线上线下双模式教育的应用——以机械电子工程专业必修课《热力学与传热学基础》为例

后疫情时代,为适应教学要求,逐渐衍生出线上线下双模式的教学方式。本文以机械电子工程专业的必修课《热力学与传热学基础》为例介绍了线上线下双模式教育在教学中的应用。首先介绍了《热力学与传热学基础》这门专业必修课的主要授课内容、学习目标和考核标准,其次以理想气体基本热力学过程的p-v图和T-s图为例,说明了双模式教育的应用为教学带来的好处。

免疫检查点T细胞激活抑制物免疫球蛋白可变区结构域、人内源性逆转录病毒-H长端重复相关蛋白2在子宫内膜癌中的表达及临床意义

目的分析免疫检查点T细胞激活抑制物免疫球蛋白可变区结构域(VISTA)、人内源性逆转录病毒-H长端重复相关蛋白2(HHLA2)在子宫内膜癌(EC)中的表达及临床意义。方法选取2017年9月至2019年10月唐山市妇幼保健院收治的120例的EC患者作为研究对象,收集其的EC组织和癌旁正常组织。检测EC组织和癌旁正常组织VISTA、HHLA2的表达;采用Spearman分析免疫检查点VISTA、HHLA2的相关性;Kaplan-Meier分析VISTA、HHLA2与预后的关系;Cox回归分析影响EC患者预后的危险因素。结果EC组织中VISTA、HHLA2阳性表达率显著高于正常癌旁组织(P<0.05)。Spearman相关性结果显示EC组织中VISTA与HHLA2表达呈正相关性(r=0.587,P<0.05)。EC组织中VISTA、HHLA2表达与临床病理特征有关(P<0.05)。Kaplan-Meier曲线结果显示VISTA阳性表达患者3年生存率低于阴性表达患者(χ^(2)=11.864,P<0.05),HHLA2阳性表达患者3年生存率低于阴性表达患者(χ^(2)=4.975,P<0.05)。Cox回归分析结果显示VISTA和HHLA2是影响EC患者预后的危险因素(P<0.05)。结论免疫检查点VISTA、HHLA2在EC中高表达,其是影响EC预后的危险因素,二者可能是有价值的预后标志物。

黄河流域近40年土地利用/覆被时空变化特征

[目的]研究土地利用/覆被时空变化特征对于黄河流域土地资源保护与合理开发具有重要意义,可为黄河流域生态保护与高质量发展战略实施提供重要参考。[方法]基于黄河流域1980-2021逐年土地利用/覆被数据,采用Mann-Kendall和滑动t检验、地学信息图谱、标准差椭圆和重心迁移模型等方法,探究近40年黄河流域土地利用/覆被变化特征。[结果](1)1980-2021年林地、灌丛、水域、建设用地显著增加,耕地、草地、湿地显著减少。(2)流域土地利用/覆被变化时段可划分为1980-1992年,1993-2001年,2002-2012年,2013-2021年,数量结构逐渐呈现快速变化特点,建设用地、湿地和水域变化敏感。土地利用结构均衡度逐渐增强,呈现的阶段性变化与实施的重大战略措施关联性高,并与划分的阶段较符合。(3)流域中上游以2012-2021年和间歇变化型、耕地和草地的相互转换为主,下游以2001-2012年和2012-2021年变化型、耕地转为建设用地和草地为主。流域内宁夏北部、内蒙古东部及部分沿黄河水系分布的地区变化频繁。(4)湿地、水域和建设用地的重心向西迁移,分别呈现向西南集中分布、向东分散、向西北集中分布态势。[结论]土地利用结构在政策导向下总体趋势变好,未来应重点关注湿地以及土地利用变化频繁的地区。

基于Python语言辅助化工热力学教学

化工热力学由于公式繁多,概念抽象,计算求解过程中通常要用到迭代试差而成为化工专业课程中教学难度较大的课程之一。随着计算机技术的迅速发展与应用,将其融入化工热力学教学已经成为培养新时代化工专业人才的必然趋势。结合近年来流行的Python语言及其优势,重点介绍其在p-V-T关系计算中的应用实例。通过Python语言编程解决化工热力学中的计算问题,可以有效解决化工热力学教学中的难点问题,很大程度提升课堂的教学质量和效率。

新型免疫检查点分子VISTA的研究进展

T细胞活化V结构域免疫球蛋白抑制因子(VISTA)是一种新型免疫检查点蛋白,具有与B7家族相似但独特的结构。VISTA在多种细胞中表达,包括髓系细胞和肿瘤细胞。在肿瘤中,VISTA可能通过调节髓系细胞和T细胞起到免疫抑制的作用。临床研究发现,VISTA在多种癌症中表达并与患者预后相关,可能是癌症治疗的潜在靶点,已有多种VISTA拮抗剂正在研发中。然而对VISTA分子机制和在免疫治疗中的确切作用仍需进一步研究。VISTA最新研究进展包括其与配体的相互作用以及其在肿瘤免疫治疗中的应用可能是免疫检查点抑制剂治疗实体肿瘤的新理论依据。

