bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coupling quintessence kinetics to electromagnetism
Authors: Barros Bruno J. , da Fonseca Vitor 
Published: June 2023

Abstract
We propose a general model where quintessence couples to electromagnetism via its kinetic
term. This novelty generalizes the linear dependence of the gauge kinetic function on ϕ,
commonly adopted in the literature. The interaction naturally induces a time variation of the
fine-structure constant that can be formulated within a disformally coupled framework, akin to a
Gordon metric. Through a suitable parametrization of the scalar field and the coupling function,
we test the model against observations sensitive to the variation of α. We undertake a
Bayesian analysis to infer the free parameters with data from Earth based, astrophysical and early
Universe experiments. We find that the evolution of α is specific to each cosmological era
and slows down at late times when dark energy accelerates the Universe. While the most stringent
bound on the interaction is obtained from atomic clocks measurements, the quasars provide a
constraint consistent with weak equivalence principle tests. This promising model is to be further
tested with upcoming and more precise astrophysical measurements, such as those of the
ESPRESSO spectrograph.
Implications of multi-axion dark matter on structure formation
Authors: Chen Chong-Bin , Soda Jiro 
Published: June 2023

Abstract
Axions are candidates for dark matter in the universe.We develop an accurate Boltzmann
code to calculate the linear growth of the plasma. As an interesting example, we investigate a
mixed dark matter model consisting of cold dark matter (CDM) and two-axion dark matter. We
analyze the growth of the structure numerically and analytically. We find that an effective single
axion with an effective mass and an effective abundance is useful to characterize the two-axion
cosmology. Moreover, we generalize the effective single axion description to multi-axion dark
matter cosmology. We also compare the results with those of warm dark matter (WDM) model.
Moreover, we calculate halo mass functions for the mixed model by using the Press-Schechter model
and linear perturbations and then determine the mass function as a function of masses and axion abundance.
Prospects of testing late-time cosmology with weak lensing of gravitational waves and galaxy surveys
Authors: Balaudo Anna , Garoffolo Alice , Martinelli Matteo , Mukherjee Suvodip , Silvestri Alessandra 
Published: June 2023

Abstract
We investigate the synergy of upcoming galaxy surveys and gravitational wave (GW) experiments in constraining late-time cosmology, examining the cross-correlations between the weak lensing of gravitational waves (GW-WL) and the galaxy fields. Without focusing on any specific GW detector configuration, we benchmark the requirements for the high precision measurement of cosmological parameters by considering several scenarios, varying the number of detected GW events and the uncertainty on the inference of the source luminosity distance and redshift.
We focus on ΛCDM and scalar-tensor cosmologies, using the Effective Field Theory formalism as a unifying language. We find that, in some of the explored setups, GW-WL contributes to the galaxy signal by doubling the accuracy on non-ΛCDM parameters, allowing in the most favourable scenarios to reach even percent and sub-percent level bounds. Though the most extreme cases presented here are likely beyond the observational capabilities of currently planned individual GW detectors, we show nonetheless that — provided that enough statistics of events can be accumulated — GW-WL offers the potential to become a cosmological probe complementary to LSS surveys, particularly for those parameters that cannot be constrained by other GW probes such as standard sirens.
Development of A High-temperature Piezoelectric Ultrasonic Transducer Based on a Glass Substrate
Authors: Liu Yue , Sun Changhe 
Published: June 2023

Abstract
The piezoelectric ultrasonic transducer is a key device in ultrasonic applications. In oil logging, the bottom-hole temperature increases with the drilling depth. With the rapid increase of deep and ultra-deep well exploration, the bottom-hole temperature can reach 175°C or even higher, so new requirements are made for the stability of piezoelectric ultrasonic transducers for logging to work in such high-temperature environments. In this paper, a high-temperature piezoelectric ultrasonic transducer (HT-PUT) based on the high-temperature glass substrate has been developed and characterized in detail. After HT-PUT device fabrication and electromechanical experimental tests, it is shown that both the resonant frequency curve and the effective electromechanical coupling coefficient can be regulated and optimized by changing the size of the through-hole cavity in the glass substrate. After designing an appropriate through-hole cavity, the effective electromechanical coupling coefficient of the HT-PUT in the thickness-extensional mode can be significantly improved by 64.9%. The HT-PUT was tested in the temperature range of 25 °C to 250 °C, and its resonant frequency was only shifted down by 3.2%. This work demonstrates a high-temperature glass-based piezoelectric ultrasonic transducer that can operate in harsh conditions above 250°C, such as oil and gas exploration applications.
Research on onboard multistage digital demultiplexer for satellite communication based on MF-TDMA system
Authors: Yang Ye , Wu Jiang , Wu Hao , Wang Yu 
Published: June 2023

