Numerical simulation of base flow with hot base bleed for two jet models

In order to improve the benefits of base bleed in base flow field,the base flow with hot base bleed for two jet models is studied.Twodimensional axisymmetric Navier-Stokes equations are computed by using a finite volume scheme.The base flow of a cylinder afterbody with base bleed is simulated.The simulation results are validated with the experimental data,and the experimental results are well reproduced.On this basis,the base flow fields with base bleed for a circular jet model and an annulus jet model are investigated by selecting the injection temperature from 830 K to 2200 K.The results show that the base pressure of the annular jet model is higher than that of the circular jet model with the changes of the injection parameter and the injection temperature.For the circular jet model,the hot gases are concentrated in the vicinity of the base.For the annular jet model,the bleed gases flow into the shear layer directly so that the hot gases are concentrated in the shear layer.The latter temperature distribution is better for the increase of base pressure.

Improvement of Nickel-Stanogermanide Contact Properties by Platinum Interlayer

We report an effective method to improve the formation of nickel stanogermanide（Ni Ge Sn） by the incorporation of a platinum（Pt） interlayer. After the Ni/Pt/Ge Sn samples are annealed we obtain uniform Ni Ge Sn thin films,which are characterized by means of sheet resistance, atomic force microscopy, scanning electron microscopy,cross-section transmission electron microscopy, and energy dispersive x-ray spectroscopy. These results show that the presence of Pt increases the smoothness and uniform morphology of Ni Ge Sn films.

可持续热固性树脂的高性能和功能化设计合成

传统热固性树脂的大量使用与石化资源的枯竭和环境恶化之间的矛盾日益突出,使得高性能热固性树脂的可持续发展正面临着严峻的挑战.以可再生资源替代传统的石油化工产品用于生物基热固性树脂的合成,是实现其绿色化的重要方式之一.除此以外,如何赋予生物基热固性树脂良好的使役性能、复杂应用环境下的多功能性、高效且高质的可回收再利用性,也是保证其可持续发展的重要内容.早在10年前,本团队就开始了可持续热固性树脂的高性能与功能化设计合成,并致力于从原料选择、合成过程、树脂功能化、高附加值回收利用等全生命周期实现热固性树脂的可持续发展.基于多年的研究积累和经验,本文回顾和总结了我们在生物基平台化合物筛选、树脂结构功能一体化设计和高附加值回收利用等方面的工作,展望了可持续热固性树脂的发展前景和未来趋势.

Seasonal pattern of Echinococcus re-infection in owned dogs in Tibetan communities of Sichuan, China and its implications for control

Background:Human cystic echinococcosis(CE)and alveolar echinococcosis(AE)are highly endemic in Tibetan communities of Sichuan Province.Previous research in the region indicated that domestic dog was the major source of human infection,and observations indicated that domestic dog could have more access to intermediate hosts of Echinococcus spp.:both domestic livestock(CE)viscera and small mammals(AE),in early winter and again in spring.We hypothesized that there would therefore be a significant increase in the risk of canine infection with Echinococcus spp.in these two seasons and conducted a reinfection study to investigate this further.Methods:Faecal samples were collected from owned dogs in seven townships in Ganze Tibetan Autonomous Prefecture(Sichuan Province,China),and Echinococcus spp.infection status was determined using copro-antigen ELISA.Dogs were sampled in April(spring),July(early summer),September/October(autumn/early winter)and December(winter)in 2009;and in April(spring)2010.Dogs were treated with praziquantel following each of the five sample collections to eliminate any tapeworms.Information on dog sex,age and body weight was also collected.The t-test,Fisher’s exact test,Poisson regression and logistic regression were used to compare means and prevalences,and to identify factors associated with infection status.Results:The proportion of female dogs was significantly lower than that of male dogs;female dogs had significantly higher(22.78%)baseline copro-ELISA prevalence than males(11.88%).Dog body weight,sex,age,county and previous infection status at any sampling point had no influence on the re-infection prevalence in general.Poisson regression did not found a significant influence on the re-infection prevalence due to different deworming/sampling time spans.Dogs exhibited significantly higher re-infection prevalences in spring and early summer of 2009 and in early winter between September/October and December of 2009,suggesting a higher infection pressure in these seasons comparing with other seasons.Conclusion:Following praziquantel treatment,dog body weight,sex,age,county,deworming time span and previous infection status at any sampling point had no influence on the re-infection prevalence in the region in general.The differences between re-infection prevalences were probably due to the seasonality in Echinoccocus spp.infection pressure in the region.Early winter,spring and early summer should be important seasons for optimal dog deworming intervention in these Tibetan communities.

