scholarly journals On real anti-bicanonical curves with one double point on the 4-th real Hirzebruch surface

2015 ◽  
Author(s):  
Sachiko Saito
Keyword(s):  
Double Point ◽  
Hirzebruch Surface

Cross Double Point Discharge as Enhanced Excitation Source for Highly Sensitive Determination of Arsenic, Mercury and Lead by Optical Emission Spectrometry

2021 ◽  
Author(s):  
Lin He ◽  
Peixia Li ◽  
Kai Li ◽  
Tao Lin ◽  
Jin Luo ◽  
...  
Keyword(s):  
Double Point ◽  
Hydride Generation ◽  
Optical Emission ◽  
Sample Introduction ◽  
Excitation Source ◽  
Emission Spectrometry ◽  
Highly Sensitive ◽  
Point Discharge ◽  
Sensitive Determination

A new cross double point discharge (CrossPD) microplasma was designed as an excitation source to construct a miniaturized optical emission spectrometer with hydride generation (HG) for sample introduction. The CrossPD...

scholarly journals Non Kählerian surfaces with a cycle of rational curves

2021 ◽  
Vol 8 (1) ◽  
pp. 208-222
Author(s):  
Georges Dloussky
Keyword(s):  
Deformation Theory ◽  
Complex Surface ◽  
Rational Curves ◽  
Intersection Form ◽  
Connected Component ◽  
Hirzebruch Surface ◽  
Compact Complex Surface ◽  
A Chain

Abstract Let S be a compact complex surface in class VII0 + containing a cycle of rational curves C = ∑Dj . Let D = C + A be the maximal connected divisor containing C. If there is another connected component of curves C ′ then C ′ is a cycle of rational curves, A = 0 and S is a Inoue-Hirzebruch surface. If there is only one connected component D then each connected component Ai of A is a chain of rational curves which intersects a curve Dj of the cycle and for each curve Dj of the cycle there at most one chain which meets Dj . In other words, we do not prove the existence of curves other those of the cycle C, but if some other curves exist the maximal divisor looks like the maximal divisor of a Kato surface with perhaps missing curves. The proof of this topological result is an application of Donaldson theorem on trivialization of the intersection form and of deformation theory. We apply this result to show that a twisted logarithmic 1-form has a trivial vanishing divisor.

Geometric Characteristics of the Center-Point Curve Based on the Kinematics of the Compatibility Linkage

1992 ◽  
Author(s):  
J. A. Schaaf ◽  
J. A. Lammers
Keyword(s):  
Complex Number ◽  
Change Point ◽  
Double Point ◽  
Classification Scheme ◽  
Center Point ◽  
Degenerate Form ◽  
Point Curve ◽  
Position Synthesis ◽  
Point Form

Abstract In this paper we develop a method of characterizing the center-point curves for planar four-position synthesis. We predict the five characteristic shapes of the center-point curve using the kinematic classification of the compatibility linkage obtained from a complex number formulation for planar four-position synthesis. This classification scheme is more extensive than the conventional Grashof and non-Grashof classifications in that the separate classes of change point compatibility linkages are also included. A non-Grashof compatibility linkage generates a unicursal form of the center-point curve; a Grashof compatibility linkage generates a bicursal form; a single change point compatibility linkage generates a double point form; and a double or triple change point compatibility linkage generates a circular-degenerate or a hyperbolic-degenerate form.

scholarly journals An Intramolecular Salt Bridge in Bacillus thuringiensis Cry4Ba Toxin Is Involved in the Stability of Helix α-3, Which Is Needed for Oligomerization and Insecticidal Activity

2017 ◽  
Vol 83 (20) ◽  
Author(s):  
Sabino Pacheco ◽  
Isabel Gómez ◽  
Jorge Sánchez ◽  
Blanca-Ines García-Gómez ◽  
Mario Soberón ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Double Point ◽  
Single Point ◽  
Three Dimensional ◽  
Point Mutations ◽  
Salt Bridge ◽  
Dimensional Structure ◽  
Cry Toxins ◽  
Content Type ◽  
Domain I

ABSTRACT Bacillus thuringiensis three-domain Cry toxins kill insects by forming pores in the apical membrane of larval midgut cells. Oligomerization of the toxin is an important step for pore formation. Domain I helix α-3 participates in toxin oligomerization. Here we identify an intramolecular salt bridge within helix α-3 of Cry4Ba (D111-K115) that is conserved in many members of the family of three-domain Cry toxins. Single point mutations such as D111K or K115D resulted in proteins severely affected in toxicity. These mutants were also altered in oligomerization, and the mutant K115D was more sensitive to protease digestion. The double point mutant with reversed charges, D111K-K115D, recovered both oligomerization and toxicity, suggesting that this salt bridge is highly important for conservation of the structure of helix α-3 and necessary to promote the correct oligomerization of the toxin. IMPORTANCE Domain I has been shown to be involved in oligomerization through helix α-3 in different Cry toxins, and mutations affecting oligomerization also elicit changes in toxicity. The three-dimensional structure of the Cry4Ba toxin reveals an intramolecular salt bridge in helix α-3 of domain I. Mutations that disrupt this salt bridge resulted in changes in Cry4Ba oligomerization and toxicity, while a double point reciprocal mutation that restored the salt bridge resulted in recovery of toxin oligomerization and toxicity. These data highlight the role of oligomer formation as a key step in Cry4Ba toxicity.

A stable superconducting double point-contact magnetometer in which the voltage sensitivity is improved by filling the hole with copper

Physica ◽  
1972 ◽  
Vol 59 (1) ◽  
pp. 155-160 ◽  
Author(s):  
A.Th.A.M. de Waele ◽  
C.P.M. Vergouwen ◽  
A.A.J. Matsinger ◽  
R. de Bruyn Ouboter
Keyword(s):  
Double Point ◽  
Point Contact ◽  
Voltage Sensitivity

A series of rational loci with one apparent double point

1931 ◽  
Vol 27 (3) ◽  
pp. 399-403 ◽  
Author(s):  
D. W. Babbage
Keyword(s):  
Finite Number ◽  
Double Point ◽  
General Point ◽  
Pass Through

1. A locus Vn, of dimension n, in [2n + 1], for example a curve in [3] or a surface in [5], has ∞ 2n chords, of which a finite number pass through a general point of the space.

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