基于并行BICGSTAB的不可压流场计算方法

不可压缩流动广泛存在于日常生活及工程应用之中,随着数值模拟规模不断扩大,CFD算法越来越重视并行计算。该文采用SIMPLE算法对不可压流场进行求解,为求解算法中的大型稀疏矩阵,该文发展一套基于MPI框架的并行BICGSTAB矩阵求解方法。最后采用定常顶盖驱动流算例及非定常圆柱绕流算例验证并行算法的可行性及准确性。

Simulated Indonesian Throughflow in Makassar Strait across the SODA3 products

The Indonesian Throughflow(ITF), which connects the tropical Pacific and Indian oceans, plays important roles in the inter-ocean water exchange and regional or even global climate variability. The Makassar Strait is the main inflow passage of the ITF, carrying about 77% of the total ITF volume transport. In this study, we analyze the simulated ITF in the Makassar Strait in the Simple Ocean Data Assimilation version 3(SODA3) datasets. A total of nine ensemble members of the SODA3 datasets, of which are driven by different surface forcings and bulk formulas, and with or without data assimilation, are used in this study. The annual mean water transports(i.e.,volume, heat and freshwater) are related to the combination of surface forcing and bulk formula, as well as whether data assimilation is employed. The phases of the seasonal and interannual variability in water transports cross the Makassar Strait, are basically consistent with each other among the SODA3 ensemble members. The interannual variability in Makassar Strait volume and heat transports are significantly correlated with El Ni?oSouthern Oscillation(ENSO) at time lags of-6 to 7 months. There is no statistically significant correlation between the freshwater transport and the ENSO. The Makassar Strait water transports are not significantly correlated with the Indian Ocean Dipole(IOD), which may attribute to model deficiency in simulating the propagation of semiannual Kelvin waves from the Indian Ocean to the Makassar Strait.

基于高光谱技术的枇杷总酚含量无损检测

为评估高光谱成像技术(hyperspectral imaging,HSI)用于冷藏过程中枇杷总酚含量(totally phenolic content,TPC)预测的可能性,在可见光/近红外波段(363~1026 nm)采集115个枇杷样本高光谱信息,通过福林酚法对样本TPC进行测定。再采用蒙特卡洛算法对异常样本进行剔除,竞争性自适应加权算法(competitive adaptive reweighted sampling,CARS)对特征波长进行提取,分别建立枇杷TPC的非线性迭代偏最小二乘法(nonlinear iterative partial least square,NIPALS)预测模型和简单偏最小二乘法(simple partial least square,SIMPLS)预测模型并进行验证。结果显示,CARS共提取到特征波段47条,占波长总数7.62%;在最佳主成分数时,CARS-NIPALS与CARS-SIMPLS的建模集决定系数R^(2)_(c)分别为0.9221、0.9160,预测集决定系数R^(2)_(p)分别为0.8166、0.8128,NIPALS与SIMPLS两种算法表现相似,HSI能对冷藏过程中的枇杷TPC进行有效预测。

The Early Mesozoic NE-SW Extensional Model and Exhumation Processes at the Southeastern Margin of the Central Asian Orogenic Belt:Insights from the Strain and Kinematic Vorticity Analysis of the Sonid Zuoqi Ductile Detachment Zone

The Sonid Zuoqi ductile detachment zone is located at the southeastern margin of the Central Asian orogenic belt(CAOB),striking EW and dipping to the S.The major rock type of the Sonid Zuoqi ductile detachment zone is mylonite derived from granite.The sequence of mylonite features is:(1)S and C foliations of mylonite,and(2)extensional crenulation cleavage(ecc)or C′and the kinematic vorticity(Wk)value changed from 0.70 to 0.95 and from 0.37 to 0.69,respectively;the strain type of the mylonites within the Sonid Zuoqi ductile detachment zone is compressional to planar strain.The strong deformation mylonite and Halatu plutons yielded a zircon U-Pb age of 244 Ma and a zircon(U-Th)/He age of 214 Ma,respectively.Based on the strain and kinematic vorticity analysis,together with the zircon U-Pb and zircon(U-Th)/He ages and the regional tectonic background,the study area experienced three stage evolution:tangential simpleshear(244 Ma),simple-shear-dominated general shear represented by upper crustal extension(224 Ma)and pure-shear-dominated general shear represented by the Halatu pluton doming(214 Ma),which constrained the early Mesozoic NE-SW crustal extension at the southeastern margin of the CAOB.This NE-SW extension probably originated from the postorogenic extensional collapse of the CAOB,subsequent exhumation being controlled by the far afield effects of the closure of the Mongol-Okhotsk belt.