Prevale nee and spatial distribution patterns of human echinococcosis at the township level in Sichuan Province, China

Background:Echinococcosis is a global zoonotic parasitic disease caused by Echinococcus larvae.This disease is highly endemic in Sichuan Province,China.This study investigates the prevalence and spatial distribution characteristics of human echinococcosis at the township level in Sichuan Province,geared towards providing a future reference for the development of precise prevention and control strategies.

A multiplex PCR for differential detection of Echinococcus granulosus sensu stricto,Echinococcus multilocularis and Echinococcus canadensis in China

Background:Echinococcosis caused byEchinococcus is one of the most major infectious diseases in north-west highland of China.E.granulosus sensu strict,E.multilocularis,andE.canadensis are known to be the only three species related to human health transmitting in the areas.To achieve targeted treatment and control of echinococcosis,the accurate identification and discrimination of the species are important.However,currently the available diagnostic approaches do not present ideal results either in accuracy or efficiency.Methods:In the study,a set of primers were designed to aim at the three human-pathogenicEchinococcus species in China.The one-step multiplex PCR assay was developed and evaluated for the specificity and sensitivity.A total of 73parasitic lesions and 41 fecal materials obtained from human and various animals collected in the clinic and the field were tested to assess the applicability of this method.Results:The multiplex PCR effectively detected the individual DNA from the targeted species and their random mixtures generating with distinguishable expected size of products.The detection limit of the assay for each of the three species was 5 pg/μl when they were tested separately.When DNA mixtures of the targeted species containing the same concentration were used as templates,the lowest amount of DNA which can be detected was 50 pg/μl,10 pg/μl and 5 pg/μl forE.granulosus s.s.,E.multilocularis,andE.canadensis respectively.No cross-reactivity was observed when DNA from eight genetically close species was used as control templates.The multiplex PCR identifications of all samples were in line with the original sequencing results except for those infected withE.shiquicus,which showed negative signals in the developed assay.Of all the tested stool materials,16 were previously found positive forEchinococcus by visual and microscopic examination.Among these 16 samples,13 were confirmed by the multiplex PCR,and the other three tested negative.Additionally,the multiplex PCR identified another 14 positive feces from the remained 25 stool samples which absence of worms.Conclusions:The developed multiplex PCR shows advantages in fast diagnosis and large-scale epidemiological investigation,which proven to be a promising tool utilized in clinic and surveillance system.

Geographic distribution of echinococcosis in Tibetan region of Sichuan Province,China

Background:Echinococcosis is a parasitic zoonosis caused by Echinococcus larvae parasitism causing high mortality.The Tibetan Region of Sichuan Province is a high prevalence area for echinococcosis in China.Understanding the geographic distribution pattern is necessary for precise control and prevention.In this study,a spatial analysis was conducted to explore the town-level epidemiology of echinococcosis in the Sichuan Tibetan Region and to provide guidance for formulating regional prevention and control strategies.Methods:The study was based on reported echinococcosis cases by the end of 2017,and each case was geo-coded at the town level.Spatial empirical Bayes smoothing and global spatial autocorrelation were used to detect the spatial distribution pattern.Spatial scan statistics were applied to examine local clusters.Results:The spatial distribution of echinococcosis in the Sichuan Tibetan Region was mapped at the town level in terms of the crude prevalence rate,excess hazard and spatial smoothed prevalence rate.The spatial distribution of echinococcosis was non-random and clustered with the significant global spatial autocorrelation(I=0.7301,P=0.001).Additionally,five significant spatial clusters were detected through the spatial scan statistic.Conclusions:There was evidence for the existence of significant echinococcosis clusters in the Tibetan Region of Sichuan Province,China.The results of this study may assist local health departments with developing better prevention strategies and prompt more efficient public health interventions.

Flexible Subclavian Artery Closure for an Inadvertent Injury to the Internal Mammary Artery During Internal Jugular Vein Catheterization

Central vein catheter （CVC） placement, which is widely utilized in clinical departments, is also highly important in preoperative preparations for radiofrequency catheter ablation （RFCA）. The internal jugular vein or subclavian vein is the routine target. Arterial injury is not uncommon during the procedure but is potentially devastating in spite of the safety and advantages of the Seldinger technique. Compressing of the airway by a hematoma, as well as hemothorax, pseudoaneurysm, arteriovenous fistula, stroke, and even death, has been well-described.

