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Caffeine is a crucial secondary metabolic product in tea plants. Although the presence of caffeine in tea plants has been identified, the molecular mechanisms regulating relevant caffeine metabolism remain unclear. For the elucidation of the caffeine biosynthesis and catabolism in Camelliaplants, fresh, germinated leaves from four Camelliaplants with low (2), normal (1), and high (1) caffeine concentrations, namely, low-caffeine tea 1 (LCT1, Camellia crassicolumna), low-caffeine tea 2 (LCT2, C. crassicolumna), Shuchazao (SCZ, C. sinensis), and Yunkang 43 (YK43, C. sinensis) were used in this research. Transcriptome and purine alkaloids analyses of these Camellialeaves were performed using RNA-Seq and liquid chromatography–mass spectrometry (LC–MS). Moreover, 15N-caffeine tracing was performed to determine the metabolic fate of caffeine in leaves of these plants. Caffeine content was correlated with related gene expression levels, and a quantitative real-time (qRT) PCR analysis of specific genes showed a consistent tendency with the obtained transcriptomic analysis. On the basis of the results of stable isotope-labeled tracer experiments, we discovered a degradation pathway of caffeine to theobromine. These findings could assist researchers in understanding the caffeine-related mechanisms in Camelliaplants containing low, normal, and high caffeine content and be applied to caffeine regulation and breeding improvement in future research.

The indoor thermal environment usually is measured in the condition of heating or cooling. This paper studies the thermal environment in direct gain solar and heating rooms. The indoor and outdoor temperature and relative humidity, inner surface temperature, human action, and times of opening door per day, are field tested and analyzed. PMV index is used to evaluate thermal environment. The results show that the relative humidity in direct gain solar and heating rooms is too low to comfortable. The curtain from closed to open, the window inner surface temperature decreases 13.9 ℃ in north orientation room, and decrease 10.3 ℃ in south orientation room. The indoor air temperature, relative humidity and inner surface temperature at the height of 1.5 m change a little by normal opening door. Thermal environment evaluation proves that in cloudy day, north orientation room is more comfortable than the south orientation room, while in sunny day, their difference of thermal sensation decreases. So we suggest that in order to keep thermal comfort, the curtain should be closed on the condition of no solar energy, the relative humidity should be designed during heating design, and the facing correction factors should be revised, so that the south orientation room is comfort in cloudy day. For energy conservation, the north exterior window should be smaller than the south exterior window.

Qinghai province is one of the important provinces in the development of the western region. It has a continental plateau climate and is extreme cold in winter. There are many local heating modes. Based on the field investigation, this paper presents six heating modes, independent stove, stove Kang, stove heating system, heated Kang, passive solar house, active and passive integration solar house, and compares their advantages and disadvantages. The heating information presented in this paper is significant for the development of heating, and has reference value for heating, ventilation and air conditioning (HVAC) engineers.

Based on the research of settlement landscape and field study, this paper starts with the sustainable development idea, takes the Daping village settlement of landscape design in Sichuan for example, analyzes the spatial pattern and finds out the suitable design form for the local landscape, which can establish a harmonious human settlement in village.