China’s economic structure has made subtle changes with the development of digital economy. Along with the marginal diminishing effect of Chinese monetary policies and the increase of the overall leverage ratio, the Chinese economic growth mode of relying on real estate, trade and infrastructure construction in the past will not be sustainable in the next decade. This paper makes a theoretical analysis on the reduction of the search cost in digital economy. Also, this paper used empirical methods to study the relationship between China’s economic growth and digital infrastructure construction. In conclusion, the digital economy has reduced the search cost for people, and big data will become a product factor participating in labor distribution. In addition, this paper proposes for the first time that digital economy can effectively restrain inflation. The Chinese government needs to attach importance to the issue that current internet enterprise oligarchs will probably monopolize the usage of big data in the development of digital economy in the future and become the obstacle to effective economic growth. In addition, close attention should be paid to the vulnerabilities of financial and taxation systems for digital economic entities to avoid continuous disguised tax subsidies to internet oligarchs, thus preventing industrial monopoly.

Taking the geographic information industry as the research object, using the authorized invention patent data, this paper puts forward the research method of industrial innovation chain structure based on the geographic information industry chain. Then, from the perspective of overall structure and specific regional structure, the development status of the innovation chain is quantitatively evaluated, which is helpful to all countries in the world. The structural integrity and leading links of the innovation chain especially in China, the United States and Japan are compared and analyzed. The results show that: (1) from the perspective of the overall structure, the global innovation chain presents an “inverted triangle” structure due to the weak innovation ability of downstream links. From the perspective of specific regional structure, the innovation chain of geographic information industry in most countries and regions is incomplete, and there are broken links or isolated links. The global innovation chain except China has cracks between the upstream and downstream due to the relative weakness of the midstream links, showing “hourglass-shaped” structure with a wide upper part, narrow lower part and narrow middle part. (2) Relatively speaking, China’s industrial innovation chain is relatively complete, and the midstream link has significant comparative advantages in the global market. However, the industry university research cooperation in the innovation chain is weak, the degree of marketization is low, and the technological competitiveness lags behind that of the United States.

In order to explore the influence of the ferroelectric surface on the structure and properties of semiconductor oxides, the growth of CdS nanocrystals was regulated and controlled by taking single-crystal perovskite PbTiO₃ nanosheets as the substrate through a simple hydrothermal method. Through composition design, a series of PbTiO₃-CdS nanocomposite materials with different loading concentrations were prepared, and their microstructure and photocatalytic properties were systematically analyzed. Studies show that in the prepared product, CdS nanoparticles selectively grow on the surfaces of PbTiO₃ nanosheets, and their morphology is affected by the exposed surfaces of PbTiO₃ nanosheets. There is a clear interface between the PbTiO₃ substrate and CdS nanoparticles. The concentration of the initial reactant and the time of hydrothermal reaction also significantly affect the crystal morphology of CdS. Photocatalysis studies have shown that the prepared PbTiO₃-CdS nanocomposite material has a significant degradation effect on 10 mg/L of Rhodamine B aqueous solution. The degradation efficiency rises with the increase of CdS loading concentration. When degrading 10 mg/L Rhodamine B aqueous solution, the PbTiO₃-CdS sample with a mass fraction of 3% can reach a degradation rate of 72% within 120 min.

Municipal authorities in industrialized and in developing countries face unceasingly the issues of congestion, insufficiency of transport means capacity, poor operability of transport systems and a growing demand for reliable and effective urban transport. While the expansion of infrastructure is generally considered as an undesirable option, in specific cases, when short links or ring roads are missing, new infrastructure projects may provide beneficial solutions. The upgrading and renewal of existing networks is always a challenge to the development of a modern city and the welfare of citizens. Central governance and management of transport systems, the establishment of smart and digital infrastructure, advanced surveillance and traffic monitoring, and intra-city energy-harvesting policy are some of the steps to be taken during the transition to a green and sustainable urban future.
Municipal authorities have also to consider other options and strategies to create a citizen-friendly setting for mobility: diminish the need for trips (digitalization of services, e-commerce, etc.), shift from private to public transport and transform the urban form to promote non-motorized transport in favor of the natural environment and public health. A citizen-friendly policy based on the anticipation of future needs and technological development seems to be a requisite for European cities searching for a smooth integration of their networks into urban space.

An α, α^′-dipyridyl adduct of a complex compound hexaaquatribenzene-1,2,4,5-tetracarbonatotetra iron (III) with porous structure was synthesized for the first time. According to the results of elemental, X-ray, IR-spectroscopic and differential-thermal analyses the individuality, chemical formula, thermal destruction, and form of coordination of acidic anion and dipyridyl were established. During interaction of a complex compound with dipyridyl, it completely loses all crystallization molecule of water resulting in a compound with a chemical formula of Fe₄(C₆H₂(COO)₄)₃(dpy)₂(dipyridyl). Using the identification of diffraction pattern the parameters of lattice cell of the complex compound were determined.