Thermal effects on wear behavior of additively manufactured NiTi shape memory alloys

NiTi alloys fabricated by laser powder bed fusion(LPBF)additive manufacturing technology not only address the compositional instability resulting from complex processes but also solve the challenges of difficult machining of intricate aerospace structures.However,there are very few reports on the wear behavior of LPBF-NiTi alloys.In the present work,the effects of microstructure and thermal treatment,including heat treatment and frictional heat,on the wear behavior of LPBF-NiTi alloy and 100Cr6 ball were analyzed through a series of tribological experiments with different sliding speeds.As the average sliding speed increases(0.079–0.216 m/s),the wear rate of the as-built and heat-treated samples tends to decrease in the range of 2.69×10^(-3)–0.97×10^(-3)mm^(3)/m.Although the heat-treated LPBF-NiTi alloy is 46%harder than the as-built alloy is,the latter has a higher toughness(505 MJ/m^(3))and greater transformation strain of SIM(0.097).This leads to a coupling effect of heat treatment and sliding speed on the wear resistance.In addition,the wear track morphologies under different sliding speeds are asymmetric due to the 24% greater acceleration at the far end from the motor and the 2.15 mm deviation between the maximum speed position and the geometric center of the track.The wear modes of the as-built and heat-treated samples included adhesive,abrasive and delamination wear.Moreover,the wear morphologies and dominant wear modes change with the frictionally caused heat release induced by the sliding speed.

Mechanisms and Prevention of Acceleration Exposure-Induced Cardiovascular Injuries

Background: The development of high-performance flighter aircraft requires better anti-G ability of aircrew. Under the influence of continuous ±Gz or ±Gx acceleration, aircrew can suffer from cardiovascular change or injuries, which pose a huge threat to flight safety. In recent years, some achievements have been made in the physiological research of sustained ±Gz or ±Gx acceleration, especially the research on the cardiovascular physiological mechanism of sustained ±Gz or ±Gx acceleration. This paper analyzes the research progress. Methods: Original studies of any related fields will be included in the analysis. Searching of databases and manual scanning of the reference lists of the articles found during the original search will be performed. The following data items of included studies will be abstracted for analysis: publication year, first author, country, institution, journal and research priorities. Results: 28 papers were included in this study. The annual number of publications showed an ascending tendency as a whole and reached its peak in 2014 with a total of 6 documents. The country with the most publications was China. The journals of these papers focused on different fields, including military medicine, integrative medicine, preventive medicine, space medicine, environmental medicine and pharmacology. Research priorities mainly covered cardiac arrhythmia, cardiac structure, cardiovascular function, myocardial injury and myocardial enzyme. Conclusions: This paper analyzes the progress of research in the cardiovascular compensatory response. It is expected to provide reference for subsequent exploration of the mechanism of sustained ±Gz or ±Gx acceleration and the selection of ways to protect against anti-G.

Evaluation of the Effectiveness of the “1 + 1 + 1” Method in Theoretical Teaching of Emergency Pericardiocentesis

Background: Pericardial effusion may progress to cardiac tamponade when pressure around the heart increases to a level comparable to that of the right and left atria. Patients with cardiac tamponade need timely completion of emergency pericardiocentesis to relieve the threat to the patient’s life, and to save valuable time for patients who need emergency thoracotomy and pericardial window drainage. Pericardiocentesis is a necessary clinical skill for residents in standardized training. In addition, nurses who are familiar with this technology can better assist clinicians to perform this operation. In order to make the medical staff quickly master the theoretical knowledge of emergency pericardiocentesis, we designed a “1 + 1 + 1” teaching method for the theoretical teaching of emergency pericardiocentesis. Objective: This study aims to explore the effectiveness of the “1 + 1 + 1” teaching method in the theoretical teaching of emergency pericardiocentesis. Methods: We used an English teaching video of emergency pericardiocentesis and applied the “1 + 1 + 1” teaching method for theoretical teaching. A questionnaire survey was conducted before and after the lecture among 19 medical staff of different years of service to understand their mastery of the theoretical content of emergency pericardiocentesis before and after the lecture. According to the years of service, the medical staff were divided into three groups: 1 - 3 years (Group A), 4 - 10 years (Group B), and over 10 years (Group C), and the changes in the mastery of various contents by the overall medical staff and each group were statistically analyzed. Results: Before the lecture, the number of people who mastered the indications, contraindications, most commonly used methods, and common complications of emergency pericardiocentesis were 15, 12, 16, and 17, respectively, whereas after the lecture, these numbers increased to 17, 19, 19, and 19, respectively. The overall mastery before and after the lecture was statistically significant (p Conclusion: The “1 + 1 + 1” teaching method can effectively improve the overall mastery level of medical staff’s theoretical knowledge of emergency pericardiocentesis, especially in improving the mastery of contraindications of this operation.

