model

摘要： A two-dimensional mathematical model is used to simulate the influence of water flow on the piers of a bridge for different incidence angles.In particular,a finite volume method is used to discretize the Navier-Stokes control equations and calculate the circumferential pressure coefficient distribution on the bridge piers’surface.The results show that the deflection of the flow is non-monotonic.It first increases and then decreases with an increase in the skew angle.

摘要： The rice planting area in Northeast China has reached 5.6 million ha,but the utilization rate of comprehensive culture area in paddy field is only 2%.It is mainly dominated by fish culture in paddy field and crab culture in paddy field,which has broad development prospects.In recent years,the comprehensive planting and culture area of paddy fields in Liaoning Province has developed rapidly with a total of 80000 ha.In accordance with the local environmental conditions,Heilongjiang and Jilin regions have introduced a new model and technology of comprehensive planting and culture in paddy fields,and developed a comprehensive planting and breeding model of paddy fields with characteristics.At present,the comprehensive planting and culture in paddy fields in Northeast China is still in the stage of rapid development,which needs to be further developed towards specialization,scale,industrialization,high quality and brand.

摘要： In a previous article, a model for the coronavirus pandemic was developed. This model was based on simple, uninhibited population growth with rate of infection assumed to be proportional to the existing infected population. Validity of this model was verified by testing it against the infection case data published by the Center for Disease Control and the World Health Organization for the United States and the world, respectively. Discrepancies between infection case data and model predictions can be accounted for by implementation of infection prevention measures enforced during the pandemic. The goal of this article is to explore which prevention measures were most effective in reducing the spread of coronavirus in the United States. It turns out that among various prevention measures implemented, lockdown is by far the most effective one.

摘要： This study investigates the community-based ecotourism (CBE) model using a sample of the Aksu-Zhabagly nature reserve (NR). The aim is to propose a suitable CBE model for Aksu-Zhabgly nature-based tourism destinations by employing a combination of field observation, examination, evaluation, and SWOT analysis. The study determines the strategic suggestions for CBE model designing by the results of SWOT analysis. It concludes that convenient transportation and superior location, diversified wild animals and plants, rich in ethnocultural resources, traditional and tranquil life in a typical rural setting, hospitality and positive attitude of locals to tourism and great potential of the region for sustainable development of ecotourism are the strengths. At the same time, the far residential location from the provincial cities, low-quality service, outdated facilities and shortage of skilled employees in tourism management are the main weakness. Another group of constraints to tourism development is lack of tourism marketing and promotion agencies, lack of transparency, poor institution arrangement and corruption, and lack of preferential policies for CBE development. Finally, the paper recommends that economic development, environmental protection, culture and heritage, marketing and image, favorable political environment, and local residents’ empowerment are the main essential to effectively implement the sustainable development of CBE in the Aksu-Zhabagly tourist destination.

摘要： Objective:The differences of ovarian morphology,reproductive hormones,glucose and lipid metabolism and intestinal bacteria in rats with polycystic ovary syndrome(PCOS)induced by triazole were compared.Method:Eighteen 21 SPF female SD rats were randomly divided into group A(3-week group),group B(5-week group)and group D(control group)by random number table.Group A received letrozole+CMC-Na mixture by gavage in the first 3 weeks and CMC-Na solution by gavage in the last 2 weeks,group B received letrozole+CMC-Na mixture by gavage for 5 weeks,and group D received CMC-Na solution by gavage for 5 weeks,and all three groups of rats were fed with normal diet.At the end of gavage,the body weight of rats in each group was observed,the histological changes of ovaries were observed by hematoxylin-eosin(HE)staining,the serum levels of estradiol(E2),follicle stimulating hormone(FSH),luteinizing hormone(LH),testosterone(T),total cholesterol(TC),triglyceride(TG),fasting blood glucose(Glu),fasting insulin(FINS)and lipopolysaccharide(LPS)were measured by enzyme-linked immunosorbent assay(ELISA),and the LH/FSH ratio and insulin resistance index(HOMA IR)were calculated;the intestinal bacteria of rats were detected by 16S rRNA technique.Result:1.Comparison of ovary histomorphology:Under light microscope,multiple luteum and oocytes were observed in mature follicles in group D,and granulosa cells were orderly arranged and multilayered,without cystic dilated follicles.There were no mature follicles in the ovarian tissues of group A and GROUP B.The follicles were irregular in structure and more cystic dilated follicles were visible.The number of granular cells in some follicles decreased or even disappeared.2.Comparison of sex hormone levels:compared with group D,T level in group B was significantly increased(P0.05);The LH/FSH levels in group A and B were significantly increased(P0.05),and the abundance of Bacteroidetes in groups A and B decreased(P3).Conclusion:The phenotype of PCOS rats was related to the length of modeling,and the phenotypic characteristics of PCOS in rats at 5 weeks of modeling were more typical than those in rats at 3 weeks of modeling;PCOS can cause changes in intestinal flora,and the changes in the structure of intestinal flora between groups are related to different modeling duration.

