Experimental measurements of bulk modulus for two types of hydraulic oil at pressures to 140MPa and temperatures to 180°C

Bulk modulus of hydraulic oil represents the resistance of hydraulic oil to compression and is the reciprocal of compressibility. The bulk modulus is a basic thermodynamic property of hydraulic oil that has a very important influence on work efficiency and dynamic characteristics of hydraulic systems, especially for the hydraulic systems at ultra-high pressure or ultra-high temperature. In this study, a bulk modulus experimental equipment for hydraulic oil was designed and manufactured, two types of hydraulic oil were selected and its isothermal secant bulk modulus were measured at pressures to 140MPa and temperatures of 20~180°C. Compared the experimental results with the calculated results from the prediction equations of liquid bulk modulus that proposed by Klaus, Hayward, and Song, it is found that the experimental results are not completely identical with the calculated results

The Ratio of Sunflower Pollens Foraged by Apis mellifera Is More Than That of Apis cerana Does During Sunflower Blooming

Bias foraging of pollen is general in different pollinators since various nutrition demanding, co-evolution and interaction of insect-plant. To clarify the preference of pollen foraging during sunflower blooming, the pollen foraging behaviors of Apis mellifera Linnaeus and Apis cerana Fabricius were observed. Our results displayed that two summits of pollen foraging occurred in the morning before the ambient temperature climbed up to thirty-one degree centigrade and in the afternoon after the ambient temperature decreased below thirty-one degree centigrade, respectively. Notably, the first foraging summit of Apis cerana emerged one hour earlier than that of Apis mellifera. These results imply that Apis mellifera is less resistant to low temperature but more resistant to high temperature than Apis cerana does. The colonies were surrounded by sunflowers with sporadic weeds, while only few maize dispersed over two hundred meters away. However, no more than forty percent of total pollens foraged by Apis mellifera was from sunflower, and which was no more than twenty percent in Apis cerana group. These results suggest that sunflower pollens are not the prior choice for both honey bee species, while the ratio of sunflower pollens foraged by Apis mellifera is more than that of Apis cerana does

Prediction of the post-translational modifications of adipokinetic hormone receptors from solitary to eusocial bees

Adipokinetic hormone receptor (AKHR) was regarded as the crucial regulator of lipid consuming, but now has been renewed as a pluripotent neuropeptide G protein-coupled receptor. It has been identified in all sequenced bee genomes from the solitary to the eusocial. In the current study, we try to clarify the transitions of AKHR on lipid utilization and other potential functions from solitary to eusocial bees. The results showed that the AKHRs were divided into different groups based on their social complexity approximately. Nevertheless, the critical motifs and tertiary structures were highly conserved. As to the post-translational modifications, the eusocial possessed more phosphorylation residues and modification patterns, which might be due to the necessity of more diverse functions. These results suggest that AKHRs are highly conserved on both primary motifs and tertiary structures, but more flexible on posttranslational modifications so as to accommodate to more complicated eusocial life

Fast and simple high-capacity quantum cryptography with error detection

Quantum cryptography is commonly used to generate fresh secure keys with quantum signal transmission for instant use between two parties. However, research shows that the relatively low key generation rate hinders its practical use where a symmetric cryptography component consumes the shared key. That is, the security of the symmetric cryptography demands frequent rate of key updates, which leads to a higher consumption of the internal one-time-pad communication bandwidth, since it requires the length of the key to be as long as that of the secret. In order to alleviate these issues, we develop a matrix algorithm for fast and simple high-capacity quantum cryptography. Our scheme can achieve secure private communication with fresh keys generated from Fibonacci- and Lucas- valued orbital angular momentum (OAM) states for the seed to construct recursive Fibonacci and Lucas matrices. Moreover, the proposed matrix algorithm for quantum cryptography can ultimately be simplified to matrix multiplication, which is implemented and optimized in modern computers. Most importantly, considerably information capacity can be improved effectively and efficiently by the recursive property of Fibonacci and Lucas matrices, thereby avoiding the restriction of physical conditions, such as the communication bandwidth

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Methylprednisolone as Adjunct to Endovascular Thrombectomy for Large-Vessel Occlusion Stroke

