PSR-FCCLP model based total maximum allocated loads optimization of TN and TP in Bohai Bay.

Eutrophication is a global problem for coastal ecosystems, one that Bohai Bay, China, has been severely afflicted due to rapid economic and social development in the past decades. It was urgent to manage the total maximum allocated loads (TMALs) of the total nitrogen (TN) and total phosphorus (TP) on land-based, which was closely related to coastal eutrophication. In this study, from the perspective of economy-resources-environment (ERE) system, we presented the fuzzy credibility constrained linear programming based on pressure-state-response (PSR-FCCLP) model, which calculated the TMALs of TN and TP at three credibility levels (λ = 0.55, 0.75, and 0.95) in Bohai Bay. The results showed that when the credibility level increased from 0.55 to 0.95, the TMALs of TN and TP would decrease from 13,573.38 t/a to 12,820.00 t/a and from 2665.58 t/a to 2514.90 t/a, respectively. This study will provide support for environmental management in coastal regions.

Study on Mechanical Properties of Basalt Fiber Shotcrete in High Geothermal Environment.

With the development of infrastructure, there are growing numbers of high geothermal environments, which, therefore, form a serious threat to tunnel structures. However, research on the changes in mechanical properties of shotcrete under high temperatures and humid environments are insufficient. In this paper, the combination of various temperatures (20 °C/40 °C/60 °C) and 55% relative humidity is used to simulate the effect of environment on the strength and stress-strain curve of basalt fiber reinforced shotcrete. Moreover, a constitutive model of shotcrete considering the effect of fiber content and temperature is established. The results show that the early mechanical properties of BFRS are improved with the increase in curing temperature, while the compressive strength at a later age decreases slightly. The 1-day and 7-day compressive strength of shotcrete at 40 °C and 60 °C increased by 10.5%, 41.1% and 24.1%, 66.8%, respectively. The addition of basalt fiber can reduce the loss of later strength, especially for flexural strength, with a increase rate of 11.9% to 39.5%. In addition, the brittleness of shotcrete increases during high temperature curing, so more transverse cracks are observed in the failure mode, and the peak stress and peak strain decrease. The addition of basalt fiber can improve the ductility and plasticity of shotcrete and increase the peak strain of shotcrete. The constitutive model is in good agreement with the experimental results.

Copper-catalyzed intramolecular cyclization to N-substituted 1,3-dihydrobenzimidazol-2-ones.

An efficient and convenient method was developed for preparing N-substituted 1,3-dihydrobenzimidazol-2-ones from N'-substituted N-(2-halophenyl)ureas via a CuI/DBU-catalyzed cyclization in DMSO under microwave heating. High yields were obtained and a variety of functional groups were tolerated under these conditions, including N'-aryl, alkyl, heterocyclic, various N-(substituted 2-halophenyl) and N-(2-iodopyridyl)ureas.

Microwave-assisted efficient and convenient synthesis of 2,4(1H,3H)-quinazolinediones and 2-thioxoquinazolines.

An efficient and convenient method was developed for the preparation of 2,4(1H,3H)-quinazolinediones and 2-thioxoquinazolinones. Substituted methyl anthranilate reacted with various iso(thio)cyanates in DMSO/H2O without any catalyst or base by using microwave irradiation to generate diversity on the 2,4(1H,3H)-quinazolinediones or 2-thioxoquinazolinones. A variety of substrates can participate in the process with good yields and high purities, making this methodology suitable for library synthesis in drug discovery efforts.