无监督异常检测模型的鲁棒性基准

由于生产环境的复杂性和多样性,了解无监督异常检测模型对常见降质的鲁棒性是至关重要的。为了系统地探索这个问题,我们提出一个名为MVTec-C的数据集来评估无监督异常检测模型的鲁棒性。基于这个数据集,我们探索了五种不同范式的方法的鲁棒性,包括基于重建的、基于表征相似度的、基于归一化流的、基于自监督表征学习的和基于知识蒸馏的范式。此外,我们还探讨了两种最佳的方法中不同模块对鲁棒性和准确性的影响,包括Patch Core方法中的多尺度特征、邻域大小、采样比例和Reverse Distillation方法中的多尺度特征、MMF模块与OCE模块、多尺度蒸馏。最后,我们提出了一个特征对齐模块(FAM),以减少降质带来的特征偏移,并将Patch Core和FAM结合起来,得到一个同时具备高准确率和高鲁棒性的模型。我们希望这项工作能够作为一种鲁棒性评估手段,并在将来为构建鲁棒的异常检测模型提供经验。

Potential clinical application of microRNAs in bladder cancer

Bladder cancer(BC)is the tenth most prevalent malignancy globally,presenting significant clinical and societal challenges because of its high incidence,rapid progression,and frequent recurrence.Presently,cystoscopy and urine cytology serve as the established diagnostic methods for BC.However,their efficacy is limited by their invasive nature and low sensitivity.Therefore,the development of highly specific biomarkers and effective noninvasive detection strategies is imperative for achieving a precise and timely diagnosis of BC,as well as for facilitating an optimal tumor treatment and an improved prognosis.microRNAs(miRNAs),short noncoding RNA molecules spanning around 20–25 nucleotides,are implicated in the regulation of diverse carcinogenic pathways.Substantially altered miRNAs form robust functional regulatory networks that exert a notable influence on the tumorigenesis and progression of BC.Investigations into aberrant miRNAs derived from blood,urine,or extracellular vesicles indicate their potential roles as diagnostic biomarkers and prognostic indicators in BC,enabling miRNAs to monitor the progression and predict the recurrence of the disease.Simultaneously,the investigation centered on miRNA as a potential therapeutic agent presents a novel approach for the treatment of BC.This review comprehensively analyzes biological roles of miRNAs in tumorigenesis and progression,and systematically summarizes their potential as diagnostic and prognostic biomarkers,as well as therapeutic targets for BC.Additionally,we evaluate the progress made in laboratory techniques within this field and discuss the prospects.