摘要： BACKGROUND Methods for predicting the prognosis of patients undergoing surgery for recurrent hepatolithiasis after biliary surgery are currently lacking.AIM To establish a nomogram to predict the prognosis of patients with recurrent hepatolithiasis after biliary surgery.METHODS In this multicenter,retrospective study,data of consecutive patients in four large medical centers who underwent surgery for recurrent hepatolithiasis after biliary surgery were retrospectively analyzed.We constructed a nomogram to predict the prognosis of recurrent hepatolithiasis in a training cohort of 299 patients,following which we independently tested the nomogram in an external validation cohort of 142 patients.Finally,we used the concordance index(C-index),calibration,area under curve,decision curve analysis,clinical impact curves,and visual fit indices to evaluate the accuracy of the nomogram.RESULTS Multiple previous surgeries[2 surgeries:Odds ratio(95%confidence interval),1.451(0.719-2.932);3 surgeries:4.573(2.015-10.378);≥4 surgeries:5.741(1.347-24.470)],bilateral hepatolithiasis[1.965(1.039-3.717)],absence of immediate clearance[2.398(1.304-4.409)],neutrophil-to-lymphocyte ratio≥2.462[1.915(1.099-3.337)],and albumin-to-globulin ratio≤1.5[1.949(1.056-3.595)]were found to be independent factors influencing the prognosis.The nomogram constructed on the basis of these variables showed good reliability in the training(C-index:0.748)and validation(C-index:0.743)cohorts.Compared with predictions using traditional classification models,those using our nomogram showed better agreement with actual observations in the calibration curve for the probability of endpoints and the receiver operating characteristic curve.Dichloroacetate and clinical impact curves showed a larger net benefit of the nomogram.CONCLUSION The nomogram developed in this study demonstrated superior performance and discriminative power compared to the three traditional classifications.It is easy to use,highly accurate,and shows excellent calibration.

摘要： The incompressible models for the pressure-strain correlation are unable to correctly predict the turbulence flows evolving with significant compressibility. Huang and Fu use a damping function of the turbulent Mach number to modify two numerical coefficients of the incompressible model for the pressure strain developed by Launder, Reece and Rodi. This model predicts the spreading rate and the shear stress behavior in compressible turbulent mixing well. However, the model does not show the well-known compressibility effects on the compressible homogenous shear flow. In the present work, the model of Huang-Fu is revised, all resulting model coefficients become dependent on the turbulent Mach number, the gradient Mach number and the convective Mach number. The proposed model is tested in different compressible turbulent homogeneous shear flow and mixing layers cases. In general, the predicted results from the proposed model are in an acceptable agreement with DNS and experiment data.

摘要： This paper formulates the light timing calculations for each interferometer arm;one that is parallel to the direction of motion of the interferometer through space and the other that is perpendicular. The calculations are done for a vacuum-mode interferometer and then for a gas-mode interferometer. The calculations show that no light timing difference is detectable in a vacuum-mode interferometer, but once an optical medium is present in the light path down the arms of the interferometer, this is no longer the case and a timing difference is detectable. Further to this, the timing equations obtained from the analysis are used to model the historical experiments of Michelson-Morley and Miller (Mt Wilson) and predictions are made by the model that accurately match the actual recorded results from those experiments. Thus, this timing analysis confirms that there is a light speed anisotropy in a reference frame that is moving through space, indicating the presence of a preferred Aether reference frame through which the Earth is moving.

摘要： Pharmaceutical continuous manufacturing,especially under the context of COVID-19 pandemic,is regarded as an emerging technology that can guarantee the adequate quality assurance and mitigate process risk while guaranteeing the desirable economic performance.Flexibility analysis is one approach to quantitively assess the capability of chemical process to guarantee feasible operation in face of variations on uncertain parameters.The aim of this paper is to provide the perspectives on the flexibility analysis for continuous pharmaceutical manufacturing processes.State-of-the-art and progress in the flexibility analysis for chemical processes including concept evolution,mathematical model formulations,solution strategies,and applications are systematically overviewed.Recent achievements on the flexibility/feasibility analysis of the downstream dosage form manufacturing process are also touched upon.Further challenges and developments in the field of flexibility analysis for novel continuous manufacturing processes of active pharmaceutical ingredients along with the integrated continuous manufacturing processes are identified.

摘要： BACKGROUND Crohn’s disease(CD)is a chronic nonspecific intestinal inflammatory disease.The aetiology and pathogenesis of CD are still unclear.Anal fistula is the main complication of CD and is a difficult problem to solve at present.The main limitation of developing new therapies is bound up with the short of preclinical security and effectiveness data.Therefore,an ideal animal model is needed to establish persistent anal fistula and an inflamed rectal mucosa.AIM To improve the induction method of colitis and establish a reliable and reproducible perianal fistulizing Crohn’s disease animal model to evaluate new treatment strategies.METHODS Twenty male New Zealand rabbits underwent rectal enema with different doses of 2,4,6-trinitrobenzene sulfonic acid to induce proctitis.Group A was treated with an improved equal interval small dose increasing method.The dosage of group B was constant.Seven days later,the rabbits underwent surgical creation of a transsphincteric fistula.Then,three rabbits were randomly selected from each group every 7 d to remove the seton from the fistula.The rabbits were examined by endoscopy every 7 days,and biopsy forceps were used to obtain tissue samples from the obvious colon lesions for histological analysis.The disease activity index(DAI),colonoscopy and histological scores were recorded.Perianal endoscopic ultrasonography(EUS)was used to evaluate the healing of fistulas.RESULTS Except for the DAI score,the colonoscopy and histological scores in group A were significantly higher than those in group B(P<0.05).In the ideal model rabbit group,on the 7 th day after the removal of the seton,all animals had persistent lumens on EUS imaging,showing continuous fullthickness high signals.Histological inspection of the fistula showed acute and chronic inflammation,fibrosis,epithelialization and peripheral proctitis of the adjoining rectum.CONCLUSION The improved method of CD colitis induction successfully established a rabbit perianal fistula CD preclinical model,which was confirmed by endoscopy and pathology.

摘要： Groundwater contamination by petroleum products has become a common problem. These chemicals could contaminate groundwater and cause significant health risk. Benzene, one species of the seproducts, gave rise to specific concern due to its relatively high water solubility and toxicity. Becausedissolved oxygen (DO) in groundwater is often lacking, biodegradation has indicated limited ability tocompletely restore benzene-contaminated aquifer. The slow-release oxygen source (SOS) technique canincrease DO concentrations in groundwater and accelerate biodegradation process. Thereby, a transport modelincluding benzene, DO and one microbial species was built and relevant modified program codes werecompiled on the basis of MODFLOW/MT3DMS. Then, a two-dimensional synthetic aquifer with a pointsource of benzene was simulated by the modified model to analyze SOS’s treatment efficiency. There were 5scenarios for different well location, different oxygen release rate and simultaneity 7 release oxygen wellsalong transverse direction. The results showed that the modified model can be used to simulate benzenetransport under SOS technique where Monod kinetic reactions occur. Placing the release oxygen well closer tosource was more efficient. For the same well location, higher oxygen release rate would enhancebioremediation effect. Enough DO maybe accelerate the growth of microbial species, and more benzene couldbe consumed by increasing microbial mass.

摘要： Adsorption refrigeration is a kind of environmental friendly green refrigeration technology. Its major superiority is the capability of using low-grade thermal energy and environmental protection. In this thesis,the heat and mass transfer performances and thermody namic mechanism of solid adsorption refrigerating system using active carbon-ammonia as working pairs were investigated. The mathematic model for the dynamrcoperation of the heat transfer was built.The no dimensional heat transfer equation was solved by using finitedifference method and the calculation program of the model was made by using programming language-Matlab.

摘要： This paper address problem of how to select most favorable English text book for university students. Based on data from history and method of empirical analysis, the paper establish a SVM model. Bytest, It's a effective and good way to judge a quality of English textbook before used.rn Teaching material, as an essential teaching tool, notonly links up teachers, students and academic knowledge,but has a great influence on the improvement of students'learning and development, and an impact on teachers'professional skills. For college English course, its course book is especially different from others. Actually, college English course book is characteristics of plenty of selecdons with more linguistic culture and communication activities. To take a better employment of some Englishcourse book, teachers need to have a real understanding of its construction and evaluation. And thus, they can make a creative study and application of this book and reach the expected teaching target.

