Improved electrochemical performance of silicon-carbon anodes by different conductive agents

Journal of Materials Science: Materials in Electronics - Silica/silicon/polyacrylonitrile (SiO2/Si/PAN) composites were prepared as active anode for lithium-ion batteries (LIBs) using a rational...     

Self-healing and wearable conductive hydrogels with dynamic physically crosslinked structure

Traditional hydrogels are easily frozen or evaporated under colder or hotter temperatures, resulting in their performance degradation. In this paper, polyacrylic acid, sodium alginate, carbon nanotubes, water, and glycerol are used to synthesize self-healing, wearable, freezing resistance, and dry resistance conductive hydrogels with interpenetrating crosslinking network structure. The dynamic cross-linking network structure of the hydrogel can rapidly recover and restructure after damage. In addition, the conductive hydrogels exhibit excellent adhesion to various materials (including PTFE, iron, glass, plastic, and skin). Conductive hydrogel has excellent strain-electric sensing properties, and has high sensitivity, significant stability and repeatability. The conductive hydrogel can be used to test the movement of fingers and knee joints by strain sensing, and has excellent, sensitive, and stable resistance response. Therefore, the conductive hydrogel can be used as a wearable strain sensor for real-time detection of human joint movement. The hydrogel has better environmental adaptability and broad application prospects.

     

Hydrogeochemical Processes and Inverse Modeling for a Multilayer Aquifer System in the Yuaner Coal Mine,Huaibei Coalfield,China

Coal mining can dramatically change hydrogeological conditions and induce serious environmental problems. Fifty groundwater samples were collected from the main aquifers in the Yuaner coal mine (Anhui Province, China). The results show that the main hydrogeochemical processes in the mine include dissolution, precipitation, pyrite oxidation, desulfurization, and cation exchange. The Neogene porous aquifer is affected by groundwater flow conditions; its main hydrogeochemical processes are dissolution of carbonate minerals and gypsum, and cation exchange. The Permian coal measure’s fractured sandstone aquifer was confirmed to be controlled by the region’s geological structure; its main hydrogeochemical processes are desulfurization and cation exchange. The Carboniferous Taiyuan limestone aquifer was determined by both groundwater flow conditions and regional geological structure; its main hydrogeochemical processes are dissolution of carbonate minerals and gypsum, pyrite oxidation, and cation exchange. Additionally, hydrogeochemical inverse modeling of the groundwater flow path confirm the hydrochemistry results and principal component analysis.

     

Cu掺杂对有序Sr3YCo4-xCuxO10.5+δ多晶的结构与物理性能的影响

采用固相反应法制备了四方Sr3YCo4-xCuxO10.5+δ(x=0~1.0)多晶。用热重-差示扫描量热分析,X射线衍射研究了多晶的有序化相变及结构。在固溶范围内(x=0~0.4),观察到有序峰(103)和(215),说明四方Sr3YCo4-xCuxO10.5+δ多晶为超结构,这是由于合成时在1000℃以上发生了吸氧(δ)有序化相变；当x=0.6~1.0时,978℃时在晶界处形成了单斜杂相,破坏了Sr3YCo4-xCuxO10.5+δ多晶的有序。当x=0~0.4时,多晶呈半导体输运行为。随着Cu掺杂量的增加,Co4+提供的空穴载流子浓度增大,电阻率明显下降；由于Cu的固溶,自旋熵增加,载流子浓度和自旋熵的共同作用使x=0~0.2多晶的热电势不变,x=0.4的热电势降低。并且Cu掺杂导致的晶格畸变使Co3+离子由高自旋态转变为高/低自旋混合态,磁化强度和铁磁转变温度(Tc)降低,磁结构由G-型反铁磁转变为铁磁。在进行二次烧结后,300K时电阻率明显降低,热电势为一次烧结的2倍,可能是二次烧结使多晶的有序化程度增大,提高了铁磁有序排列。     

