Ring Chain Research Articles

Expanders on matrices over a finite chain ring, I

In this work and its sequel, we study the expanding phenomenon of matrices over a finite chain ring of large residue field. A sum-product estimate is proved. It is shown that [Formula: see text] is a moderate expander on [Formula: see text] matrices with exponent [Formula: see text]. These results generalize the main theorems in the recent work [29] of Xie and Ge. The proofs use spectral graph theory and elementary divisor theory.

High-Bonding-Strength Polyimide Films Achieved via Thermal Management and Surface Activation.

In this study, thermal and argon (Ar) plasma/wetting treatments were combined to enhance the bonding strength of polyimide (PI) films. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) was used to analyze the changes in the PI imidization degrees. The contact angles of the PI films were also measured. The results show that the contact angles of the fully cured PI films markedly decreased from 78.54° to 26.05° after the Ar plasma treatments. X-ray photoelectron spectroscopy (XPS) analysis was also conducted on the PI surfaces. We found that the intensities of the C-OH and C-N-H bonds increased from 0% to 13% and 29% to 57%, respectively, after Ar plasma activation. Such increases in the C-OH and C-N-H intensities could be attributed to the generation of dangling bonds and the breakage of the imide ring or polymer long chains. Shear tests were also conducted to characterize the bonding strength of the PI films, which, after being treated with the appropriate parameters of temperature, plasma power, and wetting droplets, was found to be excellent at greater than 35.3 MPa.

Two families of few-weight codes over a finite chain ring

Linear codes over finite chain rings meeting the Griesmer bound are particularly interesting since they are closely related to minihyper in projective Hjelmslev spaces. In this paper, motivated by the nice article (Li et al., 2018 [23]), two classes of linear codes with few non-zero Hamming weights over the finite chain ring R=Fq+uFq are constructed, and one of them meets the Griesmer bound over finite commutative local rings. By a Gray map, we obtain that the Gray images of the constructed codes over the ring R are linear codes with two weights over the finite field Fq with q elements, and these codes are optimal with respect to the well-known Griesmer bound under certain conditions. Our results give an affirmative answer to two (related) open questions raised in the article mentioned above. Remarkably, some of the constructed linear codes over R presented in this paper correspond to minihypers in projective Hjelmslev spaces over finite chain rings. Besides, their Gray images can be used to construct secret sharing schemes with nice access structures and other applications thanks to the minimality property that possesses our constructed codes.

Novel phenolic modified acrylates: Synthesis, characterization and application in 3D printing

Three phenolic modified acrylate derivatives were synthesized by the reaction of nonylphenol (NP), 2-aminoethanol (AE) and paraformaldehyde (PA) with neopentyl glycol diacrylate (NPGDA), trimethylolpropane triacrylate (TMPTA) and 1,6-hexanediol diacrylate (HDDA), respectively. The molecular structures of the products were characterized by 1H NMR and electrospray ionization high resolution mass spectrometry (ESI-HRMS). The photopolymerization kinetics of phenolic modified acrylate was investigated by interval infrared spectroscopy. The results show that the phenolic modified acrylate with 1 wt% of 2-isopropylthioxanthone (ITX) can be cured to form a transparent film under UV irradiation. The UV curing speed of phenolic modified acrylate with 1 wt% of ITX was better than that of NPGDA with 1 wt% of ITX and 3 wt% of ethyl 4-(dimethylamino) benzoate (EDB) as co-initiator. The modified acrylate has high UV curing activity and low shrinkage of cured product due to the existence of active amine, aromatic rigid ring and flexible alkyl long chain structure. Based on DFT theoretical calculation, the hydrogen abstraction site of phenolic-modified acrylate was discussed, and the plausible photopolymerization mechanism was proposed. The composition of phenolic-modified acrylate and RJ313 resin can be 3D printed into various models with smooth surface, good precision and 99.7% of gel content.

Nucleobase Specific Understanding about the Interaction of Antimalarial Drug Chloroquine with Duplex DNA.

