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Recently, great breakthroughs in natural gas exploration have been achieved in the Nanpu Sag, Bohai Bay Basin, eastern China; however, the genetic type and formation mechanisms of the gas are still unclear, impeding further exploration. Chemical and isotopic compositions were investigated to determine the origins for the gas. Three groupings of the natural gases are recognized: oil-type gas, coal-type gas, and mixed-source gas. The oil-type gases are relatively depleted in 13 C (δ 13 C 1 < −43‰); δ 13 C 2 < −29‰ and low wetness (0.60–0.89). The coal-type gases are enriched in 13 C (δ 13 C 1 > −40‰; δ 13 C 2 > −28‰) with higher wetness (0.80–0.95). The third grouping of gases exhibits intermediate molecular and isotopic values. Most of the gases in the shallow layers of the No. 1 and 4 structural belts have δ 13 C values similar to those of underlying gases and display evidence for microbial alteration. Primary cracking of kerogen is responsible for the generation of most of this gas. Pyrolysis of the source rocks combined with maturity estimations revealed that the relatively shallow oil-type gas was derived primarily from Oligocene and Eocene (Ed 3 –Es 1 ) source rocks bearing Type I–II 1 kerogen, whereas the coal-type gas was generated from the Eocene (Es 2+3 ) source rocks containing II 2 –III kerogen. We concluded that the kerogen type and maturity of the source rocks and the activity of source-connecting faults primarily controlled the distribution of the different gases. We suggest that there is significant deep gas potential in the Nanpu Sag, perhaps even over the whole Bohai Bay Basin, that would be prospective for further deep gas exploration in the area. [ABSTRACT FROM AUTHOR]

Photonic integrated circuits (PICs) technologies in China have made rapid progress in the past decade. In this paper, recent advances and future prospective of PICs in China are introduced and discussed, respectively. More than nine major projects in the field of PICs have been issued. Various material platforms and technologies have been developed to realize photonic integrated devices for many applications focusing on broadband communication, such as optical and wireless network, optical interconnects, and optical coherent communication. Many research achievements and breakthrough have been made under the support of these projects, such as silicon photonics transceiver, InP-based transceiver, and optical and microwave signal processing chips. It can be expected that the PICs technology will be continuously supported in the next five years, since it has been considered as one of the key enabling technologies for supporting several national major assignments and strategies, such as broadband communication, supercomputing and datacenter. [ABSTRACT FROM AUTHOR]