EAST装置中新型吸附剂泵(NEG)抽速标定研究

粒子排出是控制燃料粒子再循环、提升等离子体性能的关键因素之一。因此研究了新型吸附剂泵(NEG)在粒子排出技术中的潜在应用。NEG泵基于ZAO新型合金材料制成,对氢及其同位素抽速大、容量高,安装、运行、维护简单,兼容等离子体环境,适用于偏滤器区域的超高热流和复杂的空间结构。在EAST托卡马克装置安装4套HV800模组,开展了定期的抽速标定、再生研究以评估其周期性能变化。EAST真空室壁表面积较大,金属壁放气、杂质气体影响NEG泵抽速计算。通过计算EAST整体漏放率与氢及其同位素放气率,利用计算机模拟抽气过程,提出了一种用于修正NEG泵抽速的方法。研究结果表明在偏滤器区域工作压力下,对氘平均抽速可达1200 L/s。

差压法测定NEG吸氢性能

通过对定压法进行改进提出了差压法,用于测试非蒸散型吸气剂(NEG)的吸氢性能。该方法在进气室和吸气室之间安装固定流导元件,利用调节微调阀提供可控的进气流量,通过测量吸气室、进气室和参考室的压力计算NEG的吸气性能参数。利用两种NEG比较了差压法和改进的定压法所测吸气性能。结果表明:差压法测得的吸气容量比改进的定压法测得的吸气容量低0.07268 Pa·L;腔室壁面吸附能力使改进定压法的试验结果高于理论结果,而差压法的试验结果不受影响;对改进的定压法进行优化后,其计算结果与差压法的接近。差压法可以获得更准确、更有效的吸气剂性能参数,在差压法中,参考部分和试验部分同时进行测试,可缩短测试时间,减少控制进气带来的误差。

The Prevalence of Overweight/Obesity and Related Comorbidities among HIV-Positive and HIV-Negative Patients Attending the Same Clinics in Gaborone, Botswana

Context: Antiretroviral therapy (ART) helps restore the health status of people living with HIV (PLHIV). Likewise, it increases the risk of overweight/obesity and related comorbidities among the recipients. In countries like Botswana where ±84% of PLHIV is on ART, the paucity of data comparing overweight/obesity between HIV-positive on ART and HIV-negative patients may impede clinical and policy decision-making. This study sought to estimate and compare: i) the prevalence of overweight/obesity between HIV-positive on ART and HIV-negative patients;ii) the prevalence of hypertension (HTN), diabetes mellitus (DM)/coronary heart disease (CHD) between HIV-positive patients on ART and HIV-negative patients attending same outpatient departments of general clinics in Gaborone, Botswana. Patients and Methods: Five hundred eighty-one (581) outpatients were recruited in four major clinics of Gaborone, Botswana, between June and July 2019;294 or 51% of them were HIV-negative and 287 or 49% were HIV-positive on ART. The prevalence of overweight/obesity and of HTN and DM/CHD were calculated and examined using stratified analysis. Subgroups were compared using Chi-square analysis with Yates correction or Fisher exact test and t-student test for continuous data. Results: Major findings after stratification of the study population by HIV status were: i) the prevalence of all categories of (BMI), including overweight/obesity, were comparable between HIV-negative-patients and HIV-positive. In fact, there were 24 (8.0%) cases of underweight among HIV-negative-Patients and 15(5%) cases among HIV-positive patients, p = 0.2;145 (49%) HIV-negative-patients and 128 (45%) HIV-positive, p = 0.07 cases of normal weight;72 (25%) HIV-negative-patients and 87 (30%) HIV-positive, p = 0.08, were overweight;53 (18%) HIV-negative-patients and 57 (20%) HIV-positive, p = 0.12, were obese;125 (43%) HIV-negative patients and 144 (50%) HIV-positive, p=0.06 were overweight/obese;ii) the prevalence of HTN and DM/CHD among HIV-positive-patients were significantly lower (p < 0.05) compared to HIV-negative patients: There were 32 (10.9%) cases of HTN among HIV-negative patients compared to 18 (6.3%) cases of HTN among HIV-positive patients, p = 0.001;32 (11%) cases of DM/CHD HIV-negative patients compared to 4 (1.4%) cases of DM/CHD among HIV-positive patients, p = 0.001. Conclusion: the prevalence of overweight/obesity observed between HIV-negative and HIV-positive patients may suggest that the two groups shared the same exposure factors. That HTN and DM/CHD prevalence was lower among HIV-positive compared to HIV-negative patients, is possibly due to interplay factors of ART, HIV or the host population. Further studies are, however, recommended for clarifications.