Antimalarial action of a drug is closely associated with the interaction with the parasite's DNA. Hence, in this study, the interaction of an important antimalarial drug, chloroquine (CLQ), has been investigated with six different sequences of DNA having pure adenine (A)-thymine (T) and pure cytosine (C)-guanine (G) as well as mixed nucleobases to achieve the nucleobase level of information in the binding of antimalarial drug with DNA along with binding induced stabilization/destabilization of DNA using different spectroscopic methods and molecular dynamics simulation technique. Further, the experiments have been also performed with 4-amino-7-chloroquinoline (7CLQ), an analogue of CLQ, to understand the role of the quinoline ring and side chain of CLQ in the binding with different sequences of DNA. The binding efficiency of CLQ with any sequence of DNA is higher than 7CLQ suggesting that the presence of charge on CLQ plays a prominent role in DNA binding. The data suggest that the binding of drug as well as induced stabilization of DNA depends significantly on the nature as well as the arrangement of the nucleobases. In general, the binding of CLQ with pure CG DNA is higher than with pure AT DNA; moreover, it prefers an alternate order of CG/AT than continual nucleobases in duplex DNA. CLQ predominately accommodates in the minor groove of AT DNA and prefers to form hydrogen bond mostly with the adenine nucleobase. In contrast to AT DNA, CLQ intrudes into the both major and minor grooves, but it is primarily accommodated into the major groove of CG DNA. CLQ forms a hydrogen bond mainly with guanine in the major groove and cytosine in the minor groove of CG DNA which enhances the binding of CLQ compared to AT DNA as well as induces higher stabilization in CG DNA. The molecular level information obtained about the functional group responsible for the interaction of CLQ as well as the role of chemical nature of nucleobases along with its ordering on the binding of CLQ with DNA may be useful in comprehensive understanding of its action mechanism.

Hydrodynamics of the fast-start caridoid escape response in Antarctic krill, Euphausia superba

Krill are shrimp-like crustaceans with a high degree of mobility and variety of documented swimming behaviors. The caridoid escape response, a fast-start mechanism unique to crustaceans, occurs when the animal performs a series of rapid abdominal flexions and tail flipping that results in powerful backward strokes. The current results quantify the animal kinematics and three-dimensional flow field around a free-swimming Euphausia superba as it performs the caridoid escape maneuver. The specimen performs a single abdominal flexion-tail flip combination that leads to an acceleration over a 42 ms interval allowing it to reach a maximum speed of 57.0 cm/s (17.3 body lengths/s). The krill’s tail flipping during the abdominal closure is a significant contributor to the thrust generation during the maneuver. The krill sheds a complex chain of vortex rings in its wake due to the viscous flow effects while the organism accelerates. The vortex ring structure reveals a strong suction flow in the wake, which suggests that the pressure distribution and form drag play a role in the force balance for this maneuver. Antarctic krill typically swim in a low to intermediate Reynolds number (Re) regime where viscous forces are significant, but as shown by this analysis, its high maneuverability allows it to quickly change its body angle and swimming speed.

Molecular Conformation and Intermolecular Interactions of Linear and Cyclic Amylose Derivatives in Solution

AbstractFour kinds of rigid and semiflexible ring polymers are synthesized from flexible cyclic amylose. Their conformational properties in dilute solution are determined from dimensional and hydrodynamic properties in terms of the wormlike ring model. The helix rise per residue h of some ring polymers is larger or smaller than that for the corresponding linear chains, indicating that the local helical structure of the ring polymer is not the same as that for the linear chain. Intermolecular interactions detected by the second virial coefficient and chiral recognition ability of some ring polymers are different from the linear chain, suggesting the local structural change causes the intermolecular interactions. The study also finds that rigid ring polymers can form liquid crystal phase at high concentration. X‐ray diffraction results suggest that the ring chains form pseudo rodlike conformation in the liquid crystal phase, showing that intermolecular excluded volume effects significantly influence the conformation of the polymer chains.

