Mineral
... Nonsilicate Mineral- a mineral that does not contain compounds of silicon and oxygen Nonsilicate minerals comprise about 4% of Earth’s crust. Nonsilicate minerals are organized into six major groups based on their chemical compositions. The six major groups of nonsilicate minerals are carbonates, ha ...
... Nonsilicate Mineral- a mineral that does not contain compounds of silicon and oxygen Nonsilicate minerals comprise about 4% of Earth’s crust. Nonsilicate minerals are organized into six major groups based on their chemical compositions. The six major groups of nonsilicate minerals are carbonates, ha ...
Schramm and P. Scott Hefty L. Yuan, Scott Lovell, Kevin P. Battaile
... while SAH hydrolysis provides precursors for biosynthesis of quorum sensing compounds. Thus, proper MTAN function is essential to bacteria that require these pathways. Purified recombinant CT263 was incubated with a variety of potential MTAN substrates, including AFL, SAH, MTA and ATP. HPLC analysis ...
... while SAH hydrolysis provides precursors for biosynthesis of quorum sensing compounds. Thus, proper MTAN function is essential to bacteria that require these pathways. Purified recombinant CT263 was incubated with a variety of potential MTAN substrates, including AFL, SAH, MTA and ATP. HPLC analysis ...
On Contact Numbers of Finite Lattice Sphere
... In light of this recent research interest at the interface of discrete geometry and materials science, we construct a formalism for understanding all molecular geometries that translates theorems from discrete geometry into existential bounds on the realizability and structure of chemical compounds. ...
... In light of this recent research interest at the interface of discrete geometry and materials science, we construct a formalism for understanding all molecular geometries that translates theorems from discrete geometry into existential bounds on the realizability and structure of chemical compounds. ...
Volcanoes and Igneous Activity Earth
... + protons in an atom •Isotope = atom that exhibits variation in its mass number •Unstable isotopes emit particles and energy in a process known as radioactive decay ...
... + protons in an atom •Isotope = atom that exhibits variation in its mass number •Unstable isotopes emit particles and energy in a process known as radioactive decay ...
Crystal-Structure Analysis with Moments of the Density-of
... The set of discrete values of x is a direct consequence of occupying the sublattice that corresponds to one Wyckoff position with only one species of atoms at a time. As the A15 and C15 phases have no internal degrees of freedom, the variation of moments with x reflects the difference in atomic size ...
... The set of discrete values of x is a direct consequence of occupying the sublattice that corresponds to one Wyckoff position with only one species of atoms at a time. As the A15 and C15 phases have no internal degrees of freedom, the variation of moments with x reflects the difference in atomic size ...
Chapter 3 Mass Relationships in Chemical Reactions
... 29. The molecular formula of aspirin is C9H8O4. How many aspirin molecules are present in one 500-milligram tablet? A. B. C. D. E. ...
... 29. The molecular formula of aspirin is C9H8O4. How many aspirin molecules are present in one 500-milligram tablet? A. B. C. D. E. ...
Specifying a quartz crystal for a VCXO
... Equation 1 is complex, and we are interested in the imaginary part only, which is called the crystal’s reactance curve and is depicted in Figure 3. In Figure 3, the point marked as fs is where the motional capacitance C1 resonates and cancels the motional inductance L1. A crystal calibrated to the d ...
... Equation 1 is complex, and we are interested in the imaginary part only, which is called the crystal’s reactance curve and is depicted in Figure 3. In Figure 3, the point marked as fs is where the motional capacitance C1 resonates and cancels the motional inductance L1. A crystal calibrated to the d ...
cis and trans isomers of 1,2-cyclohexanediol and 2,3
... be about as favorable as the average of A:A and B:B interactions. The isomers have different shapes, but Pauling & Delbrueck (1940) pointed out that it is the than ca 10% of the time (see references cited above). The complementarity of molecules rather than their identity that presence of improper s ...