摘要： China puts forward high standards, high quality, high demand for the ability of operation andmanagement of various types of sports events in the new era, at the same time, shows that exploration andestablishment of the operation and management model of sports events in the new era can't be delayed.According to emphasis on the nature of sports in sports competitions, sports competitions can be divided intothe mass events, competitive events, performing events. China defines "sports competition showing business"to the areas of competitive events and performing events in long term, while ignoring the existence of massevents, which intrinsically linked with the development features of China's sports in specific historical period.China should strongly insist on localization road, and actively absorb foreign "nutrients", establish operationand management model of sports events with Chinese characteristics.

摘要： In view of the deficiencies existing in the teaching models in military academies the thesis puts forward that interactive teaching models should be used to improve the situation. The paper first analyzes the basic contents of interactive teaching models, and then discusses several principles which should be followedin interactive teaching. On this basis, it analyzes and discusses a few links to which attention should be paid to grasping in the application of interactive teaching models.

摘要： To address the problems in air ticket system such as high cost and slow response, this paper firststudies the concept of cloud computing, characteristics and architectures, then introduces cloud computinginto air ticketing system. An air ticketing system model is established based on cloud computing platform,and also feasibility and critical problems of cloud computing applications in the air ticketing system areanalyzed.

摘要： 本文阐述了无人驾驶直升机的突出优点和应用，并详细介绍了Model 379/Fire Scout、Cypher 、Ka--137和Camcopter等四种典型型号无人驾驶直升机的性能和技术参数，并展望了军用无人驾驶直升机的发展趋势。

摘要： 本文阐述了无人驾驶直升机的突出优点和应用，并详细介绍了Model 379/Fire Scout、Cypher 、Ka--137和Camcopter等四种典型型号无人驾驶直升机的性能和技术参数，并展望了军用无人驾驶直升机的发展趋势。

摘要： 本文阐述了无人驾驶直升机的突出优点和应用，并详细介绍了Model 379/Fire Scout、Cypher 、Ka--137和Camcopter等四种典型型号无人驾驶直升机的性能和技术参数，并展望了军用无人驾驶直升机的发展趋势。

摘要： 本文阐述了无人驾驶直升机的突出优点和应用，并详细介绍了Model 379/Fire Scout、Cypher 、Ka--137和Camcopter等四种典型型号无人驾驶直升机的性能和技术参数，并展望了军用无人驾驶直升机的发展趋势。

摘要： 本发明提供的一种基于Topic Model的本体构建方法。本发明提出了AOL方法，该方法支持自动的领域本体构建，发明了一种信息的计算概念之间语义相似性的度量方法，用来计算LDA模型产生的概念之间的语义相似性，AOL方法不限制根节点的子节点数量，不需要有种子本体作为初始学习本体的辅助。实验结果表明，本发明提出的利用Topic Model进行自动本体构建的方法是非常有效的。

摘要： 本发明涉及一种支持混合模型融合的Model Ensemble方法，两个模型的输出均包括实例框和类别分布，分别对两个实例框和两个类别分布进行加权融合，对加权融合后的输出去重获得唯一的模型融合输出。当两个模型中有一个分类模型时，将该分类模型的输出改造成检测模型输出，用“检测模型的实例框+分类模型的类别分布”来构造一个虚拟的检测模型输出。本方法不限于分类模型融合，可以融合不同AI模型。

摘要： 本发明公开了建模(Modeling)面膜化妆料组成物，对于纯净水100重量份，褐藻酸盐(Alginate)1～10wt％，保湿剂1～20wt％，增粘剂1～10wt％，乳化剂0.5～3wt％，皮肤保护剂0.1～8wt％，保存剂1～3wt％组成。因此，根据本发明，作为含有褐藻酸盐(Alginate)的凝胶形态的一体型剥离(Peel Off)建模(Modeling)面膜，该组合物不混合单独的水或2剂，以具有粘性的凝胶(Gel)形态提高使用便利性和便携性，同时提高营养成分。

