织物表面导电线路喷射打印起始端凸起形成过程研究

为提高织物表面微滴喷射打印导电线路的成形质量,针对导电线路喷射打印过程中线路沉积形貌的起始端凸起现象,利用高速相机对线路成形过程进行采集,研究微滴间融合振荡过程中左右接触角的动态变化,微滴与线路融合以及液体向线路起始端的输送过程,提出线路起始端凸起的消除方案并进行实验。结果表明:在融合振荡过程中,微滴向起始端的振荡趋势始终大于向另一侧的振荡趋势,导致打印线路起始端的织物基板润湿区域不断扩大;微滴与线路接触后,其中一部分液体润湿织物基板拓展线路长度,一部分通过线路以恒定速度输送至起始端,在线路起始端形成凸起;利用抗坏血酸溶液润湿织物表面后,成形线路起始端凸起现象得到消除,整体线路路径均匀,沉积形貌良好。     

The control of paracetamol particle size and surface morphology through crystallisation in a spray dryer

The parameters governing the crystallisation of paracetamol using various conventional techniques has been extensively studied, however the factors influencing the drug crystallisation using spray drying is not as well understood. The aim of this work was to investigate the crystallisation of an active pharmaceutical ingredient through evaporative crystallisation using a spray dryer to study the physicochemical properties of the drug and to use semi-empirical equations to gain insight into the morphology and particle size of the dried powder. Paracetamol solutions were spray dried at various inlet temperatures ranging from 60 °C to 120 °C and also from a series of inlet feed solvent compositions ranging from 50/50% v/v ethanol/water to 100% ethanol and solid-state characterisation was done. The size and morphology of the dried materials were altered with a change in spray drying parameters, with an increase in inlet temperature leading to an increase in particle Sauter mean diameter (from 3.0 to 4.4 µm) and a decrease in the particle size with an increase in ethanol concentration in the feed (from 4.6 to 4.4 µm) as a result of changes in particle density and atomised droplet size. The morphology of the dried particles consisted of agglomerates of individual crystallites bound together into larger semi-spherical agglomerates with a higher tendency for particles having crystalline ridges to form at higher ethanol concentrations of the feed.     

Numerical verification of the continuous calculation method for tip stress during the driving process of the dynamic penetration test

This paper presents a calculation method for obtaining the continuous variation in stress between the tip and the soil during dynamic penetration tests, particularly in the case of using the Panda 3® penetration testing device. The originality of the method is that the tip stress can be computed continuously throughout the driving process. For each impact of the hammer on the penetrometer, data are recorded by sensors located at the top of the apparatus. Then, the stress at the tip and the displacement of the apparatus are calculated with a method based on the propagation of waves in the device. A three-dimensional numerical model of the penetration test, based on the Panda 3® specifications and using the discrete element method (DEM), is proposed in this paper. The purpose of the simulations is to validate the calculation method by comparing the curves of the tip stress versus the penetration distance obtained in two different ways, the first being the distance directly observed at the tip and the second being the distance calculated from the data recorded at the top of the penetrometer, as with the experimental device. The entire apparatus is represented, including the hammer, the rod, and the tip, and is driven into the model soil. The calculation method is applied, and the results are compared to the actual response of the soil to the driving of the penetrometer directly at the tip, which can be obtained with the numerical model. The responses are found to be very similar, confirming the theoretical framework and its underlying assumptions. This method is applied to dynamic penetration tests and provides the opportunity to obtain mechanical parameters other than the tip resistance from the tests.     

Sintering,microwave properties,and circulator applications of textured Sc-substituted M-type ferrite thick films

Sc³⁺ substituted M-type ferrites are effective microwave magnetic materials with a ferromagnetic resonance frequency in the range of 20 GHz–50 GHz. We report on the fabrication of oriented ferrite thick films as microwave components for application in the K_a-band at 30 GHz. Films of BaFe_11.5.Sc_0.5O₁₉ were prepared by screen-printing on alumina substrates, drying in an external magnetic field, and sintering at 900 °C. Low-temperature sintering is achieved through use of a mixed BBSZ/CuO sintering aid. A strong anisotropy of the sintered ferrite films is revealed by XRD analysis. Microwave properties of the films were determined in a coplanar waveguide setup. The ferromagnetic resonance frequency of the films is at 30 GHz and the textured films possess good nonreciprocal properties which scale with film thickness. The films were tested in a Y-junction circulator, and represent promising materials for self-biased microwave components fabricated in thick film technology.     

Electric transport properties of rare earth doped YbxCa1-xMnO3 ceramics (part I: Optimization of ceramic processing)

A comprehensive study was performed in order to find the effect of different calcination and sintering conditions on the physical properties of calcium manganite ceramics in dependence of temperature T and partial pressure of oxygen p(O₂). The eventual formation of oxygen vacancies during sintering was investigated and the results were confirmed by monitoring the release of oxygen using a ZrO₂ oxygen sensor. The phase transition behavior was studied using thermogravimetric analysis (TGA) in a wide range of p(O₂) ≈ 10^?1 MPa down to 10^-19 MPa at high temperatures accompanied by dilatometry- and XRD-measurements. Furthermore, the present study reveals for the first time a way for reducing and preventing crack formation that may occur during sintering. The present systematic research provides essential fundamental information before performing electrical measurements necessary in order to understand important factors about charge carriers and electrical transport mechanism.     

