Search

To reduce climate change, absorbing CO2 directly from the air (DAC) with high-efficient CO2 absorption, low-cost, and environmentally friendly system has been attracted much attention for several decades. In this work, a series of aqueous diamine solutions was examined for 400 ppm CO2 absorption at ambient temperature. The absorbents exhibited CO2 absorption with molar ratio of 1 molCO2/molamine, and aqueous isophorone diamine (IPDA) in particular showed >99% CO2 removal even under a 500 mL min-1 flow of 400 ppm CO2-N2 with the contact rate of 13,761.5 h-1 between CO2 and IPDA aqueous solution and the CO2 absorption rate of 4.46 mmol/L min. A precipitate of carbamic acid of IPDA was formed by reaction with CO2, and the CO2 removal efficiency was enhanced by increasing the solution viscosity by the formation of this precipitate. The CO2 was absorbed in aqueous IPDA solution as carbamic acid of IPDA and bicarbonate/carbonate species, and the absorbed CO2 could desorb by heating under O2-containing gas flow, which indicates our system is applicable to the CO2 condensation for a plant growth. This work provides fundamental information to establishing a solid-liquid phase change system with a high-efficient and environmentally friendly DAC system using aqueous solvent. [ABSTRACT FROM AUTHOR]

Ti–NiCrAl coating was fabricated on the substrate of Ti6Al4V alloy by laser cladding (LC), in which the Ti originated from the diluted element of substrate. The results show the Ti–NiCrAl coating is composed of NiTi and NiTi2 phases with the trace CrO and Al2O3 phases, in which the oxide phases are acted as an effective barrier to provide high-temperature protection for the substrate. The coefficient of friction (COF) and wear rate of Ti–NiCrAl coating are decreased with the elevated temperatures, which is attributed to the phase transformation of NiTi and NiTi2. The wear mechanism is the combination of abrasive wear and adhesive wear, in which the phase transformation of NiTi and NiTi2 phases play the roles of friction reduction and wear resistance. [ABSTRACT FROM AUTHOR]

When recovering a shredded document that has numerous mixed pieces, the difficulty of the recovery process can be reduced by clustering, which is a method of grouping pieces that originally belonged to the same page. Restoring homologous shredded documents (pieces from different pages of the same file) is a frequent problem, and because these pieces have nearly indistinguishable visual characteristics, grouping them is extremely difficult. Clustering research has important practical significance for document recovery because homologous pieces are ubiquitous. Because of the wide usage of Chinese and the huge demand for Chinese shredded document recovery, our research focuses on Chinese homologous pieces. In this paper, we propose a method of completely clustering Chinese homologous pieces in which the distribution features of the characters in the pieces and the document layout are used to correlate adjacent pieces and cluster them in different areas of a document. The experimental results show that the proposed method has a good clustering effect on real pieces. For the dataset containing 10 page documents (a total of 462 pieces), its average accuracy is 97.19%. [ABSTRACT FROM AUTHOR]

Wearable and sensitive photodetectors (PDs) have been demonstrated based on a blend film of PbS quantum dots (QDs) and QDs modified multiwalled carbon nanotubes (MWCNTs). Owing to the synergetic effect from high light sensitivity of PbS QDs and excellent conductive and mechanical properties of MWCNTs, the blend PDs show high sensitivity and flexibility performance: device responsivity and detectivity reach 583mA/W and 3.25 × 1012Jones, respectively, and could stand large number (at least 10000 cycles) and wide angle (up to 80°) bending. Furthermore, the wearable and sensitive PDs have been applied to measure the heart rate in both red and near infrared (NIR) ranges. The presented PDs are expected to work as sensor candidates in integrated electronic skin. [ABSTRACT FROM AUTHOR]

Continuous extruding/ extending forming process for A20/7 alloy in semisolid state was proposed through installing extending die at the outlet of shearing-cooling-rolling (SCR) machine. A series of experiments to produce flat bar of A 2017 alloy were carried out. The forming process, metal flow behavior in die and microstructure and mechanical property of products were investigated. It is shown that if the pouring temperature of melt was higher, the die was filled with semi-solid slurry with low solid fraction and periodical cracks would occur on the product surface; If its pouring temperature was lower or the preheating temperature of die was lower, semisolid slurry would solidify rapidly and block the die after entering the cavity. The analysis of mass flow trace shows that the semi-solid slurry moves forward layer by layer and fills the die extending caviiy in radiation manner and the velocity of mass flow in the central area of extending cavity and exit of mould is the maximum, and then decreases gradually from the center to both sides of die wall. By increasing the die extending angle, the velocity of mass flow becomes more homogeneous. Under rational process control and die design, the A2017 flat bar with transverse section of 10 × 50 mm and with good surface and fine equiaxed grains can be obtained by continuous extruding/ extending forming process. The product’s tensile strength and elongation are 420.5 MPa and 14.2%, respectively. [ABSTRACT FROM AUTHOR]