算力新质生产力对全要素生产率增长作用机制研究

算力作为数字经济时代的新质生产力,对赋能数字经济新增长、推动数字经济高质量发展至关重要。基于算力的公共性、外部性、网络性与迭代升级特征,研究算力新质生产力的网络外溢效应与全要素生产率之间的关系及作用机理;利用面板随机前沿分析方法测算全要素生产率,发现算力新质生产力对全要素生产率具有显著的促进效应,这种效应来源于算力新质生产力对智算技术效率与规模效率的促进作用。省际个体的算力新质生产力对与该省份在地理、经济、人口方面相关联的其他省份的全要素生产率具有显著的正网络外溢效应。研究表明:(1)算力新质生产力网络外溢效应通过提升创新数量、创新质量对全要素生产率提升产生正向的积极作用;(2)算力新质生产力网络外溢效应通过缓解算力投资错配、数字技能劳动力错配对全要素生产率提升产生正向的积极作用;(3)算力基础设施数量网络与算力基础设施质量网络通过创新促进全要素生产率增长时具有异质性。相关研究成果有利于创新拓展数字经济背景下算力新质生产力对全要素生产率增长作用机制的理论研究,为政府制定数字经济政策提供有益参考。基于此,提出推动算力技术创新、促进算效提升、汇聚算力资源、优化算力要素供给、加大智慧教育投入力度、培育算力基础设施创新人才等建议。

华数探索广电新质算力基础设施发展路径

在信息技术快速送代及新兴应用市场需求演变升级的双轮驱动下,全球数字化建设加速推进。本文探讨了新质算力基础设施的发展路径,通过研究国内及省内智算与超算的发展现状,总结了华数当前的算力网络基础及需求,提出了通用算力网络和智算中心的实现路径,并分析了其在云渲染、视频云+AI智能视频、视听行业大规模训练和内容安全监管等领域的新机遇与挑战,通过系统的分析和建议,为发展新质算力提供有价值的参考和借鉴。

红枣热风干燥试验过程的热质衡算及经济效益分析

通过对红枣热风干燥过程中的物料衡算和热量衡算进行分析,分析了在不同风温(45、55、65℃)和不同风速(0.5、1.0、2.0m/s)条件下红枣干燥特性、干燥速率和耗能量情况等。结果得出:当干燥温度为55℃、风速为1.0m/s时,干燥室的传热传质过程增快,干燥效率升高,获得最佳的节能效果。最后,提出了红枣干燥过程中相应的节能技术措施。该研究为红枣干燥的优质节能高效提供了理论基础,对于推进红枣产业技术进步、增加果农的经济收入,具有十分重要的理论和实践意义。

行程长度压缩算法的改进

本文主要研究了行程长度压缩算法(RLE)的改进方法,此方法对含有大量重复信息的文字和含有大量空白信息的数据文件有较好的压缩效果,同时也给出了解压缩算法.

3D Printing with a 5-Axis FDM Printer Using Bézier Techniques

In the last decade,3D printing,especially fused deposition modeling(FDM),has revolutionized manufacturing with intricate designs.Traditional 3-axis FDM printers face challenges with complex geometries,but 5-axis versions offer more design freedom.However,it requires specialized strategies.This research presents a model for 5-axis FDM printers using Bézier curves with an algorithm to enhance print quality.The result shows significant accuracy improvements,especially for curve-based tasks.In addition,this study deepens the understanding of 5-axis FDM technology,setting a solid basis for further research and potentially refining manufacturing methods.

Scoring and Consequential Validity Evidence of Computer-and Paper-Based Writing Tests in Times of Change

Little is known about how the assessment modality,i.e.,computer-based(CB)and paper-based(PB)tests,affects language teachers’scorings,perceptions,and preferences and,therefore,the validity and fairness of classroom writing assessments.The present mixed-methods study used Shaw and Weir’s(2007)sociocognitive writing test validation framework to examine the scoring and consequential validity evidence of CB and PB writing tests in EFL classroom assessment in higher education.Original handwritten and word-processed texts of 38 EFL university students were transcribed to their opposite format and assessed by three language lecturers(N=456 texts,152 per teacher)to examine the scoring validity of CB and PB tests.The teachers’perceptions of text quality and preferences for assessment modality accounted for the consequential validity evidence of both tests.Findings revealed that the assessment modality impacted teachers’scorings,perceptions,and preferences.The teachers awarded higher scores to original and transcribed handwritten texts,particularly text organization and language use.The teachers’perceptions of text quality differed from their ratings,and physical,psychological,and experiential characteristics influenced their preferences for assessment modality.The results have implications for the validity and fairness of CB and PB writing tests and teachers’assessment practices.

