Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Crystal and Electronic Structure of Perovskite Oxides
Perovskites have been proven to be the one of best cathodes for the solid oxide electrolyte cell (SOEC) devices, in particular, Co-based ones usually exhibit extremely high catalytic performances due to the multivalent properties of Co ions. Thorough understanding of the crystal and electronic structure of perovskite oxides are important.
  • 528
  • 02 Nov 2022
Topic Review
Recent Advances in Fabricating Wurtzite AlN
As a representative ultrawide bandgap (UWBG) semiconductor material, wurtzite aluminum nitride (AlN) material has many excellent properties such as high electron mobility (1100 cm2/Vs), high breakdown voltage (11.7 MV/cm), high piezoelectric coefficient, high thermal conductivity (320 W/m·K), high hardness (nine on the Mohs scale), high corrosion resistance, high chemical and thermal stability, as well as high bulk acoustic wave velocity (11,270 m/s).
  • 523
  • 10 Jan 2022
Topic Review
Engineering Crystal Packing in RNA
The crystal packing strategies described in this entry can reduce the flexibility of the interacting regions. Some of these crystal packing modules generate symmetry, which should promote crystallization because proteins with molecular symmetry are known to crystallize more readily than those without molecular symmetry. For example, the kissing loop complex generates two-fold symmetry, the G-quadruplex generates a four-fold symmetry, and the 3WJ junction has been further engineered to form a stable planar triangle, square, and pentagon using oligonucleotides.
  • 494
  • 07 Sep 2021
Topic Review
Ti:Sa Crystals
In this paper, Ti:Sa amplifiers with crystals of the different geometries are discussed. Benefits of using this active medium for a thin disk (TD) and slab amplifiers are evaluated numerically and tested experimentally. Thermal management for amplifiers with multi-kW average power and multi-J pulse energy has been demonstrated. The presented numerical simulations revealed the existing limitations for heat extraction in TD geometry in the sub-joule energy regime for higher repetition rate operation. Geometry conversion from TD to thin-slab (TS) and cross-thin-slab (XTS) configurations significantly increases the cooling efficiency with an acceptable crystal temperature for pump average power values up to few kW with room temperature cooling, and up to tens of kW with cryogenic cooling. The abilities to attain 0.3 J output energy and a greater than 50% extraction efficiency were demonstrated with a repetition rate exceeding 10 kHz with room temperature cooling and one order more of a repetition rate with cryogenic conditions with pulsed pumping. Direct diode pumping simulated for CW regimes demonstrated 1.4 kW output power with 34% extraction efficiency using room temperature cooling and more than 10 kW and ~40% efficiency with cryogenic cooling.
  • 409
  • 19 Oct 2021
Topic Review
Liquid Crystalline Materials Based on Copper(I) Complexes
This paper provides insight into the various studies that have already been carried out on liquid crystalline materials based on copper(I) complexes. Even though the study of copper(I) complexes with respect to their liquid crystalline property is quite few, metallomesogens prepared with different structural components and ligands from groups such as aza macrocycles, alkyl thiolates, ethers, isocyanides, phenanthroline, Schiff bases, pyrazoles, phosphine, biquinoline, and benzoyl thiourea have been reported. A special section is dedicated to the discussion of the emission properties of copper(I) metallomesogens.
  • 402
  • 28 Jul 2023
Topic Review
Disruption of Claudin-Made Tight Junction Barriers by CpE
Claudins are a family of integral membrane proteins that enable epithelial cell/cell interactions by localizing to and driving the formation of tight junctions. Via claudin self-assembly within the membranes of adjoining cells, their extracellular domains interact, forming barriers to the paracellular transport of small molecules and ions. The bacterium Clostridium perfringens causes prevalent gastrointestinal disorders in mammals by employing an enterotoxin (CpE) that targets claudins. CpE binds to claudins at or near tight junctions in the gut and disrupts their barrier function, potentially by disabling their assembly or via cell signaling means—the mechanism(s) remain unclear.
  • 398
  • 10 Mar 2022
Topic Review
Inhibitor-Enzyme Complexes for New Anti-TB Agents
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is the most devastating human pathogen, as confirmed by the latest TB Report published in October.
  • 393
  • 23 Jan 2022
Topic Review
New Modification of PbF(IO3)
New crystals of PbF(IO3) polytype modification are synthesized hydrothermally and demonstrate strong SHG optical response. They are phase-matchable at the fundamental wavelength of 1064 nm. The crystal structure was solved in two space groups, orthorhombic C2ma and monoclinic Pn, of which monoclinic is true and is described with a twinning by mirror plane introduced in structural refinements taken into account. Orthorhombic symmetry was used in comparison with the related structures and deviation close similarity in the selected suggested family MX(IO3), M = Bi, Ba­, Pb, X= O, F, (OH) with series of members. These compounds were also characterizing as similar to Aurivillius phases with fluorite-like layer and perovskite-like layer substituted by (IO3) groups. The optical nonlinearity of the iodates of the Aurivillius family and structurally related iodates is determined by the polar orientation of the iodate groups, which make an overwhelming contribution to the optical nonlinearity. From crystal chemistry point of view, the heavy atoms in these structures are located in the second cation environments in relation to the iodate groups and indirectly affect the nonlinearity. In particular, large Ba-cations without single electron pairs provoke a symmetric variant of the Aurivillius type structure, in contrast to the acentric Bi3+ and Pb2+ cations known in polar iodates with strong second-order optical nonlinearity. There is wide diversity in the extended series of related compounds which includes variation of fluorite-like layers (single or double), perovskite-like layers presented by octahedral or more complicate polyhedral, or by IO3 (BrO3) groups, or by Cl-atoms, or by NH4-groups. This allows the development of future search for new promising phases.
  • 330
  • 01 Feb 2023
Topic Review
Variable Combinations of Tridentate Ligands in Pt(η3-X3L)(PL) Derivatives
There are over fifty examples in which the inner coordination spheres about the Pt(II) atoms of the Pt(η3-X3L)(PL) type are formed by variable combinations of donor atoms of tridentate ligands. Each η3-ligand creates two metallocyclic rings. The complexes based on membered metallocyclic rings can be divided into four groups: 1. 6+6-Membered Metallocyclic Rings, 2. 6+5-Membered Metallocyclic Rings, 3. 5+6-Membered Metallocyclic Rings, and 4. 5+5-Membered Metallocyclic Rings.
  • 225
  • 18 Apr 2023
Topic Review
SDPD Methods to Pharmaceutical Cocrystals and Salts
Modern X-ray diffractometers, powerful computers, and the continuously improving methods of structure determination from powder data, so called SDPD methods, provide a reliable basis for conducting such research in laboratories of any level. 
  • 207
  • 06 Jul 2023
  • Page
  • of
  • 4
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Feedback