bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyzing the risk contagion effect of stock market and foreign exchange market in the context of Sino-US trade frictions based on the perspective of behavioral finance
Authors: Sun Wanting
Published: June 2023

For the empirical study in this paper, the trade friction variables represented by the effectively applied weighted average tariffs imposed by the U.S. on China and technical barriers to trade have a negative impact on the size of China's export trade, and the impact of technical barriers to trade has a lag. In the analysis of the impact of trade structure, from the perspective of technology intensity, the impact of Sino-US trade frictions on China's exports to the United States of low- and medium-technology industries is significantly greater than that of high-technology industries, mainly due to the high technology level of high-technology products, strict standard requirements, strong innovation capacity, the impact of trade frictions is not significant; from the perspective of product end-use, investment goods are significantly more affected by Sino-US trade frictions than consumer goods, and the impact on industrial manufactured products is much greater than primary products, the results of the difference is mainly affected by the nature of the product, export volume and the area of friction.
Whether the Lean Management can Affect The Innovative Performance in the Manufacturing Industry – a Case Study of a Chinese State-Owned Company
Authors: Zhang Ruiya
Published: June 2023

With the rapid development of modern Chinese companies, small-and-medium companies play a more and more critical role. At the same time, the competition among Chinese SMEs is also intensifying. This paper proposes the significance of lean management under current enterprise management through the introduc-tion of lean management, how it affects innovation, and the case analysis of a manufacturing SME. The case analysis includes quality process management and improvement, waste elimination, employee participation, good leadership, and supplier relationship. These measures of lean management give a general under-standing of how the company inspires innovation and further show that LM has a remarkable effect on SMEs, especially in the manufacturing sector.
Construction of Power Grid Equipment Management Performance Evaluation Index System Based on Process and Results
Authors: Lan Guofeng
Published: June 2023

As an asset-oriented enterprise, the power grid company's equipment accounts for more than 80% of its total assets, and the external environment has undergone profound changes, putting forward higher requirements for equipment management. At present, the management of power grid equipment is not adaptive. It is necessary to build a performance evaluation index system of power grid equipment management based on the process and results according to the current status and problems of power grid equipment management, analyze the construction effect of the provincial power grid company's equipment management system, and point out the direction for the construction of power grid equipment management system.
Analysis on the constituent elements of competence of grassroots management cadres based on safeguarding national security
Authors: Cai Yongkui , Tan Yanni
Published: June 2023

This article from a holistic approach to national security to the basic requirements of grassroots management cadres to maintain national security, the overall concept of national security to the basic requirements of grassroots management cadres to maintain national security, grassroots management cadres to maintain national security need to have competency, improve the grassroots cadres to maintain national security competency of several thinking to explore the elements of grassroots management cadres competency, To provide reference and reference for improving the security management ability of grassroots management cadres.
Countermeasures of Financial Internal Supervision Institutions of Administrative Institutions Based on the Double Game
Authors: Zhang Kan , Zhou Ke , Deng Xiao , Han Ruyi
Published: June 2023

The state audit in the new era focuses on strengthening the restriction and supervision of public power, and it will inevitably require strengthening the audit and supervision of administrative institutions, which leads to the discussion of the efficiency of the internal supervision institutions in administrative institutions. In order to effectively control the finance internal supervision risk, a moral hazard monitoring model with a two-tier game mechanism is proposed. In the model, it establishes an upper-level game and a lower-level game analysis framework for the "lazy" and "Free-riding" behaviors in moral hazard. Combining the equilibrium conditions to explain the game results, and put forward the overall risk monitoring countermeasures for the two behaviors.
Auf eigenen Beinen stehen
Authors: Rinker Julia , Hügler Stephanie
Published: June 2023

Ein Bandscheibenvorfall klingt nach einer Allerweltserkrankung, die fast jeden
treffen kann. Doch bei Julia Rinker war der Verlauf besonders schwer. Aktuell
ist sie nicht nur berufsunfähig, sondern auch ab dem 7. Brustwirbel
gelähmt. Doch Julia gibt nicht auf. Als Physiotherapeutin weiß
sie, dass es sich lohnt, zu kämpfen.
Armkrafttraining in der Schlaganfallrehabilitation
Authors: Högg Susan
Published: June 2023

Nach einem Schlaganfall sehen sich die Patient*innen häufig mit
Einschränkungen der Armfunktionen und bei Armaktivitäten
konfrontiert, was oft mit großen Herausforderungen im Alltag verbunden
ist. Ein gezieltes Armkrafttraining kann zur Erholung der Armfunktionen und
somit zur Erlangung körperlicher Unabhängigkeit beitragen. Dabei
sind die verwendete Trainingsmethodik und deren Anpassung an die individuellen
Fähigkeiten, Komorbiditäten und Ziele der Patient*innen
entscheidend für den Rehabilitationserfolg.
Adipositas-assoziierte Hypertonie
Authors: Engeli Stefan
Published: June 2023

