bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of resistive switching in δ-CsPbI3 devices by inserting carbon nanotube
Authors: Yang Xiaoting , Ye Zhanhong , Wang Ke , Zhang Ruoxuan , Wei Huanqi , Cui Yimin
Published: February 2023

CsPbI3 is considered to one potential material in the future resistive random access memory(RRAM). There are four crystal types of CsPbI3, among which δ phase is the most stable and available to commercialize. However, the inherent defect of δ-CsPbI3 results in its inferior switching performance to other crystal types. Here, we present a new structure to solve this problem. Carbon nanotube (CNT) was inserted into the two interfaces of Ag/δ-CsPbI3/ITO and Ag/δ-CsPbI3/FTO to adjust its resistance switching performance. It is found that the introduction of carbon nanotube layer can effectively control durability of RRAM devices through influencing strength of conductive filaments. These findings present a new strategy for the future design of δ-CsPbI3 memory.
Cooperativity and clusters properties in ferromagnetic spin transition systems
Authors: Metatla Abboud , Nicolazzi William , Latelli H’mida , Bousseksou Azzedine
Published: February 2023

A Swendsen-Wang cluster Monte Carlo dynamics simulation technique has been used to simulate a 2D-ferromagnetic Ising-type model for spin transition systems. In the purpose to investigate the link between the strength of cooperative interactions and the clusters properties, we shed light on the size and the number of clusters forming the system. Results show that clusters properties in highly cooperative systems are totally different from those in weakly cooperative ones.
The fate of horizons under quantum corrections
Authors: Álvarez Enrique , Anero Jesús , Velasco-Aja Eduardo
Published: February 2023

In this paper, we study the physical effects of deforming the usual Einstein-Hilbert
lagrangian with the Goroff-Sagnotti counterterm (the first which is nonvanishing on shell). Only
spherically symmetric solutions are discussed. The facts that Schwarzschild's spacetime is not a
solution to the corresponding equations of motion and Birkhoff's theorem validity are analyzed and
some consequences worked out.
Catastrogenesis: DM, GWs, and PBHs from ALP string-wall networks
Authors: Gelmini Graciela B. , Simpson Anna , Vitagliano Edoardo
Published: February 2023

Axion-like particles (ALPs), a compelling candidate for dark matter (DM), are the pseudo
Nambu-Goldstone bosons of a spontaneously and explicitly broken global U(1) symmetry. When the
symmetry breaking happens after inflation, the ALP cosmology predicts the formation of a
string-wall network which must annihilate early enough, producing gravitational waves (GWs) and
primordial black holes (PBHs), as well as non-relativistic ALPs. We call this process
catastrogenesis. We show that, under the generic assumption that the potential has
several degenerate minima, GWs from string-wall annihilation at temperatures below 100 eV could be
detected by future CMB and astrometry probes, for ALPs with mass from 10-16 to
106 eV. In this case, structure formation could limit ALPs to constitute a fraction of the DM
and the annihilation would produce mostly “stupendously large” PBHs. For larger annihilation
temperatures, ALPs can constitute 100% of DM, and the annihilation could produce supermassive
black holes with a mass of up to 109
M
⊙ as found at the center of large
galaxies. Therefore our model can solve two mysteries, the nature of the DM and the origin of
these black holes.
Scalar overproduction in standard cosmology and predictivity of non-thermal dark matter
Authors: Lebedev Oleg
Published: February 2023

Stable scalars can be copiously produced in the Early Universe even if they have no
coupling to other fields. We study production of such scalars during and after (high scale)
inflation, and obtain strong constraints on their mass scale. Quantum gravity-induced
Planck-suppressed operators make an important impact on the abundance of dark relics. Unless the
corresponding Wilson coefficients are very small, they normally lead to overproduction of dark
states. In the absence of a quantum gravity theory, such effects are uncontrollable, bringing
into question predictivity of many non-thermal dark matter models. These considerations may have
non-trivial implications for string theory constructions, where scalar fields are abundant.
Deep Large Binocular Camera r-band Observations of the GOODS-N Field
Authors: Ashcraft Teresa A. , McCabe Tyler , Redshaw Caleb , Windhorst Rogier A. , Jansen Rolf A. , Cohen Seth H. , Carleton Timothy , Ganzel Kris , Koekemoer Anton M. , Ryan Russell E. , Nonino Mario , Paris Diego , Grazian Andrea , Fontana Adriano , Giallongo Emanuele , Speziali Roberto , Testa Vincenzo , Boutsia Konstantina , O’Connell Robert W. , Rutkowski Michael J. , Scarlata Claudia , Teplitz Harry I. , Wang Xin , Rafelski Marc , Grogin Norman A.
Published: February 2023

