Study on Surface Plotting Methods in Parts Plotting

According to the factors that confirm the shape of surface, it is classified into two categories： arc surface and curve surface The method to confirm the category of surfaces and the plotting methods are discussed in this paper, which provide guidance for parts plotting.

Computer plotting of multisystem p-T, T-X, p-X phase diagrams

As a continuation to the work reported by Yin in 1992, a new procedure is presented for computer plotting of the stable equilibrium phase diagram of an n-component system composed of (n + k) stoichiometric phases (or fluid species) where 2≤k≤4. The main points of the procedure are: (i) using the technique of sequential-absence of phases (SAP) to determine the possible invariant and univariant assemblages in a given multisystem; (ii) using the matrix inverse technique to generate and balance the univariant reactions from the corresponding univariant assemblages; (iii) comparing the phase assemblage at each invariant point with that of each univariant reaction to select the univariant curves about the corresponding invariant point; (iv) locating the invariant points with the technique of finding common equilibrium relation (CER); (v) using the sign function matrix (SFM) technique to discriminate between the stable portion of a univariant curve and its metastable extension about the corresponding invariant point; and (vi) using a new SFM method to identify the stabilities of the invariant points. The source program for microcomputers, PHD, is written in TURBO-PASCAL.

Determinants of generalized anxiety and construction of a predictive model in patients with chronic obstructive pulmonary disease

BACKGROUND Patients with chronic obstructive pulmonary disease(COPD)frequently experience exacerbations requiring multiple hospitalizations over prolonged disease courses,which predispose them to generalized anxiety disorder(GAD).This comorbidity exacerbates breathing difficulties,activity limitations,and social isolation.While previous studies predominantly employed the GAD 7-item scale for screening,this approach is somewhat subjective.The current literature on predictive models for GAD risk in patients with COPD is limited.AIM To construct and validate a GAD risk prediction model to aid healthcare professionals in preventing the onset of GAD.METHODS This retrospective analysis encompassed patients with COPD treated at our institution from July 2021 to February 2024.The patients were categorized into a modeling(MO)group and a validation(VA)group in a 7:3 ratio on the basis of the occurrence of GAD.Univariate and multivariate logistic regression analyses were utilized to construct the risk prediction model,which was visualized using forest plots.The model’s performance was evaluated using Hosmer-Lemeshow(H-L)goodness-of-fit test and receiver operating characteristic(ROC)curve analysis.RESULTS A total of 271 subjects were included,with 190 in the MO group and 81 in the VA group.GAD was identified in 67 patients with COPD,resulting in a prevalence rate of 24.72%(67/271),with 49 cases(18.08%)in the MO group and 18 cases(22.22%)in the VA group.Significant differences were observed between patients with and without GAD in terms of educational level,average household income,smoking history,smoking index,number of exacerbations in the past year,cardiovascular comorbidities,disease knowledge,and personality traits(P<0.05).Multivariate logistic regression analysis revealed that lower education levels,household income<3000 China yuan,smoking history,smoking index≥400 cigarettes/year,≥two exacerbations in the past year,cardiovascular comorbidities,complete lack of disease information,and introverted personality were significant risk factors for GAD in the MO group(P<0.05).ROC analysis indicated that the area under the curve for predicting GAD in the MO and VA groups was 0.978 and 0.960.The H-L test yieldedχ^(2) values of 6.511 and 5.179,with P=0.275 and 0.274.Calibration curves demonstrated good agreement between predicted and actual GAD occurrence risks.CONCLUSION The developed predictive model includes eight independent risk factors:Educational level,household income,smoking history,smoking index,number of exacerbations in the past year,presence of cardiovascular comorbidities,level of disease knowledge,and personality traits.This model effectively predicts the onset of GAD in patients with COPD,enabling early identification of high-risk individuals and providing a basis for early preventive interventions by nursing staff.