Microstructure evolution and mechanical performance of tetrahedral amorphous carbon coatings with dense droplets during annealing

Tetrahedral amorphous carbon (ta-C) coatings with approximately 50% sp3C were deposited onto cemented carbide alloy YG6 and Si wafers via direct vacuum cathode arc (DVCA) evaporation at different substrates temperatures. Coated specimens were annealed in a 5 Pa argon atmosphere. The micromorphology and chemical bonding structure of these coatings with different treatments were characterized using field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The mechanical performance was tested using a nanoindenter and film stress instrument. The obtained ta-C coatings contained dense droplets of various sizes (“abnormal particles” (An-Ps)). The densities of the An-Ps were controlled by the graphite cathode target arc rather than the substrate temperature, and their ID/IG ratios were close to their counterpart coating matrix. Increasing the substrate temperature was beneficial for increasing the sp2C fraction and the number of aromatic ring sp2C sites. Growth, coalescence, and leveling-diffusion of aggregates in the coating matrix and An-Ps occurred during annealing, which was related to the existing state of the sp2C sites, including the olefinic chain and aromatic ring. The residual stress variation with annealing temperature also depended on the sp2C state. The residual stress in the coating increased during annealing when the number of aromatic ring sp2C sites exceeded a certain critical value.

Comparison of Photocatalytic Performance of Sr0.9La0.1TiO3 and Sr0.25Ca0.25Na0.25Pr0.25TiO3 Towards Metoprolol and Pindolol Photodegradation

The photocatalytic performance of Sr0.9La0.1TiO3 and Sr0.25Ca0.25Na0.25Pr0.25TiO3 perovskite–based catalysts were studied under different radiation types (simulated solar, LED, and UV radiation) for removal of metoprolol and pindolol. The results showed that both materials effectively removed metoprolol and pindolol, with the highest degradation efficiency observed under UV radiation. The degradation efficiency of metoprolol went up to 30% using Sr0.9La0.1TiO3 and Sr0.25Ca0.25Na0.25Pr0.25TiO3 using all mentioned radiation types. Pindolol was degraded more efficiently, using Sr0.9La0.1TiO3 68%, 94%, and 100% of pindolol was degraded after 240 min, under SSI, UV-LED, and UV irradiation. Using Sr0.25Ca0.25Na0.25Pr0.25TiO3, degradation efficiency was 65%, 84%, and 93%, under SSI, UV-LED, and UV irradiation, respectively. The chemical oxygen demand showed that these materials were highly efficient in mineralizing metoprolol and pindolol as well as their intermediates. The mechanisms behind the degradation of metoprolol using perovskite catalysts are complex. Still, ongoing research has indicated that the degradation mechanism occurs through hydroxylation of the aromatic ring or side chains. A similar degradation pathway is suggested for the degradation of pindolol, including opening an indol ring at the nitrogen atom site.

Submodule codes as spherical codes in buildings

We give a generalization of subspace codes by means of codes of modules over finite commutative chain rings. We define a new class of Sperner codes and use results from extremal combinatorics to prove the optimality of such codes in different cases. Moreover, we explain the connection with Bruhat–Tits buildings and show how our codes are the buildings’ analogue of spherical codes in the Euclidean sense.

Simultaneous monitoring of ceftaroline fosamil and its active form ceftaroline during stability study of commercial sample - a new stability-indicating HPLC method, drug decomposition in clinical use conditions and degradation products by LC-MS

Ceftaroline fosamil (prodrug) and ceftaroline (active form; degradation product) were simultaneously determined by a new stability-indicating HPLC method. These two forms were monitored during stability investigation of drug formulation reconstituted solution following the same conditions used for clinical use (refrigeration and room temperature). In general terms, ceftaroline fosamil is stable when stored at refrigerator until 48 h, with a drug residual content of 93.99% (in saline diluent) and 97.18% (in 5% glucose diluent). At room temperature, its chemical stability is critical, being necessary attention in the time infusion. Ceftaroline free basis was formed during stability testing, and its concentration has increased along the time. A forced degradation study was also performed for evaluation of the main degradation products, which were identified by LC-MS analysis. Applying selected stress conditions, five degradation products were structurally identified, with variation on side chain and cephalosporinic ring. The opened β-lactam ring and ceftaroline free basis can be highlighted.

