The research on citizens' color preference is an important prerequisite for the scientific formulation of urban color planning. Color preferences are normally identified over the Internet or through questionnaire surveys and adjective descriptions. But the analysis has its limitations due to the uncertainty of color descriptions. Based on the quantitative analysis of the three attributes of hue, blackness, and chromaticness, this article obtains the inherent law of color preference of citizens, and compares it with the results of color adjective preference done by our research group before, which can supplement the accuracy of adjective description, so as to provide a reference for the color positioning of urban color planning. This article obtains the three attributes of color samples chosen by the public in the form of questionnaires as well as color sample selections. Among which 36 representative sites in Shanghai were selected according to the six types of land use. Adopting a more detailed method of dividing nine color series, viz. yellow (Y), red‐yellow (YR), red (R), red‐blue (RB), blue (B), blue‐green (BG), green (G), green‐yellow (GY), and the neutrals (WS). Moreover, chi‐square test and multiple logistic regression model were used to analyze the color preference factors and explore the relationship between citizen attributes and the three attributes of color sample selection. Research findings are as follows: (a) The citizens' favorite colors of urban architecture center round red, high whiteness, and mid‐low chromaticness. (b) The main factors that influence citizens' hue preference include gender, age, and monthly income; the main factors that influence citizens' blackness preference include: questionnaire distribution points, the frequency of coming to Shanghai, and whether to go abroad; gender and age are the main factors that affect citizens' chromaticness preference. (c) Compared with the previous studies on adjective selection among citizens, it is found that the effect of gender, age, monthly income, and educational background on color preference is similar; differences are in the occupational types, frequency of coming to Shanghai, and whether travels abroad.

Soil is the foundation of agricultural sustainable development. After nearly 40 years of rapid economic development and highly intensive agricultural production, our country’s farmland soil is facing severe soil heavy metal pollution. The situation of heavy metal pollution in farmland soil in China is not optimistic and poses a threat to the safe production of agricultural products and food safety. Therefore, the treatment and restoration of soil heavy metal pollution has received extensive attention. According to the actual situation of soil pollution in our country, the prevention, control and remediation of soil heavy metal pollution has become a major national demand. This article discusses the current status of soil heavy metal pollution control in our country and the main remediation technologies. Aiming at the characteristics and shortcomings of various remediation technologies, it proposes the improvement and development direction of heavy metal contaminated soil remediation technology to provide reference for soil remediation technology research.

Rheum palmatum L. is a perennial herb of the Rheum genus Polygonaceae. It is a traditional Chinese herbal medicine which has extremely high medicinal value. Rhubarb has scarce seeds in subtropical regions, and natural planting conditions have limitations. In recent years, the demand of rhubarb has increased, and the means of sowing and raising seedlings can no longer meet the needs of the market. Traditional sowing and propagation methods have limitations such as long cycle and low reproduction coefficient. Tissue culture technology can shorten the reproduction cycle that increase the reproduction coefficient and maintain the excellent characteristics of the parents, which is an effective way to promote the large-scale and commercial production of fine varieties of rhubarb. The results of the study showed that: (1) Analysis of the characteristics of Qinghai Rhubarb seeds. (2) Seed sterilization treatment. (3) Primary culture medium selection. (4) Callus induction. (5) Callus proliferation culture. (6) Hypocotyl callus bud differentiation.(7)Rooting culture. (8) Qinghai Rhubarb tissue culture seedling transplantation. Using the method of the present invention to establish a Qinghai Rhubarb in vitro culture aseptic propagation system, high-quality Qinghai Rhubarb seeds as explants and different hormone medium ratios, Qinghai Rhubarb hypocotyl induction rate reached 90%, and the proliferation coefficient reached 4.3. The survival rate of transplanting tissue cultured seedlings reaches 95% which can improve the reproduction efficiency of Qinghai Rhubarb, and provide theoretical basis and technical support for subsequent research on transgenic and genetic improvement. It can also provide a basis for medicinal value for the systematic research and commercial production of Qinghai Rhubarb.