一种基于FPGA的宽范围绝缘测试系统设计与研究

针对工业领域对绝缘测试越来越高的需求,提出了一种基于FPGA的宽范围绝缘测试系统,同时针对大电阻测试情况下工频干扰对测试精度的影响,提出了采用双T型陷波器的方法。首先,分析绝缘测试平台的测试原理,并给出系统整体设计框架,该绝缘测试平台分为上位机和下位机两部分,两者通过以太网进行通信;其次,分析电路原理,根据原理和测试需求提出相应的硬件设计,陷波器采用双T结构,电阻测试原理采用二线法;再次,根据电路和测试原理设计软件和通信协议;最后,对电路仿真并进行实物测试。测试结果表明,绝缘测试系统测试范围能覆盖至10Ω~10 MΩ,双T型陷波器能够滤除大电阻测试情况下的工频干扰,滤波后的测试误差均在10%以内。

V频段宽带高效率功率合成放大器设计

介绍了一种基于混合波导魔T的V频段宽带高效率功率合成放大器。采用混合波导魔T结构和超宽带扇形开路薄膜电阻,设计了一款覆盖整个V频段的新型小型化高隔离二路功分器,实测在50~75 GHz频率范围内,平均电路损耗0.2 dB,输入回波小于-20 dB,隔离和输出回波小于-14 dB。基于该电路结构,采用V频段宽带GaN功放芯片,研制了一种3.5 W功率模块,以该功率模块为基本单元,并采用16路高效率功率分配/合成网络,研制出一款V频段宽带高效率功率合成放大器。实测在50~75 GHz的V频段全频段范围内,连续波饱和输出功率大于47 dBm,小信号增益大于46 dB,合成效率全频带内大于82%,在全频段实现了高效率合成和大功率输出。该电路结构紧凑,工作频带宽,合成效率高且便于散热,具有很好的工程应用价值。

Strong ground motion characteristics observed in the February 6,2023 M_(W)7.7 Türkiye earthquake

Türkiye is located in a seismically active region,where the Anatolian,African,and Arabian tectonic plates converge.High seismic hazards cause the region to be struck repeatedly by major earthquakes.On February 06,2023,a devastating M_(W)7.7 earthquake struck Türkiye at 01:17 am local time(01:17 UTC).In this regard,near and far-field ground motion data within the distance of 120 km are compiled and later characterized to identify the key ground motion intensity measures.Additionally,the vertical components of ground motions were examined to capture the complete three-dimensional nature of the seismic event.Moreover,the effect of Pulse-Like(PL)and Non-Pulse-Like(NPL)ground motion on a representative RC frame structure built as per the Türkiye code was investigated.The results indicate that PL behavior was observed in both horizontal and vertical components of ground motions and PL behavior were noted both near the epicenter and at higher distances from the epicenter.Moreover,the ratio of the peak vertical acceleration to peak horizontal acceleration at certain stations was found to be close to 1.Finally,the non-linear time history analysis of the representative reinforced concrete frame structure for ground motions recorded at stations located equidistant from the epicenter,indicated that PL ground motions led to more significant damage compared to NPL ground motions.

Frequency of the C677T Polymorphism of MTHFR, G20210A of Prothrombin and R506Q of Factor V Leiden in Type 2 Diabetics in Abidjan

In Africa, the prevalence of diabetes is escalating and remains a concern due to the numerous complications it causes. Vascular damage associated with diabetes leads to a prothrombotic state observed in diabetic individuals. Diabetes is a complex and multifactorial disease involving genetic components. With the aim of preventing complications and contributing to an efficient management of diabetes, we investigated genes likely to lead to a risk of thrombosis, in particular the C677T of MTHFR, G20210A of prothrombin, and R506Q of factor V Leiden in type 2 diabetics in Abidjan receiving ambulatory care. A descriptive cross-sectional study was carried out on consenting type 2 diabetic patients. Mutation detection was carried out using the PCR-RFLP method employing restriction enzymes. Hemostasis tests (fibrinogen, D-dimers, fibrin monomers, and von Willebrand factor) were performed using citrate tubes on the Stage? Star Max automated system. Plasminogen activator inhibitor was assayed by ELISA method, and biochemical parameters were determined using the COBAS C311. The study population consisted of 45 diabetic patients, 51.1% of whom presented vascular complications, mainly neuropathy. Disturbances in hemostasis parameters were observed, with 15.5% of patients showing an increase in fibrin monomers. Mutation analysis revealed an absence of factor V mutation (factor V Leiden) and of G20210A mutation of the prothrombin gene. However, 15.6% of subjects had a heterozygous C677T mutation of MTHFR, with 57% of them being anemic. The exploration of biological and genetic factors associated with thrombotic risk is of significant interest in the optimal management of African type 2 diabetics.

The Application of Modern Art Techniques in T.S. Eliot's The Waste Land

The literature in 20th century is mainly characterized by irrationalism presented in modernism. Under the background, this paper aims to explore how Eliot attempts to use modern art techniques in The Waste Land to reveal a real life to readers.

地质灾害监测预警管理平台建设研究

为实现地质灾害监测预警工作的科学化、信息化和精细化,提高地质灾害实时监测和动态预警预报能力,本文利用GIS、三维可视化、云计算等先进技术,基于云服务的T-C-V(terminal-cloud-virtual)框架,构建了地质灾害监测预警数据库,开发了地质灾害监测预警管理平台,实现了地质灾害的二三维一体化展示、基本信息管理、监测预警管理、应急指挥管理等功能,有效地提高了地质灾害的监测预警能力和管理水平。

Study on Land Use Structure Changes and Countermeasures

Land structure change not only relates to the coordinated development of regional social economic,but also determines the ecological environment security in certain region. Ili river valley was chose as the study area. The scientific and quantitative assessment of land use struc- ture and spatial pattern is significant to the sustainable development of the Ili river valley area. Based on the detailed investigation date of land use from 2002 to 2008,and social and economic statistics of the Ili river valley in eight counties and one city in 2008,the study area's land use structure changes were discussed in three aspects from the land use structure,the degree of land use,to the land use efficiency. The changes of land use structure were analyzed by the use of qualitative and quantitative methods. Factors that influence land use structure changes were analyzed. In the end,suggestions were put forward to optimize the management.

Analysis of T.S.Eliot's The Waste Land from the Discourse of Animality

T.S.Eliot's works have the didactic purpose of turning his readers away from what he considered the selfindulgence of the Romantics and toward the sterner splendors of Elizabethan drama and the 17th-century metaphysical poetry.Associated with the rise of literary modernism,he was established as the voice of a disillusioned generation by The Waste Land(1922).Especially,Eliot's description of the discourse of animality received highly artistic effect on the aspect of expressing his "impersonal theory".The discourse of animality in The Waste Land in plenty,thus,it made the author's expressive force more vivid.Furthermore,various imagos of different animals drew a mythical picture of modern waste land.So that,Eliot's The Waste Land also has the epic signification.

Analysis on Capitalization of Rural Land Ownership in China by Law and Economics

To find solutions for legal system for capitalization of rural land ownership in China,this paper studied and analyzed existing problems in rural land system and legal environment using legal theory and transaction cost theory. Results indicated that(i) the restriction of institutional condition upon property right and transaction is more essential,and key points include the relationship of entities of right formed jointly by the state,collective and farmers,accurate positioning of property right structure,and security for land appreciation income right and allocation mechanism;(ii) the land property right structure should select a legal structure with minimum transaction cost. It is concluded that entitling the ownership to a single entity is an economical method to eliminate current conflict of rural land right.

Dynamic Spatial Evolution of Market-oriented Supply Level of State-owned Land

The purpose of this study is to analyze the characteristics of the spatial distribution and change trend of the marketing level of stateowned land supply so as to provide policy recommendations. Method of spatial autocorrelation analysis is employed. The results indicate that the spatial layout of the land supply marketing level is generally dispersed,but it does assemble in some specific area. The correlation between the marketing level of state-owned land supply and the economic development is not statistically significant. But their relations fluctuate obviously. The overall marketing level of state-owned land supply is increasing and spatially concentrated. The expansion rate of marketing has decreased first and then increased and stabilized now. The high-value cluster center of marketing level of state-owned land supply exists all over the country; however the existence probability of the cluster is bigger in undeveloped areas. It is concluded that spatial autocorrelation analysis is a good method to quantitatively analyze the spatial variation of marketing level of state-owned land supply in China. To grasp the spatial and temporal variations of the marketing level of state-owned land supply is also good to enhance running of the state-owned land market.

PARAMETRIC MODELING OF COMPONENT LIBRARY FOR LANDING GEAR BASED ON CATIA/CAA

The design of landing gear is complicated due to the numerous considered elements.And the initial elements related to each other can also be influenced by different factors.Landing gear design often involves a very large variety of configurations,especially in the conceptual design phase.However,traditional method costs more time to complete the whole procedure for suitable configurations of landing gears.Therefore,the parametric modeling of component library for landing gear based on computer aided three-dimensional interface application/component application architecutre(CATIA/CAA)is proposed.According to the analysis of the characteristics of landing gear components,a method is presented to extract the primary parameters of landing gear components so that a systematic classification can be established.Further,the related theories and methods,including receiving geometrical parameters of the components and updating the parametrical model,displaying the component parts,are also illustrated.Finally,the development technology for component library is explained.The proposed modeling method can improve the efficiency of the whole design cycle for landing gear.