Parameter Identification of Structural Nonlinearity by Using Response Surface Plotting Technique

With rigorous dynamic performance of mechanical products,it is important to identify dynamic parameters exactly.In this paper,a response surface plotting method is proposed and it can be applied to identify the dynamic parameters of some nonlinear systems.The method is based on the principle of harmonic balance method(HBM).The nonlinear vibration system behaves linearly under the steady-state response amplitude,which presents the equivalent stiffness and damping coefficient.The response surface plot is over two-dimensional space,which utilizes excitation as the vertical axis and the frequency as the horizontal axis.It can be applied to observe the output vibration response data.The modal parameters are identified by the response surface plot as linearity for different excitation levels,and they are converted into equivalent stiffness and damping coefficient for each resonant response.Finally,the HBM with first-order expansion is utilized for identification of stiffness and damping coefficient of nonlinear systems.The classical nonlinear systems are applied in the numerical simulation as the example,which is used to verify its effectiveness and accuracy.An application of this technique for nonlinearity identification by experimental setup is also illustrated.

Study on Chaotic Characteristics of the Friction Process between High Hardness Alloy Steel and Cemented Carbide under C60 Nanoparticle Fluid Lubrication

Friction and wear phenomenon is a complex nonlinear system,and it is also a significant problem in the process of metal cutting.In order to systematically analyze the friction and wear process of tool material-workpiece material friction pair in the cutting process of high hardness alloy steel under different lubrication conditions,the chaotic characteristics of friction process between high hardness alloy steel and cemented carbide under the lubrication C60 nano-particles fluid are studied based on the chaos theory.Firstly,the friction and wear experiments of the friction pair between high hardness alloy steel and cemented carbide tool are carried out based on the ring-block friction and wear tester,and the results of friction force signal in time domain and wear width are obtained.Then,the friction signals in time domain are processed and transformed based on phase space reconstruction and recurrence plot theory,and the recurrence plots of different experimental groups under different lubrication conditions are generated.The evolution law of recurrence plot is further observed and studied,and the recursive quantitative index is analyzed.Finally,the cutting experiments of tool wear are carried out.The results show that the proposed method can intuitively and accurately reveal the wear evolution process and the wear feature identification law of the tool material-high hardness alloy steel pair under different lubrication conditions.Meanwhile,it is found that when the concentration of C60 nanoparticles is 200∼300 ppm,the stability of the friction pair system is best.The proposed method can provide a strategy for wear prediction in cutting process,and provide a theoretical basis and technical support for antifriction lubrication methods in practical cutting applications.

Investigation of multinucleon transfer processes in the Langevin equation model

Multinucleon transfer in low-energy heavy-ion collisions is increasingly considered a promising approach for generating exotic nuclei.Understanding the complex mechanisms involved in multinucleon transfer processes presents significant challenges for the theoretical investigation of nuclear reactions.A Langevin equation model was developed and employed to investigate multinucleon transfer processes.The^(40)Ar+^(232)Th reaction was simulated,and the calculated Wilczyński plot was used to verify the model.Additionally,to study the dynamics of multinucleon transfer reactions,the^(136)Xe+^(238)U and^(136)Xe+^(209)Bi reactions were simulated,and the corresponding TKE-mass and angular distributions were computed to analyze the energy dissipation and scattering angles.This investigation enhances our understanding of the dynamics involved in multinucleon transfer processes.

Predicting Rock Burst in Underground Engineering Leveraging a Novel Metaheuristic-Based LightGBM Model

Rock bursts represent a formidable challenge in underground engineering,posing substantial risks to both infrastructure and human safety.These sudden and violent failures of rock masses are characterized by the rapid release of accumulated stress within the rock,leading to severe seismic events and structural damage.Therefore,the development of reliable prediction models for rock bursts is paramount to mitigating these hazards.This study aims to propose a tree-based model—a Light Gradient Boosting Machine(LightGBM)—to predict the intensity of rock bursts in underground engineering.322 actual rock burst cases are collected to constitute an exhaustive rock burst dataset,which serves to train the LightGBMmodel.Two population-basedmetaheuristic algorithms are used to optimize the hyperparameters of the LightGBM model.Finally,the sensitivity analysis is used to identify the predominant factors that may incur the occurrence of rock bursts.The results show that the population-based metaheuristic algorithms have a good ability to search out the optimal hyperparameters of the LightGBM model.The developed LightGBM model yields promising performance in predicting the intensity of rock bursts,with which accuracy on training and testing sets are 0.972 and 0.944,respectively.The sensitivity analysis discloses that the risk of occurring rock burst is significantly sensitive to three factors:uniaxial compressive strength(σc),stress concentration factor(SCF),and elastic strain energy index(Wet).Moreover,this study clarifies the particular impact of these three factors on the intensity of rock bursts through the partial dependence plot.