《缀术算经》“自质说”及其理学思想渊源

江户时代日本数学家建部贤弘（Takebe Katahiro，1664-1739）的《缀术算经》（1722）不同于其他东亚传统算书，书中尽管充满创造性的算法，但其著作目的并非单纯叙述算法，而是通过具体算例阐述数学方法论及其研究算学的感悟，书末所附“自质说”集中阐述其数学思想与方法论。文章分析“自质说”的数学思想。追溯其思想在宋明理学中的渊源，以揭示中国哲学对日本传统科学文化的影响。

A first-principle calculation of structural,mechanical and electronic properties of titanium borides

The first-principle calculations are performed to investigate the structural,mechanical and electronic properties of titanium borides （Ti2B,TiB and TiB2）.Those calculated lattice parameters are in good agreement with the experimental data and previous theoretical values.All these borides are found to be mechanically stable at ambient pressure.Compared with parent metal Ti （120 GPa）,the larger bulk modulus of these borides increase successively with the increase of the boron content in three borides,which may be due to direction bonding introduced by the boron atoms in the lattice and the strong covalent Ti-B bonds.Additionally,TiB can be regarded as a candidate of incompressible and hard material besides TiB2.Furthermore,the elastic anisotropy and Debye temperatures are also discussed by investigating the elastic constants and moduli.Electronic density of states and atomic Mulliken charges analysis show that chemical bonding in these titanium borides is a complex mixture of covalent,ionic,and metallic characters.

Non-premixed Combustion Model of Fluidized Bed Biomass Gasifier for Hydrogen-Rich Gas

Fluidized bed biomass gasifiers can be employed to produce hydrogen-rich gas. A non-premixed combustion model is used for biomass air-steam gasification in the gasifier, and the simulations were carried out by using the FLUENT 6.0 software. The simulation results are compared with the experimental data. The effects of the steam to biomass ratio （S/B）, the equivalence ratio （ER）, and the size of biomass particles on the hydrogen yield were studied. Meanwhile, the distributions of hydrogen inside the gasifier at different conditions are also described.

MULTI-CLASS TRAFFIC QOS ROUTING FOR LEO SATELLITE NETWORKS

Due to the diversified demands of quality of service（QoS） in volume multimedia application, QoS routings for multiservice are becoming a research hotspot in low earth orbit（LEO） satellite networks. A novel QoS satellite routing algorithm for multi-class traffic is proposed. The goal of the routing algorithm is to provide the distinct QoS for different traffic classes and improve the utilization of network resources. Traffic is classified into three classes and allocated priorities based on their QoS requirements, respectively. A priority queuing mechanism guarantees the algorithm to work better for high-priority classes. In order to control the congestion, a blocking probability analysis model is built up based on the Markov process theory. Finally, according to the classification link-cost metrics, routings for different classes are calculated with the distinct QoS requirments and the status of network resource. Simulations verify the performance of the routing algorithm at different time and in different regions, and results demonstrate that the algorithm has great advantages in terms of the average delay and the blocking probability. Meanwhile, the robustness issue is also discussed.

An Analysis of the Structure of Carbide-tool Utilization Expert System

The necessity and feasibility of an expert system for carbide-tool utilization are analyzed and a practical system named CUES(carbide-tool utilization expert system ) is developed and realized. The system concept, module structure, data management, inference strategy and the interface design of the system are discussed in.detail. The system would be useful not only for the preparation of tool bank of FMS or CIMS, but the for the proper application of cemented carbide tools in conventional machining Processes.

First principles investigation of binary intermetallics in Mg-Al-Ca-Sn alloy:Stability,electronic structures,elastic properties and thermodynamic properties

The structural stability, electronic structures, elastic properties and thermodynamic properties of the main binary phases Mg_（17）Al_（12）, Al_2Ca, Mg_2 Sn and Mg_2 Ca in Mg-Al-Ca-Sn alloy were determined from the first-principles calculation. The calculated lattice parameters are in good agreement with the experimental and literature values. The calculated heats of formation and cohesive energies show that Al_2Ca has the strongest alloying ability and structural stability. The densities of states（DOS）, Mulliken electron occupation number, metallicity and charge density difference of these compounds are given. The elastic constants of Mg_（17）Al_（12）, Al_2Ca, Mg_2 Sn and Mg_2 Ca phases are calculated, and the bulk moduli, shear moduli, elastic moduli and Poisson ratio are derived. The calculations of thermodynamic properties show that the Gibbs free energies of Al_2Ca and Mg_2 Sn are lower than that of Mg_（17）Al_（12）, which indicates that Al_2Ca and Mg_2 Sn are more stable than Mg_（17）Al_（12） phase. Hence, the heat resistance of Mg-Al-based alloys can be improved by adding Ca and Sn additions.

First-principles study of intrinsic defects,dopants and dopant-defect complexes in LiBH_4

A first-principles study was reported based on density functional theory of hydrogen vacancy,metal dopants,metal dopant-vacancy complex in LiBH4,a promising material for hydrogen storage.The formation of H vacancy and metal doping in LiBH4 is difficult,and their concentrations are low.The presence of one kind of defect is helpful to the formation of other kind of defect.Based on the analysis of electronic structure,the improvement of the dehydrogenating kinetics of LiBH4 by metal catalysts is due to the weaker bonding of B—H and the new metal-like system,which makes H atom diffuse easily;H vacancy accounts for a trace amount of BH3 release during the decomposing process of LiBH4;metal dopant weakens the strength of B—H bonds,which reduces the dehydriding temperature of LiBH4.The roles of metal and vacancy in the metal dopant-vacancy complex can be added in LiBH4 system.