Solar-assisted two-stage catalytic membrane reactor for coupling CO_(2) splitting with methane oxidation reaction

A two-stage catalytic membrane reactor(CMR)that couples CO_(2) splitting with methane oxidation reactions was constructed based on an oxygen-permeable perovskite asymmetric membrane.The asymmetric membrane comprises a dense SrFe_(0.9)Ta_(0.1)O_(3-σ)(SFT)separation layer and a porous Sr_(0.9)(Fe_(0.9)Ta_(0.1))_(0.9)Cu_(0.1)O_(3-σ)(SFTC)catalytic layer.In thefirst stage reactor,a CO_(2) splitting reaction(CDS:2CO_(2)→2CO+O_(2))occurs at the SFTC catalytic layer.Subsequently,the O_(2) product is selectively extracted through the SFT separation layer to the permeated side for the methane combustion reaction(MCR),which provides an extremely low oxygen partial pressure to enhance the oxygen extraction.In the second stage,a Sr_(0.9)(Fe_(0.9)Ta_(0.1))_(0.9)Ni_(0.1)O_(3-σ)(SFTN)catalyst is employed to reform the products derived from MCR.The two-stage CMR design results in a remarkable 35.4%CO_(2) conversion for CDS at 900℃.The two-stage CMR was extended to a hollowfiber configuration combining with solar irradiation.The solar-assisted two-stage CMR can operate stably for over 50 h with a high hydrogen yield of 18.1 mL min^(-1) cm^(-2).These results provide a novel strategy for reducing CO_(2) emissions,suggesting potential avenues for the design of the high-performance CMRs and catalysts based on perovskite oxides in the future.

Single-pulse Emissions of PSRs J1611-0114 and J1617+1123

In this paper,the emissions from two pulsars,PSRs J1611-0114 and J1617+1123,were investigated using th Five-hundred-meter Aperture Spherical radio Telescope operating at a central frequency of 1250 MHz.Th average pulse profile of PSR J1611-0114 shows two components,the first of which is relatively weak in intensity The two-dimensional pulse stack exhibits an obvious nulling phenomenon,with an estimated nulling fraction o40.1%±5.4%.The durations of the nulls and bursts are consistent with power-law distributions,and no periodi nulling phenomenon is found.The results from PSR J1617+1123 demonstrate that the average pulse profile i composed of four components.The peak intensity of the fourth component varies significantly,causing an unstabl integrated profile.In addition,the modulation characteristics of J1611-0114 and J1617+1123 were studied by analyzing the modulation index,longitude resolved fluctuation spectrum and two-dimensional fluctuation spectrum using the software PSRSALSA.It was found that the two pulsars exhibit intensity modulation.In particular,J1611-0114 displays even-odd modulation,with the modulation period of approximately two pulses.The modulation period of J1617+1123 is relatively broad.There is an obvious subpulse drift phenomenon,and the value of P_(2)i~0.125c/P_(0),corresponding to 12 pulse longitude bins,and the drift rate(P_(2)/P_(3))is about 0.29.

Valorization of wheat bran arabinoxylan: A review on nutritional and materials perspectives

Wheat bran, a principal byproduct of flour milling, stands as an abundant source of dietary fiber, yet its economic potential remains under-exploited in current forage applications. Arabinoxylan(AX), constituting the core of dietary fiber, emerges as a versatile compound with multifaceted functionalities. Its nutritional significance,coupled with its role in cereal food processing, has prompted a surge of studies focusing on the valorization of wheat bran AX. Moreover, the hydrolyzed derivative, arabinoxylan oligosaccharides(AXOS), demonstrates prebiotic and antioxidant properties, offering potential avenues to mitigate the risk of chronic diseases. This review summarizes current knowledge on the valorization of wheat bran AX in terms of the processing and nutritional properties of AX. Moreover, multiple novel applications of AX in the materials area, including biodegradable food packaging films, delivery of bioactive substances as nanoparticles, and the manufacture of food emulsifiers, are also highlighted to extend the utilization of AX. This review underscores the immense potential of wheat bran AX, advocating for its exploitation not only as a nutritional asset but also as a primary ingredient in advanced materials. The synthesis of nutritional and materials perspectives accentuates the multifaceted utility of wheat bran AX, thereby paving the way for sustainable valorization pathways. By unraveling the latent potential within AX, this paper advocates for the holistic and sustainable utilization of wheat bran in diverse, value-added applications.