Abstract
A new multicarrier multi-rate digital demultiplexer system structure based on MF-TDMA(Multi-Frequency Time Division Multiple Access) in a wideband satellite communication system is described. Compared with the traditional tree multicarrier demultiplexer method, the new structure uses a half-band filter instead of the quadrature mirror filter, which has three advantages: 1) It fully avoids the shortcomings of the traditional method, such as confusion distortion and amplitude distortion. 2) The computation to achieve filtering is reduced by nearly half. 3) It effectively improves the demodulation performance of the system. In this paper, the new structure performs the multistage digital demultiplexer and demodulation of the MF-TDMA signal. The results show no obvious signal distortion, which is demultiplexed by the new structure. The bit error rate of the demodulated signal is better than that of the traditional single carrier demodulator. The bit error rate is very close to the theoretical value of QPSK demodulation.
The Surface ligands of PbSe Colloidal Quantum Dots Towards the High-Performing Infrared Photodetection
Authors: Wen Zheng , Ke Guanlin , Yi Fangzhou , Sun Zhenhua 
Published: June 2023

Abstract
Lead selenide colloidal quantum dots (PbSe CQDs) have the characteristics of an adjustable band gap, low cost, and easy processing. It is one of the ideal materials for developing infrared photodetectors and has broad application prospects in optical fiber communication, biomedical imaging, national defense, and other fields. Indium gallium zinc oxide (IGZO) is an n-type semiconductor material with high mobility. In this paper, an infrared photodetector with IGZO-PbSe CQDs heterojunction is fabricated, with the PbSe CQDs capped by MPA, TBAI, or EDT. The photodetection performance of these photodetectors is studied and compared, to reveal the best choice of the surface ligand of the PbSe CQDs for the photodetection. This work provides useful and solid knowledge that shall enlighten the optoelectronic application of PbSe CQDs.
A Fast-Transient Responses Power-efficiency LDO Regulator with Transient-current Enhanced Buffer
Authors: Liao Pengfei , Lai Baichong , Pu Lin , Li Peng , Yang Feng , Du Songyang , Huang Xiaozong 
Published: June 2023

Abstract
In this paper, we introduce a Low-Dropout (LDO) Regulator that features a transient-current enhanced buffer, providing fast transient responses and high-power efficiency. The buffer, which incorporates an AC-coupled network and a high-gain stage, enhances the load transient response by boosting the charging or discharging current to the gate capacitor of the power transistor, without consuming extra power under varying load conditions. The LDO was designed using a standard 65 nm CMOS process and has a load capacitance of 100 pF and an on-chip compensation capacitance of only 2.7 pF. Simulation results reveal that the LDO has a low static current of 20 μA and a maximum load capacity of 200 mA. When the LDO output switches from a light load of 100 μA to a heavy load of 20 mA within 1 μs, the undershoot voltage is 53 mV and the transient response time is 1.34 μs. Conversely, when switching from heavy load to light load, the overshoot voltage is 51 mV and the transient response time is 0.50 μs.
Development of a 7T 1H/2H dual-tuned transceiver separation active decoupler MRI probe
Authors: Wang Wei , Liu Kewen , Liu Xinjie , Zhang Zhi , Cheng Xin , Bao Qingjia , Zhou Xin , Liu Chaoyang 
Published: June 2023