乙酰泽泻醇降低胆固醇分子机制研究

目的从分子水平探讨乙酰泽泻醇降低胆固醇(TC)的作用机理。方法利用试剂盒法测定了调脂中药泽泻主要有效成分23-乙酰泽泻醇B和24-乙酰泽泻醇A对高脂小鼠TC的影响,利用试剂盒法、Western blotting技术结合分子模拟技术研究两者对TC代谢关键酶3-羟基-3-甲基戊二酸单酰辅酶A(HMG-Co A)还原酶作用的分子机理。结果乙酰泽泻醇能显著降低高脂小鼠TC(P<0.01,P<0.05),23-乙酰泽泻醇B作用强度高于24-乙酰泽泻醇A(P<0.05),同时在体内、体外均可剂量依赖性下调HMG-Co A还原酶活性(P<0.01),且23-乙酰泽泻醇B对该酶作用强于24-乙酰泽泻醇A(P<0.05)。两者均未显著下调HMG-Co A还原酶的蛋白表达(P>0.05)。两者与HMG-Co A还原酶结合的关键氨基酸残基可能为Lys691、Asp767、Asn658。结论乙酰泽泻醇降低TC的机制可能是其原型药物通过抑制HMG-Co A还原酶活性来达到,且可能是通过直接竞争性与HMG-Co A还原酶结合抑制其作用,乙酰泽泻醇的舵手基团为其侧链,侧链与母环折叠结合弱,打开结合强。

Changes in Violaxanthin Deepoxidase Activity and Unsaturation of Thylakoid Membrane Lipids in Indica and Japonica Rice Under Chilling Condition and Strong Light

To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under chilling condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of chilling and strong light treatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activity of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin M decreased, the ratio of (A+Z)/ (A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chilling and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D, protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chilling and strong light.

A Convolutional Deep Neural Network Approach for miRNA Clustering

The regulatory role of the Micro-RNAs (miRNAs) in the messenger RNAs (mRNAs) gene expression is well understood by the biologists since some decades, even though the delving into specific aspects is in progress. Clustering is a cornerstone in bioinformatics research, offering a potent computational tool for analyzing diverse types of data encountered in genomics and related fields. MiRNA clustering plays a pivotal role in deciphering the intricate regulatory roles of miRNAs in biological systems. It uncovers novel biomarkers for disease diagnosis and prognosis and advances our understanding of gene regulatory networks and pathways implicated in health and disease, as well as drug discovery. Namely, we have implemented clustering procedure to find interrelations among miRNAs within clusters, and their relations to diseases. Deep clustering (DC) algorithms signify a departure from traditional clustering methods towards more sophisticated techniques, that can uncover intricate patterns and relationships within gene expression data. Deep learning (DL) models have shown remarkable success in various domains, and their application in genomics, especially for tasks like clustering, holding immense promise. The deep convolutional clustering procedure used is different from other traditional methods, demonstrating unbiased clustering results. In the paper, we implement the procedure on a Multiple Myeloma miRNA dataset publicly available on GEO platform, as a template of a cancer instance analysis, and hazard some biological issues.

华北低丘山区栓皮栎生态系统氧同位素日变化及蒸散定量区分

利用稳定同位素技术对华北低丘山区栓皮栎生态系统氧同位素日变化及蒸散定量区分进行研究,为华北低丘山区森林生态系统水汽交换研究提供基础。试验采用离轴积分腔输出光谱技术(OA-ICOS)连续测定生态系统不同高度水汽浓度和δ18O值,同时采用真空提取和液态水同位素分析仪测定枝条和土壤的δ18O值。结果显示,4个晴天中大气水汽浓度日变化复杂,变化趋势差异大,而δ18O日变化均成高-低-高的"V"型变化,最小值出现在12:00—18:00。Keeling方程在10:00—12:00的相关系数R2均大于0.71,方程达到极显著水平,表明此时段蒸腾速率较高,满足植物蒸腾的同位素稳定态假设。利用Keeling方程估算的栓皮栎生态系统δET值有相似的低-高-低日变化,与大气的δv值变化趋势相反。同位素分割结果显示栓皮栎生态系统中蒸腾占蒸散比例日变化呈现低-高-低的趋势,10:00—14:00蒸腾占蒸散比例达到90%以上,尽管6:00—10:00和14:00—18:00的蒸腾占蒸散比例下降,但平均值仍高达69.38%,表明华北低丘山区栓皮栎生态系统的蒸散主要来源于植物蒸腾。