Applying Hybrid Clustering in Pulsar Candidate Sifting with Multi-modality for FAST Survey

Pulsar search is always the basis of pulsar navigation,gravitational wave detection and other research topics.Currently,the volume of pulsar candidates collected by the Five-hundred-meter Aperture Spherical radio Telescope(FAST)shows an explosive growth rate that has brought challenges for its pulsar candidate filtering system.Particularly,the multi-view heterogeneous data and class imbalance between true pulsars and non-pulsar candidates have negative effects on traditional single-modal supervised classification methods.In this study,a multi-modal and semi-supervised learning based on a pulsar candidate sifting algorithm is presented,which adopts a hybrid ensemble clustering scheme of density-based and partition-based methods combined with a feature-level fusion strategy for input data and a data partition strategy for parallelization.Experiments on both High Time Resolution Universe SurveyⅡ(HTRU2)and actual FAST observation data demonstrate that the proposed algorithm could excellently identify pulsars:On HTRU2,the precision and recall rates of its parallel mode reach0.981 and 0.988 respectively.On FAST data,those of its parallel mode reach 0.891 and 0.961,meanwhile,the running time also significantly decreases with the increment of parallel nodes within limits.Thus,we can conclude that our algorithm could be a feasible idea for large scale pulsar candidate sifting for FAST drift scan observation.

Spin Evolution of the Magnetar SGR J1935+2154

Fast radio bursts(FRBs)are short pulses observed in radio frequencies usually originating from cosmological distances.The discovery of FRB 200428 and its X-ray counterpart from the Galactic magnetar SGR J1935+2154suggests that at least some FRBs can be generated by magnetars.However,the majority of X-ray bursts from magnetars are not associated with radio emission.The fact that only in rare cases can an FRB be generated raises the question regarding the special triggering mechanism of FRBs.Here we report long time spin evolution of SGR J1935+2154 until the end of 2022.According to v and v,the spin evolution of SGR J1935+2154 could be divided into two stages.The first stage evolves relatively steady evolution until 2020 April 27.After the burst activity in2020,the spin of SGR J1935+2154 shows strong variations,especially for v.After the burst activity in 2022October,a new spin-down glitch with△v/v=(-7.2±0.6)×10^(-6)is detected around MJD 59876,which is the second event in SGR J1935+2154.At the end,spin frequency and pulse profile do not show variations around the time of FRB 200428 and radio bursts 221014 and 221021,which supply strong clues to constrain the trigger mechanism of FRBs or radio bursts.

A Narrowband Burst from FRB 20190520B Simultaneously Observed by FAST and Parkes

Fast radio bursts(FRBs)are short-duration radio transients with mysterious origins.Since their uncertainty,there are very few FRBs observed by different instruments simultaneously.This study presents a detailed analysis of a burst from FRB 20190520B observed by FAST and Parkes at the same time.The spectrum of this individual burst ended at the upper limit of the FAST frequency band and was simultaneously detected by the Parkes telescope in the 1.5–1.8GHz range.By employing spectral energy distribution(SED)and spectral sharpness methods,we confirmed the presence of narrow-band radiation in FRB 20190520B,which is crucial for understanding its radiation mechanisms.Our findings support the narrow-band characteristics that most repeaters exhibit.This work also highlights the necessity of continued multiband observations to explore its periodicity and frequency-dependent properties,contributing to an in-depth understanding of FRB phenomena.

Oral bacteria-associated liver abscess in conjunction with pulmonary arteriovenous fistula:a case report

Pulmonary arteriovenous fistul a(PAVF)represents an abnormal direct connection between the pulmonary artery and vein,circumventing the alveolar capillary network.A right-to-left shunt in the lungs precluding proper gas exchange and reduces pulmonary capillary filtration.