扭矩-竖向荷载联合作用下楔形端承摩擦桩承载性能分析

为了讨论楔形端承摩擦桩在扭矩T-竖向荷载V联合作用下的承载性能,考虑地基土剪切模量在地面处为非零值且随深度呈幂函数的分布形式,根据能量法和变分原理,分别得出基桩在桩顶竖向荷载和扭矩作用下的桩身竖向位移以及扭转角微分控制方程。采用MATLAB编制程序求解楔形端承摩擦桩的极限竖向荷载、极限扭矩,得到相应的承载力包络图。在T→V加载顺序下,通过改变初始扭矩值,分析了初始扭矩对楔形端承摩擦桩竖向承载特性的影响。对T-V联合受荷楔形端承摩擦桩进行了参数影响分析。研究结果表明:与等截面桩相比,纯压和纯扭作用下楔形端承摩擦桩的极限竖向荷载和极限扭矩有所提高。在T→V加载顺序下,楔形端承摩擦桩承载力包络线相比等截面桩有所外扩。随着桩径变化率的增大,楔形端承摩擦桩的承载力包络线也随之向外扩张。当初始扭矩与极限扭矩之比超过一定值时,楔形端承摩擦桩极限竖向荷载开始显著降低,需注意T-V组合效应。对于大直径长桩而言,需要重视初始扭矩对基桩竖向承载性能的影响。一味提高混凝土标号并不能极大的改善基桩在T→V受荷模式下的竖向承载性能。

T细胞活化免疫球蛋白抑制V型结构域在幼年特发性关节炎中作用的初步研究

目的分析T细胞活化免疫球蛋白抑制V型结构域(V-domain Ig suppressor of T cell activation,VISTA)在幼年特发性关节炎(juvenile idiopathic arthritis,JIA)患儿外周血的表达情况,探讨其在发病中的作用。方法前瞻性收集不同亚型JIA患儿(47例)及健康儿童(10例)的外周血,利用流式细胞术检测CD14+单核细胞、CD4+T淋巴细胞、CD8+T淋巴细胞上VISTA、干扰素-γ(interfern-γ,IFN-γ)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的表达情况。结果VISTA在JIA患儿中的表达水平比健康儿童低(P<0.05);不同亚型JIA患儿VISTA表达差异有统计学意义,以全身型表达水平最低(P<0.05);不同免疫细胞表达VISTA差异有统计学意义,单核细胞表面VISTA表达水平更高(P<0.05)。相关性分析发现CD4+T细胞上VISTA与IFN-γ(r=-0.436,P<0.05)、TNF-α(r=-0.382,P<0.05)表达呈负相关,CD8+T细胞上VISTA与IFN-γ(r=-0.348,P<0.05)、TNF-α(r=-0.487,P<0.05)表达呈负相关;CD14+单核细胞上VISTA与IFN-γ(r=-0.582,P<0.05)、TNF-α(r=-0.603,P<0.05)表达呈负相关。结论VISTA表达不足可能与JIA发病相关,增强VISTA的免疫调节作用可能是未来治疗JIA的途径之一。

面向“无人区创新”的科研项目立项和管理机制研究——基于国内外实践经验的分析

开展“无人区创新”是中国实现进入创新型国家前列的重要支撑,而传统的科研项目立项和管理机制无法有效支持国内相关主体探索科研无人区,亟需从“以项目为中心”转变为“以人为中心”。本文根据科研项目研究目标的具体程度将“无人区创新”进一步划分为自由探索类基础研究、颠覆性技术研究、关键核心技术研究等三大类别,运用案例分析法梳理国内外针对“无人区创新”的新型科研项目立项和管理机制,总结其共性特点。最后针对中国科研项目体制机制改革提出3条建议,即根据不同类型科研活动特点设计项目选拔和支持机制、建立更加灵活的项目监督和考评机制、重视对研究人员和项目管理人员自身能力的培养。

基于V9203的电能实时监控模块设计

针对传统制造业数字化升级改造过程中的能耗管理问题,基于STM32F030C8T6和V9203芯片,设计一款通用型电能实时监控模块,能够实时采集每一台高能耗设备电能参数,经模块初步处理后通过USART发送给主控设备(采集设备运行参数、智能控制等)。模块通过互感器采集设备的电信号,其硬件设计主要包括主控和计量芯片的外围电路、采样电路以及存储电路设计,软件开发主要包括主程序、计量程序、线温度采集程序、存储程序和串行通讯程序的开发。该模块结构精巧,可方便嵌入到主控设备中;工作稳定,经测试线性误差可控制在0.2%以内,完全能满足工业需求。