离子型稀土矿山淋洗及尾水富集试验研究

对浸矿后离子型稀土原地浸矿场采用清水进行淋洗，在184天的清水淋洗过程中，尾水氨氮值从最开始的507mg/L，降低至140mg/L，淋洗尾水pH4.52~3.10。淋洗尾水采用两级反渗透膜分离，既回收有价资源稀土，又能使出水氨氮达标。结果表明，产水氨氮浓度稳定低于15mg/L，对稀土的截留率高于98.25%，浓水中稀土离子平均浓度313.4mg/L，可进一步回收稀土资源。     

Characteristic tryptic peptides and gelling properties of porcine skin gelatin affected by thermal action

Thermal action in extraction process had effects on characteristic tryptic peptides identification and gelling properties of porcine gelatin. SDS-PAGE, HPLC-LTQ/Orbitrap high-resolution mass spectrometry, texture analyser and rheometer were used to evaluate collagen depolymerisation degree, characteristic tryptic peptides and gelling properties of gelatins prepared in various thermal actions. Results showed that with increasing temperature and time, depolymerisation degree enlarged, while gel strength, gelling and melting temperature decreased. Mass spectra showed that 47 and 49 common characteristic tryptic peptides were identified in gelatins extracted at 50 °C and 100 °C with various times, respectively. Moreover, 34 common characteristic tryptic peptides were identified in all gelatin samples. Further comparison between this work and our previous investigations yielded 20 common characteristic tryptic peptides, which stably exist in various thermal actions. These common characteristic tryptic peptides may be very helpful for the accurate authentication of porcine gelatin.     

Effects of high hydrostatic pressure on the structure and retrogradation inhibition of oat starch

As a non-thermal processing technology, high hydrostatic pressure (HHP) can be used for starch modification without affecting the quality and flavour constituents. The effect of HHP on starch is closely related to the treatment pressure of HHP. In this paper, we investigated the impacts of HHP treatment pressure (0, 100, 200, 300, 400, 500, 600 MPa) on the microstructure and retrogradation characteristics of oat starch, established the retrogradation kinetic model and elaborated the mechanism of HHP treatment inhibiting the retrogradation of oat starch. Results show that HHP treatment caused the microstructure of oat starch experienced crystallisation perfection (100–300 MPa), crystallisation destruction (400 MPa), crystallisation disintegration and gelatinisation (500–600 MPa). Results of oat starch retrogradation showed that, after treated at 500 MPa for 15 min, the recrystallisation rate of oat starch was reduced, the formation of nuclei at the early stage of oat starch retrogradation suppressed and its nucleation mode was changed from instantaneous to spontaneous, otherwise, the mobility of water in oat starch gel system reduced. Therefore, 500 MPa treated for 15 min can inhibits the retrogradation of oat starch. This study provides theoretical guidance for the application of HHP technology in starch modification and food processing.     

Lactobacillus plantarum ZLC-18 fermentation improve tyrosinase inhibition activity and antioxidant capacity in soybean hulls

Soybean hulls, the main byproduct in soybean processing, have many biological activities. However, the value of this byproduct is still far from being fully exploited. In this study, we investigated the anti-tyrosinase and antioxidant capacities in soybean hulls fermented by Lactobacillus plantarum ZLC-18 (L. plantarum ZLC-18). We found that L. plantarum ZLC-18 fermentation could markedly improve the anti-tyrosinase and antioxidant activities of soybean hulls. The anti-tyrosinase and antioxidant activities were positively correlated with the total phenolic and flavonoid contents. UPLC–MS analysis suggested that phenolic compounds (daidzin, genistin, vanillic acid and so on) were increased in soybean hulls after fermentation, and some of these compounds were shown to have anti-tyrosinase and antioxidant activities. Our study demonstrates that fermentation is an efficient strategy to enhance the bioactive function of soybean hulls. Moreover, this study provides evidence that soybean hulls can be used as a kind of functional food ingredient, thereby improving their economic benefits.     

Research and Application of Plunger Airlift Draining Gas Recovery Intelligent Control Technology in Shale Gas Horizontal Wells

Chemistry and Technology of Fuels and Oils - For shale gas wells, plunger lift is challenged by the difficulties like difficult tool tripping in and high operation risks due to the liquid phase...