Adipositas erhöht das Risiko, hypertensive Blutdruckwerte zu entwickeln.
Hypertonie ist einer der bedeutendsten Risikofaktoren für
Gefäßerkrankungen und spielt eine besondere Rolle im Herz, in
den Nieren und im Gehirn. Die Initiierung nichtmedikamentöser und
medikamentöser blutdrucksenkender Maßnahmen hängt
letztlich von der Blutdruckhöhe und vom kardiovaskulären
Gesamtrisiko ab. Der Nutzen aller nichtmedikamentösen und
medikamentösen blutdrucksenkenden Maßnahmen hängt eher
vom Ausmaß der Blutdruckreduktion ab, vermutlich nicht von den
Maßnahmen selber. Eine gut verträgliche Kombinationstherapie mit
mehreren blutdrucksenkenden Arzneimitteln und nichtmedikamentösen
Maßnahmen ist die Therapie der Wahl. In dieser Übersicht werden
die wichtigsten Leitlinienempfehlungen zur Therapie zusammengefasst, spezielle
Implikationen für Patient*innen mit adipositas-assoziierter
Hypertonie lassen sich – auch mangels geeigneter Studien –
daraus aber nicht ableiten.
Point-of-care procalcitonin testing for lower respiratory tract infection in pulmonary outpatient care has limited value
Authors: Raupach David , Joean Oana , Fuge Jan , Welte Tobias , Rademacher Jessica
Published: June 2023

Lower respiratory tract infections (LRTI) are frequently the reasons for patients to visit their general practitioners or lung specialists; however, physicians tend to prescribe antibiotics less frequently than necessary. A readily available biomarker could help distinguish between viral and bacterial cause of LRTI. The primary objective of our study was to determine the diagnostic accuracy of point-of-care testing (POCT) of procalcitonin (PCT) in identifying bacterial pneumonia in outpatients with LRTI. All patients aged 18 years or older with signs and symptoms of LRTI who visited a respiratory physician were included in the study and their PCT levels were measured. In 110 patients enrolled in the study, three patients (2.7%) had PCT values above the threshold of 0.25 µg/L without proven bacterial infection, in contrast to seven patients with typical radiological signs of pneumonia without elevated POCT PCT levels. The AUC for PCT for the detection of pneumonia was 0.56 (p=0.685). POCT PCT showed limited specificity and sensitivity in distinguishing pneumonia from bronchitis or exacerbation of chronic respiratory diseases. PCT is a marker of severe bacterial infections and not suitable for milder infections in outpatient care.
Impact of High-Fidelity Microvascular Surgery Simulation on Resident Training
Authors: Joy Matthew T. , Applebaum Matthew A. , Anderson William M. , Serletti Joseph M. , Capito Anthony E.
Published: June 2023

Background Microsurgery requires a high level of skill achieved only through repeated practice. With duty-hour restrictions and supervision requirements, trainees require more opportunities for practice outside the operating room. Studies show simulation training improves knowledge and skills. While numerous microvascular simulation models exist, virtually all lack the combination of human tissue and pulsatile flow.

Methods The authors utilized a novel simulation platform incorporating cryopreserved human vein and a pulsatile flow circuit for microsurgery training at two academic centers. Subjects performed a standardized simulated microvascular anastomosis and repeated this task at subsequent training sessions. Each session was evaluated using pre- and postsimulation surveys, standardized assessment forms, and the time required to complete each anastomosis. Outcomes of interest include change in self-reported confidence scores, skill assessment scores, and time to complete the task.

Results In total, 36 simulation sessions were recorded including 21 first attempts and 15 second attempts. Pre- and postsimulation survey data across multiple attempts demonstrated a statistically significant increase in self-reported confidence scores. Time to complete the simulation and skill assessment scores improved with multiple attempts; however, these findings were not statistically significant. Subjects unanimously reported on postsimulation surveys that the simulation was beneficial in improving their skills and confidence.

Conclusion The combination of human tissue and pulsatile flow results in a simulation experience that approaches the level of realism achieved with live animal models. This allows plastic surgery residents to improve microsurgical skills and increase confidence without the need for expensive animal laboratories or any undue risk to patients.
Preoperative Imaging Mapping of DIEP Perforators and Intraoperative Selection: Does It Correlate?
Authors: Gravina Paula , Singh Aspinder , Conlon Christopher , Spiegel Aldona
Published: June 2023

Background Preoperative imaging prior to deep inferior epigastric perforator (DIEP) flap harvest is a common practice to locate perforators and identify aberrant anatomy.

Methods We report a retrospective review of 320 consecutive patients who underwent preoperative computed tomographic angiography (CTA) or magnetic resonance angiography prior to DIEP flap breast reconstruction. The locations relative to the umbilicus of preoperatively identified perforators were compared with the selected intraoperative perforators. The diameter of all intraoperative perforators was also measured.

Results Across the 320 patient, 1,833 potentially suitable perforators were identified on preoperative imaging. A total of 564 of the 795 perforators selected intraoperatively for DIEP flap harvest were within 2 cm of a predicted perforator, for a rate of 70.1%. The size of the perforator was unrelated to the detection rate.