Screening of glucosinolates degrading lactic acid bacteria and their utilization in rapeseed meal fermentation

Rapeseed meal is a promising food ingredient, but its utilization is limited by the presence of some potentially harmful ingredients, such as glucosinolates. Fermentation is a cost-effective method of detoxication but a food-grade starter culture with glucosinolates degradation capacity is required. In this study, 46 strains of lactic acid bacteria from traditional paocai brines were screened for their ability to glucosinolate degradation. The results showed that more than 50% of the strains significantly degraded glucosinolates. Two strains of Lactiplantibacillus(p7 and s7) with high capacity of glucosinolates degradation through producing enzymes were identified. Then,an optimized condition for rapeseed meal fermentation by p7 was established to degrade glucosinolates, which can achieve about 80% degradation. UPLC/Q-TOF-MS analysis showed that the degradation rate of individual glucosinolates was different and the degradation rate of gluconapin and progoitrin in rapeseed meal can reach more than 90%. Meanwhile, fermentation with p7 can improve safety of rapeseed meal by inhibiting the growth of Enterobacteriaceae and improve its nutritional properties by degrading phytic acid. The in vitro digestion experiments showed that the content of glucosinolates in rapeseed meal decreased significantly during gastric digestion. Meanwhile, fermentation with p7 can greatly improve the release of soluble protein and increase the contents of free essential amino acids, such as lysine(increased by 12 folds) and methionine(increased by 10 folds).

Benchmark simulations of radiative transfer in participating binary stochastic mixtures in two dimensions

We study radiative transfer in participating binary stochastic mixtures in two dimensions(2D)by developing an accurate and efficient simulation tool.For two different sets of physical parameters,2D benchmark results are presented,and it is found that the influence of the stochastic mixture on radiative transfer is clearly parameter-dependent.Our results confirm that previous multidimensional results obtained in different studies are basically consistent,which is interpreted in terms of the relationship between the photon mean free path l_(p)and the system size L.Nonlinear effects,including those due to scattering and radiation-material coupling,are also discussed.To further understand the particle size effect,we employ a dimensionless parameter l_(p)/L,from which a critical particle size can be derived.On the basis of further 2D simulations,we find that an inhomogeneous mix is obtained for l_(p)/L>0.1.Furthermore,2D material temperature distributions reveal that self-shielding and particle-particle shielding of radiation occur,and are enhanced when l_(p)/L is increased.Our work is expected to provide benchmark results to verify proposed homogenized models and/or other codes for stochastic radiative transfer in realistic physical scenarios.

Direct visualization of laser-driven dynamic fragmentation in tin by in situ x-ray diffraction

We present a novel method for investigating laser-driven dynamic fragmentation in tin using in situ X-ray diffraction.Our experimental results demonstrate the feasibility of the method for simultaneously identifying the phase and temperature of fragments through analysis of the diffraction pattern.Surprisingly,we observe a deviation from the widely accepted isentropic release assumption,with the temperature of the fragments being found to be more than 100 K higher than expected,owing to the release of plastic work during dynamic fragmentation.Our findings are further verified through extensive large-scale molecular dynamics simulations,in which strain energies are found to be transferred into thermal energies during the nucleation and growth of voids,leading to an increase in temperature.Our findings thus provide crucial insights into the impact-driven dynamic fragmentation phenomenon and reveal the significant influence of plastic work on material response during shock release.

Publisher’s Note:“Benchmark simulations of radiative transfer in participating binary stochastic mixtures in two dimensions”[Matter Radiat.Extremes 9, 067802 (2024)]

This article was originally published online on 30 August 2024.Due to a production error,as originally published the author list was not in its intended order.All online versions of this article were corrected on 9 September 2024 and it appears correctly in print.AIP Publishing apologizes for this error.

Harm of Hail to Crops and Countermeasures of Artificial Hail Suppression in Ulanqab City

Hail is one of meteorological disasters affecting crop growth in Ulanqab City.It happens frequently from May to September,and this period is also the main growing season of crops.In this period,hail will cause damage to crops,make farmland soil harden,and bring varying degrees of harm to agricultural production.Artificial hail suppression is an important scientific and technological means for disaster prevention and mitigation.It is necessary to strengthen the monitoring,analysis and forecast of severe convection weather,intensify the release of early warning information of hail weather,provide accurate and reliable real-time information for the implementation of artificial hail suppression operations,strengthen the implementation of artificial weather modification,effectively carry out artificial hail suppression operations,and avoid and reduce the impact of hail disaster.

