Energy-saving and emission-reduction potential of fuel cell heavy-duty trucks in China during the fuel life cycle.

Exploring alternative fuels and advanced vehicle technology is a crucial strategy for vehicle emission reduction. Fuel cell heavy-duty trucks (FC-HDTs) have a promising application prospect to alleviate the high energy consumption and emissions of road freight, but their environmental performance during the fuel life cycle should be further studied. This study is aimed at evaluating the fossil fuel consumption and GHG emissions of FC-HDTs in China using the updated GREET model. The results show that (1) comparing various hydrogen production pathways, it is found that the coke oven gas (COG) pathway can provide the best environmental performance, while the energy consumption and greenhouse gas (GHG) emissions of the coal gasification (CG) and grid power water electrolysis (GPWE) pathways will be significantly decreased in the future. (2) Among the involved vehicles in China, FC-HDT with GVWR18 has the greatest energy-saving and emission-reduction potential. (3) The application of carbon capture and storage (CCS) technology in hydrogen production is conducive to improving the emission-reduction effect of FC-HDT while increasing its energy consumption slightly. The key to achieving upstream carbon neutrality is to optimize the hydrogen production structure and electricity mix, along with adjusting the hydrogen production process and transportation mode. Furthermore, the fuel economy and payload of the FC-HDT affect its environmental performance, indicating the importance of improving the technology of the drivetrain, fuel cell, and hydrogen storage tank.

Impact assessment of crude oil mix, electricity generation mix, and vehicle technology on road freight emission reduction in China.

To achieve net zero emissions, the global transportation sector needs to reduce emissions by 90% from 2020 to 2050, and road freight has a significant potential to reduce emissions. In this context, emission reduction paths should be explored for road freight over the fuel life cycle. Based on panel data from 2015 to 2020 in China, China's version of the GREET model was established to evaluate the impact of crude oil mix, electricity mix, and vehicle technology on China's reduction in road freight emissions. The results show that the import share of China's crude oil has increased from 2015 to 2020, resulting in an increase in the greenhouse gas (GHG) emission intensity of ICETs in the well-to-tank (WTT) stage by 7.3% in 2020 compared with 2015. Second, the share of China's coal-fired electricity in the electricity mix decreased from 2015 to 2020, reducing the GHG emission intensity of battery electric trucks (BETs), by approximately 6.5% in 2020 compared to 2015. Third, different vehicle classes and types of BETs and fuel cell electric trucks (FCETs) have different emission reduction effects, and their potentials for energy-saving and emission reduction at various stages of the fuel life cycle are different. In addition, in a comparative study of vehicle technology, the results show that (1) for medium-duty trucks (MDTs) and heavy-duty trucks (HDTs), FCETs have lower GHG emission intensity than BETs, and replacing diesel-ICETs can significantly reduce GHG emissions from road freight; (2) for light-duty trucks (LDTs), BETs and FCETs have the highest GHG emission reduction potential; thus, improving technologies such as electricity generation, hydrogen fuel production, hydrogen fuel storage, and transportation will help to improve the emission reduction capabilities of BETs and FCETs. Therefore, policymakers should develop emission standards for road freight based on vehicle class, type, and technology.

Silk fibroin/copolymer composite hydrogels for the controlled and sustained release of hydrophobic/hydrophilic drugs.

In the present study, a composite system for the controlled and sustained release of hydrophobic/hydrophilic drugs is described. Composite hydrogels were prepared by blending silk fibroin (SF) with PLA-PEG-PLA copolymer under mild aqueous condition. Aspirin and indomethacin were incorporated into SF/Copolymer hydrogels as two model drugs with different water-solubility. The degradation of composite hydrogels during the drug release was mainly caused by the hydrolysis of copolymers. SF with stable ß-sheet-rich structure was not easily degraded which maintained the mechanical integrity of composite hydrogel. The hydrophobic/hydrophilic interactions of copolymers with model drugs would significantly alter the morphological features of composite hydrogels. Various parameters such as drug load, concentration ratio, and composition of copolymer were considered in vitro drug release. Aspirin as a hydrophilic drug could be controlled release from composite hydrogel at a constant rate for 5 days. Its release was mainly driven by diffusion-based mechanism. Hydrophobic indomethacin could be encapsulated in copolymer nanoparticles distributing in the composite hydrogel. Its sustained release was mainly degradation controlled which could last up to two weeks. SF/Copolymer hydrogel has potential as a useful composite system widely applying for controlled and sustained release of various drugs.

Silk fibroin/sodium alginate fibrous hydrogels regulated hydroxyapatite crystal growth.

Use of organic templates for controlling the growth of inorganic crystals is one of the research topics in biomimetic field. In particular, oriented growth of hydroxyapatite (HAp) in organic fibrous matrix is provided a new view angle to study biomineralization of bone and its potential biomedical applications. The crystallization of HAp in fibrous hydrogels could mimic such biomineralization. In this paper, we report HAp nanorod crystal synthesized successfully by a biomimetic method using calcium chloride and ammonium dihydrogen phosphate as reagents in the presence of silk fibroin/sodium alginate (SF/SA) fibrous hydrogels. The effects of influence factors such as mineral times, pH, and temperature on controlling HAp nanorod crystals are discussed. The elongated HAp nanorods with rectangular column are grown with the increase of mineral times in biomimetic process. By changing pH, HAp nanorod crystals are obtained at alkaline condition in fibrous hydrogels. Moreover, compared to other temperatures, rod-shaped HAp crystals were formed at 20°C. The results imply this to be an effective method for preparing HAp crystals with controllable morphology for bone repair application.

[The investigation about the influence of deviated nasal septum on the adolescents learning quality].

OBJECTIVE: To investigate the incidence rate of deviated nasal septum (DNS) of the young men who are going to join the army, and of the students in key high schools in Jimo, and record their educational background, then analysis the influence of DNS on the youth's learning quality. METHOD: Random select 3085 young men who are going to be recruited in 2006-2008, and 2628 students in 3 key high schools of Jimo. Investigate the two groups' incidence rate of DNS and make a correlative statistic analyses with their educational background. RESULT: There are 395 young men with DNS, which account 12.8% of the 3085 men, with the educational background of college degree and above account 3.0%; high school diploma 12.4%; junior secondary education 27.5%. One hundred and ninety-four students with DNS in key high schools, which account 7.4, and the subsequent entrance examination results shows, undergraduate students account 14.9%, junior college students and considerable education 32.5%, and graduates 52.6%. CONCLUSION: DNS can influence the learning quality of the adolescent. It is necessary to operate on those patients and improve the complaint symptom.