We obtained 838 Sloan r-band images (∼28 hr) of the GOODS-North field with the Large Binocular Camera (LBC) on the Large Binocular Telescope in order to study the presence of extended, low surface brightness features in galaxies and investigate the trade-off between image depth and resolution. The individual images were sorted by effective seeing, which allowed for optimal resolution and optimal depth mosaics to be created with all images with seeing FWHM < 0.″9 and FWHM < 2.″0, respectively. Examining bright galaxies and their substructure as well as accurately deblending overlapping objects requires the optimal resolution mosaic, while detecting the faintest objects possible (to a limiting magnitude of m
AB ∼ 29.2 mag) requires the optimal depth mosaic. The better surface brightness sensitivity resulting from the larger LBC pixels, compared to those of extant WFC3/UVIS and ACS/WFC cameras aboard the Hubble Space Telescope allows for unambiguous detection of both diffuse flux and very faint tidal tails. Azimuthally-averaged radial surface brightness profiles were created for the 360 brightest galaxies in each of the two mosaics. On average, these profiles showed minimal difference between the optimal resolution and optimal depth surface brightness profiles. However, ≲15% of the profiles show excess flux in the galaxy outskirts down to surface brightness levels of

μ

r

AB

≃ 31 mag arcsec−2. This is relevant to Extragalactic Background Light (EBL) studies as diffuse light in the outer regions of galaxies are thought to be a major contribution to the EBL. While some additional diffuse light exists in the optimal depth profiles compared to the shallower, optimal resolution profiles, we find that diffuse light in galaxy outskirts is a minor contribution to the EBL overall in the r-band.
TRPV1-mediated sonogenetic neuromodulation of motor cortex in freely moving mice
Authors: Xu Kevin , Yang Yaoheng , Hu Zhongtao , Yue Yimei , Gong Yan , Cui Jianmin , Culver Joseph P , Bruchas Michael R , Chen Hong
Published: February 2023

Background. Noninvasive and cell-type-specific neuromodulation tools are critically needed for probing intact brain function. Sonogenetics for noninvasive activation of neurons engineered to express thermosensitive transient receptor potential vanilloid 1 (TRPV1) by transcranial focused ultrasound (FUS) was recently developed to address this need. However, using TRPV1-mediated sonogenetics to evoke behavior by targeting the cortex is challenged by its proximity to the skull due to high skull absorption of ultrasound and increased risks of thermal-induced tissue damage. Objective. This study evaluated the feasibility and safety of TRPV1-mediated sonogenetics in targeting the motor cortex to modulate the locomotor behavior of freely moving mice. Approach. Adeno-associated viral vectors was delivered to the mouse motor cortex via intracranial injection to express TRPV1 in excitatory neurons. A wearable FUS device was installed on the mouse head after a month to control neuronal activity by activating virally expressed TRPV1 through FUS sonication at different acoustic pressures. Immunohistochemistry staining of ex vivo brain slices was performed to verify neuron activation and evaluate safety. Results. TRPV1-mediated sonogenetic stimulation at 0.7 MPa successfully evoked rotational behavior in the direction contralateral to the stimulation site, activated cortical neurons as indicated by the upregulation of c-Fos, and did not induce significant changes in inflammatory or apoptotic markers (GFAP, Iba1, and Caspase-3). Sonogenetic stimulation of TRPV1 mice at a higher acoustic pressure, 1.1 MPa, induced significant changes in motor behavior and upregulation of c-Fos compared with FUS sonication of naïve mice at 1.1 MPa. However, signs of damage at the meninges were observed at 1.1 MPa. Significance. TRPV1-mediated sonogenetics can achieve effective and safe neuromodulation at the cortex with carefully selected FUS parameters. These findings expand the application of this technique to include superficial brain targets.
Conceptual design of solid-type Pb
x
Li
y
eutectic alloy breeding blanket for CFETR
Authors: Jiang K. , Wu Q. , Chen L. , Liu S.
Published: February 2023

As a key component of the Chinese Fusion Engineering and Test Reactor (CFETR), the blanket is responsible for tritium breeding, neutron shielding and energy conversion. Blankets can be classified into solid and liquidaccording to the form of tritium breeder. Among them, the solid blanket utilizes the pebble beds as both the tritium breeder and neutron multiplier, and it has been a popular scheme due to its advantages, such as good material compatibility and non-magnetohydrodynamic effects. However, it usually adopts beryllium or an alloy (i.e. Be and Be12Ti) for multiplying neutrons, causing a very high cost of the solid blanket due to the scarcity of natural resources of beryllium, and this hinders its development. In this paper, a novel solid blanket utilizing a PbLi eutectic alloy was proposed to make up the above deficiency. Pb83Li17 is usually applied in a liquid blanket due to its lowmelting point. However, this kind of alloy can have a higher melting point by adjusting the atomic ratio of Pb/Li, and thus it can be used in the solid blanket both for the tritium breeder and neutron multiplier. Based on the blanket modular design of CFETR, the optimization of the radial layouts, the atomic ratio of Pb/Li and the packed structure of the pebble beds are studied through neutronic and thermal hydraulic analysis. The results indicate that the solid-type Pb
x
Li
y
can satisfy the requirement of tritium self-sufficiency, and the global tritium breeding ratio is larger than 1.0. In addition, the cooling system design can retain the maximum temperature of Pb
x
Li
y
at a lower level without melting. Overall, this kind of solid-type Pb
x
Li
y
blanket is feasible from the perspective of neutronic and thermal hydraulics, and it avoids using beryllium; thus, the cost is highly reduced.
Isotope effects on intrinsic rotation in hydrogen, deuterium and tritium plasmas
Authors: Nave M.F.F. , Delabie E. , Ferreira J. , Garcia J. , King D. , Lennholm M. , Lomanowski B. , Parra F. , Fernandez P.R. , Bernardo J. , Baruzzo M. , Barnes M. , Casson F. , Hillesheim J.C. , Hubber A. , Joffrin E. , Kappatou A. , Maggi C.F. , Mauriya A. , Meneses L. , Romanelli M. , Salzedas F.
Published: February 2023