Parent-offspring relationship recognition based on SSR and mtDNA confirmed resource supplement effect of Fenneropenaeus chinensis release

The resource of Fenneropenaeus chinensis has declined sharply due to excessive fishing intensity,ecological changes and diseases.In order to supplement the fishing yield and restore resources of F.chinensis,the relevant authorities have carried out the activities of stock enhancement and releasing.It can increase biomass and recover resources.However,compared with increasing biomass,there were still few reports on its effect on the recovery of resources.Resource recovery is a process related to whether the released individuals can form a reproductive population.Up to now,there has been a lack of evidence whether the released F.chinensis can complete the entire life history,and form reproduction population.In this study,gravid female shrimp after spawning migration were captured from coastal waters of Haiyang,Qingdao,and Yellow Sea.After identifying parentage relationships using simple sequence repeat(SSR)and mtDNA haplotype,it was finally confirmed that there were eight released individuals in the recapture samples.It was confirmed for the first time that at least part of the released F.chinensis can complete overwintering and reproductive migration,and maintain the migration habits as their wild counterparts.Therefore,we infered that the released shrimp can reproduce under natural conditions,these F.chinensis can form reproductive populations theoretically if without human intervention.These results indicated that enhancenment and release activities have a positive effect on resource recovery.

Assessment of liquefaction potential based on shear wave velocity:Strain energy approach

Liquefaction assessment based on strain energy is significantly superior to conventional stress-based methods.The main purpose of the present study is to investigate the correlation between shear wave velocity and strain energy capacity of silty sands.The dissipated energy until liquefaction occurs was calculated by analyzing the results of three series of comprehensive cyclic direct simple shear and triaxial tests on Ottawa F65,Nevada,and Firoozkuh sands with varying silt content by weight and relative densities.Additionally,the shear wave velocity of each series was obtained using bender element or resonant column tests.Consequently,for the first time,a liquefaction triggering criterion,relating to effective overburden normalized liquefaction capacity energy(WL=s’c)to effective overburden stresscorrected shear wave velocity(eVs1)has been introduced.The accuracy of the proposed criteria was evaluated using in situ data.The results confirm the ability of shear wave velocity as a distinguishing parameter for separating liquefied and non-liquefied soils when it is calculated against liquefaction capacity energy(WL=s’c).However,the proposed WL=s’c-Vs1 curve,similar to previously proposed cyclic resistance ratio(CRR)-Vs1 relationships,should be used conservatively for fields vulnerable to liquefaction-induced lateral spreading.

Identification of time-varying system and energy-based optimization of adaptive control in seismically excited structure

The combination of structural health monitoring and vibration control is of great importance to provide components of smart structures.While synthetic algorithms have been proposed,adaptive control that is compatible with changing conditions still needs to be used,and time-varying systems are required to be simultaneously estimated with the application of adaptive control.In this research,the identification of structural time-varying dynamic characteristics and optimized simple adaptive control are integrated.First,reduced variations of physical parameters are estimated online using the multiple forgetting factor recursive least squares(MFRLS)method.Then,the energy from the structural vibration is simultaneously specified to optimize the control force with the identified parameters to be operational.Optimization is also performed based on the probability density function of the energy under the seismic excitation at any time.Finally,the optimal control force is obtained by the simple adaptive control(SAC)algorithm and energy coefficient.A numerical example and benchmark structure are employed to investigate the efficiency of the proposed approach.The simulation results revealed the effectiveness of the integrated online identification and optimal adaptive control in systems.

