多级矩阵结构冷却除湿器的除湿性能研究

为了降低空分系统压缩机功耗,提高压缩机运行可靠性,本文提出一种用于压缩机进气除湿的多级矩阵结构的冷却除湿器,并搭建了多级冷却除湿实验台,测试了除湿器的除湿性能。实验结果表明,在进口空气含湿量和温度固定为11.7g/(kg干空气)和24.4℃时,当空气质量流量由0.48 kg/s增至0.78 kg/s,空气出口含湿量由7.1 g/(kg干空气)增至7.7g/(kg干空气);在进口空气质量流量和温度固定为0.53 kg/s和25.2℃时,当冷却水温度由6.9℃升至11.9℃,空气出口含湿量由7.1 g/(kg干空气)增至9.4 g/(kg干空气)。本研究针对除湿器内部传热传质过程建立了稳态数值模型,将模拟结果与实验结果进行对比,结果表明:该模型对于除湿器出口空气含湿量和温度的平均误差分别为8.6%和2.1%,显示出较好的可靠性;并进一步模拟研究了多级矩阵结构与单级叉流结构冷却除湿器的除湿性能,发现采用多级结构可以有效提高除湿效率,在进口空气质量流量和冷却水质量流量分别为0.53 kg/s和0.3 kg/s时,多级结构的除湿量可以提高4.3%,除湿效率可以提高2.5%;通过增加填料模块的长度...     

DTI扩散张量的一种稳健估计方法

为了获得更精确的DTI扩散张量场,提出了一种基于约束M估计子的稳健估计方法,首先对扩散加权图像序列进行双树复数小波降噪预处理,以减少热噪声影响,然后通过试探法找到一个合适的回归起始点,并通过Cholesky分解对扩散张量进行正定约束,最后寻找局部最小获得DTI扩散张量的约束M估计,并在模拟二阶张量场和真实DTI数据集上进行了实验.与最小二乘法和M估计子回归模型相比,该方法可以更有效地排除热噪声和生理性离群点影响,对DTI扩散张量估计很有价值.     

LiNi1/3Co1/3Mn1/3O2/polypyrrole composites as cathode materials for high-performance lithium-ion batteries

Polypyrrole is successfully introduced to enhance the reaction stability and ionic conductivity of LiNi_1/3Co_1/3Mn_1/3O₂ material through an ultrasound dispersion method and applied as cathode materials for lithium-ion batteries. This polymer can significantly advance the electrochemical properties. Expectedly, the 8 wt.% LiNi_1/3Co_1/3Mn_1/3O₂/polypyrrole composite has lower mixing degree of Li⁺/Ni²⁺, higher c/a value, which delivers the first discharge capacity of 199.2 mAh g⁻¹, which abate to 121.3 mAh g⁻¹ in the 300th cycle at 0.2 C between 2.5 and 4.5 V. Even at 3 C, it continues to reveal a reversible capacity of 86.4 mAh g⁻¹ after 100 cycles. All the consequences implied that the 8 wt.% LiNi_1/3Co_1/3Mn_1/3O₂/polypyrrole verified a minor charge transfer resistance and better Li⁺ diffusion ability, hence establishing preferable rate and cycling performance compared with the primordial LiNi_1/3Co_1/3Mn_1/3O₂.     

Temporal Action Detection with Structured Segment Networks

International Journal of Computer Vision - This paper addresses an important and challenging task, namely detecting the temporal intervals of actions in untrimmed videos. Specifically, we present a...     