Development of a void ratio-moisture ratio-net stress framework for the prediction of the volumetric behavior of unsaturated granular materials

Despite extensive research on the behavior of unsaturated fine-grained materials, there is still a lack of understanding of the volumetric behavior of unsaturated granular materials. In this research, a model has been developed to predict the fundamental volumetric behavior of unsaturated granular materials through loading and wetting state paths. In this regard, a loading-wetting surface was developed in a space of void ratio-moisture ratio-net stress. A distinctive feature of the proposed model is the relative simplicity in obtaining the model parameters using conventional geotechnical testing equipment. Two types of recycled granular materials, commonly applied in unbound pavements were used, namely, recycled crushed brick (CB) and excavation waste rock (WR). The uniqueness of the developed surface was evaluated by employing a number of loading and wetting state paths. The results indicate that the developed surface is unique in its loading state paths; however, it only shows uniqueness in its wetting state paths for stress levels greater than 2000 kPa. The proposed model seeks to introduce the application of the unsaturated soil mechanics theory, for predicting the behavior of granular materials in the field, by providing a practical and cost-effective methodology.     

AG2.0型超声波蒸发传感器遇低温结冰时记录的处理

文章分析了3a马尔康国家基准气候站AG2.0型超声波蒸发传感器观测数据,结果表明:蒸发传感器遇低温结冰时段自动观测数据偏大。对1d中部分时间段内蒸发水结冰、融化以及冬季全天结冰期很短的观测数据进行了分析,分析认为数据偏大主要是因为蒸发桶和测量筒的材料物理性质以及测量的水体面积不同。最后提出了数据记录处理建议。     

Influence of LiBO2 addition on the microstructure and lithium-ion conductivity of Li1+xAlxTi2−x(PO4)3(x = 0.3) ceramic electrolyte

Concerning the safety problems of conventional Li-ion batteries with liquid electrolytes, it is crucial to develop reliable solid-state electrolytes with high ionic conductivity. Li_1+xAl_xTi_2?x(PO₄)₃ (LATP, x = 0.3) is regarded as one of the most promising solid electrolytes due to its high ionic conductivity and excellent chemical stability to humidity.Herein, a new strategy is proposed for improving the sintering behavior and enhancing the ionic conductivity of LATP by using LiBO₂ as the sintering aid via liquid phase sintering. The as-prepared sample LATP with homogeneous microstructure and high relative density of 97.1% was successfully synthesized, yielding high total ionic conductivity of 3.5 × 10^?4 S cm^?1 and low activation energy of 0.39 eV at room temperature. It was found that the addition of LiBO₂ could effectively enhance the densification and increase the ionic conductivity of LATP electrolyte, proving an effective way to synthesis LATP ceramics by a simple and reliable route.     

厚煤层一次采全高煤壁失稳原因及控制技术

针对成庄煤矿四盘区层一次采全高煤壁失稳问题,对观测统计数据进行分析,发现片帮主要表现形式分五种:顶部、腰部、顶底部、底部以及斜切片帮,据此采用对顶板超前预爆破和煤壁超前预加固技术来控制大采高煤壁稳定性,不仅对煤壁失稳的控制取得了良好的效果,而且经济效益显著。可为相似条件下的厚煤层一次采全高煤壁失稳控制提供借鉴。     

Cross-regional integrated energy system scheduling optimization model considering conditional value at risk

Integrated energy system is a very important way to improve energy efficiency. Based on the combined heating cooling and power system, combined with energy storage equipment, a cross-regional integrated energy system scheduling optimization problem is studied. An integrated energy system scheduling optimization model is established that meets the requirements of electrical, heating, and cooling load under a variety of energy sources while both considering the interaction of electrical, heating, and cooling load between regions, and complementation of them within one region. Meanwhile, the value at risk (VaR) theory is introduced and the operating constraints of equipment in the integrated energy system fully considered, the integrated energy system scheduling model with VaR is established. The example shows that the model can realize multi-type electrical, heating, and cooling load optimized by schedule across regions under the premise of satisfying the balance of energy supply and demand, which can reduce the system operation cost. The sensitivity analysis of the minimum expected cost and the influencing factors of conditional VaR is carried out to verify the validity and feasibility of the proposed model.

• An integrated energy system scheduling optimization model is established that meets the requirements of electrical, heating, and cooling load under a variety of energy sources while both considering the interaction of electrical, heating, and cooling load between regions, and complementation of them within one region.
• By using the conditional value at risk theory to consider various types of the integrated energy system complements and evaluates the operational risk of the system under optimal operating conditions of the system.
• The total cost of system scheduling operation is proportional to the storage capacity, which is inversely proportional to the heat storage capacity and inversely proportional to the pipeline capacity within a certain interval.