... be about as favorable as the average of A:A and B:B interactions. The isomers have different shapes, but Pauling & Delbrueck (1940) pointed out that it is the than ca 10% of the time (see references cited above). The complementarity of molecules rather than their identity that presence of improper s ...
Crystalline Solids: Diffraction
... Many mixed oxides of transition metals crystallise into a cubic structure called the perovskite structure, with primitive cell ABO3 , in which A and B are cations with different size and valence. The small cation, generally A2+ , is surrounded by an octahedron of oxygen atoms, while the large cation ...
... Many mixed oxides of transition metals crystallise into a cubic structure called the perovskite structure, with primitive cell ABO3 , in which A and B are cations with different size and valence. The small cation, generally A2+ , is surrounded by an octahedron of oxygen atoms, while the large cation ...
complexes with bidentate N,N?-bis(b-phenylcinnamaldehyde)
... interaction between Hb and the chloride atoms in ZnLCl2. However, the observed variation in the Hb chemical shifts could be attributed to an intramolecular interaction with metal atom in the form of C /H Zn weak hydrogen bonds (see more details in the crystal structures). Such interactions have ...
... interaction between Hb and the chloride atoms in ZnLCl2. However, the observed variation in the Hb chemical shifts could be attributed to an intramolecular interaction with metal atom in the form of C /H Zn weak hydrogen bonds (see more details in the crystal structures). Such interactions have ...
Minerals
... –temperature (T) –pressure (P) –pH (acid/base) –eH (oxidizing/reducing). –Lattice Structure, Symmetry Each mineral belongs to one of a small number of symmetry classes, such as hexagonal or cubic. The symmetry class is a reflection of the internal symmetry of the mineral’s unit cell. Sometimes, the ...
... –temperature (T) –pressure (P) –pH (acid/base) –eH (oxidizing/reducing). –Lattice Structure, Symmetry Each mineral belongs to one of a small number of symmetry classes, such as hexagonal or cubic. The symmetry class is a reflection of the internal symmetry of the mineral’s unit cell. Sometimes, the ...
Minerals
... depends partly on how rapidly the magma cools. When magma cools slowly, the crystals that form are generally large enough to see with the unaided eye, as shown in Figure 4A. This is because the atoms have enough time to move together and form into larger crystals. When magma cools rapidly, the cryst ...
... depends partly on how rapidly the magma cools. When magma cools slowly, the crystals that form are generally large enough to see with the unaided eye, as shown in Figure 4A. This is because the atoms have enough time to move together and form into larger crystals. When magma cools rapidly, the cryst ...
Three new structures of the core domain of HIV
... protein (residues 188–193) was fairly disordered and highly mobile, with some disconnected electron density, which was interpreted as a loop with no secondary structure. In one of the monomers of crystal form I, as well as in both monomers of crystal form II and in two monomers of crystal form III o ...
... protein (residues 188–193) was fairly disordered and highly mobile, with some disconnected electron density, which was interpreted as a loop with no secondary structure. In one of the monomers of crystal form I, as well as in both monomers of crystal form II and in two monomers of crystal form III o ...
Cryo-trapping the Six-coordinate, Distorted
... tures were ®ve-coordinate and azide complexes had a 6-coordinate distorted-octahedral active site manganese ion (Lah et al., 1995). Cryogenic X-ray absorption spectroscopy of the iron site in FeSOD indicated that at neutral pH the iron atom is ®vecoordinate, at pH 10.5 it is six-coordinate and at pH ...
... tures were ®ve-coordinate and azide complexes had a 6-coordinate distorted-octahedral active site manganese ion (Lah et al., 1995). Cryogenic X-ray absorption spectroscopy of the iron site in FeSOD indicated that at neutral pH the iron atom is ®vecoordinate, at pH 10.5 it is six-coordinate and at pH ...
