bluuebunny/crossref_metadata_2025 huggingface dataset:
Allosteric communication between ligand binding domains modulates substrate inhibition in adenylate kinase
Authors: Scheerer David , Adkar Bharat V. , Bhattacharyya Sanchari , Levy Dorit , Iljina Marija , Riven Inbal , Dym Orly , Haran Gilad , Shakhnovich Eugene I.
Published: April 2023

Enzymes play a vital role in life processes; they control chemical reactions and allow functional cycles to be synchronized. Many enzymes harness large-scale motions of their domains to achieve tremendous catalytic prowess and high selectivity for specific substrates. One outstanding example is provided by the three-domain enzyme adenylate kinase (AK), which catalyzes phosphotransfer between ATP to AMP. Here we study the phenomenon of substrate inhibition by AMP and its correlation with domain motions. Using single-molecule FRET spectroscopy, we show that AMP does not block access to the ATP binding site, neither by competitive binding to the ATP cognate site nor by directly closing the LID domain. Instead, inhibitory concentrations of AMP lead to a faster and more cooperative domain closure by ATP, leading in turn to an increased population of the closed state. The effect of AMP binding can be modulated through mutations throughout the structure of the enzyme, as shown by the screening of an extensive AK mutant library. The mutation of multiple conserved residues reduces substrate inhibition, suggesting that substrate inhibition is an evolutionary well conserved feature in AK. Combining these insights, we developed a model that explains the complex activity of AK, particularly substrate inhibition, based on the experimentally observed opening and closing rates. Notably, the model indicates that the catalytic power is affected by the microsecond balance between the open and closed states of the enzyme. Our findings highlight the crucial role of protein motions in enzymatic activity.
Consequences of poly(ethylene oxide) and poloxamer P188 on transcription in healthy and stressed myoblasts
Authors: Crabtree Adelyn A. , Boehnke Natalie , Bates Frank S. , Hackel Benjamin J.
Published: April 2023

Poly(ethylene oxide) (PEO) and poloxamers, a class of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers, have many personal and medical care applications, including the stabilization of stressed cellular membranes. Despite the widespread use, the cellular transcriptional response to these molecules is relatively unknown. C2C12 myoblasts, a model muscle cell, were subjected to short-term Poloxamer 188 (P188) and PEO181(8,000 g/mol) treatment in culture. RNA was extracted and sequenced to quantify transcriptomic impact. The addition of moderate concentrations (14 µM) of either polymer to unstressed cells caused substantial differential gene expression, including at least twofold modulation of 357 and 588 genes, respectively. In addition, evaluation of the transcriptome response to osmotic stress without polymer treatment revealed dramatic change in RNA expression. Interestingly, the addition of polymer to stressed cells—at concentrations that provide physiological protection—did not yield a significant difference in expression of any gene relative to stress alone. Genome-scale expression analysis was corroborated by single-gene quantitative real-time PCR. Changes in protein expression were measured via western blot, which revealed partial alignment with the RNA results. Collectively, the significant changes to expression of multiple genes and resultant protein translation demonstrates an unexpectedly broad biochemical response to these polymers in healthy myoblasts in vitro. Meanwhile, the lack of substantial transcriptional response to polymer treatment in stressed cells highlights the physical nature of that protective mechanism.
Mechanical theory of nonequilibrium coexistence and motility-induced phase separation
Authors: Omar Ahmad K. , Row Hyeongjoo , Mallory Stewart A. , Brady John F.
Published: April 2023

Nonequilibrium phase transitions are routinely observed in both natural and synthetic systems. The ubiquity of these transitions highlights the conspicuous absence of a general theory of phase coexistence that is broadly applicable to both nonequilibrium and equilibrium systems. Here, we present a general mechanical theory for phase separation rooted in ideas explored nearly a half-century ago in the study of inhomogeneous fluids. The core idea is that the mechanical forces within the interface separating two coexisting phases uniquely determine coexistence criteria, regardless of whether a system is in equilibrium or not. We demonstrate the power and utility of this theory by applying it to active Brownian particles, predicting a quantitative phase diagram for motility-induced phase separation in both two and three dimensions. This formulation additionally allows for the prediction of novel interfacial phenomena, such as an increasing interface width while moving deeper into the two-phase region, a uniquely nonequilibrium effect confirmed by computer simulations. The self-consistent determination of bulk phase behavior and interfacial phenomena offered by this mechanical perspective provide a concrete path forward toward a general theory for nonequilibrium phase transitions.
The origin of blinking in both mudskippers and tetrapods is linked to life on land
Authors: Aiello Brett R. , Bhamla M. Saad , Gau Jeff , Morris John G. L. , Bomar Kenji , da Cunha Shashwati , Fu Harrison , Laws Julia , Minoguchi Hajime , Sripathi Manognya , Washington Kendra , Wong Gabriella , Shubin Neil H. , Sponberg Simon , Stewart Thomas A.
Published: April 2023