Dissociation Pathway Analysis of Thymine under Low Energy VUV Photon Excitation

Photon-induced dissociation pathways of thymine are investigated with vacuum ultraviolet photoionization mass spectrometry and theoretical calculations. The photoionization mass spectra of thymine at different photon energy are measured and presented. By selecting suitable photon energy, exclusively molecular ion m/z=126 is obtained. At photon energy of 12.0 eV, the major ionic fragments at m/z=98, 97, 84, 83, 70, and 55 are obtained, which are assigned to C4H6N2O＋, C4H5N2O＋, C3H4N2O＋ （or C4H6NO＋）, C4H5NO＋, C2NO2＋, and C3H5N＋, respectively. With help of theoretical calculations, the detailed dissociation pathways of thymine at low energy are well established.

Effect of Co substitution on magnetic properties of Ni-Mn-Sn magnetic shape memory alloys

The effect of Co substitution on magnetic properties of Ni-Mn-Sn shape memory alloy was revealed by first-principles calculations. Large magnetization difference in Ni-Mn-Sn alloy obtained by addition of Co arises from enhancement of magnetization of austenite due to change of Mn-Mn interaction from anti-ferromagnetism to ferromagnetism. Total energy difference between paramagnetic and ferromagnetic austenite plays an important role in magnetic transition of Ni-Co-Mn-Sn. The altered Mn 3d states due to Co substitution give rise to difference in magnetic properties.

Glacier Changes during the Past 40 Years in the West Kunlun Shan

Recent studies on glaciers in the West Kunlun Shan, northwest Tibetan Plateau, have shown that they may be stable or retreating slightly. Here, we assess changes in the mass of the glaciers in the West Kunlun Shan(WKS) in an attempt to understand the processes that control their behavior. Glaciers over the recent 40 years(1970-2010) have shrunk 3.4±3.1%in area, based on a comparison between two Chinese glacier inventories. Variations of surface elevations, derived from ICESat-GLAS(Ice, Cloud, and Land Elevation Satellite-Geoscience Laser Altimeter System) elevation products(GLA14 data) using the robust linear-fit method, indicate that the glaciers have been gaining mass at a rate of 0.23±0.24 m w.e./a since 2003. The annual mass budget for the whole WKS range from 2003 to 2009 is estimated to be 0.71±0.62 Gt/a. This gain trend is confirmed by MOD10A1 albedo for the WKS region which shows a descent of the mean snowline altitude from 2003 to 2009.

Approximation Property of the Modified Elman Network

A new type of recurrent neural network is discussed, which provides the potential for modelling unknown nonlinear systems. The proposed network is a generalization of the network described by Elman, which has three layers including the input layer, the hidden layer and the output layer. The input layer is composed of two different groups of neurons, the group of external input neurons and the group of the internal context neurons. Since arbitrary connections can be allowed from the hidden layer to the context layer, the modified Elman network has more memory space to represent dynamic systems than the Elman network. In addition, it is proved that the proposed network with appropriate neurons in the context layer can approximate the trajectory of a given dynamical system for any fixed finite length of time. The dynamic backpropagation algorithm is used to estimate the weights of both the feedforward and feedback connections. The methods have been successfully applied to the modelling of nonlinear plants.

Computational Mass Transfer Method for Chemical Process Simulation

The recent works on the development of computational mass transfer （CMT） method and its applications in chemical process simulation are reviewed. Some development strategies and challenges in future research are also discussed.

Classification of VxOy^q Clusters by △=2y＋q-5x

Vanadium oxide clusters VxOy^q（x≤8, q=0, ±1） are classified according to the oxidation index （△=2y＋q-5x） of each cluster. Density functional calculations indicate that clusters with the same oxidation index tend to have similar bonding characters, electronic structures, and reactivities. This general rule leads to the findings of new possible ground state struc- tures for V206 and V3O6＋ clusters. This successful application of the classification method on vanadium oxide clusters proves that this method is very effective in studying the bonding properties of early transition metal oxide clusters.

First-principles investigations of structural, mechanical, electronic and optical properties of U_3Si_2-type AlSc_2Si_2 under high pressure

The structural, elastic, electronic and optical properties for U3Si2-type AlSc2Si2 compound under pressure were systematically investigated by using the first-principles calculations. The values of elastic constants and elastic moduli indicate that AlSc2Si2 keeps mechanical stability under high pressure. The mechanical properties of AISc2Si2 are compared with those of Al3Sc. The results indicate that AlSc2Si2 is harder than AI3Sc. Anisotropic constant AU and 3D curved surface of elastic moduli predict that AISc2Si2 is obviously anisotropic under pressure. The electronic structure of AlSc2Si2 exhibits metallic character and the metallicity decreases with the elevated pressure. In addition, optical properties as a function of pressure were calculated and analyzed. The present work provides theoretical support for further experimental work and industrial applications.