Main focus of parents of children with attention deficit hyperactivity disorder and the effectiveness of early clinical screening

BACKGROUND Attention deficit hyperactivity disorder(ADHD)is a common mental and behavioral disorder among children.AIM To explore the focus of attention deficit hyperactivity disorder parents and the effectiveness of early clinical screening METHODS This study found that the main directions of parents seeking medical help were short attention time for children under 7 years old(16.6%)and poor academic performance for children over 7 years old(12.1%).We employed a two-stage experiment to diagnose ADHD.Among the 5683 children evaluated from 2018 to 2021,360 met the DSM-5 criteria.Those diagnosed with ADHD underwent assessments for letter,number,and figure attention.Following the exclusion of ADHD-H diagnoses,the detection rate rose to 96.0%,with 310 out of 323 cases identified.RESULTS This study yielded insights into the primary concerns of parents regarding their children's symptoms and validated the efficacy of a straightforward diagnostic test,offering valuable guidance for directing ADHD treatment,facilitating early detection,and enabling timely intervention.Our research delved into the predominant worries of parents across various age groups.Furthermore,we showcased the precision of the simple exclusion experiment in discerning between ADHD-I and ADHD-C in children.CONCLUSION Our study will help diagnose and guide future treatment directions for ADHD.

Comparing pharmacotherapy and transcranial magnetic stimulation for the treatment of anxiety and depression after aortic dissection surgery

BACKGROUND Aortic coarctation is a potentially fatal condition that is primarily treated surgically.Despite successful procedures,patients frequently experience postoperative anxiety and depression,which can hinder recovery and worsen outcomes.Pharmacological interventions,such as 5-hydroxytryptamine(5-HT)and norepinephrine reuptake inhibitors,are commonly prescribed;however,their efficacy alone or in combination with non-invasive brain stimulation techniques,such as repetitive transcranial magnetic stimulation(TMS),remains unclear.AIM To assess the effect of medications and TMS on post-aortic surgery anxiety and depression.METHODS We analyzed the outcomes of 151 patients with anxiety and depression who were hospitalized for aortic dissection between January 2020 and September 2022.Using the random number table method,75 and 76 patients were allocated to the normal control and study groups,respectively.All the patients were treated using routine procedures.The control group was administered anti-anxiety and antidepression drugs,whereas the study group was treated with TMS in addition to these medications.The patients in both groups showed improvement after two courses of treatment.The Hamilton Anxiety Scale(HAMA)and the Hamilton Depression Scale(HAMD)were used to assess anxiety and depression,respectively.The serum levels of brain-derived neurotrophic factor(BDNF)and 5-HT were determined using enzyme-linked immunosorbent assay.The Pittsburgh Sleep Quality Index(PSQI)was used to estimate sleep quality,and the Repeatable Battery for the Assessment of Neuropsychological Status(RBANS)was used to assess cognitive function.RESULTS The HAMD and HAMA scores reduced in 2 groups,with the study group achieving a lower level than control(P<0.05).In the control group,43 patients recovered,17 showed improvement,and 15 were deemed invalid.In the study group,52 recovered,20 improved,and four were invalid.The efficacy rate in study group was 94.74%compared to 80.00%in control(P<0.05).The BDNF and 5-HT levels increased in both groups,with higher levels observed in the experimental group(P<0.05).Moreover,the PSQI scores decreased in 2 groups,but were lower in the intervention group than control(P<0.05).The scores of the RBANS items increased,with the study group scoring higher than control(P<0.05).CONCLUSION Combining anti-anxiety and anti-depressive drugs with repetitive TMS after aortic surgery may enhance mood and treatment outcomes,offering a promising clinical approach.

Simple and effective method for treating severe adult skeletal class II malocclusion: A case report

BACKGROUND Severe skeletal class II malocclusion is the indication for combined orthodontic and orthognathic treatment.CASE SUMMARY A woman with a chief complaint of a protruding chin and an inability to close her lips requested orthodontic camouflage.The treatment plan consisted of extracting the right upper third molar,right lower third molar,left lower second molar,and left upper third molar and moving the maxillary dentition distally using a convenient method involving microimplant nail anchors,push springs,long arm traction hooks,and elastic traction chains.After 52 months of treatment,her overbite and overjet were normal,and her facial profile was favorable.CONCLUSION This method can be used for distal movement of the maxillary dentition and to correct severe skeletal class II malocclusion in adults.