Blinking, the transient occlusion of the eye by one or more membranes, serves several functions including wetting, protecting, and cleaning the eye. This behavior is seen in nearly all living tetrapods and absent in other extant sarcopterygian lineages suggesting that it might have arisen during the water-to-land transition. Unfortunately, our understanding of the origin of blinking has been limited by a lack of known anatomical correlates of the behavior in the fossil record and a paucity of comparative functional studies. To understand how and why blinking originates, we leverage mudskippers (Oxudercinae), a clade of amphibious fishes that have convergently evolved blinking. Using microcomputed tomography and histology, we analyzed two mudskipper species,
Periophthalmus barbarus
and
Periophthalmodon septemradiatus
, and compared them to the fully aquatic round goby,
Neogobius melanostomus
. Study of gross anatomy and epithelial microstructure shows that mudskippers have not evolved novel musculature or glands to blink. Behavioral analyses show the blinks of mudskippers are functionally convergent with those of tetrapods:
P. barbarus
blinks more often under high-evaporation conditions to wet the eye, a blink reflex protects the eye from physical insult, and a single blink can fully clean the cornea of particulates. Thus, eye retraction in concert with a passive occlusal membrane can achieve functions associated with life on land. Osteological correlates of eye retraction are present in the earliest limbed vertebrates, suggesting blinking capability. In both mudskippers and tetrapods, therefore, the origin of this multifunctional innovation is likely explained by selection for increasingly terrestrial lifestyles.
Structural insights into HIV-1 polyanion-dependent capsid lattice formation revealed by single particle cryo-EM
Authors: Highland Carolyn M. , Tan Aaron , Ricaña Clifton L. , Briggs John A. G. , Dick Robert A.
Published: April 2023

The HIV-1 capsid houses the viral genome and interacts extensively with host cell proteins throughout the viral life cycle. It is composed of capsid protein (CA), which assembles into a conical fullerene lattice composed of roughly 200 CA hexamers and 12 CA pentamers. Previous structural analyses of individual CA hexamers and pentamers have provided valuable insight into capsid structure and function, but detailed structural information about these assemblies in the broader context of the capsid lattice is lacking. In this study, we combined cryoelectron tomography and single particle analysis (SPA) cryoelectron microscopy to determine structures of continuous regions of the capsid lattice containing both hexamers and pentamers. We also developed a method of liposome scaffold-based in vitro lattice assembly (“lattice templating”) that enabled us to directly study the lattice under a wider range of conditions than has previously been possible. Using this approach, we identified a critical role for inositol hexakisphosphate in pentamer formation and determined the structure of the CA lattice bound to the capsid-targeting antiretroviral drug GS-6207 (lenacapavir). Our work reveals key structural details of the mature HIV-1 CA lattice and establishes the combination of lattice templating and SPA as a robust strategy for studying retroviral capsid structure and capsid interactions with host proteins and antiviral compounds.
Allelic resolution of insect and spider silk genes reveals hidden genetic diversity
Authors: Frandsen Paul B. , Hotaling Scott , Powell Ashlyn , Heckenhauer Jacqueline , Kawahara Akito Y. , Baker Richard H. , Hayashi Cheryl Y. , Ríos-Touma Blanca , Holzenthal Ralph , Pauls Steffen U. , Stewart Russell J.
Published: April 2023

Arthropod silk is vital to the evolutionary success of hundreds of thousands of species. The primary proteins in silks are often encoded by long, repetitive gene sequences. Until recently, sequencing and assembling these complex gene sequences has proven intractable given their repetitive structure. Here, using high-quality long-read sequencing, we show that there is extensive variation—both in terms of length and repeat motif order—between alleles of silk genes within individual arthropods. Further, this variation exists across two deep, independent origins of silk which diverged more than 500 Mya: the insect clade containing caddisflies and butterflies and spiders. This remarkable convergence in previously overlooked patterns of allelic variation across multiple origins of silk suggests common mechanisms for the generation and maintenance of structural protein-coding genes. Future genomic efforts to connect genotypes to phenotypes should account for such allelic variation.
The risk of losing health insurance in the United States is large, and remained so after the Affordable Care Act
Authors: Einav Liran , Finkelstein Amy
Published: April 2023

Health insurance coverage in the United States is highly uncertain. In the post-Affordable Care Act (ACA), pre-COVID United States, we estimate that while 12.5% of individuals under 65 are uninsured at a point in time, twice as many—one in four—are uninsured at some point over a 2-y period. Moreover, the risk of losing insurance remained virtually unchanged with the introduction of the landmark ACA. Risk of insurance loss is particularly high for those with health insurance through Medicaid or private exchanges; they have a 20% chance of losing coverage at some point over a 2-y period, compared to 8.5% for those with employer-provided coverage. Those who lose insurance can experience prolonged periods without coverage; about half are still uninsured 6 mo later, and almost one-quarter are uninsured for the subsequent 2 y. These facts suggest that research and policy attention should focus not only on the “headline number” of the share of the population uninsured at a point in time, but also on the stability and certainty (or lack thereof) of being insured.
Climate change, tree demography, and thermophilization in western US forests
Authors: Rosenblad Kyle C. , Baer Kathryn C. , Ackerly David D.
Published: April 2023

Climate change is driving widespread changes in ecological communities. Warming temperatures often shift community composition toward more heat-tolerant taxa. The factors influencing the rate of this “thermophilization” process remain unclear. Using 10-y census data from an extensive forest plot network, we show that mature tree communities of the western United States have undergone thermophilization. The mean magnitude of climate warming over the 10-y study interval was 0.32 °C, whereas the mean magnitude of thermophilization was 0.039 °C. Differential tree mortality was the strongest demographic driver of thermophilization, rather than growth or recruitment. Thermophilization rates are associated with recent changes in temperature and hydrologic variables, as well as topography and disturbance, with insect damage showing the strongest standardized effect on thermophilization rates. On average, thermophilization occurred more rapidly on cool, north-facing hillslopes. Our results demonstrate that warming temperatures are outpacing the composition of western US forest tree communities, and that climate change may erode biodiversity patterns structured by topographic variation.
Exploiting conformational dynamics to modulate the function of designed proteins
Authors: Rennella Enrico , Sahtoe Danny D. , Baker David , Kay Lewis E.
Published: April 2023

With the recent success in calculating protein structures from amino acid sequences using artificial intelligence-based algorithms, an important next step is to decipher how dynamics is encoded by the primary protein sequence so as to better predict function. Such dynamics information is critical for protein design, where strategies could then focus not only on sequences that fold into particular structures that perform a given task, but would also include low-lying excited protein states that could influence the function of the designed protein. Herein, we illustrate the importance of dynamics in modulating the function of C34, a designed α/β protein that captures β-strands of target ligands and is a member of a family of proteins designed to sequester β-strands and β hairpins of aggregation-prone molecules that lead to a variety of pathologies. Using a strategy to “see” regions of
apo
C34 that are invisible to NMR spectroscopy as a result of pervasive conformational exchange, as well as a mutagenesis approach whereby C34 molecules are stabilized into a single conformer, we determine the structures of the predominant conformations that are sampled by C34 and show that these attenuate the affinity for cognate peptide. Subsequently, the observed motion is exploited to develop an allosterically regulated peptide binder whose binding affinity can be controlled through the addition of a second molecule. Our study emphasizes the unique role that NMR can play in directing the design process and in the construction of new molecules with more complex functionality.
Noun phrases in mixed Martinican Creole and French
Authors: Vaillant Pascal
Published: April 2023

Contact between French and Martinican Creole (MC) takes place in a society where bilingualism is the standard, in a situation of constant language mixing. French and MC, although related, show significant typological divergences on some specific features, e.g. the order between noun and definite determiner in the noun phrase, or the use of a linker to mark a possessive embedded noun phrase. In this paper, I explore the possible combination of the different values of these features in mixed noun phrases occurring in corpora. I inquire about the possible parameters which may influence the outcome and explain the relative frequencies of these different combinations. It appears that there is a partially common pool of elementary structures. Many utterances fall into the category termed byMuysken (2000)‘congruent lexicalization’. I also observe that apparent complex double embeddings have an internal logic, as they result from adjunction of multi-word modifiers. Finally I propose a model which accounts for the observed occurrences by postulating a level in the speech generation process where language itself is underspecified, and where it is in a position to be specified on the fly by contextual factors, coming either from the lexicon or from the constructional frame.
Exploring the structural, optoelectronic, elastic, and thermoelectric properties of cubic ternary fluoro-perovskites sodium based NaMF3 (M = Si and Ge) compounds for heterojunction solar cells applications
Authors: Rahman Nasir , Husain Mudasser , Sohail Mohammad , Khan Rajwali , Zaman Tahir , Neffati Riadh , Murtaza Ghulam , Khan Aurangzeb , Khan Abid Ali , Iqbal Zaffar
Published: April 2023

In the current research, the structural, optoelectronic, elastic, and thermoelectric properties of NaMF3 (M = Si and Ge) ternary halide perovskites compounds are computed within the DFT framework using first-principle modeling. The obtained results of phonons dispersion curves and the tolerance factor is calculated for NaSiF3 and NaGeF3 and is found to be 1.001 and 1.004 respectively, which reveals that these compounds are structurally and thermodynamically stable in the cubic phase. The elastic constants and other mechanical parameters demonstrate that these compounds are mechanically stable, hard to scratch, ductile, anisotropic, and possess resistance to plastic distortion. The band structure and density of states (DOS) demonstrate that NaSiF3 and NaGeF3 compounds are semiconductors and possess a direct band gap of 1.15 eV and 3.31 eV respectively from ‘R-R’ symmetries points. The optical properties are investigated and it is observed that the selected compounds possesses strong optical conduction and absorption coefficients and are transparent at low incident photons energy ranges. This led us to the conclusion that for high-fRequency UV devices, these compounds possess suitable applications. The thermoelectric properties indicate that both materials possess notable power factors and figures of merit (ZT), due to which their applications in solar cells can be deemed. To our knowledge, this is the first theoretical computational systematic study of structural, optoelectronic, elastic, and thermoelectric properties for NaMF3 (M = Si and Ge), which will be experimentally validated. Our findings add comprehensive insight into predicting high-performance Heterojunction Solar Cells.
Design and simulation of chalcogenide perovskite BaZr(S,Se)3 compositions for photovoltaic applications
Authors: Thakur Nikhil , Kumar Pawan , Neffati R , Sharma Pankaj
Published: April 2023