Molecular Detection of Resistance and Virulence Genes in Coagulase Negative Staphylococci Isolated from Blood Cultures at the University Teaching Hospital of Bouake

Introduction: Coagulase-negative staphylococci (CoNS) are currently recognized as genuine pathogens. However, little is known about the resistance and virulence genes that explain their pathogenicity in hospitals in Cte d'Ivoire. The aim of this study was to contribute to the genotypic identification of resistance and virulence genes in CoNS isolated from blood cultures at the University Teaching Hospital (CHU) of Bouak, in order to improve patient management. Material and Methods: This was a descriptive study conducted from September to December 2023. The CoNS isolates studied came from the collection of strains isolated from blood cultures of febrile patients hospitalized or attending consultations at the CHU of Bouak. The strains were analyzed using conventional simplex PCR. Results: Of the 45 isolates analyzed, 46.7% carried both the aacA-aphD and tetK genes and 40% carried the mecA gene. With regard to virulence genes, only the LukS-PV gene was observed in S. epidermidis and S. haemolyticus isolates. Conclusion: The high prevalence of CoNS isolates carrying the mecA gene and the presence of virulence genes observed in this study give cause for concern in hospitals. It is important to develop comprehensive surveillance strategies against nosocomial and multi-resistant infections at the CHU of Bouak.

Low-Level Antibiotic Resistance among Staphylococcus aureus and Gram-Negative Pathogens from Infected Skin and Soft Tissues in Rural Kenya

Introduction: Bacterial skin and soft tissue infections (SSTIs) are a cause of frequent inpatient and outpatient care visits whose causative agents are associated with a high antimicrobial resistance burden. For insights on antimicrobial susceptibilities in a rural setting, we examined specimens from suspected SSTIs from two public health facilities in Kenya. We additionally assessed antibiotic use, appropriateness of empiric therapy and risk factors for SSTI. Methodology: Between 2021 and 2023, 265 patients at Kisii and Nyamira County Referral hospitals were enrolled. Wound swabs/aspirates were collected and processed following standard microbiological procedures. Identification and antimicrobial susceptibility were performed using the VITEK 2 Compact platform. Demographic, clinical, and microbiological data were analyzed with R Statistical software. Results: S. aureus was isolated in 16.2% (43/265) of patients with a methicillin resistance (MRSA) proportion of 14% (6/43). While 13/15 drugs elicited susceptibilities ranging from 84% - 100%, penicillin (16%) and trimethoprim-sulfamethoxazole [TMP-SXT] (23%) yielded the lowest susceptibilities. Escherichia coli (n = 33), Klebsiella pneumoniae (n = 8), Pseudomonas aeruginosa (n = 8), and Citrobacter species (n = 4) were the most commonly isolated gram-negative species. Gram-negative strains showed high susceptibilities to most of the tested drugs (71% - 100%) with the exception of ampicillin (18%), TMP-SXT (33%), and first and second generation cephalosporins. Conclusions: The low MRSA prevalence and generally high antibiotic susceptibilities for S. aureus and gram-negative bacteria present opportunities for antibiotic stewardship in the study setting. Diminished susceptibilities against penicillin/ampicillin and TMP-SXT accord with prevailing local data and add a layer of evidence for their cautious empiric use.

两体高维系统Negativity的研究

首先从理论上对Negativity的两种定义进行比较,然后推导出二参量两体高维量子系统Negativity的表达式.

两体高维量子系统的Negativity

量子纠缠及其度量在量子通讯中起着至关重要的作用.文章采用一种量子纠缠的计算方法—Negativity,推导得到了二参量两体高维量子系统Negativity的一般解析表达式.此方法的优点是计算方便,物理意义明确.

