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关键词： 品牌营销  

ISBN: (纸本)9787520826471

摘要： 本书分为三部分, 共10章, 主要内容包括: 营销裂变的新模式 ; 成功企业的营销密码 —— 快速转化客户的裂变能力 ; 爆品思维才是裂变的引子 ; 打造支撑爆品的营销体系 ; 裂变开始: 企业的自身修炼 ; 初期裂变: 早期用户转化, 成功闭环 ; 裂变增长: 从早期用户到规模用户 ; 多渠道营销管理等。

摘要： 科技日报2023年9月5日报道,科学家首次观测到一种新的衰变模式.在这种衰变中,氧的一种较轻的形式,即氧-13(有8个质子和5个中子),通过分裂出3个氦核(一个没有周围电子的原子)、1个质子而衰变.这项研究发表在最新一期《物理评论快报》杂志上.

摘要： One of the most well-established codes for modeling non-linear Magnetohydrodynamics (MHD) for tokamak reactors is JOREK, which solves these equations with a Bezier surface based finite element method. This code produces a highly sparse but also very large linear system. The main solver behind the code uses the Generalized Minimum Residual Method (GMRES) with a physics-based preconditioner. Even with the preconditioner there are issues with memory and computation costs and the solver doesn't always converge well. This work contains the first thorough study of the mathematical properties of the underlying linear system, enabling us to diagnose and pinpoint the cause of hampered convergence. In particular, analyzing the spectral properties of the matrix and the preconditioned system with numerical linear algebra techniques will open the door to research and investigate more performant solver strategies, such as projection methods.

摘要： The purpose of this dissertation is the study of the spectrum and strong decay properties of hybrid mesons within the framework of the constituent gluon model. Hybrid mesons are mesons composed of a quark-antiquark pair plus gluonic degrees of freedom. A detailed study of hybrid mesons, besides being intersting in its own merit, can offer a window into the role of gluonic degrees of freedom in non-perturbative Quantum Chromodynamics (QCD) - a question that still remains unanswered. Different versions of constituent gluon models have been developed in the last five decades and have recently gained much support from lattice gauge theory studies. Our model assumes that the gluon is a constituent particle with specific quantum numbers. The basis for the model is the Quantum Chromodynamics Hamiltonian in Coulomb Gauge, which leads to an instantaneous Coulomb interaction between the constituents. Firstly, we compute a spin-averaged spectrum of charmonium hybrids, for which there is extensive lattice data with which to compare our results. As a check for the robustness of the model, we also calculate spin-averaged energies for conventional heavy quarkonium, which can be directly compared to the available experimental data. Secondly, we compute hadronic decays of charmonium hybrids and again compare our results to those of the lattice. Lastly, we calculate hadronic decays of light hybrids (hybrids made of u, d and s quarks). In the case of light hybrids, lattice data is now supplemented by a scant but growing body of experimental results which include the isovector π 1 (1600) and the recently discovered isoscalar η 1 (1885), both light hybrid candidates with J P C = 1 −+.

摘要： Introduction. Knee osteoarthritis (KOA) is a highly prevalent whole joint disease that arises from various knee tissues. The infrapatellar fat pad (IPFP) is a source of knee pain in patients suffering from KOA or its precursor, patellofemoral pain (PFP). KOA diagnosis is supported by magnetic imaging resonance (MRI), from which several features can be extracted and correlated with bio- logical markers. However, few studies refer radiomics analyses for KOA (or PFP) assessment. Objectives. This study aims to automatically extract radiomic features from the femur, tibia, patella and IPFP, and assess their ability to predict KOA development over a 48-month period as well as distinguish between patients with PFP and healthy controls. Methods. Sagittal three-dimensional (3D) fast-spoiled gradient-echo (SPGR) MRI sequences with and without fat saturation (FS) from the TripleP study (n=64 PFP patients, n=70 controls) were used to study the IPFP and assess PFP. Knee structure analysis for KOA prediction was per- formed using the 3D double echo steady state water excitation MRI sequence, from the POMA dataset (n=355 KOA patients, n=355 controls). Automatic structure segmentation was achieved using nnU-Net (3D U-Net configuration), trained with 30 manually segmented knees and 5-fold cross-validation. The Workflow for Optimal Radiomics Classification toolbox was used for fea- ture extraction (n=452), and different classifiers were evaluated, namely Support Vector Machines (SVM) and Elastic Net. To compute it, SGDClassifier and Logistic Regression were selected, including hyperparameter optimization using 10-fold stratified cross-validation with a grid search and 10 repetitions. Three main models were evaluated based on: 1) patients' information (age, sex and BMI), 2) radiomic features, and 3) combination of models 1 and 2. Models' performance was evaluated using the area under the receiver operating characteristic (ROC AUC) and precision- recall (PR AUC) curves, and 95% confide