The isotope effect on intrinsic rotation was studied at the Joint European Torus (JET) tokamak. With the unique capability of JET to operate with tritium (T), for the first time, experiments in hydrogen (H), deuterium (D) and T in Ohmic plasmas were compared. Two rotation reversals per isotope type are observed in plasma density scans spanning the linear and the saturated Ohmic confinement regimes. A clear isotope mass dependence is observed at the higher densities. The magnitude of the core rotation was found to depend on isotope mass, with stronger co-current rotation observed in H. Change on intrinsic rotation characteristics coexist with a stronger thermal energy confinement in T.
The IAEA DEMO Programme Workshop Series: 2012–2021 report
Authors: Gonzalez de Vicente S.M. , Surrey E.
Published: February 2023

The IAEA DEMO Programme Workshop Series was initiated to be the reference forum to debate, evaluate and establish the next steps to be taken within the international fusion community to deliver fusion as a reliable source of clean energy. The DEMO programme refers predominantly to a future magnetic confinement Tokamak design concept, after the ITER project, with a goal of delivering electricity to the grid. To enable this, the programme workshop series provides a unique frame where the discussion and analysis of the progress and findings of the various DEMO programmes, and not just the presentation of results being the major goals. More recently, due to the construction development of ITER, the workshop has also provided a forum to bring together the fusion community and industry. This is an important development for DEMO programmes, which will be more reliant on industry given their focus on devices proximate to a commercial fusion power plant. In this paper a summary of all editions of this workshop (2012–2013–2015–2016–2018–2019) up to 2021 are summarized. Topics addressed are listed and findings and open questions pointed out for each edition.
Reliability Evaluation of Remote Wind-storage Plant Based on Substitutable Output Capacity
Authors: Qi Tengyun , Wu Qiren , Shen Ziqi , Liu Jianping , Mei Shengwei
Published: February 2023

Energy storage is widely introduced and integrated into generating systems involving renewable energy usage, as it can smooth power output, alleviate system volatility, and reduce renewable power spillage. This paper studies the reliability evaluation of remote wind-storage plants. The dispatch procedure is formulated to supply smooth power output during a long-time horizon. The concept of substitutable output capacity is introduced to evaluate the capability of a wind-storage plant that provides steady power during most time segments. The proposed model can provide meaningful inference on the reliability and stationarity of a renewable plant, reflecting the advantage of storage-assisted generation.
Design of collaborative control system for low temperature operation of air-cooled proton exchange membrane fuel cell
Authors: Pang Jian , Ma Chunyan , Dou Yinke , Hou Maolin
Published: February 2023

The air-cooled proton exchange membrane fuel cell has an open cathode, so the temperature, air volume and humidity of the air participating in the cathode reaction and the air used for heat dissipation will directly affect the performance of the fuel cell. In this paper, the relationship between the optimal working temperature of the air-cooled proton exchange membrane fuel cell and the ambient temperature, ambient humidity and working current is obtained through experiments, and a collaborative control system based on BP neural network fuzzy incremental PID stack temperature and working chamber temperature is designed. Experiments show that the control system can make the stack and working cabin reach the set temperature in low temperature environment.
Stability Assessment Method for New Energy Stations Merged into the Receiving End Power Grid
Authors: Sheng Siiqng , Wang Xu
Published: February 2023

Replacing thermal power with new energy is the future power grid development trend. Many distributed new energy stations are integrated into the power grid in areas with concentrated loads, such as Shandong Province. The short-circuit ratio (SCR) is often used to evaluate the system’s stability, but the short-circuit ratio index is a static index with no actual physical meaning, so it is difficult to reflect the transient stability problem after the new energy station is connected. In this paper, an analytical calculation method for the fault-clearing time of new energy power stations is proposed according to the operating state of the induction motor. The fault limit clearing time is used as an index to evaluate the system’s stability, which has practical physical significance and good results.
Effect of Janus Nanoparticles on Foam Stability
Authors: Du Ruotong , Li Ning , Cui Zijing , He Zongli , Zhou Likang , Tang Zixiang , Wang Yang
Published: February 2023

The foam properties of different surfactants were evaluated by the stirring method. The synergistic foam stabilizing effect was formed by the combination of lauryl glucoside and hydrophilic nanoparticles, but the result was feeble. The blend of Janus nanoparticles and surfactants significantly improves foam stability, and the two have a strong synergistic effect on foam stability. The compound system has a specific temperature resistance. Kruss dynamic surface tensiometer and surface dilatation rheometer were used to measure the gas-liquid interface properties of the hydrophilic nanoparticles compound system, Janus nanoparticles compound system, and surfactant system, respectively. The effects of Janus nanoparticles on the surface tension and surface dilatation modulus of the compound system were analyzed, which were correlated with the stability of the foam.
A Research on the Method of Thermal Design for Lithium-ion Battery Modules
Authors: Lai Yilin , Liu Hao , Yang Kai , Qu Zhanzhan , Zhang Mingjie , Gao Fei
Published: February 2023