Conclusion We were able to demonstrate a sensitivity of 70% of clinically selected DIEP perforators identified on preoperative imaging in this large series. This contrasts with the nearly 100% predictive value reported by others. Continued reporting of findings and methods of measuring are needed to improve the practical efficacy of CTA and raise awareness about the limitations of CTA, despite its well-documented usefulness.
Remote Back Strain: A Strategy for Modulating the Reactivity of Triarylboranes
Authors: Ogoshi Sensuke , Hoshimoto Yoichi , Sakuraba Mahiro , Morishita Taichi , Hashimoto Taiki
Published: June 2023

A strategy for modulating the Lewis acidity of triarylboranes is proposed based on the concept of remote back strain. Steric repulsion and noncovalent interactions, both generated between the aryl meta-substituents of triarylboranes, are found to be critical for determining the strength of the remote back strain. Applying this concept, we synthesized B[2,6-F2-3,5-(TMS)2-C6H]3 and the liquid B[2,6-F2-3,5-(allyl)2-C6H]3 and we demonstrated their superior catalytic activity for the hydrogenation of quinoline relative to B(C6F5)3 or B(2,6-F2C6H3)3. Moreover, we established the first example of the catalytic hydrogenation of quinoline by using B[2,6-F2-3,5-(allyl)2-C6H]3 in the presence of a gaseous 1:1:1 molar mixture of H2, CO, and CO2.
Welcome to the fertility clinic of the future! Using speculative design to explore the moral landscape of reproductive technologies
Authors: Willems W. , Heltzel A. , Nabuurs J. , Broerse J. , Kupper F.
Published: June 2023

The evolving field of reproductive technologies greatly alters our practices of conception and pregnancy. It is thus crucial to develop such innovations in a democratic and sustainable manner through public participation. To date, participation has mostly focused on patients or health professionals deliberating on technological risks, benefits, costs, and healthcare experiences. Thereby, the opportunity is missed to consider broader social and moral implications. Speculative design has been presented as a promising way to open up deliberation on the impacts of new technologies. In this study, speculative design was used to gain insight into citizens’ views and concerns about the social and moral implications of the new reproductive technologies. Six themes of concern were found: the rights of the unborn; access and equality; social implications of individual choices; society as a community; ecology; and the value of wonder. Notably, the latter two issues are not commonly described in the participatory literature on reproductive technologies, indicating that speculative design is suitable for broadening the debate by including issues that have not been addressed yet. Furthermore, the study brought insight into the motivations and complex values that lie behind arguments in which the naturalness of reproductive practices is emphasized. A point of critical reflection is that to broaden the range of reflections probed by speculative design even more, both the designers and the audiences should become more diverse. If this is achieved, it is suggested using speculative design in the context of public deliberation with a more direct influence on innovation trajectories and as a means for the public to become more skilled in critically engaging with imagined futures.
Integrable decomposition for the (2+1)-dimensional AKNS hierarchy and its applications
Authors: Zhu Xiaoming
Published: June 2023

In this paper, we are concerned with the integrable decomposition for the (2+1)-dimensional Ablowitz–Kaup–Newell–Segur (AKNS) hierarchy. By utilizing recursive relations and symmetric reductions, we propose that the (n2 − n1 + 1)-flow of the (2+1)-dimensional AKNS hierarchy can be decomposed into the corresponding n1-flow and n2-flow of the (1+1)-dimensional AKNS hierarchy, both in the coupled and reduced cases. As an appropriate generalization, the integrable decompositions for the standard (2+1)-dimensional Heisenberg ferromagnet equation, the standard (2+1)-dimensional modified Heisenberg ferromagnet equation, and their two coupled generalizations are investigated. With no loss of generality, one-soliton solutions and their dynamic projections for the relevant gauge equivalent structures are discussed and illustrated through some figures.
High-speed rotor for microparticle impact studies
Authors: De la Cruz Abraham , Achtnich Timon , Décosterd Emile , Sevy Eric T. , Asplund Matthew C. , Austin Daniel E.
Published: June 2023

We report on the design, construction, and testing of a high-speed rotor intended for use in hypervelocity microparticle impact studies. The rotor is based on a four-wing design to provide rotational stability and includes flat “paddle” impact surfaces of ∼0.5 cm2 at the tips of each wing. The profile of each wing minimizes the variation in tensile forces at any given rotational speed. The rotor was machined using titanium (grade 5) and operated in high vacuum using magnetically levitated bearings. Initial experiments were run at several speeds up to 100 000 rpm (revolutions per minute), corresponding to a tip speed of 670 m/s. Elongation at the wing tips as a function of rotational speed was measured with a precision of several micrometers using a focused diode laser and found to agree with an elastic modulus of 1.16 GPa for the rotor material. Applications to microparticle impact experiments are discussed.
Spectral fingerprints of individual Mn2+ impurities and Mn2+ pairs in magic-sized nanoclusters
Authors: Bieniek Jan , Baek Woonhyuk , Hyeon Taeghwan , Bacher Gerd , Fainblat Rachel
Published: June 2023