Detection of cognitive impairment in patients with obstructive sleep apnea hypopnea syndrome using mismatch negativity

In this experiment, 97 patients with obstructive sleep apnea hypopnea syndrome were divided into three groups （mild, moderate, severe） according to minimum oxygen saturation, and 35 healthy subjects were examined as controls. Cognitive function was determined using the mismatch negativity paradigm and the Montreal Cognitive Assessment. The results revealed that as the disease worsened, the mismatch negativity latency was gradually extended, and the amplitude gradually declined in patients with obstructive sleep apnea hypopnea syndrome. Importantly, mismatch negativity latency in severe patients with a persistent time of minimum oxygen saturation 〈 60 seconds was significantly shorter than that with a persistent time of minimum oxygen saturation 〉 60 seconds. Correlation analysis revealed a negative correlation between minimum oxygen saturation latency and Montreal Cognitive Assessment scores. These findings indicate that intermittent night-time hypoxemia affects mismatch negativity waveforms and Montrea Cognitive Assessment scores. As indicators for detecting the cognitive functional status of obstructive sleep apnea hypopnea syndrome patients, the sensitivity of mismatch negativity is 82.93%, the specificity is 73.33%, the accuracy rate is 81.52%, the positive predictive value is 85.00%, the negative predictive value is 70.21%, the positive likelihood ratio is 3, and the negative likelihood ratio is 0.23. These results indicate that mismatch negativity can be used as an effective tool for diagnosis of cognitive dysfunction in obstructive sleep apnea hypopnea syndrome patients.

Geometrical quantum discord and negativity of two separable and mixed qubits

We studied quantum correlation and quantum entanglement of a quantum system in which a coherent state light field interacts with two qubits that are initially prepared in a separable and mixed state.The influence of mean photon number of the coherent field and distribution probability of the atom on the geometrical quantum discord and the negativity are discussed.Our results show that the mean photon number of light field and distribution function of the atom can regulate and control the quantum correlation and quantum entanglement.

Superiority Effect in Detecting Phylogenetic Threats Under Unattentional Condition: A Visual Mismatch Negativity Study

Rapid and accurate perception of threat information is a critical ability and a prerequisite to survive natural selection for humans.To investigate whether threatening stimuli,especially phylogenetic and ontogenetic threats,are processed automatically,we analyzed the visual mismatch negativity(vMMN,an event-related potential component reflecting automatic processing)elicited by the threats with a cross-modal oddball paradigm,where participants were required to focus on the auditory stimuli and ignore the visual stimuli in each block.In this study,neutral(non-threatening)images served as standard stimuli(80%),and phylogenetic(10%)and ontogenetic(10%)threat stimuli served as deviant stimuli when testing a large sample(N=96)of healthy volunteers.Threat-related visual mismatch negativity(threat-vMMN)was obtained by subtracting the event-related potential(ERP)elicited by standard stimuli from that elicited by deviant stimuli.The results indicated that the vMMN can be elicited by threat information.More importantly,the phylogenetic threat information elicited larger threat-vMMN than ontogenetic threat information.These findings suggest that perception of threat information was automatic,providing an evidential basis for the attentional advantages of survival processing.That is,automatic perception of phylogenetic threats has a particular evolutionary origin.

Effect of escitalopram on cognitive function in depressionA mismatch negativity potentials study

We detected the event-related potential mismatch negativity （MMN） of 30 depression patients and compared to 30 age,gender,and education-matched healthy controls.Results showed that amplitudes of frequency and duration MMN were lower in depression patients compared with control patients,indicating abnormality in auditory processing （i.e.,cognitive impairment）.Following escitalopram treatment for 8 weeks,the amplitudes of frequency and duration MMN were significantly increased and Hamilton Rating Scale for Depression scores were significantly decreased in depression patients.These data suggest that escitalopram can improve cognitive function of patients with depression.Further,MMN may be a useful tool for evaluating cognitive function and treatment effects.

PP-Neg型“把/被”字句否定式产生的动因——语言接触还是自身演变?