The thermal management of lithium-ion battery modules for energy storage is of great significance to the safe operation of battery modules. In this paper, a thermal design method of lithium-ion battery modules is proposed to test the real-time heating power of lithium-ion batteries, and simulate the temperature field change during the charging and discharging process of the battery module through CFD simulation software. A 6kWh lithium-ion battery module is designed using the method. The maximum temperature difference between the simulation results and the test results of the module prototype is only 1°C, proving that the simulation method has high accuracy.
Research on Suppression of Fuses of Potential Transformer Fuse
Authors: Zhao Xiayao , Guo Hongbing , Yang Yue
Published: February 2023

In this paper, through the analysis of an electromagnetic Potential Transformer (PT) fuse fault in the distribution network, it is found that the cause of this type of fault is the low-frequency oscillation and inrush current of the voltage transformer caused by the disturbance, and its occurrence mechanism is studied and explained. After analyzing the advantages and disadvantages of the common PT fuse-blowing fault control measures, this paper proposes a treatment plan for the PT neutral point to suppress the fuse blowing through a nonlinear flow-sensitive harmonic elimination device. The harmonic device has a remarkable suppression effect on the PT fuse blown fault.
Stress analysis of the knuckle of the cylinder based on ABAQUS
Authors: Ren Tenghui , Jin Mei , Liu Hongjiao , Wang Xiaoyu
Published: February 2023

In this paper, three kinds of knuckle of heat exchanger cylinders are proposed: the knuckle of the cone, the knuckle of equal wall thickness, and the knuckle of the equal fillet. The stress analysis of the three structures is carried out by using the finite element software ABAQUS. The location of the maximum stress of the three structures is determined. Through comparative analysis, it is found that the knuckle of equal fillet has better pressure-enduring capacity.
Voltage Difference Envelope to the Control Simulating of Connection Frequency of Seamless Shoring
Authors: Huang Zijin , Xiao Leming , Fang Zimeng
Published: February 2023

Through the intelligent control of single chip microcomputer and Hall sensor detection technology and signal transmission technology, the frequency, voltage and voltage phase of the shore power and the ship power are detected to form the lowest point of voltage difference envelope, and the seamless connection of the shore power and the ship power is controlled. The load transfer control between the shore power and the ship power realizes the ideal synchronous control of grid-connected closing and load transfer by establishing the ratio control of frequency difference between the shore power and the ship power and power change during load transfer.
Single Loop Voltage Control Strategy Based on Model Predictive Control for NPC-UPS
Authors: Li Zhiyan , Zhu Xiaobo , Ye Qing , Tian Shuaituan , Xiang Huilun
Published: February 2023

UPS can provide stable electrical energy for sensitive loads when severe grid disturbance happens. A neutral point clamped (NPC) three-level voltage source converter is used as the circuit topology for UPS. In this study, the discrete mathematical model of UPS is derived and a single voltage loop control strategy based on model predictive control is presented. The proposed method has a simple control structure and a fast response speed and omits the current inner loop and modulator. Furthermore, it can achieve ac voltage control and the balance of dc-side voltages. A three-level UPS simulation model is set up in PSCAD, and the efficacy of the proposed method is verified by means of simulation results under various types of loads.
Pure Electric Vehicle Power System Matching Design and Simulation
Authors: Zheng Minghua , Zhou Heng , Zheng Jingtang
Published: February 2023

According to the design requirements of pure electric drive modification of a certain A-class car and the vehicle’s fundamental parameters, the longitudinal dynamics theory of the vehicle is used to analyze the driving motor, power battery and fixed speed ratio transmission, and other key components. With the help of Cruise simulation software, a pure electric vehicle powertrain model was established and simulation tests were carried out on the New European Driving Cycle, 60km/h isokinetic range cruise, 100km/h acceleration time, and hill-climbing degree and other operating conditions. The results show that the parameters of the power system of pure electric vehicles are reasonably selected, and the power indicators, driving range, and power consumption per 100 kilometers meet the performance design requirements of the whole vehicle, which have theoretical guiding significance for the development of the whole vehicle.
Research on Composition of White Powders in High-voltage XLPE Cable with Buffer Layer Failure
Authors: Yang Youmin , Li Mailin , Yang Le , Lan Tianbao , Li Kejian
Published: February 2023