The chemical synthesis of (CdSe)13 magic-sized clusters (MSCs) allows the replacement of host atoms by individual transition metals such as Mn. By analyzing the spectral fingerprints of the Mn2+ photoluminescence (PL) in MSCs with different dopant concentrations, we are able to distinguish between single Mn2+ ions and coupled Mn2+ pairs. In case of Mn2+ pair emission, temperature-dependent studies show a pronounced red shift, followed by a distinct blue shift of the PL energy upon heating. This is related to a spin ladder formation of the ground and excited states due to Mn2+–Mn2+ exchange interaction at cryogenic temperatures, which is assumed to vanish at higher temperatures. In contrast, single Mn2+ ion PL exhibits a unique redshift with increasing temperature, which can be attributed to a particularly strong coupling to vibronic modes due to the ultimate small size of the MSCs.
Incompressible squeeze-film levitation
Authors: Atalla Mostafa A. , van Ostayen Ron A. J. , Sakes Aimée , Wiertlewski Michaël
Published: June 2023

Transverse vibrations can induce the non-linear compression of a thin film of air to levitate objects, via the squeeze-film effect. This phenomenon is well captured by the Reynolds' lubrication theory; however, the same theory fails to describe this levitation when the fluid is incompressible. In this case, the computation predicts no steady-state levitation, contradicting the documented experimental evidence. In this Letter, we uncover the main source of the time-averaged pressure asymmetry in the incompressible fluid thin film, leading the levitation phenomenon to exist. Furthermore, we reveal the physical law governing the steady-state levitation height, which we confirm experimentally.
Efficient separation and low thermalization of hot carriers in natural superlattice of BiOCuCh (Ch = S, Se, Te)
Authors: Han Jian , Xu Ben , Lan Jinle , Ding Jingxuan , Liu Yaochun , Wang Huanchun , Lin Yuan-hua , Nan Ce-Wen
Published: June 2023

The optic-electronic response is usually limited by poor electron–hole separation and phonon thermalization. Here, we show that natural superlattice materials with charged layers in BiOCuCh (Ch = S, Se, Te) can effectively suppress bulk carrier recombination and dissipation from phonon. The photogenerated hot carriers in BiOCuCh are separated by the intrinsic p–n junction naturally composed of the [Cu2Ch2]2− and [Bi2O2]2+ layers, and transport occurs with high speed within the two layers. Moreover, its dissipation can be substantially reduced because the interlayer coupling leads to low phonon thermalization. As a result, these materials both show prominent response to full-spectrum solar lights and resemble cocatalysts in their characteristics. Because of these merits, these oxychalcogenides provide a penetration point up-and-coming platform for the exploration of materials with an extraordinary optoelectric response.
The nonlinear dynamics of magnetic nanoparticles: A thermometry in complex magnetic fields
Authors: Liu Jingxin , Huang Pengquan , Zhang Zhihui , Xie Qingguo , Liu Wenzhong
Published: June 2023

In this Letter, we propose a thermometry method for magnetic nanoparticles in complex magnetic fields. Complex magnetic fields result in intricate magnetization that can be influenced by temperature and relaxation mechanisms. We derive a set of approximate equations from the results of a numerical simulation of the nonlinear dynamic magnetic response to describe the relationship between particle temperature and the cubic susceptibility phase under complex magnetic fields. The thermometry of various magnetic nanoparticles in suspended or immobilized states is achieved with measured susceptibility. The experimental results show that the temperature measurement accuracy is less than 0.1 K for temperatures ranging from 309 to 333 K. Furthermore, the combination of complex magnetic fields and suspension samples typically dominated by Brown relaxation leads to errors of less than 0.05 K, suggesting that the significant relaxation process improves the accuracy of the temperature measurements. The method also has potential for noninvasive and quantitative temperature monitoring in magnetic particle imaging with complex magnetic fields.
Sucrose transport inside the phloem: Bridging hydrodynamics and geometric characteristics
Authors: Nakad Mazen , Domec Jean-Christophe , Sevanto Sanna , Katul Gabriel
Published: June 2023

In plants, the delivery of the products of photosynthesis is achieved through a hydraulic system labeled as phloem. This semi-permeable plant tissue consists of living cells that contract and expand in response to fluid pressure and flow velocity fluctuations. The Münch pressure flow theory, which is based on osmosis providing the necessary pressure gradient to drive the mass flow of carbohydrates, is currently the most accepted model for such sucrose transport. When this hypothesis is combined with the conservation of fluid mass and momentum as well as sucrose mass, many simplifications must be invoked to mathematically close the problem and to resolve the flow. This study revisits such osmotically driven flows by developing a new two-dimensional numerical model in cylindrical coordinates for an elastic membrane and a concentration-dependent viscosity. It is demonstrated that the interaction between the hydrodynamic and externally supplied geometrical characteristic of the phloem has a significant effect on the front speed of sucrose transport. These results offer a novel perspective about the evolutionary adaptation of plant hydraulic traits to optimize phloem soluble compounds transport efficiency.
Linear stability analysis of second-mode attenuation via porous carbon-matrix ceramics
Authors: Sousa Victor C. B. , Wartemann Viola , Wagner Alexander , Scalo Carlo
Published: June 2023

