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关键词： 高中数学   函数教学   数学思想方法   抽象思维   数形结合   逻辑推理  

摘要： 函数在高中数学教学中占有举足轻重的地位,它是数学中既有理论又有实践的核心概念。高中数学教学的内容和方法也随着社会的发展,教育理念的更新而不断更新和完善。传统的数学教学往往注重理念的传授,注重课题的训练,但这样的教学模式容易使学生产生抵触数学的心理,从而影响对学习的效果。因此,针对高中数学函数教学中数学思想方法开展探究,以期能为相关教学人员提供参考。

关键词： 锅炉给水系统   设备故障   异常处理   运维策略  

摘要： 我国渤海稠油资源丰富,近年来海上稠油热采飞速发展,在技术创新、经济效益提升、环保安全等方面均取得了显著进展。蒸汽锅炉作为稠油热采过程中核心设备,其对于进水水质有极高要求,不达标水质极易导致锅炉结垢和盘管腐蚀等情况,降低锅炉使用寿命,甚至引发事故。本文基于现场生产过程中给水系统设备发生的故障及异常,给出处理措施,尽快恢复设备正常运行。同时本文针对给水系统不同设备括预处理单元、脱盐单元和脱氧单元,针对不同工况调整运维策略、进行流程优化,以确保锅炉给水系统能够满足高标准的水质要求。通过策略实施,可以显著减少锅炉给水系统的故障率,延长设备寿命,降低运维成本,从而为海上稠油热采的顺利进行提供坚实的技术支撑。

关键词： 大语言模型   检索增强生成   知识库   多模态  

摘要： 针对大语言模型在计算机类课程教学问答系统中面临的知识碎片化、动态更新迟滞及多模态资源整合不足等问题,该研究提出了一种基于检索增强生成(Retrieval-Augmented Generation,RAG)的课程知识库系统构建方法。该方法旨在通过动态意图识别和混合检索策略算法,实现计算机类课程知识点的高效组织与精准服务。动态意图识别通过构建上下文感知的语义推理网络,实时解析用户查询中隐含的实践操作需求与知识拓扑关联,有效缓解传统方法对复合型教学意图的误判问题。混合检索策略融合了语义推理与跨模态对齐技术,采用动态权重分配机制,实现文本、操作流程等多源数据的协同检索。实验结果表明,基于RAG的混合检索方法相比纯大语言模型,在准确率和召回率上均有明显提升。

关键词： 虚拟教研室   智能财务   会计基础  

摘要： 智能财务推动数字技术不断融入企业的经营与财务管理,提高了财务组织对公司战略决策和业务经营的支持。在此背景下,本文以会计基础类课程虚拟教研室的建设为例,探究虚拟教研作为一种新的组织形式,突破了时空和专业的限制,采取扁平化管理模式;“线上+线下”结合的教研模式,实现资源共享。虚拟教研室顺应教育理念和教学方式的发展,树立教学团队共同的价值观取向,培养良好的责任意识和协作精神,以问题为导向通过共建、共享、共同管理教学资源,有利于构建多元化的教师团队,实现教学资源共建共享和优化教学改革,提升教学质量。

关键词： 含参函数   高中数学   解题方法  

摘要： 单调性是函数的重要性质之一,对研究函数极值、最值具有重要的作用.函数单调性问题通常会给出一个确定区间,利用函数的不确定性进行设问,而带来不确定性的因素就是参数.本文以一道含参函数单调性问题为例,利用数学思想方法从不同角度巧解这道问题,以供读者参考.

关键词： Colchicine (COLC)   Platelet reactivity   VerifyNow (TM)   Aspirin reaction units (ARU)   P2Y(12) reaction units (PRU)  

摘要： IntroductionThis prospective, single-arm pharmacodynamic study assessed the effect of colchicine (COLC) [Strides Pharma UK Ltd, Watford, Hertfordshire, England] 0.5 mg administered orally once daily for 14 days on platelet reactivity with respect to aspirin reaction units (ARUs) and P2Y12 reaction units (PRUs). MethodsTwenty-two patients with stable coronary artery disease (CAD) on dual antiplatelet therapy (DAPT) with daily maintenance aspirin and clopidogrel were recruited. Baseline platelet function was evaluated with the VerifyNow (TM) ARU and PRU assays (Werfen, Bedford, MA, USA) and assessed post-completion of COLC 0.5 mg once daily for 14 days. ResultsIn this study, the median ARU baseline score was 463, and post-COLC it was 436, which was not statistically significant (p = 0.485). The mean difference in scores was -18.31 (95% confidence interval [CI] -74.34 to 37.71, p = 0.504). At baseline, 27.3% of the patients had "aspirin resistance" or were non-responders, compared to 13.6% post-COLC (p = 0.423). The median baseline PRU score was 210, and post-COLC it was 199, which was also not statistically significant (p = 0.581). The mean difference in scores was -7.31 (95% CI -31.1 to 16.5, p = 0.530). At baseline, 50% of the patients had "clopidogrel resistance" or were non-responders, compared to 45.5% post-COLC (p = 0.999). Two patients experienced mild gastrointestinal upset during the trial without interruption of COLC, and there were no serious adverse events or treatment-emergent adverse events. ConclusionsThere were no significant differences in ARUs and PRUs post-COLC trial in patients with stable CAD. This pilot pharmacodynamic study could be clinically informative in patients on DAPT. Further studies are required to confirm these exploratory findings. Trial *** identifier, NCT06567678, prospectively registered 20/8/2024.

