Nowadays, the intensification of global warming leads to the increased frequency of extreme temperature events. Many studies reported that different regions are facing the threat of extreme hot and cold temperature in some degree. The Qinghai-Tibet Plateau Transportation Project is a major project in China, and it is beneficial for public to study the extreme temperature events along the railway and avoid the risk induced by the extreme temperature. This study estimated the daily maximum, minimum and average near-surface air temperature along the railway. Sixteen extreme temperature indices defined by ETCCDI (the Expert Team on Climate Change Detection and Indicators) were used to represent the extreme temperature events, and Mann-Kendall trend test and Sen's slope estimation method were employed to explore the spatial-temporal variation trends of the extreme temperature along the Qinghai-Tibet Plateau Transportation Corridor from 1981 to 2019. In addition, the response of extreme temperature events to altitude was discussed.The results show that the climate becomes warming along the Qinghai-Tibet Plateau Transportation Corridor from 1981 to 2019, and the extreme hot events are detected in most areas, while the extreme cold events mainly occurs in the east and southwest part. The significant increasing trend is found according to the indices representing the hot events (SU25, TR20, TX90p, TN90p, TXx, TXn, TNx, TNn and WSDI), while the indices representing the cold events (FD0, ID15, TX10p, TN10p and CSDI) show a significant decreasing trend in most areas over the past nearly 40 years. Besides, the extreme temperature events is highly related to altitude variations. Compared with the middle altitude zones, extreme high temperature events tend to occur in the lower altitude zones and the higher altitude zones. It is of great significant to schedule the train in advance and reduce the disasters by investigating the long-term variation trends of extreme temperature events along the Qinghai-Tibet Plateau Transportation Corridor.
The Software Project Scheduling Problem (SPSP) focuses on the management of software engineers and tasks in a software project so as to complete the tasks with a minimal cost and duration. It's becoming more and more important and challenging with the rapid development of software industry. In this paper, we employ a Multi-objective Evolutionary Algorithm using Decomposition and Ant Colony (MOEA/D-ACO) to solve the SPSP. To the best of our knowledge, it is the first application of Multi-objective Ant Colony Optimization (MOACO) to SPSP. Two heuristics capable of guiding the algorithm to search better in the SPSP model are examined. Experiments are conducted on a set of 36 publicly available instances. The results are compared with the implementation of another multi-objective evolutionary algorithm called NSGA-II for SPSP. MOEA/D-ACO does not outperform NSGA-II for most of complex instances in terms of Pareto Front. But MOEA/D-ACO can obtain solutions with much less time for all instances in our experiments and it outperforms NSGA-II with less duration for most of test instances. The performance may be improved with tuning of the algorithm such as incorporating more heuristic information or using other MOACO algorithms, which deserve further investigation.
Long distance charge transfer will lead to the recombination of carriers, which seriously limits the practical application of photoelectrochemical (PEC) detector. In this work, a self-powered solar blind photodetector based on a mixed dimensional α-Ga2O3 nanorod arrays and Cu2O quantum dots has been prepared by a simple hydrothermal method and a two-step impregnation method. Cu2O quantum dots can form type Ⅱ heterojunction with α-Ga2O3 and effectively reduce the recombination of photoinduced electrons and holes due to their short carrier transport distances. Just because of this, α-Ga2O3 photodetectors modified by Cu2O quantum dots present special self-powered optical response at 254 nm, with optical flow densities of 13.88 μA/cm2, large responsivity of 4.57 mA/W, high detection sensitivity of 2.107×109 Jones and fast photoresponse time of 0.815 s/0.978 s. This kind of thought provides a simple and feasible method for the preparation of α-Ga2O3 and other semiconductor oxides based on PEC photodetectors.
The contamination of tetracycline antibiotics has drawn a widely public attention in recent years. In this work, one-dimensional nanofibers ZnGa2O4, ZnO, and S-scheme ZnGa2O4/ZnO heterojunction were prepared by electrostatic spinning to address the soil and aquatic pollution caused by tetracycline hydrochloride (TC-HCl). The S-scheme ZnGa2O4/ZnO heterojunction shows the best removal efficiency of 87.85% for TC-HCl (30 mg/L) within 30 min under 500 W Xe lamp irradiation, which is more than 8 times higher than the self-degradation rate of TC-HCl (11.19%) and the rate of degradation was increased by nearly 20 times on average. By the tests of electrochemical impedance spectroscopy (EIS) and photoluminescence (PL), the enhanced photocatalytic efficiency of S-scheme ZnGa2O4/ZnO heterojunction is ascribed to the increased separation of more photogenerated electrons and holes. This paper provides a new idea for the effective removal of tetracycline antibiotics.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)