Effects of porous carbon-fiber-reinforced carbon-matrix ceramics (C/C) on the stability of second-mode waves on a 7°-half-angle cone were investigated for Reynolds numbers Rem=2.43×106–6.40×106 m−1 at the freestream Mach number of M∞=7.4, for both sharp and 2.5-mm-round nose tips. A broadband time-domain impedance boundary condition was used to model the effects of the C/C porosity on the flow dynamics leveraging direct ultrasonic benchtop experiments and homogenous absorber theory. A spectral linear stability solver based on orthogonal Laguerre functions, naturally vanishing in the free stream, was used to predict linear spatial growth rates, which are in agreement with independent pulsed axisymmetric direct-numerical simulations. The latter were carried out with the quasi-spectral viscosity closure—a dynamic quasi-spectral procedure capable of deactivating the sub-filter scale stresses in the absence of turbulent break down—verifying its suitability to carry out transitional calculations without affecting ultrasonic wave dynamics. The effectiveness of a porous C/C surface is shown to decrease drastically with static pressure and its presence is shown to decrease the second-mode growth rates in regions where it is unstable as well as increasing the attenuation rates in regions where it is stable.
Presentational clefts, existentials and information structure
Authors: Carlier Anne , Lahousse Karen
Published: June 2023

Presentational c’è / il y a clefts in Italian and French have been argued to differ from the existential and locative constructions they derive from by their syntactic, semantic and information-structural properties: they would invariably convey sentence-focus. In the present study, we argue for a unitary treatment of all c’è / il y a constructions, whose meaning is locational-existential, and whose discourse function is to present the nominal argument as non-topical. This analysis de-particularizes presentational clefts with respect to locative and existential c’è / il y a constructions and accounts for the fact that, rather than conveying invariably sentence-focus, they present the same variety of information structure articulations as the non-cleft c’è / il y a constructions.
The Finnish existential clause
Authors: Huumo Tuomas
Published: June 2023

I analyze the case marking (nominative vs. partitive) and quantification of the Finnish existential S argument (Se). I focus on Se arguments quantified by mass quantifiers (e.g. paljon ‘much’) and number quantifiers (e.g. usea ‘many’). I discuss grammatical, semantic and discourse functions of the Se argument, with an emphasis on the aspectual and quantificational meanings expressed by the construction. I argue that a quantified Se designates a bounded quantity even when marked with the partitive case, which otherwise expresses unbounded quantity. This has important repercussions to the clause-level aspectual meaning of the existential construction, especially in uses where the aspectual profile of the clause is based on nominal aspect and thus on the quantity expressed by the Se.
Partition and existence
Authors: Lena Ludovica
Published: June 2023

This contribution concerns Chinese biclausal constructions introduced by the existential verb yǒu and including the bare noun rén ‘person, people’ in the pivotal position. Building upon spoken corpus data, I show that the co-occurrence of an individual-level predicate in the coda exerts a coercion on the reading of the pivot which is then interpreted as generic-partitive. I argue that, in such cases, the yǒu-construction is not used to signal referent unidentifiability. Rather, the biclausal pattern allows to prevent the bare noun rén from acquiring the universal interpretation (‘all people’) that it receives by default in the preverbal-subject position. These sentences are used to express the literal existence, namely the existence of a “subtype of people”.
Is the French verb manquer ‘lack, miss’ a negative existential predicate?
Authors: Van de Velde Danièle
Published: June 2023

This study treats French existential manquer ‘to lack’ as a positive predicate. I identify two syntactic constructions: a “locative alternating” one and an impersonal one (with a personal variant). I argue that the argument determiner constraints of manquer in the first construction can be explained by postulating an incorporated quantifier. The same assumption is valid for the second construction in spite of its explicit quantifier. Both constructions assert existence, but the existence in insufficient quantity (in reference to a norm), the inexistence / absence being a borderline case of insufficiency. The two constructions differ in that the second one, where manquer appears in the impersonal construction, adds to the simple idea of quantitative insufficiency the exact measure of the quantitative inferiority.
‘To be’ and its negation in Latvian
Authors: Petit Daniel
Published: June 2023

A striking peculiarity of the Baltic languages (Old Prussian, Lithuanian, Latvian) is the paradigm of the verb ‘to be’. Whereas Old Prussian, the only documented West Baltic language, still had an Indo-European-looking paradigm, Lithuanian and Latvian, the two members of East Baltic, have developed new forms for ‘to be’ and its negation. Most striking is the situation in Latvian, where the third person is ir ‘he is, they are’ (= Lithuanian yrà), but its negative nav ‘he is not, they are not’. The aim of this paper is to determine the origin of this suppletive relationship.
Words also exist in a world
Authors: Cappelle Bert
Published: June 2023

Clause sequences of the type ‘X’ does not exist – its correct name is ‘Y’ use descriptive negation in the first clause but also have something literally contradictory about them that is reminiscent of metalinguistic negation. I argue that the negative existential in such clause sequences exhibits a use-mention mix without blending descriptive and metalinguistic negation. The apparent contradiction can be resolved by acknowledging that words are not abstract labels lacking any substantial existence but also have a concrete reality in a ‘world of words’. Speakers often use the clause sequence studied here as a rhetorical device to point out that other speakers, for whom a word has currency, have a flawed view of the non-linguistic world.
Road potholes detection from MLS point clouds
Authors: Ma Xinjiang , Yue Dongjie , Li Siyuan , Cai Dongjian , Zhang Yi
Published: June 2023