Lead-free Perovskite materials have acquired a lot of interest owing to their potential to overcome the stability and toxicity concerns compared to traditional perovskite solar cells. Chalcogenide perovskites (ABX3, where A = Ba, B = Zr, X = S and/or Se) are emerging materials for photovoltaic (PV) applications. Computer-based designing of metal chalcogenide semiconductors, resulting in the identification of extremely appealing ABX3 substances and their derivatives that may be used as absorbers in thin-film PV devices. In this context, here the numerical studies are performed using the SCAPS-1D simulator for designing of chalcogenide perovskites-based solar cells. We used FTO (Fluorine-doped tin oxide), TiO2 as electron transport layer (ETL), BaZrS3, and BaZrSe3 as an absorber layer, Spiro-OMeTAD as a hole transport layer (HTL), and Au as a metal back contact. The simulations are conducted under AM 1.5G solar spectrum designed to maximise the efficiency of the proposed solar cell. The selection of the optimal parameters such as thickness, defect density and temperature for all the layers including absorber, FTO, ETM, and HTM is examined. The parameters are considered, keeping in mind their impact on solar cell performance, budget effectiveness, and the physics of the entire solar cell architecture. The effect of temperatures between 300 K to 450 K is studied. The results indicate that the power conversion efficiency (PCE), FF (fill factor), Voc (Open Circuit Voltage) and Jsc for BaZrS3 is 12.12%, 79.40%, 0.70 V, 22.00 mA cm−2, respectively, whereas for BaZrSe3 it is 25.84%, 77.32%, 0.72 V, 46.65 mA cm−2, respectively. This shows that BaZrSe3 has the potential to replace BaZrS3.
Quantum correlation enhanced bound of the information exclusion principle
Authors: Zhang Jun , He Kan , Zhang Hao , Yu Chang-Shui
Published: April 2023

We investigate the information exclusion principle for multiple measurements with assistance of multiple quantum memories that are well bounded by the upper and lower bounds. The lower bound depends on the observables’ complementarity and the complementarity of uncertainty whilst the upper bound includes the complementarity of the observables, quantum discord, and quantum condition entropy. In quantum measurement processing, there exists a relationship between the complementarity of uncertainty and the complementarity of information. In addition, based on the information exclusion principle the complementarity of uncertainty and the shareability of quantum discord can exist as an essential factor to enhance the bounds of each other in the presence of quantum memory.
Sustainable Porous Carbons with Ultrahigh Specific Surface Areas for High-performance Supercapacitors
Authors: Ye Yajing , Lei Dongjun , Ren Xueyun , Chen Jifan , Wang Weixing
Published: April 2023

Waste biomass residues are prospective precursors for the preparation of sustainable porous carbons. In this work, we used the residues from Lonicera japonica Thunb and Ligusticum chuanxiong Hort to prepare porous carbons with ultra-high specific surface area (> 3000 m2 g−1), which deliver excellent capacitive performance for electrochemical double-layer capacitor. Porous carbon derived from Ligusticum chuanxiong Hort displays a specific capacitance of 314.4 F g−1 (1 A g−1) in three electrode system. The energy density of Ligusticum chuanxiong Hort-based symmetric supercapacitor reaches 8.4 Wh kg−1 at the power density of 519 W kg−1 in 6 M KOH. The cell remains a high energy density of 5.1 Wh kg−1 at an increased power density of 10.8 kW kg−1. Our work indicates that the waste biomass residues are promising and competitive precursors for the preparation of ultrahigh specific surface area porous carbons for supercapacitor application.
Synthesis and Electrochemical Properties of Fe2O3/rGO Nanocomposite Anode Materials
Authors: Li Lin , Liu Qing , Cheng Jinsong , Zhao Rongfei
Published: April 2023

The Fe2O3/rGO nanocomposites were prepared through a facile approach combining sol-gel synthesis with thermal reduction. The XRD, SEM, and electrochemical performance tests were used to study the relationship between the physical character and the electrochemical properties of the electrode material. As the anode material, the Fe2O3/rGO nanocomposites delivered excellent lithium storage properties, stable cycle performance, and high rate capability (707 mAh g-1 of 100 cycles).

It is demonstrated that the preparation of Fe2O3/rGO nanocomposites structured can effectively alleviate the particle pulverization caused by volume expansion, effectively shorten the diffusion distance of lithium ions, prevents the aggregation of Fe2O3 with the graphene, and improve the cycle stability of the electrode. Meanwhile, the incorporation of the Fe2O3 particles suppressed the stack of graphene layer.
Effect of Zn on Corrosion Resistance of 5083 Alloys
Authors: Shi Jianhao , Mu Yongliang , Shen Hua , Xing Na
Published: April 2023