The numbers of fungi:are the most speciose genera truly diverse?

Fungi play vital roles in ecosystems as endophytes,pathogens and saprobes.The current estimate of fungal diversity is highly uncertain,ranging from 1.5 to 12 million,but only around 150,000 species have been named and classified to date.Since the introduction of DNA based methods for species identification,the number of newly described taxa has increased from approximately 1000 to around 2000 yearly.This demonstrates the importance of DNA based methods to identify and distin-guish species,especially cryptic species.Many novel species from recent studies have been found in historically understudied regions and habitats,but these still represent only a small percentage of the estimated species.In this paper,we examine 16 genera from the top 40 most speciose genera as listed in Species Fungorum as case studies to examine the diversity of taxa in each genus.The genera treated herein are Cercospora,Diaporthe,Meliola,Passalora,Phyllachora,Phyllosticta,Pseudocer-cospora,Ramularia(ascomycetes)and Cortinarius,Entoloma,Inocybe,Marasmius,Psathyrella,Puccinia,Russula,Uromyces(basidiomycetes).We critically evaluate the number of species in these genera and correlate these numbers with the number of entries in GenBank.We introduce 18 new species Apiospora multiloculata,Candolleomyces thailandensis,Cortinarius acutoproximus,Cortinarius melleoalbus,Cortinarius pacificus,Cortinarius parvoacetosus,Diaporthe guizhouensis,Entoloma pseudosubcorvinum,Inocybe meirensongia,Marasmius albulus,Marasmius obscuroaurantiacus,Meliola camporesii,Phyl-lachora siamensis,Phyllosticta doitungensis,Picipes yuxiensis,Pseudocercospora vignae,Puccinia maureanui and Russula inornata.We also introduce a new record of Candolleomyces cladii-marisci and Inocybe iringolkavensis.We discuss the genera Colletotrichum and Pleurotus that are speciose,but do not occur in the top 40.We hypothesize whether there might be more species in these genera and discuss why these genera have some of the largest number of species.

A Constitutive Model Describing Molecular Configuration Evolution and Transient Rheological Behavior of Entangled Polymer Solutions

Entanglement network is an important structural feature in concentrated polymer solutions and polymer melts,which has a great influe nee on the transie nt rheological behavior and molecular con figurati on evolution.However,the existi ng constitutive models have limitations in describi ng the influe nee of dyn amic entan glement behavior on molecular chain motion,resulti ng in inaccurate descriptions of the transient rheological behavior.Thus,a molecular con figuration evoluti on model for polymer solutions considering the dyn amic entanglement effect is proposed by introducing an intermolecular force that changes with the orientation of the molecular chain in this work.The intermolecular force is introduced by consider!ng the friction coefficient as anisotropic,and the orientation effect is considered by introducing an excluded volume depende nt an isotropic diffusi on.The proposed model can better describe the stress relaxation,stress growth,and dielectric an isotropy of polymer soluti ons compared with the an isotropy FENE model and FENE model.In addition,the in fluence of different model parameters on the transient and steady shear response of polymer soluti on is investigated,and the results show that the in fluence of volume loss on the fricti on anisotropy factor k0 in creases as the solution concen tration in creases.

Intramural Hematoma versus Thrombus： Radiation-induced Heart Disease Results in Mass Formation after Radiofrequency Ablation

Radiofrequency catheter ablation （RFCA）,albeit an effective therapy for drug-refractory atrial fibrillation （AF）,can be associated with complications in 3.9-22.0% of cases, of which cerebrovascular embolization,cardiac tamponade,and pulmonary vein stenosis are more common,and atrial hematoma is more rare.Here,we presented a case describing an elderly woman diagnosed with an intramural left atrial hematoma after AF ablation.

Machine learning for semiconductors

Thanks to the increasingly high standard of electronics,the semiconductor material science and semiconductor manufacturing have been booming in the last few decades,with massive data accumulated in both fields.If analyzed effectively,the data will be conducive to the discovery of new semiconductor materials and the development of semicondulctor manufacturing.Fortunately,machine learning,as a fast-growing tool from computer science,is expected to significantly speed up the data analysis.In recently years,many researches on machine learning study of semiconductor materials and semiconductor manufacturing have been reported.This article is aimed to introduce these progress and present some prospects in this field.