Clinical Epidemiology and Surgical Treatment of Spontaneous Perforations of the Terminal Ileum: A Multicentre Study in Cameroon

Background: Perforations of the terminal ileum are a frequent clinical situation and a therapeutic challenge. Surgical treatment is controversial. Several surgical modalities have been proposed and postoperative morbidity and mortality remain high. The aim of this study was to review our experience in the surgical management of perforations of the terminal ileum. Patients and methods: This is a descriptive cross-sectional study with retrospective data collection from January 1, 2017 to December 31, 2021, in five hospitals in Cameroon. Patients’ demographic, clinical presentation, surgical findings and 30-days postoperative outcomes data were collected. Results: We collected 34 files. The sex ratio was 1.4 and the average age was 20.28 years. The average consultation time was 9.1 days. Abdominal pain was present in all our patients. Peritoneal irritation was present in 46 cases (88.5%). The mean time to treatment after admission was 17.5 hours. The perforation was unique in 40 cases (76.9%) and located between 6 and 10 cm from the ileocecal valve in 29 cases (55.8%). Typhoid was the most suspected etiology intraoperatively in 38 cases (73.1%). A simple suture was performed in 18 patients (34.6%), resection with anastomosis in 11 patients (21.2%) and an ileostomy in 5 patients (9.6%). The average length of hospitalization was 21.74 days. Postoperative morbidity and mortality were 32.7% and 17.3% respectively. Conclusion: Perforations of the terminal ileum are common and affect young people. Surgical procedures are varied. Reducing consultation and care times and respecting treatment principles could improve postoperative morbidity and mortality, which remain high.

YOLO在口罩检测中的应用与研究

随着公共卫生安全意识的提升,口罩检测尤为重要。本研究探讨了YOLO算法在口罩检测应用中的有效性。首先,梳理了YOLO的核心原理与演进脉络,为算法的优化提供理论基础。其次,分析了口罩检测的紧迫性以及现有方法的局限性。在此基础上,本文介绍了数据集准备、实验环境配置,并对YOLO检测模型进行了优化,以提高口罩检测的准确率和实时性。实验结果表明,优化后的YOLO模型在口罩检测任务上展现出卓越的性能,提升了检测的效率。本研究不仅推动了计算机视觉领域的技术应用,也对当前和未来公共卫生管理实践具有重要意义。

Exploring Ester Prodrugs: A Comprehensive Review of Approaches, Applications, and Methods

The review provides an overview of the approaches, applications, and methods for ester prodrugs. Ester prodrugs are pharmacologically inactive compounds in their original form but become active drugs on biotransformation within the body, which offers advantages concerning the solubility, stability, and targeted delivery of the active drug. Several approaches of ester prodrugs have been reviewed in this review, including simple ester prodrugs, amino acid ester prodrugs, sugar ester prodrugs, lipid ester prodrugs, and polymeric ester prodrugs. This review incorporates in vitro and in vivo methods as well as the characterization of physical and chemical properties for ester prodrugs, cell culture systems, enzymatic assays, and animal models—all of these having a very important bearing on the evaluation of stability, bioavailability, and efficacy for ester prodrugs. While the benefits of using ester prodrugs are significant, there are also disadvantages like instability, poor or variable enzymatic hydrolysis, and toxicity from released promoieties or by-products. This review discusses solutions to the various limitations that include enhancing stability with ionizable promoieties and using physiologically-based pharmacokinetic modeling. The review also highlights the application of ester prodrugs in neurological disorders, such as Parkinson’s disease, and the ongoing efforts to address the critical limitations in treatment efficacy. Future prodrug strategies are poised to advance significantly by harnessing diverse transport mechanisms across the blood-brain barrier and integrating nanotechnology.

An Affordable and Easily Accessible Approach for Acrylonitrile Monomer Purification through a Simple Column Technique

This manuscript presents a dataset detailing a method for purifying monomers. Purification plays a crucial role in every chemical process, as it leads to an improvement in product quality through the removal of impurities. The primary method for monomer purification, like acrylonitrile (AN), is the distillation technique. However, this technique is unsafe and hard to set up or handle. A straightforward, risk-free, low-cost method like the column technique resolves these issues. A simple column technique demonstrated the successful execution of purifying AN. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analyses confirmed that AN was successfully purified, with purity reaching 99.8%. FTIR spectra revealed changes in the position and intensity of the stretching vibration peaks after purification. Also, the functional groups of the inhibitor monomethyl ether of hydroquinone (MeHQ) were undetected after purification. Furthermore, after purification, NMR spectra revealed the absence of aromatic protons and carbons associated with MeHQ. In conclusion, the column technique is a successful and inexpensive way to purify AN monomers. This makes it useful for a wide range of applications, especially in polymerization reactions where MeHQ needs to be removed to prevent self-polymerization during the initiation process.