The extraction of pavement damage information is one of the major difficulties in the application research of mobile laser scanning point cloud data. To address the problem of inaccurate detection results by using only relative distance to detect potholes, this paper proposes a novel pothole detection method that combines directed distance and skewed distribution. Firstly, the rapid positioning of the pothole is realized by the directed distance, which is calculated from the points and the local fitted plane. And monomerization and denoising of potential potholes are achieved by density clustering. Then, the new accurate plane is fitted by the surrounding pavement points of the potential pothole to obtain accurate directed distances. The negative skewed distribution of the directed distance histogram and the skewness coefficient are used for the accurate determination of the pothole. Finally, the three-dimensional geometric features of the pothole are extracted. Experiments were carried out on a road with poor road conditions. The experimental results validated the effectiveness and practicality of the proposed method. It can achieve automatic detection of potholes with different shapes and deformation degrees, and has effectively improved the efficiency of automatic road inspection.
Excellent ultraviolet optical limiting properties of Se nanosheets
Authors: Zhao Zhenyu , Du Binjian , Xin Yi , Ren Zihan , Xing Fei , Zhang Fang
Published: June 2023

Selenium (Se) is located in the fourth period of the periodic table in group VIA (element 34). In this experiment, three different solvents (isopropyl alcohol, N-methyl-2-pyrrolidone, and ethanol) were used to prepare the two-dimensional Se nanosheets, which were manufactured by the liquid phase exfoliation method with a thickness of 3.35–4.64 nm and a transverse scale of several hundred nanometers. The nonlinear absorption properties at 355, 532, and 1064 nm were studied using the open aperture Z-scan technique. Final results showed that Se nanosheets exhibited optical limiting (OL) effect in all three wavebands and three solvents, and had large two-photon absorption coefficients, especially in ultraviolet (UV) waveband. Which proved that Se nanosheets had great potential application as excellent OL materials in UV waveband. Our research broadens the path for the semiconductor field of Se, inspires the application of Se in nonlinear optics field.
Ordered exponential and its features in Yang–Mills effective action
Authors: Ivanov A V , Kharuk N V
Published: June 2023

In this paper, we discuss some non-trivial relations for ordered exponentials on smooth Riemannian manifolds. As an example of application, we study the dependence of the four-dimensional quantum Yang–Mills effective action on the special gauge transformation with respect to the background field. Also, we formulate some open questions about a structure of divergences for a special type of regularization in the presence of the background field formalism.
Experimental and Numerical Cracking Analysis of Precast Concrete Box Girder due to Tension
Authors: Li Jie , Zhou Lingyuan , Du Min , Wen Xiaxin , Zou Tongfei , Chen Congfei , Zhong Yingjie
Published: June 2023

The cracking problem of a precast beam of a highway in North China was investigated, and the field tests were carried out to test the stress in the cracking area during the prestress tensioning process. The distribution state of the main stress of the web and the influence of prestress tensioning on the stress concentration were obtained. A three-dimensional finite element model is also built to simulate the precast box girder, and the variation character of concrete stress with the tensioning procedure is simulated, which is compared with the test results. The results of both test and numerical analysis show that the principal tensile stress in the prestressed anchorage area and the web area near the diaphragm plate exceeds the tensile strength of the concrete. The test and numerical results predicted the correct direction of the observed crack preciously. Suggestions for reduce the principal tensile stress in the anchorage area are proposed.
An Analytical Calculation Method and Mechanical Response Laws of Buried Pipelines Subjected to the Impact of Transverse Landslides
Authors: Fan Zhiyong , Wu Bin , Liu Tianping , Zhao Ying , Liu Xiaoyu
Published: June 2023

When the buried gathering and transportation pipelines cross the landslide area transversally, the migration of the landslide mass can cause the pipelines to be subjected to lateral thrust, which can seriously affect the safe operation of the buried pipelines. In order to study the mechanical response laws of the buried pipelines under the impact of transverse landslides, based on the elastic-plastic foundation beam theory, the mechanical models of buried pipelines are established for three situations, and the analytical solution of pipeline displacement is obtained by genetic algorithm. The influences of landslide thrust, landslide width, soil resistance coefficient, the pipe outer diameter and wall thickness on pipeline peak displacement and peak stress are also investigated. The results show that under the impact of the transverse landslide, with the increase of landslide thrust, the maximum displacement and maximum tensile stress of pipeline increase exponentially, and the failure risk of pipe increases. Secondly, with the increase of landslide width, the maximum displacement of pipeline increases in the beginning and then decreases to be constant, and the maximum tensile stress decreases sharply to be constant. Thirdly, with the increase of soil resistance coefficient, the maximum displacement and maximum tensile stress of pipeline decrease in a negative power trend, and the pipeline is safer. Fourthly, when the pipe outer diameter increases to a certain value, the maximum displacement and maximum tensile stress of the pipeline change very little, hence, pipe outer diameter can be optimized when designing pipe structure. Fifthly, the smaller the pipe wall thickness is, the greater the maximum tensile stress of the pipe is, therefore, pipe corrosion protection should be paid attention to. Sixthly, when the landslide thrust is large, the landslide width is small, or the pipeline outer diameter is small, the maximum tensile stress of the pipeline is located at the centre of the landslide, otherwise, it is located at 0.56L ~ 0.7L away from the landslide centre. In order to ensure the safe operation of the pipeline, the stress state of these two positions should be focused on. It is concluded that the study can provide the basis for the evaluation of pipeline safety status and has practical significance for ensuring the safe operation of buried pipelines.
Research on Cost Control of Prefabricated Concrete Building Design Stage
Authors: Su Ying , Cai Jun , Zhang Jingdan , Qiu Xiuli , Jiang Deizhi
Published: June 2023