利用原位连续测定水汽δ^(18)O值和Keeling Plot方法区分麦田蒸散组分

利用稳定同位素技术和Keeling Plot方法可以有效分割地表蒸散量,进而加深对陆地生态系统水循环的理解。该研究通过原位连续测定麦田的水汽同位素数据,评价Keeling Plot方法在分割地表蒸散中的应用,并揭示华北冬小麦(Triticum aes-tivum)蒸腾在总蒸散中的比例。实验于2008年3-5月在中国科学院栾城农业生态站进行,利用国际上先进的H218O、HD16O激光痕量气体分析仪(TDLAS)为基础构建的大气水汽18O/16O和D/H同位素比原位连续观测系统,同时利用涡度相关技术、真空抽提技术、同位素质谱仪技术,获取了必要的数据。研究分析了一天中不同时间段的连续的大气水汽δ18O与水汽浓度倒数拟合Keeling Plot曲线的差异和可能的原因。结果显示,中午时段的拟合结果较好,这也暗示中午时段蒸腾速率高时最可能满足植物蒸腾的同位素稳定态假设。进一步的分析发现植物蒸腾的同位素稳定态并不总是成立,尤其是水分胁迫下进入成熟期的小麦,其蒸腾水汽同位素一般处于非稳定态。利用同位素分割结果显示,生长盛期麦田94%-99%的蒸散来源于植物蒸腾。

Community Structure and Diversity Distributions of Small Mammals in Different Sample Plots in the Eastern Part of Wuling Mountains

Five years＇ （2000-2004） continuous study has been carried out on small mammals such as rodents in seven different sample plots, at three different altitudes and in six different ecological environment types in the eastern part of the Wuling Mountains, south bank of the Three Gorges of Yangtze River in Hubei. A total of 29 297 rat clamps/times were placed and 2271 small mammals such as rodents were captured, and 26 small mammals were captured by other means. All the small mammals captured belonged to 8 families 19 genera and 24 species, of which rodentia accounted for 70.83% and insectivora 29.17%. Through analysis of the data, the results showed that： 1 ） although the species richness had a trend of increasing along different sample plots as altitude increased from south to north, quite a few species showed a wide habitat range in a vertical distribution （ 15 species were dispersed over three zones and two species over two zones） , indicating a strong adaptability of small mammals such as rOdents at lower altitudes in most areas and comparatively less vertical span of entire mountains; 2） whether in seven different sample plots or six different ecological types, Apodemus agrarius and Rattus norvegicus were dominant species below 1200m, and Anourosorex squamipes, Niviventer confucianus and Apodemus draco were dominant above altitudes of 1300m, however, in quantity they were short of identical regularity, meaning they did not increase as the altitude did, or decrease as the ecological areas changed; 3）the density in winter was obviously greater than that in spring, and the distribution showed an increasing trend along with altitude, but the density in different sample plots was short of identical regularity, showing changes in different seasons and altitude grades had an important impact on small mammals such as rodents; 4） in species diversity and evenness index, there were obvious changes between the seven different sample plots, probably caused by frequent human interference in this area. Comparatively speaking, there was less human interference at high altitudes where vegetation was rich and had a high diversity and evenness index, and the boundary effect and community stability were obvious. Most ecological types have been seriously interfered with due to excessive assart at low altitudes with singular vegetation and low diversity and evenness index and poor community stability, showing an ecosystem with poor anti-reversion. If human interference can be reduced in those communities at high altitudes with low diversity and evenness index, the biological diversity in the communities will gradually recover to similar levels of other ecological areas.

Electrochemical corrosion behavior of arc sprayed Al-Zn-Si-RE coatings on mild steel in 3.5% NaCl solution

Al-Zn-Si-RE coating with high Al content was deposited on mild steel by arc spraying. The electrochemical behavior of Al-Zn-Si-RE coating in 3.5%NaCl solution was systematically studied by potentiodynamic polarization, corrosion potential (φcor ) and electrochemical impedance spectroscopy techniques (EIS). The impedance data were fitted to appropriate equivalent circuits to explain the different electrochemical processes occurring at the electrode-electrolyte interface. The results indicate that Al-Zn-Si-RE coating reveals the similar polarization behavior as Zn-15Al coating. The coating has no passive region in the anodic polarization, but far lower corrosion current and much higher corrosion potential. Al-Zn-Si-RE coating provides effective sacrificial protection for steel substrate and the sacrificial anodic protection plays dominant role during the immersion process. In addition, theφcor evolution and EIS plots indicate that the corrosion process can be divided into five stages: pitting-dissolution-redeposition, activation corrosion, cathodic protection, physical barriers and the coating failure.

毛细管多维气相色谱法分析炼厂气

用ＨＰ６８９０）气相色谱仪，使用多孔层空心毛细管柱（ＰＬＯＴ），选用ＨＰ－ＰＬＯＴ／Ｐｏｒａｐａｃｋ Ｑ色谱柱测定ＣＯ２； ＨＰ－ＰＬＯＴ ５Ａ分子筛柱测定Ｏ２， Ｎ２， ＣＨ４； ＨＰ－ＰＬＯＴ／Ａｌ２Ｏ３柱测定有机烃类。采用３阀４柱色谱运行系统，用ＦＩＤ及ＴＣＤ分别检测烃类及无机气体组分。用色谱工作站控制气动切换阀切换气样走向及两种检测器数据的转换校正和归一化定量计算，用已知物对照法定性，测定了炼厂气中２０余种组分。其准确度和再现性良好。

高效PLOT碳分子筛石英毛细管柱的研制及其性能研究

选用碳分子筛作吸附剂 ,用液相沉淀法涂渍出高效PLOT碳分子筛石英毛细管色谱柱 ,并对其色谱性能进行了考察。结果表明 ,该色谱柱具有良好的分离特性 ,1次进样可分离出O2、N2、CO、CO2、CH4、C2H2、C2H4、C2H6 等组分;适用于炼厂气、烟道气、水煤气及变压器油溶解气等的分析。

小兴安岭红松阔叶混交林土壤动物群落研究

Soil animal communities of Pinus koraiensis broad_leaved mixed forest were studied.The purpose was to discuss the dynamic characteristic of soil animals and relationship with environmental factors.The ecosystem geography distribution law of soil animals, soil animals’role and function in ecological system were revealed.In June,August,October each year,three plots were selected. In each plot, four layers were sampled(litter layer,0～10 cm,10～20 cm & 20～30 cm),adding up to 72 soil sample.The area for large_sized soil animals was 50 cm×50 cm,and the area for middle_small_sized soil animals was 10 cm × 10 cm.Separated soil animals through adopting hand_picking method and Tullgren method respectively.Sampled the soil animals in two continuing years.Shannon_Wiener index was adopted to analyze the diversity of soil animals.Monad liner regression was used to search the relationship between soil animals and environmental factors.The dominant groups were Oribatida, Isotomidae.There were relatively great changes in groups and individual numbers of dominant groups and rare groups when the reason changed.The individual numbers of dominant groups and the groups of rare groups changed.The number of individual and group was the most in August.Obviously it correlated with climatic factors in middle temperate zone.The evenness was low and dominance was high. The diversity index was not most.Among the annual fluctuating there was a increasing trend. The evenness was low and dominance was high.The diversity index was low.It conformed with the law of reason change.The correlation between soil animals and atmospheric temperature,rainfall,ground temperature and sunlight showed the correlation with rainfall and soil temperature was the most significant.

Mathematica在函数作图中的应用

通过介绍Mathematica在函数作图中的应用,为数学教学、数学实验等提供了一个新的适用工具,在多媒体教 学中能直观,形象的描出各种函数的图形,使教学更加深动、形象.

PLOT柱分离GC-MS法测定酿酒发酵产品中的微量丁二酮和苯乙烯

用PLOT柱分离，气相色谱-质谱联用对酿酒发酵产品中微量丁二酮和苯乙烯含量进行测定。GC条件为：毛细管色谱柱，HP-PLOTU，30m×0．32mm×10μm；载气（He）流速，1．5mL/min；进样口温度，200℃；柱温，180℃；分流比。50：1；进样量0．5μL。MS条件：电子轰击电离源能量。70eV；选择离子扫描方式；溶剂延迟。3．0min。结果表明：丁二酬和乙醇达到基线分离。在25min内一次完成对酿酒发酵产品中微量丁二酮和苯乙烯含量的分离测定。方法的检出限为0．01mg／L，相对标准偏差小于2．0％，平均加标回收率为95％～104％。