The effect of addition of 1.5% -5% Zn (mass fraction) on the corrosion performance of alloy 5083 was studied. Homogenization and post-rolling of the alloy were analysed by immersion and electrochemical tests in 3.5% NaCl aqueous solution. The result is as follows: the rate of weight loss increases at the same soak time with the increasing of Zn element mass fraction. The weight loss rate of the alloy rolled is obviously higher than that of homogenized alloy at the same immersion time and Zn content mass fraction. The homogenization of the same components and the self corrosion potential and self corrosion current of rolled alloy at different soaking time are not very obvious. The effect of immersion time on the corrosion resistance of the alloy is not obvious. With the increasing of the Zn element mass fraction, the self-corrosion potential of the homogenized and rolled alloy decreases overall, so the corrosion resistance of the alloy decreases with the increasing of Zn element mass fraction. The homogeneously treated alloy has a higher self-corrosion potential than the alloy rolled, therefore, the alloy rolled has lower corrosion resistance than the homogenized alloy.
IRT and DIC Synchronous Detection of Stress Intensity Factors and Plastic Zone Ranges
Authors: Chen Ruohong , Huang Kai
Published: April 2023

To achieve non-contact in situ detection of stress intensity factors (SIF), this paper innovatively adopts the advanced IRT and DIC synchronous detecting system to measure SIFs as using plastic zone range to assist in determining the state of stress fields. Though this synchronous detecting method has been applied to analyze thermomechanical coupling effects of materials, it has never been used to detect SIFs, which requires a high accuracy of point stress state detection. Thus, to testify its feasibility and accuracy in SIF detection, three engineering materials were subjected to various loading conditions to provide sufficient verification. Firstly, the coefficients of volumetric strain and temperature change of different materials were calibrated by thermocouple and infrared thermography. Then, the compact tensile specimens were subjected to high-speed loading, of which the SIFs and plastic zone ranges were computed by taking several measurement points on infrared and deformation images. Compared with the theoretical values, the errors of the SIF and K-dominated range measured by this experimental method are all within 5%. It demonstrates that the synchronous detecting method has a wide application prospect in high-accurate crack tip strain field and crack development analysis.
Restoration Strategy of Distributed Power Supply in Distribution Network Based on Genetic Algorithm
Authors: Wang Lei , Niu Lin , Ma Zhiguang , Li Hongbo , Wang Li , Wang Tao , Zhang Zhenhai , Chen Lina
Published: April 2023

Nowadays, the penetration of distributed power in distribution network increases the complexity of power supply restoration. For the recovery of the traditional method in the field of distributed power supply system restore deficiency, the improving measures are put forward based on the many kinds of operation constraints, proposes the mathematical model of multi-objective optimization. In addition to conventional constraints in the mathematical model, will also be the network structure and branch power flow constraints into consideration. In view of the model, using the rough set theory, a multi-objective optimization problem into a single objective problem, and on this basis, considering the characteristic of radial network and the characteristics of the different load, by using genetic algorithm to reconstruct network, finally through the corresponding example recovery strategy is feasible and efficient.
Influence of Mg on Inclusions in 21-4N Valve Steel
Authors: Ji Dengping , Liu Beibei , Sun Han , Fu Jianxun
Published: April 2023

In order to explore the influence of different magnesium contents on the morphology, size, distribution and composition of inclusions in 21-4N austenitic valve steel, the inclusions in 21-4N austenitic valve steel with different magnesium contents smelted by high temperature resistance furnace were analyzed by Zeiss metallographic microscope and scanning electron microscope. The results show that the average yield of magnesium in steel is only 4.50% due to the high vapor pressure of magnesium in the laboratory smelting process. When the mass fraction of magnesium is 0-60ppm, with the increase of magnesium content, the main inclusions in steel mostly change from the initial Al2O3 and Al-Mn-O inclusions to Al-Mg-O spinel inclusions and Al-Mg-O composite inclusions. With the further addition of Mg, a large number of large-size MgO inclusions began to appear in steel. The average size of inclusions in 21-4N steel decreased from 4.576μm to 2.89μm, and the density of inclusions increased from 54 to 132 /mm2. The distribution uniformity of inclusions is obviously improved.
The Effect of Nonlinear Feature of Tire on the Control of Active Rear Steering at High Speed
Authors: Tan Zhenxian , Jin Yang , Liu Chengwu
Published: April 2023

The two-degree-of-freedom model of the vehicle is more accurate with considering of the nonlinear feature of tire. Based on the model, the active rear steering control strategy for achieving zero sideslip angle is yielded. Simulation results show that both of the two cases, constant and variable cornering stiffness, are useful in the control of sideslip motion, and using the variable stiffness due to the effect of load transfer in control strategy is more effective.
Seismic Behavior of Through-tenon Joints with Loose Gap
Authors: Li Shengcai , Chen Tao , Shi Shengxiang
Published: April 2023

In this paper, the dry shrinkage deformation of through-tenon joints (TTJs) is simulated by reducing the height of tenon to produce a gap between tenon and mortise. The seismic behaviors of TTJS such as the failure characteristics, hysteretic loops, skeleton curves, degradation of rigidity and energy dissipation were studied through low-cycle reversed loading experiment on 2 groups of TTJs with different degrees of dry shrinkage and sizes. The results indicate that the shape of hysteretic loops of all joints are Z shaped and the gathering effect gets more obvious with the increase of loose degree. The dry shrinkage deformation of TTJs will weaken the seismic performance of the specimens, with the energy dissipation capacity of the joint decreases with the increase of dry shrinkage deformation, and the energy dissipation capacity will be significantly weakened when the gap between the mortise and tenon increases slightly, for example, the energy dissipation capacity of the specimen will be weakened to 50% that of the intact specimen when the gap value increases to 3% height of the mortise.
Study of the Tribological Properties of Magnetic Fluid under the Surface Effects with Magnetic-pole Magnetic-groups
Authors: Xu Chunxia , Zhang Han , Hu Rui
Published: April 2023