Recently, a new type of high-voltage cross-linked polyethylene (XLPE) cable failure called buffer layer failure occurs from time to time. The failure occurs at the cable body between the insulation screen and the aluminum sheath, which is different from the traditional one that occurs at the intermediate joint or cable accessory. The main feature is white corrosion marks on the inner surface of the aluminum sheath, dotted potholes, and ablation marks on the outer surface of the insulation screen. Especially there are dotted white powder and burnt holes on the surface of the water-blocking tape. Given the white powder in this new failure, imitating the actual structure of the cable, this paper builds a three-layer model of the buffer layer in the laboratory. The water-blocking tape is placed between the insulation screen and the aluminum sheath. The white powders were reproduced by injecting water into the tape and extruding it. The micro-morphology of white powder was observed by scanning electron microscope (SEM) and the element composition was measured by energy dispersive spectrometer (EDS). The results show that the white powder of water-blocking tape contains Al, which is the product of a chemical reaction with an aluminum sheath.
Experimental research of a dual-beam compressive-mode piezoelectric energy harvester
Authors: Li Zhongjie , Peng Xuzhang , Gong Ying , Zhu Chuan , Zhang Lan , Peng Yan
Published: February 2023

In this article, we present a dual-beam compressive-mode piezoelectric energy harvester (DC-PEH). The DC-PEH is made up of a force amplifier, a piezoelectric stack, and a pair of symmetrically arranged cantilever-mass systems, supported by a base that is fixed on a rod. A two-stage force amplification mechanism of the DC-PEH is realized by coupling the elastic beams with the force amplifier. We first established a force analysis to describe the two-stage force amplification effect of the DC-PEH. Furthermore, a prototype has been fabricated and we carried out a series of experiments. We examined the open-circuit voltage and working bandwidth of the DC-PEH to verify the two-stage force amplification effect under different accelerations. Moreover, a parametric study was performed to investigate the influence of structure parameters on the output performance of the DC-PEH. We conducted the frequency sweep response and power output comparisons with different lengths of beams and different masses.
A Data-driven AC Optimal Power Flow Using Extreme Learning Machine
Authors: Liang Weichen , Wang Yajuan , Zhao Zhiyu , Liu Bo , Li Xuan
Published: February 2023

With the increasing integration of renewable energy (RE), AC Optimal Power Flow (AC OPF) becomes a necessary foundation for electricity system which has a high level of renewable energy generation. However, most current studies of AC OPF are not applicable due to the requirements of high computation speed in practical applications. To this end, we propose a data-driven method using Extreme Learning Machine (ELM) for getting the AC OPF optimal solution in a faster way. This approach can map the relationship between the optimal operation results and variations of REs and loads, avoiding the time-consuming solving process of AC OPF. Moreover, an ELM network structure suitable for AC OPF is designed to significantly improve the computational speed of ACOPF with acceptable accuracy. This method was applied to the RTS-79 system for improving the calculation efficiency of the AC OPF.
Evolution mechanism of functional groups during coal chemical looping combustion
Authors: Kuang Cao , Wang Shuzhong , Zou Xiangbo , Sun Jingli , zhao Jun , Ye Ji , Qin Shiwei , Chen Gongda
Published: February 2023

Chemical looping combustion (CLC) plays a vital role in coal combustion which released pure CO2 in the exhaust gas with low energy consumption. Researchers have developed over 1000 oxygen carriers (OCs) to enhance the properties of OCs. This study focus on the microstructural changes of coal during CLC process which could provide the performance improvement direction for OCs. Results showed that the phenolic -OH group can easily be removed by CuO while the free -OH group and the self-associating -OH group are hard to be consumed by the lattice oxygen in CuO at 800 °C, showing good stability in CLC process. Aliphatic hydrocarbons could be consumed in the gas phase rapidly. The functional group of C=O maintains high reactivity with CuO which explains why the addition of CO2 promotes the reaction rate in coal CLC. But C=C group was nonpolar bond and hard to be consumed while the -CH2 and -CH3 group and C-O-C group showed good reactivity with CuO. Higher reaction temperature affords higher reactivity of coal CLC process. But the -OH group changed slowly at higher temperature which could because that higher temperature makes the organic big molecular of the coal char decomposed and produce more -OH group.
Understanding the mechanism of ash deposition on boiler heating surface: The lattice Boltzmann and molecular dynamics simulations
Authors: Sui H , Wang Y , Kou X , Zhao J , Hou F , Li Y
Published: February 2023

Severe ash deposition can cause a decrease of the heat transfer ability on the heating surface for the furnace and the release of more pollutants. In order to get the widespread use of Zhundong coal, the temperature distribution characteristics of ash deposition for Zhundong coal was studied by lattice Boltzmann method in this paper. Furthermore, the microstructure of slag was further revealed by molecular dynamics. The results indicated that the temperature of ash deposition improves with the increase of time. The temperature of the particles in the outer and middle layers for Zhundong coal is significantly smaller than that of lignite and bituminous coal. Compared with other coal types, it is difficult to transfer heat for the deposited layer of Zhundong coal, which can not achieve better energy saving effect. Additionally, calcium and sulfur in Zhundong coal ash can easily react to form calcium sulfate, aggravating ash deposition on the heating surface of the boiler. These results provide a theoretical support to solve the problem of ash deposition burning Zhundong coal.
Modification and Application of Materials for Strong Inhibitory Drilling Fluid
Authors: Jun Jia , Lei Chen , Wei Wei
Published: February 2023