Abstract
Based on the current deuterium metabolism imaging (DMI) technology analysis, a design scheme of a dual-core imaging coil suitable for a 7T MRI system is proposed. The size and structure of the shield layer are optimized. Based on the single-layer shield structure, a double-layer shield structure is proposed to improve the stability of the probe. A detuning circuit is added to the 2H transmitting and receiving coils so that they can work in time for better decoupling. According to the design scheme, the 1H/2H dual-core imaging coil was fabricated and applied to the 7T magnetic resonance system. We performed imaging experiments on D2O samples and quantitatively compared the correlation performance (SNR) of a 1H/2H dual-tuned RF coil with the same size deuterium transceiving-receiving integrated surface coil. The results verified that deuterium metabolism imaging using 1H/2H dual-tuned transmit-receiving separation MRI probe can effectively improve the signal-to-noise ratio of the target region.
A High Peak-efficiency Cross-coupled Charge Pump with Low Input Voltage for Energy Harvesting System
Authors: Li Xinghe , Wang Yanyan , Wu Zhiqiang , Xie Zushuai 
Published: June 2023

Abstract
A high-efficient, low-voltage cross-coupled charge pump is presented in this paper. To decrease the conduction loss, a cross-coupled charge pump is proposed based on two auxiliary dynamic inverters to increase the clock swing. Meanwhile, a clocking scheme is designed to eliminate the reversion power losses. Based on proposed scheme, a higher output voltage is achieved by a three-stage topology by cascading the single stage. The proposed architectures of both single and three-stage charge pump are implemented under a standard 180nm CMOS technology. The post-layout simulation exhibits a peak power efficiency of 86.89% and 78.6%, respectively. And Monte Carlo (MC) simulation results indicate the proposed scheme features strong robustness to process variation.
A ENOB 10.3 bit, 103 μW ON-CHIP CALIBRATION SAR ADC
Authors: Song Zheng , Ma Zhi-Hua , Yao Yao , Zou Ren-fei , Hu Jian-Guo 
Published: June 2023

Abstract
Across the board, the performance of ADCs has been under increasing scrutiny because of the rapid growth of portable electronic devices and biomedical sensors. As part of the sensor’s long-term work, its power consumption should also be as low as possible. Sensors benefit from SAR ADCs’ small size and low power consumption, making them an ideal fit for ADCs. To overcome the limitations of accuracy and linearity of ADCs caused by manufacturing process deviations, a 12-bit, 1 MS/s low-power SAR ADC based on 180 nm CMOS technology is presented. The front-end analog calibration system ensures the ADC is at its best. The design also includes low fan-in SAR logic to reduce the capacitive load on the comparator and increase the comparison speed. The layout area is 0.3 mm2, approximately 30% less than conventional products of the same process.
A Low-power Level-Crossing ADC for Biosignal Acquisition
Authors: Lin Shengmin , Lin Cheng , Chen Qunchao 
Published: June 2023

Abstract
A large number of redundant signals will be generated when the traditional Nyquist sampling method is used to acquire a biological signal, leading to a system’s energy loss. A new level-crossing analog-to-digital converter (LC-ADC) with non-uniform sampling and fixed window structure is presented, with fewer data and low power consumption features. The circuit uses a 6-bit capacitive DAC to quantize the input signal, avoiding the error accumulation of the 1-bit capacitive DAC structure, and a nanoamp CMOS current bias circuit to provide a very low quiescent current for the comparator, further reducing power consumption. The structure was verified in a 0.18μm CMOS technology. The results indicate that the total power dissipation is 0.26uw@500Hz, the signal-to-noise distortion ratio (SNDR) is 59dB@500Hz, and ENOB reached 9.51bit, which is suitable for the acquisition of low-frequency biological signals.
A Novel Structure of Super-junction MOSFET with Improved Avalanche Energy Capability
Authors: Zhou Houyong , Wu Jiale , Chen Yi 
Published: June 2023