The tribological characteristics of the magnetic fluid are studied with the change of multi-pole distribution in this paper. The maximum magnetic field strength and its gradient on the surface of the magnetic-group are analyzed by the finite element analysis of the magnetic field strength distribution at the same magnetic-group with the area ratio of 30%. The research results show that the matching distribution among N-S magnetic-pole groups at the same pole area ratio of 30% has less influence on the magnetic specimen surface, but the magnetic field distribution of magnetic-pole with the rectangular permanent magnet in the annular friction surface has the optimal range of magnetic field distribution design for specific magnetic fluid lubrication, in which pole group specimen 5 is the best magnetic-pole magnetic-group combination for friction reduction, and specimen 1 is the second best.
Research on Integration of Design and Manufacturing of High Thickness Honeycomb Sandwich Structure with Lager Curvature
Authors: Lu Honglong , Hao Lei , Meng Xiangmin , Jia Shunli
Published: April 2023

Based on the characteristics of honeycomb sandwich structure with high thickness and large curvature, the idea of integration of design and manufacturing was proposed to solve the problem of mismatch among design, process and material. Facing the particularity of this kind of structure, the honeycomb deformation simulation model was established. And the composite building block verification method was simplified aiming at solving the problems of sliding and collapse of high thickness honeycomb. A variety of honeycomb stabilization methods were proposed. And the verification contents at the material level, element level, sub component level and component level were specified. Taking the landing gear door parts of large passenger aircraft as a case, the idea of design and manufacturing integration and the building block process verification method of honeycomb sandwich structure was practiced leading to the forward design of gear door parts. The honeycomb deformation simulation model was preliminarily established, which provided a reference for the forward design of similar structural parts.
Comparison of the Beam Mechanical Properties between the CDG Based Geopolymer Concrete and OPC Concrete
Authors: Wang Kai , Zha Xiaoxiong
Published: April 2023

This paper presents the results of an experimental investigation on the beam mechanical properties, based on the completely decomposed granite (CDG) & slag based geopolymer reinforced concrete, as well as the OPC reinforced concrete. The failure mode and bearing capacity of beam members were obtained. The load vs mid span deflection relationship and load vs displacement relationship were discussed. Furthermore, the results show the feasibility of the CDG & slag based geopolymer concrete in engineering application.
Preparation of Conductive Hydrogel and Its Effect on the Proliferation of Neural Stem Cells
Authors: Xie Feng , Wang Shuping , Sun Changkai , Guan Shui
Published: April 2023

Conductive hydrogels open up new possibilities for neural stem cells (NSCs) transplantation for the treatment of neurodegenerative diseases (NDs) and traumatic brain injury (TBI). In this study, a novel carboxymethyl chitosan/gelatin/poly(3,4-ethylenedioxythiophene) (CMCS/Gel-PEDOT) hydrogel with different contents of EDOT monomer was prepared by lyophilization and in-situ polymerization. The samples were characterized in terms of mechanical properties, in vitro biodegradation, swelling rate, and electrical conductivity. All the hydrogels exhibited excellent viscoelasticity, showing compression properties similar to those of rat brain tissue. Moreover, the conductive hydrogels exhibited a high swelling rate (2500%~3000%) in 60-85 h and adequate biodegradability within 6 weeks. With the increase of PEDOT content, the electrical conductivity of prepared hydrogel increased significantly, and the CMCS/Gel-0.2 EDOT hydrogel presented the highest conductivity (1.5×10−3 S/cm). In addition, compared to the suspension culture group and the group without PEDOT, NSCs seeded into the CMCS/Gel-0.2 EDOT hydrogel showed higher proliferative activity after 10 days of culturing, indicating that the conductive hydrogel may be a competitive choice for enhancing nerve regeneration in neural tissue engineering.
Experimental Study of Ultimate Bearing Capacity of Axial Compression of L-type Steel Column
Authors: Chen Xin , Zheng Xiaoyao , Wang Xintang , Wang Zhanliang
Published: April 2023

The L-type steel column studied here is a special-shaped column composed of a square steel pipe and two of T-shaped steel, which are connected by weld. Because the columns have better properties than ordinary steel columns, it may be wildly used in residential steel structures. Therefore, it is quite valuable to study the bearing capacity and stability of the new steel columns. Three of specimens of the column are tested, and behaviour of deformation, distribution of displacements and stresses, and bearing capacity are presented. Effect of related factors on property of the steel column are discussed. It is concluded that the local buckling happened before finally failure of the column, which is sensitive to geometric defects.
Research on Rolling Bearing Operating Life Based on Principal Component Analysis
Authors: Wang Wengang , Hao Xu , Wang Yingchao , Yuan Yu
Published: April 2023