基于立式泵装置的特低扬程排涝泵站研究

针对立式泵装置在特低扬程条件下水力性能较差的问题,对立式泵装置进行改进,首先设计其控制方程,然后引入密度残差对SIMPLE算法改进以提高计算效率。结果表明,改进立式泵装置的损失值在40 mm以下,数值模拟和实际工程中扬程工况点效率均在69%以上,提高了效率,并降低了水力损失。证明了改进立式泵装置的有效性及稳定性,其在特低扬程条件下具有广阔的应用前景。

Surprising New Bohr Models for H2and H2+

Niels Bohr constructed the first version of quantum mechanics. It has been called “old quantum mechanics” with a connotation of being obsolete. It is logically consistent, however, and deserves the name of simple quantum mechanics (SQM). It differs only from the semiclassical approximation by assuming that the average position and average velocity of an electron can be sharply defined on closed orbits. This assumption does not contradict Heisenberg’s uncertainty relations, since the quantization rule means that the electron can be anywhere on this orbit when it allows for stationary waves. This approach was remarkably efficient for one electron in hydrogen atoms and even for the electron pair in hydrogen molecules. However, dissociation of H2 and determination of the orbit of the single electron in H2+led to problems that remained unsolved for more than 100 years. Their solution, presented here, yields more physical insight and reveals, for instance, that mutual polarization of two hydrogen atoms can yield a metastable state.

Heat Kernel Estimates on Simple Random Walks and On-Diagonal Upper Bounds

We primarily provide several estimates for the heat kernel defined on the 2-dimensional simple random walk. Additionally, we offer an estimate for the heat kernel on high-dimensional random walks, demonstrating that the heat kernel in higher dimensions converges rapidly. We also compute the constants involved in the estimate for the 1-dimensional heat kernel. Furthermore, we discuss the general case of on-diagonal estimates for the heat kernel.

杏ISSR反应体系的优化和指纹图谱的构建

以杏品种清密沙为试材,用引物UBC825〔序列为(AC)8T〕研究了PCR反应体系的主要成分及退火温度对杏ISSR扩增结果的影响。结果表明:Primer、Mg2+、Taq酶浓度对扩增效果有明显影响,而模板DNA和dNTPs含量对扩增结果影响不大。优化的反应体系为:20μL的反应体系中含10ng模板DNA、0.1mmol/LdNTP、0.25μmol/LPrimer、2.5mmol/LMg2+,0.5UTaqPolymerase。适宜退火温度为50-52.1℃。用引物UBC825和UBC868〔序列为(GAA)5〕在优化的反应条件下建立了5个种12份杏材料的ISSR指纹图谱。

玉米穗部性状QTL定位

利用SSR分子标记构建的遗传连锁图谱对玉米的穗长、穗粗、穗行数、行粒数、轴粗、秃尖长、200粒质量和穗粒质量等8个性状进行了基因定位.穗长检测到2个QTLs,分布于Ch1-1、Ch9连锁群;穗粗检测到7个QTLs,分布于Ch1、Ch1-1、Ch2、Ch4、Ch4-1、Ch6、Ch7连锁群;穗行数检测到6个QTLs,分布于Ch1、Ch2、Ch5、Ch6、Ch9、Ch10连锁群;行粒数检测到1个QTL,位于Ch9连锁群;轴粗检测到6个QTLs,分布于Ch1、Ch4、Ch5、Ch6、Ch7、Ch10连锁群;200粒质量检测到2个QTLs,分布于Ch7、Ch8连锁群;穗粒质量检测到3个QTLs,分布于Ch5、Ch6、Ch9连锁群.研究表明,穗部性状QTLs在玉米10条染色体上分布不均匀,呈现成簇分布现象;各个QTL位点上起增、减效作用的等位基因在高值亲本和低值亲本中的分布不均匀.

互联网即时消息(Instant Messaging,IM)的研究现状与展望

即时消息(Instant Messaging,IM)是一种新兴的互联网交流方式,它具有实时性、在线性等一些很好的特性.目前IM已经成为继Email、Web之后的第三大互联网应用,基于IM的技术仍然在发展中,也出现了一些和IM相关的研究问题.本文总结了IM的特征,将IM和其他交流方式进行了比较,介绍了IM的服务模型和相关协议,讨论了IM的现有研究方向并对IM的未来发展方向进行了展望.