The effects of temperature and Ce-dopant concentration on the synthesis of zirconolite glass-ceramic

Zirconolite based glass-ceramic has been deemed as a promising waste form for high-level waste (HLW). In this study, the zirconolite (nominally CaZrTi₂O₇) glass-ceramic based on a SiO₂-B₂O₃-Na₂O-CaO-ZrO₂-TiO₂-Al₂O₃ system was sought to be synthesized by two-step thermal treatment. The temperature effects such as nucleation temperature and cooling rate were studied. The influence of the Ce-dopant concentration on crystallization behavior was also investigated. For characterization, powder X-ray diffraction (XRD), thermogravimetry-differential scanning calorimeter (TG-DSC) and scanning electron microscopy (SEM) were applied. Our results illustrate that homogeneous zirconolite with the particle size of 1.8?μm can be the target phase when the glass matrix underwent a rapid cooling process and the nucleation temperature was controlled at around 860?°C. Besides, the results also indicate that the distribution of the zirconolite along with its lattice parameters change regularly as the increase of CeO₂ concentration. A larger crystal size of zirconolite phase and some trace amounts of precipitated phases are observed when the CeO₂ concentration exceed 3?wt%. This work emphasizes the synthesis of zirconolite glass-ceramic in a SiO₂-B₂O₃-Na₂O-CaO-ZrO₂-TiO₂-Al₂O₃ system, which is expected to provide basic technical data for underground disposal of HLW.     

Latent curing agent DDM-PMMA microcapsule for epoxy resin

A microcapsule-type latent curing agent is prepared by solvent evaporation method with diaminodiphenylmethane (DDM) as the core material and PMMA as the wall material. The chemical structure, surface morphology, core content, and curing characteristics of as-prepared microcapsule-type curing agent are characterized by FTIR, SEM, TGA, and DSC. The results show that the obtained microcapsules have smooth surface and the core content is about 20 wt %. The one-component adhesive consisting of DDM-PMMA microcapsule and epoxy resin can be cured within 30 min at 130 °C, and the room temperature latent period is more than 30 days. In addition, the internal reasons influencing the core content of microcapsules are analyzed by comparing and analyzing the structural compatibility of three kinds of wall material PMMA, PS, and polyetherimide with DDM. The results show that the core content is affected by the compatibility of wall material and core material. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47757.     

Simultaneous optimization of ultrasound-assisted extraction for total flavonoid content and antioxidant activity of the tender stem of Triarrhena lutarioriparia using response surface methodology

Food Science and Biotechnology - The asparagus of Triarrhena lutarioriparia (TL) is a popular vegetable with abundant chemical compounds in China. This study aims to optimize the...     

Emerging trends of culturing microalgae for fish‐rearing environment protection

The application of microalgae biotechnology, which can recover nutrients from wastewater, improve water quality, and feed some aquatic animals, is becoming an emerging trend in the development of eco‐friendly aquaculture. Previous studies explored a variety of models to support the use of microalgae in aquaculture practice, verifying the feasibility and advantages of microalgae‐based aquaculture. However, a couple of bottlenecks and problems jeopardizing the application of microalgae biotechnology in aquaculture are discovered in the research and industrial practice. This work, hence, summarizes the research progress and the current opinions relating with the microalgae‐based aquaculture and proposes some critical thoughts about the bottlenecks challenging its industrial implementation. © 2020 Society of Chemical Industry (SCI)     

合成糊料印花的水洗新工艺

海藻酸钠作为成熟的活性印花糊料被广泛使用,但需要同时使用大量的尿素,从而使排放污水总氮超标,严重影响环境,所以必须寻找新的解决方案。介绍了一种合成糊料RECA,通过不同的水洗实验寻找更加合理的工艺,以改善对环境的影响。     

Preparation of imidazole embedded polyurea microcapsule for latent curing agent

The IZ-PU microcapsule-type curing agent was prepared by interfacial polymerization method. The shell-core structure of the IZ-PU microcapsules was demonstrated by IR and SEM. The core content and coating efficiency of the IZ-PU microcapsules were analyzed by DSC test of the one-component adhesive consisting of IZ-PU microcapsules and epoxy resin. The results showed that the IZ-PU microcapsules is a proper latent curing agent to epoxy resin, its latency at room temperature is longer than 30 days.