提要汉语“把/被”字句否定式一直存在PP-Neg型语序。关于PP-Neg型“把/被”字句否定式产生的动因,语言学界一直存在“语言接触说”,即认为这种语法结构是受蒙古语等外族语的影响而生成的。本文在说明了“语言接触说”证据不足的同时,考虑到汉语“把/被”字句(否定式)在不同方言区中的复杂情况,论证了汉语PP-Neg型“把/被”字句否定式自身演变的可能性,主要涉及连动句语法化为介词句的过程中句法语义上的演变。具体来说,汉语连动句到介词句的演变过程中,介词句S+PP+VP中的PP与VP之间的关系要比连动句S+VP1+VP2中的VP1和VP2之间的关系更为紧密,不太允许否定词插入其中。消极性条件、信息价值条件、焦点性条件、话题性条件和语篇性条件等都是影响PP-Neg型“把/被”字句否定式产生的因素。并且现代汉语中,还有S+Neg+PP+VP_动≠S+PP+Neg+VP_动及S+Neg+PP+VP_静=S+PP+Neg+VP_静这样的等与不等的关系。

Monogamous nature of symmetric N-qubit states of the W class: Concurrence and negativity tangle

Using Majorana representation of symmetric N-qubit pure states, we have examined the monogamous nature of the family of states with two-distinct spinors, the W class of states. We have evaluated the N-concurrence tangle and showed that all the states in this family have vanishing concurrence tangle. The negativity tangle for the W class of states is shown to be non-zero, illustrating the fact that the concurrence tangle is always lesser than or equal to the negativity tangle in a pure N-qubit state.

On extending the concept of double negativity to acoustic waves

The realization of double negative electromagnetic wave media, sometimes called left-handed materials (LHMs) or metamaterials, have drawn considerable attention in the past few years. We will examine the possibility of extending the concept to acoustic waves. We will see that acoustic metamaterials require both the effective density and bulk modulus to be simultaneously negative in the sense of an effective medium. If we can find a double negative (negative density and bulk modulus) acoustic medium, it will be an acoustic analogue of Veselago’s medium in electromagnetism, and share many novel consequences such as negative refractive index and backward wave characteristics. We will give one example of such a medium.

Non-Negativity Preserving Numerical Algorithms for Problems in Mathematical Finance

We give a study result to analyze a rather different, semi-analytical numerical algorithms based on splitting-step methods with their applications to mathematical finance. As certain subsistent numerical schemes may fail due to producing negative values for financial variables which require non-negativity preserving. These algorithms which we are analyzing preserve not only the non-negativity, but also the character of boundaries (natural, reflecting, absorbing, etc.). The derivatives of the CIR process and the Heston model are being extensively studied. Beyond plain vanilla European options, we creatively apply our splitting-step methods to a path-dependent option valuation. We compare our algorithms to a class of numerical schemes based on Euler discretization which are prevalent currently. The comparisons are given with respect to both accuracy and computational time for the European call option under the CIR model whereas with respect to convergence rate for the path-dependent option under the CIR model and the European call option under the Heston model.

有界流场中潜艇水压场特性的预报方法和重要特征

潜艇水压场特性是信息化海战场的重要信息源。基于势流理论研究潜艇水压场特性的工程简化预报方法,构建基于兰金体线型的解析模型和基于回转体线型的数值模型,预估多种线型的潜艇水压场特性,并在验证性研究基础上,揭示潜艇线型、潜深等因素对潜艇水压场负压峰值、负压持续时间等重要特征的影响规律。研究结果表明:随着潜深增大,潜艇水压场负压区形状由单峰值的V形逐渐变为U形,甚至双峰值的W形,线型、潜深等因素对重要特征的影响逐渐增强;同一潜深下,随着航速增大,负压持续时间均呈现先突增、后缓降规律,且无论艇体胖瘦,其水压场重要特征在1倍艇长的横距外均已衰减,即该横距外水雷已难以捕捉其目标特性。