Importance It is uncertain whether intravenous methylprednisolone improves outcomes for patients with acute ischemic stroke due to large-vessel occlusion (LVO) undergoing endovascular thrombectomy. Objective To assess the efficacy and adverse events of adjunctive intravenous low-dose methylprednisolone to endovascular thrombectomy for acute ischemic stroke secondary to LVO. Design, Setting, and Participants This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 82 hospitals in China, enrolling 1680 patients with stroke and proximal intracranial LVO presenting within 24 hours of time last known to be well. Recruitment took place between February 9, 2022, and June 30, 2023, with a final follow-up on September 30, 2023.InterventionsEligible patients were randomly assigned to intravenous methylprednisolone (n = 839) at 2 mg/kg/d or placebo (n = 841) for 3 days adjunctive to endovascular thrombectomy. Main Outcomes and Measures The primary efficacy outcome was disability level at 90 days as measured by the overall distribution of the modified Rankin Scale scores (range, 0 [no symptoms] to 6 [death]). The primary safety outcomes included mortality at 90 days and the incidence of symptomatic intracranial hemorrhage within 48 hours. Results Among 1680 patients randomized (median age, 69 years; 727 female [43.3%]), 1673 (99.6%) completed the trial. The median 90-day modified Rankin Scale score was 3 (IQR, 1-5) in the methylprednisolone group vs 3 (IQR, 1-6) in the placebo group (adjusted generalized odds ratio for a lower level of disability, 1.10 [95% CI, 0.96-1.25]; P = .17). In the methylprednisolone group, there was a lower mortality rate (23.2% vs 28.5%; adjusted risk ratio, 0.84 [95% CI, 0.71-0.98]; P = .03) and a lower rate of symptomatic intracranial hemorrhage (8.6% vs 11.7%; adjusted risk ratio, 0.74 [95% CI, 0.55-0.99]; P = .04) compared with placebo. Conclusions and Relevance Among patients with acute ischemic stroke due to LVO undergoing endovascular thrombectomy, adjunctive methylprednisolone added to endovascular thrombectomy did not significantly improve the degree of overall disability.Trial RegistrationChiCTR.org.cn Identifier: ChiCTR210005172

Fast Localization and Characterization of Underground Targets with a Towed Transient Electromagnetic Array System

A fast inversion algorithm combined with the transient electromagnetic (TEM) detection system has important significance for improving the detection efficiency of unexploded ordnance. The traditional algorithms, such as differential evolution or Gauss–Newton algorithms, usually require tens to thousands of iterations to locate the underground target. A new algorithm with a magnetic gradient tensor and singular value decomposition (SVD) to estimate the target position and characterization quickly and accurately is proposed in this paper. Two modes of magnetic gradient tensor are constructed to accurately locate shallow and deep targets, respectively. The SVD algorithm is applied to the responses to estimate the electromagnetic characteristics of the target quickly and accurately. To verify the performance of the proposed algorithm, a towed TEM sensor is designed, which is constructed with three transmitting coils and nine three-component receiving coils arranged in a 3 × 3 array. Field experiments in survey and cued modes were taken to verify the performance of the proposed algorithm and the towed system. Results show that the magnetic gradient tensor algorithm proposed in this paper can accurately locate a single target within 2.0 m depth, and the error of depth is no more than 8 cm. Even for overlapping response of multi targets, the error of depth is no more than 12 cm. The underground target can be accurately characterized by the SVD algorithm. For targets with depths over 2.0 m, the signal-to-noise ratio of characteristic response estimated by SVD is higher than that of the traditional method. The proposed method needs approximately 40 ms, only 1% of the traditional one, considerably improving detection efficiency and laying a theoretical and experimental foundation for real-time data processing

Microwave welding of cemented carbide to Cr12 cold-working steel

The feasibility of welding WC-Co cemented carbide to Cr12 cold-working steel via microwave energy was investigated. Cemented carbide powders were directly consolidated on clean Cr12 substrate surface and then heated at high temperatures in a multimode microwave furnace. The results show that under appropriate conditions such as 103°C/min heating rate, 1000-1100°C temperature and bellow 10 min soaking time, the cemented carbide can effectively be welded on the Cr12 substrate, and the whole processing cycle is approximately 20 min. SEM measurements reveal the formation of clean boundaries and the atomic diffusion from Cr12 to WC-Co. Microwave welding technique which combines the sintering of cemented carbide with the wielding of cemented carbide and Cr12 steel can reduce processing cycle and steps and have a potential prospect, but face harsh welding terms, under-sintering of cemented carbide and substrate etching