Influence of Lightning Disaster on Cities and Lightning Defense Measures

Under the influence of special terrain and climatic conditions,lightning weather in Ulanqab City is more frequent from June to August,and lightning disaster has become one of the important tasks of disaster prevention and mitigation.In this paper,based on the characteristics of lightning weather in Ulanqab City,the impact of lightning disaster on the city was analyzed,and lightning protection measures,such as strengthening supervision of lightning protection safety,establishing a long-term lightning protection mechanism,doing a good job in lightning protection construction and detection in key places,and further improving public awareness of lightning protection,were put forward to reduce and avoid urban lightning disasters as much as possible and ensure urban safety.

Spatial Identification of Urban Ecological Function on the North Slope of Qinling Mountains Based on Ecological Sensitivity—A Case Study in Baoji, China

Since the 17th National Congress of the Communist Party of China, ecological civilization has been the key construction goal in China, which has a profound impact on the process of urbanization. In recent years, with the rapid development of urbanization and unreasonable land development and utilization, the ecological environment has deteriorated sharply, and the stability of ecological environment has always been a difficult problem in the process of regional development. The spatial division of urban ecological function can be divided into different types of spatial utilization according to the fragile state of ecological environment, which not only guarantees urban construction but also maintains the ecological environment health, and has great economic benefits and ecological value in formulating regional development strategies and ecological protection. In this paper, from four perspectives of “land, water, human and forest”, eight factors affecting ecological sensitivity were selected, and GIS spatial superposition method was used to conduct qualitative and quantitative analysis on the ecological sensitivity of Baoji City, and the evaluation results of single factor ecological sensitivity and comprehensive ecological sensitivity were obtained. The areas with different ecological sensitivity are divided into extremely sensitive areas, highly sensitive areas, moderately sensitive areas, slightly sensitive areas and non-sensitive areas. The research shows that the proportion of extreme, high, moderate, mild and insensitive areas in Baoji City is 7.32%, 10.57%, 22.25%, 42.91% and 16.95% respectively. Finally, the areas with different sensitivity grades are identified as three types of urban ecological function areas: ecological conservation area, ecological coordinated moderate utilization area and ecological suitable construction area, so as to provide scientific theoretical basis for urban construction and land use optimization in Baoji City.

Genome-Wide Analysis of HAESA/HAESA-Like Kinase Family in Rice

In leucine-rich repeat (LRR) receptor-like kinase XI subfamily, Arabidopsis HAESA (AtHAE) and two closely related HAESA-LIKE (AtHSL1 and AtHSL2) constitute a small branch. Several reports have described the function and the involved signaling pathway that AtHAE and AtHSLs are involved in. However, the family members and functions of HAE and HSL in rice have not been reported. Here, we performed a genome-wide analysis of the HAE/HSL kinase family in rice. A total of 17 OsHSLs were identified in the genome. Of these, only Os11g11890 was annotated as HSL2;all the other members were annotated as HSL1. Phylogenetic analysis revealed that OsHSLs diverged into three groups, with three Arabidopsis members constituting a subgroup of group I. Domain analysis revealed that all the homologues had 9-19 LRR repeats and a typical kinase domain at the C-terminus, except that four members lost or evolved their kinase domains. Expression analysis revealed that OsHSLs were co-expressed with genes involved in biotic and abiotic stresses. Microarray data revealed that most OsHSLs were highly expressed in the vegetative tissues and only two members were highly expressed in the reproductive tissues. Most OsHSLs changed their expression profiles when subjected to drought, and salt stress treatments. Our results provide an overview of OsHSL gene family in rice, and suggest that OsHSLs possibly function under biotic and abiotic stresses, thus would help for elucidating the function of OsHSLs gene family in vivo.