摘要： 本发明提供一种基于特征分量相关性的Rich Model隐写检测特征选取方法。该方法包括：步骤1：将高维Rich Model隐写检测特征拆解为若干个Rich Model子模型；步骤2：针对每个Rich Model子模型，度量其各个特征分量的可分性，并根据可分性的度量值对各个特征分量进行降序排序；步骤3：针对每个RichModel子模型，计算其任意两个特征分量之间的相关性，根据相关性的强弱对特征分量进行特征选择；步骤4：将特征选择后的各个Rich Model子模型进行合并以作为最终的隐写检测特征。本发明应用于频域和空域的Rich Model特征时，在不影响隐写检测正确率的情况下，能够有效降低Rich Model特征维数，且在频域上的效果更为显著。

摘要： 本发明涉及一种支持混合模型融合的Model Ensemble方法，两个模型的输出均包括实例框和类别分布，分别对两个实例框和两个类别分布进行加权融合，对加权融合后的输出去重获得唯一的模型融合输出。当两个模型中有一个分类模型时，将该分类模型的输出改造成检测模型输出，用“检测模型的实例框+分类模型的类别分布”来构造一个虚拟的检测模型输出。本方法不限于分类模型融合，可以融合不同AI模型。

摘要： 本公开提供了一种基于Model‑Free抽样的涡轮机匣低周疲劳寿命预测方法，属于航空技术领域。该方法包括建立涡轮机匣参数化有限元模型；获取涡轮机匣低周疲劳寿命的原始观测样本；根据所述原始观测样本，采用Model‑Free抽样方法进行扩充获得扩充样本；根据所述扩充样本，结合Edgeworth级数方法获得涡轮机匣的低周疲劳寿命预测结果。本公开将基于少量已经通过有限元分析获得机匣模型的低周疲劳数据，通过Model‑free抽样方法来获得大量机匣低周疲劳数据，并根据这些数据通过Edgeworth级数方法来估计涡轮机匣低周疲劳寿命的预测结果，提高低周疲劳寿命概率分布预测的效率。

摘要： 本发明涉及船舶设计技术领域，尤其为一种基于TRIBON M3中的Pipe Modelling模块管子建模方法，包括有以下步骤：S1，初始化管子模型数据库；S2，定义相对坐标系；S3,制作工作图；S4，建立管子模型；S5，干涩检查，模型修改；S6，输入生产信息；S7，数据提取转换。本发明模块建立的管子模型信息都存在某一个指定的数据库中，管子模型的信息一旦存入指定的数据库，其他的用户都可以调用此管子模型的信息，数据具有高度的共享性，便于设计人员之间的协调配合。

摘要： 本发明公开了一种在Power8 L model服务器上监控功耗的方法及系统，方法包括：S1，在指定服务器编写shell脚本；S2，输入ipmi命令获取所述指定服务器的序列号、部件温度和整机功耗。在FW840之前的微码情况下，通过编写shell脚本提取ipmi命令中的信息获取服务器的硬件部件序列号、部件温度和整机功耗等信息，操作简单，信息获取成本低。

摘要： 本发明实施例公开了一种快速建立PCB差分信号的AC耦合电容signal model方法和系统，包括：产生AC耦合电容信号群原始清单列表；移除不相关信号，形成AC耦合电容目标清单列表；建立AC耦合电容signal model，产生已建立signal model的电容零件位号清单。当AC耦合电容信号群加载至原始清单列表时，可以将符合关键字规则的差分信号都包含进去；再通过筛选功能，生成差分信号AC耦合电容目标清单列表；最后通过signal model建立功能，产生已建立signal model的电容零件位号清单。本发明通过自动实现差分信号AC耦合电容signal model设定的功能，取代了当前AC耦合电容signal model手动设定的方式，极大提高了工作效率，同时减少了出错和遗漏的机率。

摘要： 本发明提供了一种基于U‑model的四旋翼无人机控制方法，包括：分别建立四旋翼无人机机翼的数学模型和四旋翼无人机轨迹的动力学模型；将所述数学模型通过解耦获得所述四旋翼无人机机翼独立控制通道的传递函数，其中所述独立通道包括：俯仰通道，翻滚通道、偏航通道和方向通道；将所述传递函数通过基于U‑model的极点配置方法，构建所述四旋翼无人机机翼的第一控制规律；根据所述动力学模型通过解耦获得所述四旋翼无人机机体的轨迹的驱动子函数；根据所述驱动子函数通过基于U模型的极点配置的方法，构建所述四旋翼无人机机体的第二控制规律；根据所述第一控制规律和所述第二控制规律，构建所述四旋翼无人机的复合控制规律。