Hydrodynamics and reaction characteristics of gas-liquid flow in circular microchannels

Cette thèse traite principalement des connaissances fondamentales en hydrodynamique et des caractéristiques des réactions gaz-liquide dans des microréacteurs capillaires. Dans une première partie, nous avons effectué des essais dans trois microcanaux circulaires en verre placés horizontalement. Les diamètres étudiés étaient de 302, 496 et 916 m. Les arrivées de gaz et de liquide se font de manière symétrique et forme un angle de 120 entre elles. Une cartographie des écoulements diphasiques gaz-liquide a été systématiquement faite pour des vitesses du liquide comprises entre 0,1 et. 2 m/s et des vitesses du gaz comprises entre 0,01 et 50 m/s Ces essais mettent en évidence l'influence du diamètre des canaux, de la viscosité du liquide et de leur tension superficielle. Ces mesures ont été comparées avec les cartes décrivant les différents régimes d'écoulement (à bulles, en bouchons de Taylor, annulaires ou sous forme de mousse) et confrontés aux modèles de la littérature qui prédisent les transitions entre les différents régimes. Nous avons mis en évidence que ces derniers n'étaient pas totalement satisfaisant et en conséquence, un nouveau modèle de transition prenant en compte les effets de taille du canal, les propriétés physiques du liquide a été proposé. Les pertes de charge engendrées par ces écoulements gaz- ont été étudiées. Nous avons constaté que la chute de pression est très dépendante du régime d'écoulement. Cependant pour décrire l'évolution de la perte de charge il est commode de la scinder en trois régions: une où les forces de tension superficielle sont le paramètre prépondérant et qui correspond aux faibles vitesses superficielle du gaz, une zone de transition et une dans laquelle les forces d'inertie sont dominantes et qui correspond aux grandes vitesses superficielles du gaz. La prédiction de cette chute de pression dans la troisième zone a été faite à partir d'un modèle de Lockhart-Martinelli. Ce modèle qui prend en compte les flux de chaque phase dépend d'un paramètre semi empirique C. Nous avons proposé de le corréler avec les nombres de Reynolds correspondant à chacune des deux phases en présence. Cette méthode permet de bien rendre compte de nos mesures. Les caractéristiques hydrodynamiques en écoulement de Taylor ont été examinées. Il a été montré que la formation des bulles dans un écoulement de Taylor est dominée par un mécanisme d'étranglement en entrée du capillaire. La taille des bulles dépend fortement de la viscosité du liquide et la tension superficielle. La chute de pression dans cette zone, lorsque le nombre capillaire est relativement faible, peut assez être bien décrite par le modèle de Kreutzer modifiée par Walsh et al En fin dans une dernière partie, nous avons réalisé une réaction chimique en écoulement de Taylor. L'oxydation du 2-hydrogéne-ethyltetrahydroanthraquinone (THEAQH2) pour former du peroxyde d'hydrogène a été expérimentalement étudiée dans un microcanal circulaire horizontal de 900 m de diamètre et 30 cm de long. La présence d'une réaction chimique ne modifie que très peu les transitions entre les différents régimes d'écoulement ni l'évolution des pertes de charge. Les cinétiques de conversion du peroxyde d'hydrogène sont environ deux fois plus rapides celles obtenues dans les réacteurs gaz liquide utilisés habituellement. Mots-clés: microcanal, écoulement diphasiques, écoulement de Taylor, pertes de charge, réaction gaz-liquide.This dissertation mainly deals with the fundamental knowledge of hydrodynamics and reaction characteristics in gas-liquid microreactors. Extensive experimental investigations have been performed in horizontal circular microchannels with diameter from 302 m to 916 m. Gas-liquid two-phase flow patterns in the microchannel have been systematic experimental investigated, in which the influence of channel diameters, liquid viscosities and surface tension were considered. Flow pattern regime maps in the present microchannels were developed, and the comparison with existing regime maps and flow pattern transition models in literature implied that transitions in present work could not be well predicted. As a result, a new transition model taking the effects of channel size, liquid physical properties into account was proposed. The gas-liquid two-phase pressure drop characteristics in microchannels were studied. It has been found that the pressure drop was highly flow patterns dependent, and the main trend can be divided into three regions: surface tension-dominated region, transitional region and inertia-dominated region. The pressure drop characteristics in surface tension-dominated and inertia-dominated region were discussed respectively. A modified Lockhart-Martinelli separated flow model in which the effects of channel diameter and liquid properties on the C-value are taken into account was proposed, and it showed a good agreement with respect to our experimental data and others' reported in literature. Hydrodynamics characteristics of Taylor flow have been examined. It was shown that the formation of Taylor flow was dominated by squeezing mechanism, on which the effects of liquid viscosity and surface tension were dramatically. The two-phase pressure drop of Taylor flow could be well predicted with the Kreutzer's model modified by Walsh et al., when capillary number was relatively low. Oxidation of hydrogenated 2-ethyltetrahydroanthraquinone (THEAQH2) in a horizontal circular microchannel have been experimental investigated. Results of visualization study on oxygen-anthraquinone working solution two-phase flow in microchannel showed that the flow pattern transition model and pressure drop model for inertia-dominated region proposed in this dissertation had good predicting accuracy. It was indicated that the gas-liquid interfacial area and space-time yield of hydrogen peroxide in the microchannel are at least one to two orders of magnitude higher than those in the conventional gas-liquid reactors. Keywords: microchannel, two-phase flow pattern, pressure drop, gas-liquid reaction, Taylor flow..SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