On J-Diagrams for the One Groups of Finite Chain Rings

Let R be a finite commutative chain ring with invariants p,n,r,k,m. The purpose of this article is to study j-diagrams for the one group H=1+J(R) of R, where J(R)=(π) is Jacobson radical of R. In particular, we prove the existence and uniqueness of j-diagrams for such one group. These j-diagrams help us to solve several problems related to chain rings such as the structure of their unit groups and a group of all symmetries of {πk′}, where k′∣k. The invariants p,n,r,k,m and the Eisenstein polynomial by which R is constructed over its Galois subring determine fully the j-diagram for H.

Asymmetric perylene-diimide-based polymeric acceptor integrating alkoxy and alkyl side chains: Synthesis and application for all-polymer solar cell

Alkoxy side chain embodying the large electronegative oxygen played the critical role in tuning the optoelectronic and photovoltaic properties. However, few efforts devoted to incorporating the alkoxy side chain into perylene diimide (PDI) building block. In this contribution, one PDI-containing asymmetric polymeric acceptor PPDI-HD-OHD-T bearing 2-hexyldecyl (HD) and 2-hexyldecyloxy (OHD) side chains was developed. Also, two symmetric polymeric acceptors PPDI-HD2-T and PPDI-OHD2-T with identical HD and OHD side chains were prepared to systematically study the impact of bonding OHD side chain on light-harvesting and electrochemical property, molecular configuration, solar cell performance and morphology. Moving from alkyl to alkoxy chains resulted in at first a red-shifted and then a blue-shifted absorption maximum, gradually downshifted HOMO and LUMO energy levels, better molecular planarity, enhanced solution and film state aggregation, and improved photo-stability, these changes resulted from the N–O σ-inductive effect induced by the inserted oxygen, along with the increased number of alkoxy side chain of PDI ring. Furthermore, PPDI-HD-OHD-T acquired a more complementary absorption to PTB7-Th, increased electron mobility and benefited morphology. Thereupon, both improved JSC and FF in PPDI-HD-OHD-T-based device contributed to the boosted PCE of 2.08%, which was higher than those of symmetric side chains PPDI-HD2-T and PPDI-HD-OHD-T-based devices. To our knowledge, it is the first attempt to introduce the alkoxy side chain to N-position of PDI to construct asymmetric polymer acceptor and demonstrated that skillfully tuning the side-chain can effectively affect the electron distribution, molecular configuration, aggregation, charge mobility, and achieve improved device efficiency in all-polymer solar cell.

Weight distributions of generalized quasi-cyclic codes over [formula omitted

In this paper, by Gauss sums, we determine Hamming weight distributions of generalized quasi-cyclic (GQC) codes over the finite chain ring Fq+uFq, where u2=0. As applications, some new infinite families of minimal linear codes with WminWmax≤q−1q and projective two-weight codes are constructed.

On Symbol-Pair Distance of a Class of Constacyclic Codes of Length 3ps over Fpm+uFpm

Let p≠3 be any prime. In this paper, we compute symbol-pair distance of all γ-constacyclic codes of length 3ps over the finite commutative chain ring R=Fpm+uFpm, where γ is a unit of R which is not a cube in Fpm. We give the necessary and sufficient condition for a symbol-pair γ-constacyclic code to be an MDS symbol-pair code. Using that, we provide all MDS symbol-pair γ-constacyclic codes of length 3ps over R. Some examples of the symbol-pair distance of γ-constacyclic codes of length 3ps over R are provided.

Double Constacyclic Codes Over Two Finite Commutative Chain Rings

Many kinds of codes which possess two cycle structures over two special finite commutative chain rings, such as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\mathbb {Z}}_{2}{\mathbb {Z}}_{4}$ </tex-math></inline-formula> -additive cyclic codes and quasi-cyclic codes of fractional index etc., were proved asymptotically good. In this paper we extend the study in two directions: we consider any two finite commutative chain rings with a surjective homomorphism from one to the other, and consider double constacyclic structures. We construct an extensive kind of double constacyclic codes over two finite commutative chain rings. And, developing a probabilistic method suitable for quasi-cyclic codes over fields, we prove that the double constacyclic codes over two finite commutative chain rings are asymptotically good.