关键词： 能力验证   土壤   镉   石墨炉原子吸收光谱法(GF-AAS)   电感耦合等离子体质谱法(ICP-MS)   一致性   稳健标准差   F检验   t检验  

摘要： 本文利用土壤中镉能力验证结果，采用稳健标准差F检验与稳健平均值t检验评价石墨炉原子吸收光谱法(GF-AAS)和电感耦合等离子体质谱法(ICP-MS)的一致性。按照不同的消解方式，对GF-AAS和ICP-MS检测土壤中镉的统计结果进行比较，采用稳健标准差F检验评估GF-AAS和ICP-MS精密度的一致性，发现ICP-MS方法的精密度与GF-AAS方法相比没有显著性差异或比GF-AAS方法精密度更好，在进行方法精密度的一致性评估时，不能完全参考F检验的数理统计结果，还需结合标准分析方法中的精密度数据来评估其一致性。采用稳健平均值t检验和稳健平均值配对样本t检验方法评估两种方法检测结果的一致性，表明相同消解方式下，采用GF-AAS和ICP-MS测定土壤中镉稳健平均值之间差异不显著，为利用能力验证结果比较不同测量方法的一致性提供了新的判定思路。

标准号: DB42/T 2096-2023

关键词： 石墨矿   X射线荧光光谱法(XRF)   熔融制样   杂质组分   固定碳  

摘要： 石墨矿中杂质组分的含量关系到石墨的性能，杂质组分的测定常采用酸溶或碱熔处理后使用电感耦合等离子体原子发射光谱法（ICP-AES）、电感耦合等离子体质谱法（ICP-MS）或经典化学湿法测定，流程较长，过程中需要大量的酸、碱等试剂；而使用压片制样-X射线荧光光谱法（XRF）测定时，样品中高含量的碳会导致其他元素的分析结果产生较大偏差。实验将石墨矿预先在1 000℃下灼烧2 h,灼烧后的样品使用Li2B4O7-LiBO2（质量比为67∶33）混合熔剂熔融制样，再采用X射线荧光光谱法测定SiO2、Al2O3、TFe2O3、MgO、CaO、Na2O、K2O、P2O5、MnO、TiO2等10种杂质组分。选择含碳量不同的国家一级标准物质建立校准曲线，线性相关系数均不小于0.995 8。按照实验方法测定石墨矿样品中10种组分，结果的相对标准偏差（RSD,n=12）均小于1%。按照实验方法对3个不同固定碳含量的石墨矿样品进行测定，结果与国家标准中化学湿法结果基本一致。

关键词： X射线荧光光谱(XRF)   磷矿石   熔融制样   粉末压片制样   文献评介  

摘要： 当今X射线荧光光谱(XRF)已成为磷矿石分析最重要的方法之一。作者收集了我国引入X射线荧光光谱技术以来至2022年间我国X射线荧光光谱技术分析磷矿石的期刊文献共计33篇。其中15篇采用熔融制样方法，12篇采用粉末压片制样方法，2篇文献为评述，1篇文献为标准物质研制，3篇文献侧重于在矿物学、工艺矿物学研究中利用X射线荧光光谱技术测定其化学组成。文章介绍了我国磷矿石成分分析概况和方法研究的基础条件，包括专著、标准物质、标准方法和相关评述文献。对其中的27篇分析技术方法的期刊文献用列表方式简介了文献和方法要点，包括所用仪器、制样方法、校准与校正方法、测定组分和主要组分测量精密度等。对其中较典型、有代表性的文献按制样方法进行了重点评介，也对现有的标准物质和标准方法在使用中的问题做了评介。最后讨论了XRF分析地质材料时的制样方法选取、样品粒度影响和磷矿石X射线荧光光谱的未来发展等问题。全篇引文53篇。