The civilization of the Yellow River valley was developed on the basis of millet-farming agriculture. The society in this area began to break up and went to civilization at about 3500 B. C. From 3000B. C.to 2100B. C. of the Longshan Times,many walled towns or cities emerged and thus the dawn of ancient Chinese civilization came into being. The following Erlitou Culture may have been the culture of the Xia people during the Xia Dynasty. The Xia State became the largest one among states in the Yellow River valley after Shaokang's rejuvenation. The Shang and Zhou expanded their forces into the Yangtze River valley and the Yanshan Mountain and the Liaohe River valley. Once ancient Chinese civilization reached its prosperity, the central place of the Yellow River valley established.
Observations of aerosol chemistry and microphysics were made at Chebogue Point, Nova Scotia, from August 16 to September 8, 1993 as part of the North Atlantic Regional Experiment (NAPE) intensive. Most of the aerosols were classified into two groups according to the geometric mean volume diameter (D-gv) of the particles which contributed the greatest volume (sub-0.5 mu m) The group-1 aerosols; representing 33% of the data, are characterized by D-gv of 0.18-0.19 mu m; the group-2 aerosols, representing 50% of the data, are characterized by D-gv of 0.20-0.22 mu m; and the remaining aerosols bear similarities to either groups 1 or 2 but lie outside the D-gv ranges. The differences between these aerosol groups are consistent with the addition of sulfate to the group-2 aerosols via recent processing through cloud. Factors supporting this possibility include the presence of low marine stratus upwind of the site only on days when the group-2 aerosol was observed, the higher D-gv for the group-2 aerosols consistent with the observed size threshold for activation in these clouds, and the association of non-sea-salt SO4= (nssSO(4)(=)) with larger particle sizes for the group-2 aerosols. In general, the masses of the most abundant inorganic and organic ions, nssSO(4)(=) and oxalate, were associated with the main volume of the sub-0.5-mu m particles. Cloud condensation nucleus (CCN) concentrations active at 0.4% supersaturation (CCN0.4) were highly correlated with the concentrations of particles >0.01 mu m and oxalate and moderately correlated with nssSO(4)(=). Concentrations of CCN active at 0.06% supersaturation (CCN0.6) correlate very well with the concentrations of particles >0.19 mu m diameter. In the case of the recently cloud-processed aerosols, for which nssSO(4)(=) is more strongly associated with particles >0.19 mu m, the CCN0.06 also correlate well with nssSO(4)(=) CCN spectra computed using the measured size distributions and aerosol chemistry agree well with the measured CCN.
Money T, Reader S, Qu L, Dunford RP, Moore G. AFLP-based mRNA fingerprinting. Nucleic Acids Research [Internet]. 1996;(13):2616-2617. 访问链接