Abstract
The UIS characteristic of the device is a key parameter of the super-junction MOSFET, which represents the reliable performance of the device in the face of extreme conditions. The maximum avalanche energy (EAS
) that the device can withstand under a single pulse of the gate electrode or the maximum avalanche energy (EAR
) that the device can withstand under multiple pulses of the gate electrode is commonly used in the industry to characterize the UIS characteristic. To solve the avalanche energy problem of super-junction MOSFET, we propose a novel structure of super-junction MOSFET with a P-type diffused region on the top of the N-column drift region.
Optimization of 25 µm gold wire lead bonding process parameters based on orthogonal test
Authors: Feng Dongdong , Wang Wei , Guan Yimin 
Published: June 2023

Abstract
The gold wire lead bonding process is a key technology to realize the electrical connection between the chip and the external control circuit to be completed. This paper introduces the basic concept of lead bonding technology and analyzes the process parameters affecting the quality of lead bonding, mainly including ultrasonic power, ultrasonic time, and bonding pressure. The orthogonal test method is used to investigate the process parameters affecting the bonding quality of 25 μm gold wire. The optimal combination of process parameters A3B2C2 is determined, i.e., the ultrasonic power value is 90 mW, the ultrasonic time is 20 ms, and the bonding pressure is 40 gf, which improves the reliability of the wire bonding process.
Experimental investigation of parameters influencing mechanical properties of hemp concretes using design of experiment method
Authors: Adam L , Isopescu D N , Lepadatu D 
Published: June 2023

Abstract
Global concerns about climate change have led to the development of building materials that use plant biomass with the added benefit of sequestering carbon from the atmosphere. Lightweight concrete made with hemp, is a material with huge potential in terms of its ability to achieve hygro-thermal performances close to those of polystyrene. This ecological material, referred to in the literature as hemp concrete, is made of some components that, depending on the chosen combination, can generate different results of the physic-mechanical properties. The method is based on a series of experiments that are generated using a program called Design of Experiments (DoE). This program uses statistical analysis of a series of experiments performed by varying one of the input parameters, like the amount of hydrated lime or cement. Following this analysis, it is possible to identify those elements used in the composition, which produced a significant influence on the physical-mechanical properties of hemp concrete. Moreover, this method also allows a quantification of the influences so that the parameters can be ranked, with a minimum number of experiments. The method is, in the same time, a modern and an economical technique used for experimental planning. The aim of the research is to quantify numerically the influence of each component element of the mixture that determines variations of the physical-mechanical properties in hemp concrete. This study will contribute in the future to the optimization of compositions, which will be differentiated on the basis of mechanical performance or thermal insulation criteria.
Technology for utilization and neutralization of municipal waste
Authors: Ezhov V , Pakhomov V , Fedyanin D , Saikov I 
Published: June 2023

Abstract
Considered the issues of environmental protection with the simultaneous use for the neutralization and disposal of urban waste containing substances of organic origin, due to solar energy and atmospheric precipitation. At present, in the Russian Federation, waste makes up 90–98% of all extracted natural resources, that is, the industry works mainly for the production of waste. Already 8 billion m3 of industrial and municipal waste has accumulated. Landfills are 50–90% full on average across the country. The volume of waste from livestock enterprises and poultry farms in the form of manure, droppings and sewage is about 700 million m3 per year, and more than 2 million hectares of land are occupied for storing this waste. Therefore, it is planned until 2020–2025 to introduce a complete ban on the storage of municipal solid waste at more than 200 landfills and dumps, where they have accumulated 31 billion tons
Laboratory study regarding recipes and strengths of concrete produced with reactive powders and metallic fibers
Authors: Scripcă S , Bărbuță M , Panaite V 
Published: June 2023