Due to the strong inhibition of drilling fluid, many polymer fluid loss additives can not play their role. Therefore, it is necessary to develop some water loss reducing materials that can withstand the strong inhibition environment. In this paper, the surface of asbestos fiber was modified and treated by indoor experiments. The physical and chemical properties of the obtained drilling fluid treatment samples were evaluated to optimize the appropriate amount of reagents used for surface treatment of asbestos. Subsequently, the drilling fluid performance of the obtained treatment agent samples were evaluated at different temperatures to analyze the effect of temperature on the drilling fluid performance. The surface of asbestos fiber was modified by adsorbed cationic surfactant CTAC which better solved the problem of entanglement of asbestos fiber in drilling fluid. The mechanism of the action of the surface of asbestos fiber was analyzed by scanning electron microscope observation experiments. Subsequently, different amounts of modified asbestos fiber was added to the drilling fluid and the performance of drilling fluid was evaluated at different temperatures. The experimental results showed that the modified asbestos fiber reduced the filtration loss of drilling fluid and still maintained good filtration loss reduction effect at 200°C.
Research on the progress of Ce3+,Tb3+ co-activated phosphate luminescent materials prepared by hydrothermal method
Authors: Qi Pengyuan , Cong Yu , Yu Linhui , Ge Xinmeng , Hao Chunlai , Wang Fei , Yang Zhongliang , Zhan Jiaxing , He Lijie
Published: February 2023

Due to the special optical properties of rare earth elements, rare earth luminescent materials have been widely used in lighting, medical radiological images, detection and recording of radiation field and other fields. Through the research and analysis of phosphate LaPO4:(Ce3+,Tb3+), Ca9Y (PO4):(Ce3+,Tb3+), GdPO4:(Ce3+,Tb3+) composite materials by the hydrothermal preparation of cerium-terbium co-activated, the hydrothermal preparation process (additives, reaction system pH, hydrothermal time, hydrothermal temperature, etc.), luminescent properties and application status were clarified. XRD and SEM were used to analyze the effect of hydrothermal preparation process on the phase composition and morphology of samples, and the energy transfer efficiency was determined. PL spectroscopic analysis shows that the 4f→5d and 5D4→7Fj (j=6,5,4,3) transitions in Ce3+-Tb3+ UV region have been demonstrated in a variety of matrix materials, enabling efficient energy transfer in co-doped ion combinations., and the concentration of doping ions will significantly affect the luminescence properties.
Untangling the importance of dynamic and thermodynamic drivers for wet and dry spells across the Tropical Andes
Authors: Klein Cornelia , Hänchen Lorenz , Potter Emily R , Junquas Clémentine , Harris Bethan L , Maussion Fabien
Published: February 2023

Andean vegetation and agriculture depend on the patterns of rainfall during the South American monsoon. However, our understanding on the importance of dynamic (upper-level wind circulation) as compared to thermodynamic (Amazon basin moisture) drivers for Andes rainfall remains limited. This study examines the effect of these drivers on 3–7 day wet and dry spells across the Tropical Andes and assesses resulting impacts on vegetation. Using reanalysis and remote sensing data from 1985–2018, we find that both dynamic and thermodynamic drivers play a role in determining the rainfall patterns. Notably, we show that the upper-level wind is an important driver of rainfall across the entire Tropical Andes mountain range, but not in the Amazon lowlands, suggesting a crucial role of topography in this relationship. From thermodynamic perspective, we find wet spell conditions to be associated with increased moisture along the Andes’ eastern foothills accompanied by a strengthened South American low-level jet, with moisture lifted into the Andes via topography and convection for all considered regions. Our results suggest that while changes in Amazon basin moisture dominate rainfall changes on daily time scales associated with three day spells, upper-level dynamics play a more important role on the synoptic time scale of 5–7 day spells. Considering impacts on the ground, we find that only 5–7 day spells in the semi-arid Andes have a prolonged effect on vegetation. Our study emphasizes the need to consider both dynamic and thermodynamic drivers when estimating rainfall changes in the Tropical Andes, including in the context of future climate projections.
Water-related conflicts: definitions, data, and trends from the water conflict chronology
Authors: Gleick Peter H , Shimabuku Morgan
Published: February 2023

Violence associated with freshwater resources has occurred throughout recorded history, with water triggering violence and armed conflict, water or water systems being used as weapons, and water or water systems becoming casualties during conflicts. Understanding the causes of water-related violence and regional and temporal trends is critical for identifying priority areas for conflict resolution and strategies to reduce the risk of future conflicts. The purpose of this paper is to introduce the structure, content, and design of The Water Conflict Chronology, an open-source online database, which tracks water-related conflicts from around the globe. Some analysis is provided with caveats about the limitations of the data, but further analysis will be forthcoming. The database is updated approximately annually using information from other conflict-related databases, news reports, eyewitness accounts, and a review of historical documents. As of October 2022, the Chronology had 1298 entries, from the earliest events around 2400 BCE through early 2022. Initial analysis of data shows trends in the nature, location, and social and political characteristics of water-related violence, including a sharp increase in water-related violence in recent years, especially where water has been a trigger or casualty of violence, a concentration of events in the Middle East, southern Asia, and the Sahel, and the increased targeting of civilian water systems during civil and regional armed conflicts.
Study of irrigation regimes of corn varieties NS-770, NS-6010 in conditions of meadow alluvial soils of Bukhara region
Authors: Juraev F U , Kadirov Z Z , Isoyeva L B , Najmiddinov M M , Bobirova M B
Published: February 2023