三阴型乳腺癌基于组织学、免疫组化分型的分析

目的探讨基于组织学、免疫组化的三阴型乳腺癌(triple-negative breast cancer,TNBC)分型标准,为完善TNBC分型治疗提供理论依据。方法根据组织学特点和免疫组化标志物AR、CD8、FOXC1的表达对TNBC进行分型,比较TNBC亚型的临床病理特征、预后差异。结果93例TNBC中腔面雄激素受体型23例(24.7%),免疫调节型24例(25.8%),基底样免疫抑制型39例(42.0%),间充质型7例(7.5%)。TNBC亚型的临床病理特征:pT分期(P=0.030)、组织学分级(P<0.001)、肿瘤间质淋巴细胞浸润模式(P<0.001)、PD-L1(P<0.001)、HER2低表达(P=0.024)差异均有统计学意义;各亚型间的无瘤生存率差异无统计学意义(P>0.05)。单因素分层生存分析:亚型间pT1分期的无瘤生存率差异有统计学意义(P=0.011),其余临床病理特征均为非独立预后因素。结论TNBC基于组织学、免疫组化分型的临床病理特征有差异,有望替代复杂基因表达谱分型,为TNBC分型和靶向治疗提供理论依据。

煤矿负碳高效充填开采理论与技术构想

矿山安全高效绿色低碳开采是永恒的主题,近零冲击地压、近零生态损害以及低碳、零碳、负碳的绿色开采将成为保障我国能源安全供应与绿色低碳发展的新要求。充填开采是实现这一要求的必然途径。然而,现有充填开采原理与技术装备体系难以突破高产高效、低碳开采的技术瓶颈,对充填材料及充填模式进行变革已势在必行。针对“千米深井资源开发和千万吨产能矿井充填(两个一千)”与“近零生态损害和近零冲击地压(两个近零)”的煤炭绿色低碳开采战略目标,提出了负碳高效充填开采技术全新构想,系统阐述了负碳高效充填开采的定义与科学内涵,提出和建立了由CO_(2)、矸石与快速胶结物混合而成的负碳高孔隙充填材料结构CGIF(CO_(2)Gangue Inorganic Framework)拓扑构型与强度理论以及CGIF混合物充填体固碳理论、快速黏凝胶结材料反应动力学理论、矿区充填开采防治冲击地压等负碳高效充填理论构想;提出了矸石快速高效胶结高孔隙充填材料制备技术、快速黏凝胶结材料绿色高效制备技术、CGIF充填体负碳高效充填开采技术、多面并采高效充填开采技术与工艺、全周期立体高效充填开采防冲技术等关键技术体系。在此基础上,明确了煤矿负碳高效充填开采“基础研究—技术攻关—工程示范”的“三阶段”发展规划,构建了煤矿负碳高效充填开采理论与技术体系构想;评估了煤矿负碳高效充填CO_(2)封存能力,可望实现煤炭负碳开采、低碳利用的煤炭开发利用全过程自身实现碳中和的新格局。

唐宋禅宗语录“VP-neg”式疑问句研究

唐宋时期流传下来的众多禅宗语录,是中古汉语研究方面的重要资料。其完整独特的自身体系,程度较高的口语化特点等,均对汉语史的共时及历时研究颇有助益。文章着眼于禅宗语录所见疑问句中的“VP-neg”式疑问句,试图在厘清该类问句基本结构形式的基础上,依据句末否定词“neg”的虚化程度对该类问句作出划分,并分析导致句末否定词虚化的具体原因。

消极情绪与团队内低地位员工创造力的倒U形关系研究

基于激活理论,以趋避动机框架构建消极情绪对团队内低地位员工创造力的倒U形影响模型,并通过120个团队578份有效问卷进行实证检验。研究结果表明,消极情绪与团队内低地位员工创造力之间存在倒U形曲线关系,地位稳定性、地位差异性在二者间起调节作用。其中,与高地位稳定性相比,低地位稳定性强化了低消极情绪对低地位员工创造力的正向影响,缓和了高消极情绪对低地位员工创造力的负向影响,且拐点位置更高;与高地位差异性相比,低地位差异性强化了低消极情绪对低地位员工创造力的正向影响,缓和了高消极情绪对低地位员工创造力的负向影响,且拐点位置更高。