The industrialization of new building represented by prefabricated building is advancing rapidly. The design stage is the key stage of cost control of the whole prefabricated project. Through the analysis of the main design tasks in the design process of prefabricated concrete building design stage on the cost of prefabricated concrete frame structure, the factors affecting the cost control difficulties are analyzed, and the corresponding control measures in the design stage are put forward to promote the development of prefabricated concrete building. Through the comparison of cost control design and application cost of engineering cases in the design stage, it is shown that the construction cost of precast concrete frame structure system can be saved through reasonable design scheme.
New ALC panel wall installation quality control and reinforcement measures
Authors: Peng Yiqing
Published: June 2023

The rapid development of the construction industry has promoted the emergence of autoclaved aerated lightweight concrete slab wall (ALC panel wall) materials. This new type of building raw material has excellent use characteristics: its light weight, fire resistance sound insulation performance, environment protecting, economic, convenient construction and other advantages, so it has been widely used in the field of construction. For example, it can be used in all kinds of residential housing, apartments, office buildings, underground garages and other buildings in the wall enclosure construction, making the above-mentioned buildings with higher quality and practicality. In this paper, based on the analysis of the basic performance of ALC panel walls, the construction process, transport storage and technological innovation are combined to demonstrate the quality and anti-cracking control methods in the installation process of ALC panel walls, and the reinforcement measures to improve the construction efficiency of ALC panel walls, in view of the cracking and quality problems.
Analysis of the Temperature Effect and Influence of Large Span Continuous Rigid Bridge in Mountainous Area
Authors: Zeng Yuyang
Published: June 2023

The temperature problem of large span bridges in mountainous areas is particularly prominent due to the large temperature difference. This paper addresses the problem of ambient temperature influence on the construction and operation of large span prestressed reinforced concrete continuous rigid frame bridges. Through finite element modeling and computational analysis of an example of a continuous rigid frame bridge, the simulation results reveal the law of temperature influence on large span continuous rigid frame bridges and provide reference for the subsequent analysis of temperature problems of continuous rigid frame bridges. Based on the force analysis of the model, a series of bridge temperature crack generation mechanisms are proposed in combination with the bridge construction process and concrete characteristics, and reasonable treatment measures are proposed for the control of temperature cracks during bridge construction to ensure the overall quality effect of bridge construction and operation.
CFD Simulation of Vortex Induced Motion of a Caisson during Installation Process
Authors: Chen Jin , Chen Min , Liu Mingyue
Published: June 2023

This paper presents the CFD investigation of the vortex induced motion (VIM) of a caisson model during the installation process. The simulations were performed by solving the unsteady 3D Navier-Stokes equation. The Dynamic Fluid-Body Interaction (DFBI) tool is utilized to simulate the motions. Typical draft conditions of a caisson during installation process are considered. The present methodology is verified through the free decay and the VIM of a cylinder simulations in two-dimension. Free decay simulations show that the natural frequency decrease with the increasing draft of the caisson. Maximum response amplitudes occur in the range of 10<Vr
<13 for the draft Dp=0.1m. The resonance occurs when the crossflow response frequency f
y is very close to the natural frequency f
n. The inline/crossflow response frequency increases as the draft increases at the same reduced velocity V
r. The response frequency in the inline direction is double of that in the crossflow direction. Eight-shaped trajectories are observed. The maximum displacements in the crossflow direction increase as the drafts increase.
Motion Strategy of Drilling Anchor Manipulator Based on Intelligent Optimization Algorithm
Authors: Liming Che , Jun Zhang
Published: June 2023

The drilling and anchoring robot is an important equipment to realize the intellectualization of fully mechanized coal mining. The control effect of its manipulator directly affects the safety and efficiency of the support operation of the drilling and anchoring robot. The control of drilling anchor manipulator usually adopts PID controller, but due to the limitation of integer order PID control algorithm and traditional empirical parameter adjustment, it is difficult to find a group of parameters with the best control effect in a short time, resulting in the failure of timely and accurate positioning of the end of the manipulator. In this paper, the combination of numerical modeling and simulation analysis is used to adjust the parameters of fractional order PIλDμ
controller by using search algorithm (GPS) and applied to the motion control of manipulator; Based on the independent joint control theory, the single input single output system model of hydraulic cylinder at the joint of manipulator is established by using Matlab-Simulink software and fractional PIλDμ
control technology. The fractional order control system is regulated by input shaping feedforward control technology(IS). The step response effect of the hydraulic system is further analyzed by setting input feedforward controllers with different gain ratios. The numerical simulation results show that the control strategy of “Input Shaping(IS) + Intelligent optimization algorithm (GPS) parameter adjustment + Fractional PIλDμ
control technology” can effectively improve the spatial accurate positioning of mining manipulator. The research expand the application of intelligent control technology in the field of mining equipment.
Study on Noise Source Contribution of Converter Cabinet Based on Transfer Path Analysis Test
Authors: Fan Liuyang , Zhang Jian , Fan Yongxiang , Zhang Xiaowei , Li Qi
Published: June 2023