关键词： nature products   polyquinane   tetraquinane   tetraquinane-type terpenes   total synthesis  

摘要： Polyquinane is a class of natural products composed of multiple fused five-membered carbocycles. Their unique structures and potential biological activities have attracted the interest of the synthetic community. Among them, the structures with four fused five-membered carbocycles (known as tetraquinane), and those with three five-membered carbocycles fused by one six-membered carbocycle that referred to as tetraquinane-type terpenes, are particularly distinctive. This review provides a chronological overview of the total synthesis efforts of tetraquinane and tetraquinane-type terpenes.

关键词： Space weather   Ozone   Temperature   Wind effects   Aerosols/ particulates  

摘要： On 8 April 2024, a total solar eclipse overpassed Texas in the southern portion of the United States. To monitor the impact of the total solar eclipse, a group of students from Texas A&M University-Corpus Christi developed two weather balloon payloads and six ground-based instrument packages using microcontrollers and low-cost sensors. These instrument packages were deployed to six different sites spanning nearly 600 km along the total eclipse path from the Mexican border to North Texas. During the total eclipse, air temperature decreased, and relative humidity increased consistently at all six stations due to the reduction in sensible heating. The dewpoint temperatures decreased at the near surface at all sites likely due to the reduction in evaporation. Five of the six ground stations observed a slight dampening of the wind speed, and two of the six stations recorded significant counterclockwise wind shifts. No consistent pattern was observed in the surface vertical electric field at the six ground stations. The two balloon payloads captured the damping of the visible and ultraviolet (UV) radiation in the upper troposphere and lower stratosphere throughout the event. Though a slight decrease in both temperature and ozone in the lower stratosphere was observed after the totality, it is difficult to determine the impact from the eclipse on the ozone mixing ratio and dynamics in the lower stratosphere from only a few vertical profiles. For the students who participated, this field campaign has provided invaluable experiences in instrumentation, fieldwork, and data collection.

摘要： The first James Webb Space Telescope/MIRI photometric observations of TRAPPIST-1 b allowed for the detection of the thermal emission of the planet at 15 mu m, suggesting that the planet could be a bare rock with a zero albedo and no redistribution of heat. These observations at 15 mu m were acquired as part of Guaranteed Time Observer time that included a twin programme at 12.8 mu m to obtain measurements inside and outside the CO2 absorption band. Here we present five new occultations of TRAPPIST-1 b observed with MIRI in an additional photometric band at 12.8 mu m. We perform a global fit of the ten eclipses and derive a planet-to-star flux ratio and 1 sigma error of 452 +/- 86 ppm and 775 +/- 90 ppm at 12.8 mu m and 15 mu m, respectively. We find that two main scenarios emerge. An airless planet model with an unweathered (fresh) ultramafic surface, that could be indicative of relatively recent geological processes, fits the data well. Alternatively, a thick, pure-CO2 atmosphere with photochemical hazes that create a temperature inversion and result in the CO2 feature being seen in emission also works, although with some caveats. Our results highlight the challenges in accurately determining a planet's atmospheric or surface nature solely from broadband filter measurements of its emission, but also point towards two very interesting scenarios that will be further investigated with the forthcoming phase curve of TRAPPIST-1 b.

关键词： Normal tissue objectives   Stereotactic radiosurgery   HyperArc   Non-coplanar RapidArc   Eclipse TPS  

摘要： Purpose To optimize NTO parameters in non-coplanar RapidArc (RA) stereotactic radiosurgery (SRS) for multiple brain metastases and compare them with HyperArc (HA) plans. Materials and methods Thirty patients with multiple brain metastases, receiving 21 Gy prescriptions, were retrospectively enrolled, with lesions ranging from two to eight and volumes between 0.27 and 10.56 cm(3). Non-coplanar RapidArc plans utilized manual NTO (RA-mNTO) with varying dose fall-off values (0.1 mm(-1), 0.5 mm(-1), 1.0 mm(-1), 2.0 mm(-1), 3.0 mm(-1)) and end doses (50%, 25% & 10%). Additionally, two HyperArc plans were generated: HA-ALDO used Automatic Lower Dose Objectives with SRS NTO, while HA-mNTO used the same beam geometry with manual NTO parameters optimized from RA-mNTO plans. TrueBeam with High-Definition Multi-leaf Collimators (HDMLC), 6 MV Flattening Filter Free (FFF) Beam at a maximum dose rate of 1400 MU/min, and Eclipse version 16.1 TPS were used. Plans were assessed for Paddick Conformity Index (CI), Gradient Index (GI), Homogeneity Index (HI), normal brain doses (V-18Gy, V-15Gy, and V-12Gy), Monitor Units (MUs), and delivery accuracy using aS1200 Digital Megavolt Imager (DMI) with 2%/2 mm gamma criteria. Statistical analysis utilized integrated scoring and the Wilcoxon signed-rank test. Results RA-mNTO plans with 0.5 mm(-)(1) dose fall-off and 10% end-dose showed superior dosimetric outcomes: CI (0.85 +/- 0.08), GI (3.63 +/- 0.87), and HI (0.36 +/- 0.06) compared to HA-ALDO (CI 0.84 +/- 0.09, GI: 3.97 +/- 0.85, HI: 0.39 +/- 0.07) and HA-mNTO (CI 0.83 +/- 0.08, GI: 3.60 +/- 0.93, HI: 0.40 +/- 0.06). MUs were comparable: RA-mNTO (9679 +/- 1882), HA-ALDO (9509 +/- 1315), and higher for HA-mNTO (10,457 +/- 1980). RA-mNTO plans exhibited significantly lower normal brain doses (V-18Gy: 1.78 +/- 1.23, V-15Gy: 3.54 +/- 2.37, V-12Gy: 6.21 +/- 4.09) compared to HA-ALDO (V-18Gy: 2.02 +/- 1.34, V-15Gy: 4.09 +/- 2.66, V-12Gy: 7.15 +/- 4.56) and HA-mNTO (V-18Gy: 1.85 +/- 1.20, V-15Gy: