Pressure and temperature dependence of second-order elastic constants from third-order elastic constants in TMC (TM=Nb,Ti, V,Zr)

In this paper, we present an efficient and effective method to predict the pressure dependence and temperature dependence of second-order elastic constants (SOECs) by introducing third-order elastic constants (TOECs) in the monocarbide ultrahigh temperature ceramics. The method is validated by comparing with experiments and previous calculations in four TMCs (TM = Nb, Ti, V, Zr). Using this method, we investigate the derivatives of SOECs against pressure and temperature as well as the anisotropic properties of polycrystalline modulus. In addition, we fit the SOECs with pressure and temperature under the framework of CALPHAD for practice usage.     

Li decorated heteroborospherene C4B32 as high capacity and reversible hydrogen storage media: A DFT study

In this work, adsorption of H₂ molecules on heteroborospherene C_2v C₄B₃₂ decorated by alkali atoms (Li) is studied by density functional theory calculations. The interaction between Li atoms and C₄B₃₂ is found to be strong, so that it prevents agglomeration of the former. An introduced hydrogen molecule tilts toward the Li atoms and is stably adsorbed on C₄B₃₂. It is obtained that Li₄C₄B₃₂ can store up to 12H₂ molecules with hydrogen uptake capacity of 5.425 wt% and average adsorption energy of ?0.240 eV per H₂. Dynamics simulation results show that 6H₂ molecules can be successfully released at 300 K. Obtained results demonstrate that Li decorated C₄B₃₂ is a promising material for reversible hydrogen storage.     

创新扩散视野下颈椎枕的产品设计策略研究

目的 针对现有产品设计在功能创新与产品采纳等方面的问题，基于创新扩散理论，以产品的功能、观念等方面及迭代策略方法为研究对象，创造和优化颈椎枕产品设计方法。方法 以智能助眠颈椎枕产品设计为实验样本，从创新扩散理论视角归纳产品创新过程中的核心问题，将产品的设计及优化方向纳入核心功能、用户体验、应用场景创新等不同优化路径，并在用户群体中划分出具有强扩散倾向的用户群体，根据其需求制定不同迭代策略，从而获得不同优化策略的细分迭代产品并投放市场进行扩散检验。结果 将2类不同产品线的迭代产品进行交叉对比验证，发现了总采纳比原产品提升了15.8%。同时对潜在用户群体进行针对性扩散实验结果，显示出显著的扩散潜量边界突破的表达。结论 探索了以创新扩散为目标的设计思路，在颈椎枕产品优化设计中的应用。提出了“扩散特征表达需求，并驱动创新，而后影响创新采纳效果”的产品设计模式。证明了根据扩散过程的信息反馈进行的产品迭代，提升了用户的新增采纳概率和模仿采纳概率。同时验证了以创新扩散需求为导向的产品设计策略研究的可行性。     

Transition metal atoms anchored on nitrogen-doped α-arsenene as efficient electrocatalysts for nitrogen electroreduction reaction

Electrocatalytic reduction of N₂ to NH₃ under ambient conditions, inspired by biological nitrogen fixation, is a new approach to address the current energy shortage crisis. As a result, developing efficient and low-cost catalysts is critical. The catalytic activity, catalytic mechanism, and selectivity of α-arsenene (α-Ars) catalysts anchored with various transition metal atoms and doped with different numbers of N atom were investigated for N₂ reduction reaction (NRR) in this paper. Results reveal that compared with WN₃-α-Ars which is coordinated with three N atoms, asym-WN₂As-α-Ars that coordinated with two N atoms not only exhibits high catalytic activity (U_L = ?0.36 V), but can also successfully suppress the hydrogen evolution reaction (HER). It is manifested that reducing the number of coordination atoms can promote the selectivity of the transition metal (TM) loaded N-doped arsenene catalysts. Furthermore, activity origin analyses show both the charge on 1N–NH and φ form volcano-type relationship with the limiting potential. The active center of the catalyst, which acts as the charge transporter and has the moderate ability to retrieve charges, is the most efficient in NRR. Overall, this research creates high performance NRR catalysts by varying the number of coordinating N atoms, which provides a novel idea for the development of new NRR catalysts.     

价值网络语境下企业设计价值创新路径研究

目的 在新的视角下，提出一种价值创新路径模型，对设计驱动型企业的价值实现方式进行有效补充。方法 通过文献研究，论述了企业关系由价值链到价值网转变的历史趋势;通过比较研究，对价值实现过程中主客体之间的4种关系进行了类比分析，提出了不同主客体关系状态下设计实践的具体表现方式。结果 在价值网络语境下，以价值论为理论依据，从主客体之间的关系入手，构建设计价值创新路径模型。结论 通过分析证明:“主客体统一状态”是企业价值创造的理想状态;主客体关系一直处于动态的变化过程中;客体对主体的“意义”也一直处于动态变化中。在这种动态变化的关系网络中，设计驱动方式已经成为企业创新的重要模式，企业如何捕获并诠释“意义”，成为价值实现的关键所在。     

学生参与电气人才创新能力培养的探索

基于“以学生为本”的OBE教育理念，本文对电气人才创新能力培养进行了探索。整个过程将专业课程体系契合学业规划以明确学生学习目标；学生参与理论、实践教学和平台搭建，在夯实其理论知识的同时丰富教学资源；在创新考核中采用“螺旋递进式”的师生互动模式，全程培养学生自主的创新能力。多年实践探索表明学生在课程实践、学科竞赛、论文发表和申报专利等方面的创新能力得到显著提升。     

“电工学”国家级一流课程建设与实践

根据新时代新工科人才需求特点和电工学课程特点,分析非电专业学生的电类实践需求,提出构建电工学课程为核心的电工电子实践创新能力培养新体系。通过优化教学内容、开展教学模式和考核模式改革、构建教学资源体系和进行教师队伍建设,使我校电工学课程教学质量提升、学生工程实践和创新能力提高、学生满意度增加、一流课程建设成效显著。     

Theoretical investigation of intrinsic point defects and the oxygen migration behavior in rare earth hafnates

In this work, the composition-dependent point defect types and formation energies of RE₂Hf₂O₇ (RE = La, Ce, Pr, Nd, Pm, Sm, Eu and Gd) as well as the oxygen diffusion behavior are systematically investigated by first-principles calculations. The possible defect reactions and dominant defect complexes under stoichiometric and non-stoichiometric conditions are revealed. It is found that O Frenkel pairs are the predominant defect in stoichiometric pyrochlore hafnates. Hf-RE cation anti-site defects, accompanied by RE vacancies and/or oxygen interstitials, are stable in the non-stoichiometric case of HfO₂ excess. On the other hand, RE-Hf anti-site defects together with oxygen vacancies and/or RE interstitials are preferable in the case of RE₂O₃ excess. The energy barriers for the migration along the V_O48f - V_O48f pathway of pyrochlore hafnates were calculated to be between 0.81 eV and 0.89 eV. Based on these results, a defect engineering strategy is proposed and the pyrochlore hafnates investigated here are predicted to exhibit potential oxygen ionic conductivity.     

Dehydrated Na6[AlSiO4]6 sodalite as a promising SO2 sorbent material: A first principles thermodynamics prediction

The capture of sulfur dioxide (SO₂) using dehydrated Na₆[AlSiO₄]₆ sodalite was investigated using the first principles density functional theory calculations and thermodynamics analysis. The adsorption geometries, energetics, and electronic structures were predicted with the increasing number of SO₂ adsorbates. Upon adsorption, the S atom of single SO₂ molecule tends to align to the framework O²⁻ and the two oxygen atoms are oriented to the framework Na⁺, through electrostatic interactions and with a minor charge transfer. Increasing the number of SO₂ adsorbates, the Na₆[AlSiO₄]₆ sodalite framework shrinks first and then expands. Statistical thermodynamics analysis suggests that the capture reaches its saturation limit of four SO₂ molecules per Na₆[AlSiO₄]₆ formula (~300 mg/g) at room temperature and a low SO₂ partial pressure of 0.001 atm, indicating that dehydrated Na₆[AlSiO₄]₆ can be an efficient SO₂ sorbent even at its extremely low concentrations. Higher SO₂ partial pressures lead to a higher capture capacity. A low baking temperature of 100-150°C can efficiently release the adsorbed SO₂ and hence restore the capture capacity of Na₆[AlSiO₄]₆.     

2018 petroleum & chemical industry development report

In 2018, the petroleum and chemical industries of China achieved steady economic growth. The main business income of the entire industry was 12.4 trillion CNY, an increase of 13.6% over the previous year. The total profit was 83.93 billion CNY, an increase of 32.1% over the previous year. The total national oil and gas production reached 334 million tons of oil equivalent, increasing by 2.4% year-on-year. Among the total production, crude oil production was 189 million tons, decreased 1.2%, and natural gas production was 161.02 billion cubic meters, increased 7.5% year on year. Imported crude oil production was 462 million tons, an increase of 10.1% over the last year. Imported gas production was 125.72 billion cubic meters, increased 31.9%. The annual processing capacity of crude oil was 604 million tons, up by 6.8%. The refined oil production was 360 million tons, up by 3.6%. The industry structure was optimized for production growth in 2018, the transformation and upgrading of enterprises and products structure adjustment were sped up, energy efficiency was improved, and overall industrial benefit was rebounded. At present, the economic operation of the industry is still not very stable, and downward pressure is still great, mainly being reflected in the overcapacity of some industries, high cost operation of enterprises, increased tax burden, and weak investment. With the slow recovery of the global economy and the key support of high-quality development through technological innovation, it is expected that the petroleum and chemical industry of China will achieve the general objective of steady growth in 2019.