Optimizing the balance of nutrients in the soil, obtaining a high yield of grain and green mass, and providing the population with food products, raw materials for industry, and nutritious feed for livestock are achieved by improving the irrigation method and irrigation procedures in the cultivation of corn in the main and repeated periods. In this regard, scientific research on the effect of using new fertilizers developed on the basis of phosphorites together with nitrogenous and potassium mineral fertilizers on the growth, development, and productivity of corn, as well as on the development of optimal technology for their use is considered relevant.
Phyllophages biotopic distribution in sparsely wooded regions plantations
Authors: Belitskaya M N , Gribust I R , Drevin V E , Morozova Z Ch , Zenina E A
Published: February 2023

The study of the main woody plants entomofauna diversity peculiarities in sparsely wooded regions with arid climate is an urgent scientific direction and the basis for the design of ecologically balanced multifunctional plantations in the arid zone. The presented materials illustrate the peculiarities of the arthropod phyllophages diversity of trees growing in the FSC of Agroecology RAS dendrological collections. The species and quantitative abundance of individual ecological and trophic groups of fauna, types of damage to plants’ different parts of the Ulmaceae, Fabaceae, Rosaceae families and a number of others were revealed. The structure of the dendrophages community was assessed. The insects’ orders distribution features according to the types of plantations were analyzed.
Changes in the morphological structure and mechanical properties of sandy soils
Authors: Yusupova M A , Idrisov X A , Abduxakimova H , Eshpulatov Sh Ya , Darmonov D Yo , Matxoliqov R B , Mamatqulov O O
Published: February 2023

The analysis of the genesis, properties of sand and sandy soils developed in different periods in Central Fergana, the changes in the agro-ecological and reclamation conditions under the influence of anthropogenic factors involves in the efficient use of land resources. The main purpose of the study is to study the genesis, geography, and formation of soils formed in sandy areas, eco-reclamation processes occurring under the influence of natural conditions and irrigation, to determine the agrochemical, physicochemical and other properties of irrigated sandy soils. The research was carried out in the field, laboratory, and cameral conditions according to generally accepted standard methods in soil science, the research used geographical, morphological, natural-historical, chemical-analytical, and cross-sectional methods. The scientific significance of the results of the study is explained by the laws of specific formation and distribution of sandy soils and irrigated sandy soils of Central Fergana, changes in the eco-reclamation state under the influence of anthropogenic factors, disclosure of physical and mechanical dynamics, productivity, conservation, and restoration.
Comparative analysis of drought resistance of plum cultivar-rootstock combinations in dry steppe conditions
Authors: Nikolskaya O A , Solonkin A V , Kikteva E N
Published: February 2023

The adaptability of the variety to abiotic environmental factors depends on a number of factors, one of which is the rootstock on which the variety is grafted. The data on the influence of various rootstocks on the drought resistance of the grafted variety and the dependence of this influence on the prevailing meteorological conditions of the growing season are presented. Drought resistance was studied in the laboratory according to the indicators of the water regime and the the ability of leaves to retain moisture. The correlation dependence of drought resistance of cultivar-rootstock combinations on the hydrothermal coefficient of the growing season is revealed. Rootstock forms were identified that have a positive effect on increasing the drought resistance of the variety and the most drought-resistant variety-rootstock combination was selected for each variety.
Study of the regularities of the influence of air heat curtains on the energy balance of livestock premises
Authors: Tikhomirov D A , Khimenko A V , Trunov S S , Kuzmichev A V
Published: February 2023

The use of air heat curtains allows you to limit the amount of cold air incoming the room through open gates or doors, as well as to heat it up. The article considers the influence of air heat curtains on the energy balance of livestock premises. The calculation method is presented and the main aerodynamic characteristics of an air curtain installed in a calf house for 50 animals are substantiated. The main heat and power and structural parameters of the air curtain have been determined. On the basis of the heat balance of the calf barn, its modes of operation are substantiated. It has been established that the power consumption for the fan drive during the operation of the air curtain is significantly less than the cost of thermal energy to compensate for the air temperature in the room from the inflow of cold air. The technical and economic calculation showed the effectiveness of the use of air heat curtains in microclimate systems for various livestock facilities of agricultural production.
Ensuring the reliability of adjusting the clearance of a four-wheel tractor
Authors: Akhmetov A A , Akhmedov Sh A , Allanazarov M A , Asamov R H
Published: February 2023

In cotton growing, three-wheeled tractors are used for inter-row processing of cotton. Despite good agrotechnical permeability, they have significant specific disadvantages associated with low resistance, the impossibility of using them for transport work and, most importantly, a negative technogenic impact on the soil. To eliminate these shortcomings of a three-wheeled tractor, “DTCAE LLC” developed a design for a four-wheeled tractor with adjustable ground clearance. Clearance adjustment, which is carried out by a screw mechanism, selected in such a way that the force of the operator would be sufficient to create a torque to drive it, but at the same time there would be no spontaneous rotation of the screw under the influence of axial force arising from the gravity of the tractor. The article presents a method for calculating the parameters of a screw-nut pair, which excludes spontaneous rotation of the screw under the influence of axial force arising from the gravity of the tractor and thereby ensures the reliability of the screw mechanism for adjusting the tractor clearance.
A system of nonlinear difference equations for recurrence relation coefficients of a modified Jacobi weight
Authors: Chen Yang , Filipuk Galina , Rebocho Maria
Published: February 2023