Abstract
Because of its multiple advantages such as durability, flexibility in use, fire resistance and low production and maintenance costs, concrete is, by far, the most popular building material currently in use. However, cement – one of the base ingredients of concrete – requires large quantities of raw materials and fossil fuels in order to be produced. In fact, in terms of pollution, it is one of the most environment-damaging products of the construction industry. A relatively recent trend in the problem of mitigating cement-related pollution is the possibility to substitute a certain percentage of cement with reactive powders, which are considered to be waste products of other industries. Concurrently, another trend is to try and obtain better performance of plain concrete, by using so-called “disperse reinforcement”. Thus, in the present article, a laboratory study is presented, regarding the obtainment and performance of concrete in which cement has been partially replaced with ultrafine silica and fly ash. Furthermore, in the case of the fly ash recipe, a percentage of metallic fibers was added, in order to study the potential performance gain with respect to plain concrete. The obtained results in compression were encouraging, in the sense that, for all recipes of concrete (plain concrete – used as reference sample versus concrete with fly ash, concrete with ultrafine silica, concrete with fly ash and fibers), the desired concrete strength class was attained. Even more, in the case of obtained results in tension by bending and splitting, the concrete with fly ash and fibers attained almost twice the tensile strength of the plain concrete. The obtained results suggest that concrete with reactive powders and/or metallic fibers can successfully substitute the plain concrete normally used in the construction industry.
Constructing Causal Life-Course Models: Comparative Study of Data-Driven and Theory-Driven Approaches
Authors: Petersen Anne Helby , Ekstrøm Claus Thorn , Spirtes Peter , Osler Merete 
Published: June 2023

Abstract
Life-course epidemiology relies on specifying complex (causal) models that describe how variables interplay over time. Traditionally, such models have been constructed by perusing existing theory and previous studies. By comparing data-driven and theory-driven models, we investigated whether data-driven causal discovery algorithms can help in this process. We focused on a longitudinal data set on a cohort of Danish men (the Metropolit Study, 1953–2017). The theory-driven models were constructed by 2 subject-field experts. The data-driven models were constructed by use of the temporal Peter-Clark (TPC) algorithm. The TPC algorithm utilizes the temporal information embedded in life-course data. We found that the data-driven models recovered some, but not all, causal relationships included in the theory-driven expert models. The data-driven method was especially good at identifying direct causal relationships that the experts had high confidence in. Moreover, in a post hoc assessment, we found that most of the direct causal relationships proposed by the data-driven model but not included in the theory-driven model were plausible. Thus, the data-driven model may propose additional meaningful causal hypotheses that are new or have been overlooked by the experts. In conclusion, data-driven methods can aid causal model construction in life-course epidemiology, and combining both data-driven and theory-driven methods can lead to even stronger models.
Physical effort paradox during reward evaluation and links to perceived control
Authors: Wu Menglin , Zheng Ya 
Published: June 2023

Abstract
Effort expenditure not only prospectively discounts the reward associated with it but also retrospectively adds the subjective value of reward, which is known as the effort paradox. This study aimed to resolve the effort paradox during reward evaluation through the critical lens of neural dynamics and its potential moderators. In total, 40 participants completed an effort-reward task wherein they exerted varying physical efforts to obtain an opportunity to win monetary rewards by active or passive decision-making. We found that after-effects of physical effort expenditure during reward evaluation unfolded as an effort paradox over time, manifesting itself as an effort discounting effect during the reward positivity (RewP) period but as an effort enhancement effect during the late positive potential (LPP) interval. Then, we found a dynamic balance between the discounting effect and the enhancement effect such that the more effort discounted the RewP at the early stage, the more effort increased the LPP at the late stage. Moreover, we observed that the effort-reward relationship was modulated by perceived control such that it increased the reward sensitivity effect and decreased the effort discounting effect. Together, our findings provide new insights into the neural mechanisms underlying the after-effects of physical effort exertion during reward evaluation.
Democracy in the digital public sphere: disruptive or self-corrective?
Authors: Trenz Hans-Jörg 
Published: June 2023

Abstract
The article assesses the post-democratic scenario of a public sphere that is detached from democracy. By describing how public spheres are transformed by the Internet, it is asked whether the co-constitutive dynamics between the public sphere and democracy still apply in the digital age, or whether we are witnessing an ultimate rupture. The field of contemporary public sphere struggles in response to the digital transformations is discussed in terms of: (1) the rebalancing of privacy and publicity; (2) the truth orientation and rationality of public debates; and (3) the modes of empowerment of the will of the people. By evaluating the empirical evidence for the deep disruptions of the public sphere and democracy, it will become possible to develop a better understanding of the self-corrective mechanisms of public sphere resilience and renewal in the digital age.