There are fan noise and transformer noise sources inside the converter cabin which may bring the environmental noise pollution through airborne or structural borne paths. In order to identify the contribution of each source and its path, transfer path analysis test was performed. Take full load working condition at full speed as an example, the contributions of fan air borne noise, fan structural borne noise, transformer air borne noise and transformer structural borne noise are 88.33%, 3.79%, 7.37% and 0.51% respectively. The contribution of air borne noise is 95.70% more than that of structural borne noise which is 4.30%. In the end the aerodynamic noise simulation of converter cabin is compared with the experimental result which is in good coincidence, this result can also verifies the noise source contribution result.
Analysis of Longitudinal Cracks of Casing in Heavy Oil Thermal Recovery Well
Authors: Cong Shen , Wang Bin , Song Enpeng , Cai Ke , Qu Tingting
Published: June 2023

This paper investigates cracking failure of the casing tube. There were longitudinal cracks in the heavy oil thermal recovery well occurred in an oil field. The fracture cause of casing was analyzed by macrographic observation, chemical composition analysis, mechanical property test, metallographic analysis, scanning electron microscope (SEM) and residual stress calculation. The results showed that the crack of the failed casing originates from the external surface of the pipe and has the characteristic of intergranular propagation. The fracture characteristics are brittle fracture. The conclusion showed that stress corrosion cracking(SCC) is the main cause of longitudinal crack of casing in the heavy oil thermal recovery well. Under the combined action of external corrosive media and internal stress, SCC cracks are generated on the surface of casing, and the cracks propagate along grain boundaries and finally lead to cracking and failure of casing. Some recommendations were proposed to avoid similar failures.
Effect of Cobalt Fraction Mixing WC Clads on Microstructural Evolution, Crack Formation and Tribological Properties by Laser Cladding
Authors: Zhang Chaoyang , Chen Shenyu , Yang Echo , Jean Mingder
Published: June 2023

In the present work, a ceramic-matrix composite coatings with different weight percentages of Co additive in the WC powders was studied on 45 steel by laser cladding. The effect of cobalt mixture with WC on mechanical properties such as microstructural evolution, hardness, wear and residual stress behavior of the coatings was carried out. The results show that high residual stresses induce significant cracking on 100% WC and that cracking activity is reduced by adding concentrations of 20% Cobalt to WC. Further, the microhardness of the coatings was more than five times higher than that of the substrate. The observation of the microstructural evolution reveals the fracture mechanism is a typical intergranular fracture in the molten zone and the crack propagates through the interior of the unmelted WC at 100% WC. Overall, the additive of high cobalt in WC did not result in a reduction of residual stresses due to less amount of brittle carbide. However, a reduced number of microstructural defects as well as a better wear behavior were obtained for the WC coated layers with suitably added Cobalt alloys.
Effect of Nano-Al2O3 on Properties of Alkali Activated GBFS Cementitious Materials
Authors: Zhou Xiaosheng , Zhang Yi , Jiao Xiaodong , Zhang Yangpeng
Published: June 2023

The effect of Nano-Al2O3 on the mechanical properties of alkali activated Granulated Blast Furnace Slag (GBFS) materials was studied. The results showed that the addition of Nano-Al2O3 can significantly increased the 28-day compressive strength. The compressive strength of the control slurry without GBFS just increased from 7.4 MPa to 8.5 MPa (14.86% increase) from 2 d to 28 d curing time, while as the addition dosage of Nano-Al2O3 increased from 1% to 5%, the compressive strength increase varied from 39.62% to 71.90% after 28d curing period. X-Ray Diffraction (XRD)-Retvieled combined with TG analysis showed that adding Nano-Al2O3 increased the amorphous phase, which may be the main cause of increasing of compressive strength.
Analysis of the Cause of Gas Pipeline Burst in a Gas Production Plant
Authors: Song Enpeng , Jin Quan , Ma Xin , Cai Ke
Published: June 2023

In order to reduce the failure of pipes, the macroscopic morphology, macroscopic crack, chemical composition, hardness, microstructure and so on were tested through the macroscopic analysis, physical and chemical property inspection, hydrogen-induced cracking test and sulfide stress cracking test. The SEM was used to analyze the microscopic cracks, fractures and element distribution at the failure site. The results show that the cracking zone of the failed pipe section has the characteristics of bulging deformation and thinning of wall thickness. The macroscopic fracture of the fracture is a typical 45° shear shape. The fracture was observed under the high magnification of scanning electron microscope and showed dimple morphology. The failure mode of the failed pipe segment is plastic fracture. The reason for the failure of this pipe is the special geographical location of this section of the pipeline, and the sudden increase of pipeline pressure after the well opening operation causes the water hammer phenomenon, which causes the local bulging of the pipe body, which further leads to burst failure.