In this paper we study one modification of the Jacobi weight. We show that the coefficients in the three term recurrence relation for polynomials orthogonal with respect to this weight satisfy a complicated system of nonlinear difference equations.
Inequality Regimes in Africa From Pre-Colonial Times to the Present
Authors: Frankema Ewout , de Haas Michiel , van Waijenburg Marlous
Published: February 2023

While current levels of economic inequality in Africa receive ample attention from academics and policymakers, we know little about the long-run evolution of inequality in the region. Even the new and influential ‘global inequality literature’ that is associated with scholars like Thomas Piketty, Branko Milanovic, and Walter Scheidel has had little to say about Africa so far. This paper is a first effort to fill that void. Building on recent research in African economic history and utilizing the new theoretical frameworks of the global inequality literature, we chart the long-run patterns and drivers of inequality in Africa from the slave trades to the present. Our analysis dismantles mainstream narratives about the colonial roots of persistent high inequality in post-colonial Africa and shows that existing inequality concepts and theories need further calibration to account, among others, for the role of African slavery in the long-run emergence and vanishing of inequality regimes.
Validation of Linear Range HER2/Estrogen Receptor/Progesterone Receptor IHControls for Daily Quality Assurance
Authors: Sompuram Seshi R , Vani Kodela , Ryan Lori , Johnson Corissa , Szabolcs Matthias , Peruyero Leonore , Balaton André , Pierrot Sandrine , Joseph Lija , Pilichowska Monika , Naber Stephen , Goldsmith Jeffrey , Green Samantha , Bogen Steve A
Published: February 2023

Objectives

To evaluate a new US Food and Drug Administration (FDA)–cleared immunohistochemistry (IHC) control (IHControls [Boston Cell Standards]) comprising peptide epitopes for HER2, estrogen receptor (ER), and progesterone receptor (PR) attached to cell-sized microspheres and to compare its performance against conventional tissue controls.

Methods

IHControls and tissue/cell line controls for HER2, ER, and PR were compared side by side daily at 5 clinical IHC laboratories for 1 to 2 months. Separately, the sensitivity of the 2 types of controls was evaluated in simulated IHC assay failure experiments by diluting the primary antibody. Additional evaluations included lot-to-lot manufacturing reproducibility of 3 independent lots and specificity against 26 antigenically irrelevant IHC stains.

Results

Side-by-side testing revealed a 99.6% concordance between IHControls and tissue controls across 5 IHC laboratories and 766 individual evaluations. Three discordant quality control events were the result of operator error. Simulated assay failure data showed that both IHControls and tissue controls are similarly capable of detecting IHC staining errors. Manufacturing reproducibility of IHControls showed less than 10% variability (coefficient of variation). No cross-reactions were detected from 26 antigenically irrelevant IHC stains.

Conclusions

IHControls, the first FDA-cleared IHC controls, can sensitively and accurately detect IHC assay problems, similar to tissue controls.
Association of Sedentary Time With Cardiocerebral Deaths: A Prospective Cohort Study
Authors: Zhou Wei , Zhu Ling-juan , Wang Tao , Bao Hui-hui , Cheng Xiao-shu
Published: February 2023

Background

To explore the association of sedentary time with cardiocerebral deaths.

Methods

A total of 12,608 community residents aged 35 years or above in Jiangxi Province who took part in “the study on prevalence of major cardiovascular diseases and key techniques in China” during 2013–2014 were enrolled in this prospective, observational cohort study. Sedentary time was obtained through baseline questionnaire, and all death events were collected by telephone follow-up, information report from the departments of public health in township health centers and village doctors, and death surveillance system of Jiangxi Center for Disease Control and Prevention. Cox proportional hazard regression model was used to evaluate the association of sedentary time with cardiocerebral deaths.

Results

A total of 11,744 participants were included in final analysis. During an average 5.4 years of follow-up (63,298 person-year), 796 all-cause deaths occurred, including 373 cardiocerebral deaths. The difference of cardiocerebral death rate was statistically significant in 3 groups of <6 h/d (2.9%), 6–8 h/d (3.9%), and >8 h/d (5.4%). Kaplan–Meier curve showed that there was a significant difference in the cumulative mortality among the 3 groups (log rank χ2 = 17.27, P < 0.01). Cox regression analysis showed that after adjusting for relevant confounding factors, older age, high diastolic pressure and body mass index, male, country of residence, unemployment, and long sedentary time were risk factors for cardiocerebral deaths. Compared with the <6 h/d group, the risk of cardiocerebral deaths increased by 68.3% (HR = 1.683, 95% CI: 1.186–2.388) for participants with sedentary time of >8 h/d.

Conclusions

Long sedentary time independently increases the risk of cardiocerebral deaths.