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Most expressways in China are tolled, making expressway transportation expensive for enterprises. Traditional location theory focuses only on transportation distances and transit costs, making it difficult to explain how expressways influence location decisions of enterprises. This research starts from the perspective of expressway travel times to explain how tolled expressways affect the location choices of new manufacturing enterprises. A geographic information system digital map of expressways for the years 2000–2013 was developed. The origin–destination matrix module was used to calculate the expressway travel times of 293 cities. Count data regression models, including probit, Poisson, zero-inflated Poisson, and negative binomial regression, were applied to empirically study the influence of expressway construction on the location selections of new manufacturing enterprises. The results show that reduced expressway travel time significantly attracts new enterprises and positively affects the location selections of manufacturing enterprises in China. Further, this finding reveals significant heterogeneity across different manufacturing industries.

Salmonella entericasubsp. entericaserovar Typhimurium (ST) is an intracellularly parasitic bacterium. This zoonotic pathogen causes food poisoning and thus imposes a severe threat to food safety. Here, to understand the regulatory roles of the novel transcription factor STM0859 on the response of ST to environmental stress and biofilm formation, the STM0859gene-deficient strain and the complementation strain ?STM0859/STM0859were generated, respectively. Then, its capacity of responding to environmental stresses and biofilm (BF) formation ability under different stresses, including acid, alkali, high salt, cholate, and oxidative stresses was tested. We further analyzed the interaction between the STM0859 protein and the promoter of the acid stress response-related gene rcsBby performing an electrophoresis mobility shift assay (EMSA). The results showed that acid resistance and BF formation capacities of ST-?STM0859strain were significantly weaker, as compared with those of SalmonellaTyphimurium SL1344 (ST-SL1344) wild strain (p< 0.01). Quantitative qRT-PCR analysis showed that the expression levels of acid stress and BF formation-related genes, rcsBand rpoS, of ST-?STM0859strain were significantly reduced at the transcription levels, while the transcription levels of these genes were fully restored in complementation strain ST-?STM0859/STM0859. The results of EMSA showed that STM0859 was capable of binding the promoter DNA fragments of the rcsBgene, suggesting that STM0859 can promote the transcription of the rcsBgene through interaction with its promoter, thereby exerting an indirectly regulatory role on the adaptive responses to acid stress and BF formation of ST. This study provided new insights into the regulatory mechanisms of the LysR family factors on the tolerances of ST under adverse environmental stresses.

The conversion coefficient C between relaxation time T2value and pore size was calibrated by a high-pressure mercury injection experiment, low-temperature nitrogen adsorption experiment, and NMR experiment for clarifying the effect of CO2huff and puff on the production characteristics of crude oil in shale micronano pores. Then, the effects of huff and puff rounds, the soaking time, and injection pressure on the seepage law of crude oil in shale pores from the microscopic scale were studied. The results showed that the pore size of the main occurrence space of shale oil was mainly distributed in the range of 1–100 nm. The oil production of matrix/matrix-fractured shale mainly depended on the first two rounds. Combined with MRI imaging technology, in the initial stage, CO2mainly used the crude oil in the surrounding area of the core for matrix shale, and CO2mainly used the crude oil in the fracture and the surrounding area of the fracture for matrix-fractured shale. With the increase of huff and puff rounds, the crude oil inside the core was gradually utilized through CO2diffusion for matrix shale and matrix-fractured shale. Prolonging the soaking time could significantly improve the recovery degree of crude oil in small pores, which increased by 4.21%, but the lower limit of pore size was reduced by only 2–3.4 nm. Increasing the injection pressure could not only reduce the lower limit of pore size, which was reduced by 2.4–3.9 nm, but also effectively improve the recovery degree of crude oil in different pores. Compared with the matrix shale core, the matrix-fractured shale core was more sensitive to the soaking time and injection pressure. The research results could provide some reference and guidance for the field test of CO2huff and puff in shale reservoirs.