees that grow in seasonall...
Optimal fold symmetry of LH2 rings on a photosynthetic membrane
LH2 rings a photosynthetic membrane
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2014/9/24
An intriguing observation of photosynthetic light-harvesting systems is theN-fold symmetry of light-harvesting complex 2 (LH2) of purple bacteria. We calculate the optimal rotational configuration of ...
Topologizing Rings of Map Germs: An Order Theoretic Analysis of Germs via Nonstandard Methods
map germ topology nonstandard
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2012/6/19
Using nonstandard analysis we define a topology on the ring of germs of functions: $(mathbb R^n,0)\rightarrow(mathbb R,0)$. We prove that this topology is absolutely convex, Hausdorff, that convergent...
Large self-injective rings and the generating hypothesis
Large self-injective rings the generating hypothesis Algebraic Topology
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2012/6/9
We construct a number of different examples of non-Noetherian graded rings that are injective as modules over themselves (or have some related but weaker properties). We discuss how these are related ...