In order to analyze the running state of rolling bearing, the principle component analysis is used to extract new parameters to analyze the running state of the rolling bearing. Firstly, the whole life cycle vibration signal of the rolling bearing is collected by using an acceleration sensor. Secondly, Empirical Mode Decomposition (EMD) is used to reduce the noise in the vibration signal. Then, the main components of the time domain parameters are extracted using the principle component of the denoised signal. And the main components are synthesized into new parameter indicators. Finally, under the new parameter index, the envelope analysis is used to analyze the signal classification. The results show that the new parameter index can divide the entire life cycle of the rolling bearing into four different operating periods, each representing a different bearing operating state.
Microstructure and Macroscopic Characteristics of Powder Superalloy under Different Plastic Deformation Process Parameters
Authors: Lan Bo , Liu Shenghong , Ma Xingyu
Published: April 2023

Through the uniaxial compression deformation test, this work focuses on analyzing the microstructure evolution of the alloy in the two stages of dynamic softening and strain hardening in the true stress-true strain curve during hot deformation, including grain size, local misorientation and The interaction of its relative mobility, and through the grain boundary orientation difference and grain orientation, explained the dynamic softening mechanism and strain hardening phenomenon, so as to find the microstructure-determining characteristic parameters of the dynamic recrystallization nucleation and core growth of the alloy and its evolution.
Research on Strength Check Method for Expansive Stressed Grouted Clamp on Complex Joint
Authors: Zhang Yifei , Chen Yong , Zhao Zhangfan
Published: April 2023

For the strength check method of expansive stressed grouted clamp for repairing damaged joints of offshore platforms, a simplified method of clamp modeling and the grout check criteria suitable for complex joints are proposed. Then, for strengthening two penetration cracks in the PL19-3 offshore platform, the corresponding expansive stressed grouted clamp was designed. And the strength check on the clamp was carried out by ANSYS software employing the suggested method. It is shown that the equivalent stress of steel structure and the Tresca stress of grout ring are all within a reasonable range. This paper provides a simplified design idea for the finite element calculation method of the expansive stressed grouted clamp to repair complex joints.
Preparation and Characterization of Chitosan Grafted Tannic Acid for Anticorrosion Coating on Bronzeware
Authors: Chen Junying , Zhang Xiaoman , Zhang Linli , Zhou Sheng , Huang Xia
Published: April 2023

The protective bronze film was prepared by mixing the reaction product of oligosaccharide (COS) and modified tannic acid (TA) with polyvinyl alcohol and polyethylene glycol. Chloroacetic acid to carboxylate TA was used to generate sodium tannate. N,N’-Dicyclohexylcarbodiumide (DCC)/1-Hydroxybenzotriazole (HOBt) was used as a condensing agent to form an amide bond between carboxylic acid and amine to form COS-TA. The synthesized product was characterized using FT-IR, NMR, and thermal analysis. The surface morphology of the coating made of the synthesized product was observed using an optical microscope and scanning electron microscope. Electrochemical methods were used to determine the stability and corrosion inhibition performance of the coating. FT-IR, NMR, and thermal analysis demonstrated that tannic acid and Chitosan oligosaccharides were successfully condensed. Electrochemical impedance spectroscopy showed that the impedance increased, the corrosion current was significantly reduced, and the coating had a significant anti-corrosion effect.
Experimental and Prediction Model Study of Carbonation Resistance of High Performance Concrete under Influence of Curing Conditions
Authors: Chen Haibo , Zhou Dan , Huang Zhousheng , Wang Jiawei
Published: April 2023

The carbonation resistance of high performance concrete is closely related to the service life of concrete structure, and is an important parameter to reflect its durability. The carbonation resistance of concrete is influenced on selection of curing conditions greatly. In the paper, based on the common curing conditions, the carbonation tests of high performance concrete under different curing methods and curing time were carried out, and the influence mechanism of curing conditions on the carbonation resistance of materials was qualitatively analyzed. The exponential function expression of curing time and carbonation depth was fitted when curing by wet straws. The results show that: in terms of carbonation resistance, the order is wet straw curtain curing, plastic film curing and curing agent curing, and should be cured in advance. The carbonation depth is effectively reduced by short-term curing (3d) and medium-term curing (7d), but the reduction rate slows down, and 7d curing is suggested. The fitted prediction model is calculated the carbonation depth of concrete materials, and the test results are provided data for the selection of curing conditions and time of engineering.
Analysis of 00Cr17Ni14Mo2 Bellows Leakage
Authors: Zhang Jingyu , Li Xiaolin , Yang Zhongwei , Cai Naijia , Xia Shengyou
Published: April 2023

A multi-layer welded bellows made of 00Cr17Ni14Mo2 was found to have leakage points in the heat-affected zone of the weld during airtight inspection and leak detection by helium mass spectrometry. In view of the leakage of multilayer welded bellows, the reasons for the leakage of multilayer welded bellows areanalyzed by means of macroscopic observation, electron microscope observation, energy spectrum analysis, metallographic examination, microhardness test and chemical composition analysis. The results show that there are liquefaction cracks in the heat-affected zone of the outer bellows, which results in air leakage in the airtight test. The generation of liquefaction crack is related to the low Ni content in the material and the pollution of S and Cu elements. The cleaning treatment of the material surface in the welding area should be strengthened before welding to reduce the generation of cracks. At the same time, should be paid attention to the control of welding raw material composition.
Spatio-temporal Evolution and Driving Factors of Carbon Dioxide Emissions from Energy Consumption in the Yellow River Basin
Authors: Kong Yawen , Liu Shuguang
Published: April 2023