Environmental Degradation of Materials
... Atomic structure & bonding in solids Atomic structure - Bohr atomic model Electrons revolve in ...
... Atomic structure & bonding in solids Atomic structure - Bohr atomic model Electrons revolve in ...
Structure of Bacillus halmapalus α-amylase crystallized with and
... different crystal forms. The first crystal form was obtained by crystallization of BHA at room temperature in the presence of acarbose and maltose; data were collected at cryogenic temperature to a resolution of 1.9 Å. It was found that the crystal belonged to space group P212121, with unit-cell pa ...
... different crystal forms. The first crystal form was obtained by crystallization of BHA at room temperature in the presence of acarbose and maltose; data were collected at cryogenic temperature to a resolution of 1.9 Å. It was found that the crystal belonged to space group P212121, with unit-cell pa ...
Hydrogen atoms stabilized in neon and nitrogen matrices
... shift, and theg factor of these atoms. We observed a considerable increase in the number of defects in the crystal lattice of nitrogen when the temperature ofthe substrate on which a sample was deposited was reduced from 4.2 to 1.6 K, which was attributed to a considerable increase in the width of t ...
... shift, and theg factor of these atoms. We observed a considerable increase in the number of defects in the crystal lattice of nitrogen when the temperature ofthe substrate on which a sample was deposited was reduced from 4.2 to 1.6 K, which was attributed to a considerable increase in the width of t ...
description and unique crystal-structure of waterhouseite, a
... absorption Z = X > Y. Electron-microprobe analyses yielded the empirical formula Mn7.29[(P1.81As0.07V0.04)1.92O7.68](OH,O)8.32, calculated on the basis of 16 O atoms. The simplified formula is Mn7(PO4)2(OH)8, in agreement with the crystal-structure determination. The strongest five lines in the pow ...
... absorption Z = X > Y. Electron-microprobe analyses yielded the empirical formula Mn7.29[(P1.81As0.07V0.04)1.92O7.68](OH,O)8.32, calculated on the basis of 16 O atoms. The simplified formula is Mn7(PO4)2(OH)8, in agreement with the crystal-structure determination. The strongest five lines in the pow ...
From Discrete Linear ZntBu2 Molecules to 1D Coordination
... [ZntBu2(bpene)] (3) were obtained from a THF solution at 0 °C. X-ray crystallographic analysis of 3 revealed the formation of the 1D zigzag-like inorganic-organic hybrid polymeric chains (Figure 3). The geometric parameters of 3 are similar to those of 2, with pyridine ligands completing a pseudotet ...
... [ZntBu2(bpene)] (3) were obtained from a THF solution at 0 °C. X-ray crystallographic analysis of 3 revealed the formation of the 1D zigzag-like inorganic-organic hybrid polymeric chains (Figure 3). The geometric parameters of 3 are similar to those of 2, with pyridine ligands completing a pseudotet ...
FRACTAL-LIKE SQUARE LATTICES OF AIR HOLES H. T. Hattori
... conventiona geometric objects [15]. These special geometrical forms have a so been applied to optica devices [16–19], eading to DFB asers with improved performance [18, 19]. Also, fractals have been applied to antennas to produce specially tailored radiation beams [20]. In this article, we combine f ...
... conventiona geometric objects [15]. These special geometrical forms have a so been applied to optica devices [16–19], eading to DFB asers with improved performance [18, 19]. Also, fractals have been applied to antennas to produce specially tailored radiation beams [20]. In this article, we combine f ...
Crystal Structure of an Enzyme-Substrate Complex Provides Insight
... participation of its hydrated form, that is, with a geminal diol on the Cb carbon atom11 (Figure 2(c)). One of the hydroxyl groups is coordinating the magnesium cation present in the active site and is directed towards the opening of the active-site cleft, while the other hydroxyl group is establish ...