Data from: Pan-genome analysis highlights the role of structural variation in the evolution and environmental adaptation of Asian honeybees

<p>The <em>Asian honeybee</em>, <em>Apis cerana</em>, is an ecologically and economically important pollinator. Mapping its genetic variation is key to understanding population-level health, histories, and potential capacities to respond to environmental changes. However, most efforts to date were focused on single nucleotide polymorphisms (SNPs) based on a single reference genome, thereby ignoring larger-scale genomic variation. We employed long-read sequencing technologies to generate a chromosome-scale reference genome for the ancestral group of<em> A. cerana</em>. Integrating this with 525 resequencing datasets, we constructed the first pan-genome of <em>A. cerana</em>, encompassing almost the entire gene content. We found that 31.32% of genes in the pan-genome were variably present across populations, providing a broad gene pool for environmental adaptation. We identified and characterized structural variations (SVs) and found that they were not closely linked with SNP distributions, however, the formation of SVs was closely associated with transposable elements. Furthermore, phylogenetic analysis using SVs revealed a novel <em>A. cerana</em> ecological group not recoverable from the SNP data. Performing environmental association analysis identified a total of 44 SVs likely to be associated with environmental adaptation. Verification and analysis of one of these, a 330 bp deletion in the Atpalpha gene, indicated that this SV may promote the cold adaptation of <em>A. cerana</em> by altering gene expression. Taken together, our study demonstrates the feasibility and utility of applying pan-genome approaches to map and explore genetic feature variations of honeybee populations, and in particular to examine the role of SVs in the evolution and environmental adaptation of <em>A. cerana</em>.</p><p>Funding provided by: National Natural Science Foundation of China<br>Crossref Funder Registry ID: https://ror.org/01h0zpd94<br>Award Number: 31971397</p><p>Funding provided by: National Natural Science Foundation of China<br>Crossref Funder Registry ID: https://ror.org/01h0zpd94<br>Award Number: 32270445</p><p>Funding provided by: Central Public-interest Scientific Institution Basal Research Fund*<br>Crossref Funder Registry ID: <br>Award Number: Y2019XK13</p><p>Funding provided by: Central Public-interest Scientific Institution Basal Research Fund*<br>Crossref Funder Registry ID: <br>Award Number: Y2021XK16</p><p>Funding provided by: Swiss National Science Foundation<br>Crossref Funder Registry ID: https://ror.org/00yjd3n13<br>Award Number: PP00P3_202669</p&gt