Based on the data of 57 cities in the Yellow River Basin (YRB) during 2006-2019, this study analyzes its spatio-temporal evolution of carbon dioxide (CO2) emissions from energy consumption, and decomposes its CO2 emissions changes into five factors. The results indicate that: (1) The CO2 emissions in the Yellow River Basin has increased but did not reach the peak from 2006 to 2019, which showed a spatial distribution pattern of “high in the east and low in the west”, with Baotou city, Taiyuan city, Xi’an City, Zhengzhou City and Zibo city forming several high CO2 emission centers of different sizes and spreading to the periphery; (2) The CO2 emission center of gravity in the Yellow River Basin shifted to the southeast as a whole. Ningxia Hui Autonomous Region and Lanzhou city were the main engine provinces and cities to promote its shift. (3) The driving factors of CO2 emissions growth are economic development level, population size and energy efficiency, while industrial structure and clean energy utilization level (CO2 emission coefficient) factors restrained the growth of CO2 emissions in the Yellow River Basin.
Practice and Prospect of Water Right Reform in Inner Mongolia
Authors: Gao Lei , Zhao Qing , Bu Fenghu , Yan Lei
Published: April 2023

The Inner Mongolia has the courage to innovate in order to solve the imbalance and insufficiency of water resources in supporting and ensuring the development of water resources, sticking to the advanced concepts of supply-side structural reform, giving priority to water saving and giving full play to the role of market mechanism in water resources allocation, a new way to break the bottleneck restriction of water resources was explored. This paper combs the practice of water right reform in Inner Mongolia, analyzes the characteristics and effects of water right reform in Inner Mongolia, and puts forward the key direction of water right market construction in Inner Mongolia during the 14th five-year plan period.
Effect of Different Excipients on Fungal Flora during Aerobic Fermentation of Thermal Hydrolyzed Kitchen Waste
Authors: Wang Zhenhua , Wu Juan , Song Jianguo , Bai Jie
Published: April 2023

In this paper, a comparative study was conducted on the aerobic fermentation of kitchen waste pretreated by thermal hydrolysis and three different excipients, the dynamic changes of temperature and organic matter of kitchen waste after thermal hydrolysis were measured during aerobic fermentation with peanut shell, corn stalk and corn cob as additives, and high-throughput sequencing was performed on the samples of the three excipients in the high temperature fermentation stage to identify the dominant bacterial community in the high temperature region of different excipients. The results showed that the dominant bacterial communities of peanut shell, corn stalk and corn cob were similar at the phylum classification level. Among them, Ascomycota accounted for 97.68%, 99.55% and 99.98% in HS, YM and YX treatment groups, respectively, which means it was the absolute dominant fungal phyla in high temperature fermentation stage. At the level of genus classification, there were differences among the dominant bacterial genera in each group. The main bacterial genera in peanut shell treatment group were Aspergillus, unclassified_f__Dipodascaceae, Penicillium, unclassified_o__Sordariales, Candida and Diutina. The main bacterial genera in corn stalk treatment group were Candida, Aspergillus and Penicillium. The main bacteria in corn cob treatment group was unclassified_o__Sordariales. The percentage of saprophytic fungi in HS, YM and YX high-temperature treatment groups was 96.40%, 99.25% and 99.97%, respectively. Saprophytic fungi played a major role in the high-temperature fermentation stage.
Multi Agent County Energy Internet Project Contribution Evaluation Model
Authors: Tan Qingkun , Wang Junhai , Zhu Chunjie , Yin Jianbing , Wu Peng , Xu Hang , Tang Wei , Chen Lin
Published: April 2023

Energy Internet is an advanced form of modern power grid, representing the future energy development trend and direction. Judging the collaborative efficiency level of county energy internet participants and putting forward countermeasures to improve the efficiency of participants with low collaborative efficiency can strengthen the level of cooperation among participants and speed up the promotion speed of county energy internet. Firstly, the affecting factors of the planning are identified through interview, and the factor index system of county energy Internet is established. Secondly, the entropy weight method is used to determine the weight of each factor. Finally, taking the county energy internet as an example, this paper analyzes the contribution degree of collaborative efficiency of different participants.
Optimization of High Pressure Forming Parameters in Conical Tubes Based on Response Surface Method
Authors: Sun Dan , Wei Bin , Wang Shuqiang
Published: April 2023

The appearance of conical muffler improves the aerodynamic performance and acoustic performance of expansion chamber muffler. The inner surface of this type of pipe has variable section and continuous smoothness. The improvement of the manufacturing efficiency of such tubes is a key issue that needs to be addressed urgently today. To this end, a method of producing conical muffler tubes using a hydraulic expansion process is proposed, using which the weight of the conical muffler tubes can be reduced while the aerodynamic impact of the weld on the muffler tubes is eliminated thereby enhancing the fuel economy of the vehicle. The effect of internal pressure, taper ratio and friction coefficient on the forming results was investigated by using finite element simulation combined with response surface optimization for the hydraulic expansion process method.