... participation of its hydrated form, that is, with a geminal diol on the Cb carbon atom11 (Figure 2(c)). One of the hydroxyl groups is coordinating the magnesium cation present in the active site and is directed towards the opening of the active-site cleft, while the other hydroxyl group is establish ...
Synthesis, crystal growth, structural, spectral, optical
... and magnetically equivalent methine protons of tartaric acid moiety in the adduct. The broad singlet signal at d 4.55 ppm is attributed to the two chemically equivalent hydroxy protons of L-tartaric acid moiety which almost overlaps with the singlet signal due to hydroxy proton of 4-hydroxy-L-prolin ...
... and magnetically equivalent methine protons of tartaric acid moiety in the adduct. The broad singlet signal at d 4.55 ppm is attributed to the two chemically equivalent hydroxy protons of L-tartaric acid moiety which almost overlaps with the singlet signal due to hydroxy proton of 4-hydroxy-L-prolin ...
Crystal-field induced dipoles in heteropolar crystals
... able to attribute the spatial extent of charge distributions to other geometrical objects, such as ellipsoids for instance. As can be seen in Fig. 2, it would be useful to characterize ionic radii r with two additional parameters: (i) the dipole strength, p, when applicable and (ii) the angle 6 betw ...
... able to attribute the spatial extent of charge distributions to other geometrical objects, such as ellipsoids for instance. As can be seen in Fig. 2, it would be useful to characterize ionic radii r with two additional parameters: (i) the dipole strength, p, when applicable and (ii) the angle 6 betw ...
Crystallization and Characterization of Galdieria sulphuraria RUBISCO in Two Crystal Forms: Structural Phase Transition Observed in P21 Crystal Form
... crystal, bathed it in fresh cryoprotecting buffer and froze it again in an N2 stream. The single crystal diffraction pattern was obtained, but with visible changes. The diffraction pattern before and after the freeze-thaw cycle is presented in Figure 2. The changes in diffraction pattern upon data c ...
... crystal, bathed it in fresh cryoprotecting buffer and froze it again in an N2 stream. The single crystal diffraction pattern was obtained, but with visible changes. The diffraction pattern before and after the freeze-thaw cycle is presented in Figure 2. The changes in diffraction pattern upon data c ...
Crystal structure of boron-rich metal borides
Metals, and specifically rare-earth elements (RE), form numerous chemical complexes with boron. Their crystal structure and chemical bonding depend strongly on the metal element M and on its atomic ratio to boron. When B/M ratio exceeds 12, boron atoms form B12 icosahedra which are linked into a three-dimensional boron framework, and the metal atoms reside in the voids of this framework. Those icosahedra are basic structural units of most allotropes of boron and boron-rich rare-earth borides. In such borides, metal atoms donate electrons to the boron polyhedra, and thus these compounds are regarded as electron-deficient solids.The crystal structures of many boron-rich borides can be attributed to certain types including MgAlB14, YB66, REB41Si1.2, B4C and other, more complex types such as RExB12C0.33Si3.0. Some of these formulas, for example B4C, YB66 and MgAlB14, historically reflect the idealistic structures, whereas the experimentally determined composition is nonstoichiometric and corresponds to fractional indexes. Boron-rich borides are usually characterized by large and complex unit cells, which can contain more than 1500 atomic sites and feature extended structures shaped as ""tubes"" and large modular polyhedra (""superpolyhedra""). Many of those sites have partial occupancy, meaning that the probability to find them occupied with a certain atom is smaller than one and thus that only some of them are filled with atoms. Scandium is distinguished among the rare-earth elements by that it forms numerous borides with uncommon structure types; this property of scandium is attributed to its relatively small atomic and ionic radii. Crystals of the specific rare-earth boride YB66 are used as X-ray monochromators for selecting X-rays with certain energies (in the 1–2 keV range) out of synchrotron radiation. Other rare-earth borides may find application as thermoelectric materials, owing to their low thermal conductivity; the latter originates from their complex, ""amorphous-like"", crystal structure.