Enhanced electron density of the π-conjugated structure and in-plane charge transport to boost photocatalytic H2 evolution of g-C3N4

Graphite carbon nitride (g-C3N4) has become an emerging metal-free photocatalyst and attracted the attention of researchers. However, pure g-C3N4 (PCN) prepared by traditional thermal condensation polymerization has a low polymerization of heptazine ring chains and a large number of charge recombination centers, which hinder in-plane charge transport, leading to undesirable photocatalytic performance. Herein, PCN fabrication by thermal treatment with ammonium oxalate monohydrate was performed to produce highly dispersed porous g-C3N4 nanosheets, and the integrity of their in-plane heptazine ring chains was successfully improved without introducing heteroatoms. Electron paramagnetic resonance and 13C nuclear magnetic resonance analyses revealed significantly increased electron density and delocalization of the π-conjugated structure. The obtained samples exhibited acceptable stability and photocatalytic activity, and the hydrogen reduction rates without and with the Pt co-catalyst were 11.2 and 5.3 times that of PCN.

The effect of methanol atmosphere and/or H-ZSM-5 catalyst on the thermal upgrading of volatiles generated from Hami lignite pyrolysis

The effects of methanol on upgrading of volatiles generated from Hami lignite pyrolysis for producing light aromatics were conducted. The yields of light aromatics were increased by applying methanol as mild hydrogen donor. Particularly, the formation of polymethylbenzene and methylphenols were greatly increased than that of coal pyrolysis under nitrogen atmosphere, suggesting that methanol also provided CH3 and OH. The proportion of deuterium in aliphatic chains were dominate under CH3OD atmosphere, indicating that methanol participated in upgrading of coal pyrolysis volatiles via the decomposition. Moreover, methanol was more inclined to supply H to branched chains of aromatic rings over ZSM-5 zeolite while providing OH without catalysts. However, excessive methanol addition contrarily brought a decrease of light aromatic yields. Unexpectedly, methanol promoted coke formation probably due to the production of polymethylbenzenes and polycyclic aromatics.

Secure Data Transactions based on Hash Coded Starvation Blockchain Security using Padded Ring Signature-ECC for Network of Things

Blockchain is one of the decentralized processes in a worldview that works with parallel and distributed ledger technology, the application process, and service-oriented design. To propose a Secure data Transaction based on Hash coded Starvation Blockchain security using Padded Ring signature-ECC for Network of Things. Initially, the crypto policy is authenticated based on the user-owner shared resource policy and access rights. This creates a Public blockchain environment with a P2P Blockchain network. The owner encrypts the data using optimized ECC through Hash-coded Starvation Blockchain security (HCSBS). This makes the encrypted block's provable partition chain Link (P2CL). The encrypted blocks are transmitted into the network of nodes monitored by NoT. During the data transmission, the Network of Things monitors the transaction flow to verify the authenticity over the network of nodes. The monitored data be securely stored in transaction Block storage with the hash-indexed block with chain ring policy (HICLP). This creates controller node aggregation over the transaction environment to securely transfer the data to the peer end. The User gets the access Key to decrypt the data with policy aggregated shared resource policy to access the data. The proposed system produces high security as well compared to the previous design.

DNA Code from Cyclic and Skew Cyclic Codes over F4[v]/⟨v3⟩

The main motivation of this work is to study and obtain some reversible and DNA codes of length n with better parameters. Here, we first investigate the structure of cyclic and skew cyclic codes over the chain ring R:=F4[v]/⟨v3⟩. We show an association between the codons and the elements of R using a Gray map. Under this Gray map, we study reversible and DNA codes of length n. Finally, several new DNA codes are obtained that have improved parameters than previously known codes. We also determine the Hamming and the Edit distances of these codes.