Exploring the interactive effect of water and fertilizer on yield, soil water and nitrate dynamics of young apple tree is of great importance to improve the management of irrigation and fertilization in the apple-growing region of semiarid northwest China. A two-year pot experiment was conducted in a mobile rainproof shelter of the water-saving irrigation experimental station in Northwest A&F University, and the investigation evaluated the response of soil water and fertilizer migration, crop water productivity (CWP), irrigation water use efficiency (IWUE), partial factor productivity (PFP) of young apple tree to different water and fertilizer regimes (four levels of soil water: 75%–85%, 65%–75%, 55%–65% and 45%–55% of field capacity, designated W₁, W₂, W₃ and W₄, respectively; three levels of N-P₂O₅-K₂O fertilizer, 30-30-10, 20-20-10 and 10-10-10 g plant⁻¹, designated F₁, F₂ and F₃, respectively). Results showed that F₁W₁, F₂W₁ and F₃W₁ had the highest average soil water content at 0~90 cm compared with the other treatments. When fertilizer level was fixed, the average soil water content was gradually increased with increasing irrigation amount. For W₁, W₂, W₃ and W₄, high levels of water content were mainly distributed at 50~80 cm, 40~70 cm, 30~50 cm and 10~30 cm, respectively. There was no significant difference in soil water content at all fertilizer treatments. However, F₁ and F₂ significantly increased soil nitrate-N content by 146.3%~246.4% and 75.3%~151.5% compared with F₃. The highest yield appeared at F₁W₁ treatment, but there was little difference between F₁W₁ and F₂W₂ treatment. F₂W₂ treatment decreased yield by 7.5%, but increased IWUE by 11.2% compared with F₁W₁ treatment. Meanwhile, the highest CWP appeared at F₂W₂ treatment in the two years. Thus, F₂W₂ treatment (soil moisture was controlled in 65–75% of field capacity, N-P₂O₅-K₂O were controlled at 20-20-10 g·tree⁻¹) reached the best water and fertilizer coupling mode and it was the optimum combinations of water and fertilizer saving.

The present study was performed to assess the quality of Potentilla fruticosa L. sampled from distinct regions of China using high performance liquid chromatography (HPLC) fingerprinting coupled with a suite of chemometric methods. For this quantitative analysis, the main active phytochemical compositions and the antioxidant activity in P. fruticosa were also investigated. Considering the high percentages and antioxidant activities of phytochemicals, P. fruticosa samples from Kangding, Sichuan were selected as the most valuable raw materials. Similarity analysis (SA) of HPLC fingerprints, hierarchical cluster analysis (HCA), principle component analysis (PCA), and discriminant analysis (DA) were further employed to provide accurate classification and quality estimates of P. fruticosa. Two principal components (PCs) were collected by PCA. PC1 separated samples from Kangding, Sichuan, capturing 57.64% of the variance, whereas PC2 contributed to further separation, capturing 18.97% of the variance. Two kinds of discriminant functions with a 100% discrimination ratio were constructed. The results strongly supported the conclusion that the eight samples from different regions were clustered into three major groups, corresponding with their morphological classification, for which HPLC analysis confirmed the considerable variation in phytochemical compositions and that P. fruticosa samples from Kangding, Sichuan were of high quality. The results of SA, HCA, PCA, and DA were in agreement and performed well for the quality assessment of P. fruticosa. Consequently, HPLC fingerprinting coupled with chemometric techniques provides a highly flexible and reliable method for the quality evaluation of traditional Chinese medicines.

The stability of biocrude oil is a significant challenge for its storage, transportation, and refining. In this investigation, the thermal and oxidative stability of Spirulina-biocrude oil derived from a plug-flow continuous hydrothermal reactor was systematically studied. The biocrude oil was stored at three temperatures to simulate the winter (4 °C), spring and autumn (15 °C), and summer (35 °C) seasons, and in two atmospheres (air and N₂) to simulate the conditions of a storage tank being sealed or kept open. Results demonstrated that the physicochemical properties of biocrude oil were highly influenced by the storage environment. The viscosity of biocrude oil increased with increasing storage temperature and time. The maximum viscosity (17,577 mPa·s) was observed when biocrude oil was stored at 35 °C and in an air condition over 84 days, 145% higher than fresh biocrude oil (7164.2 mPa·s). The viscosity increased by 10.9% when biocrude oil was sorted at 4 °C in an N₂ atmosphere after being stored for 28 days. After long-term storage, biocrude oil still exhibited comparable characteristics to petroleum, with a slight decrease in HHV (31.36–33.97 MJ·kg⁻¹) and the nitrogen-to-carbon ratio (0.087–0.092). This study indicated that the viscosity and HHV of the biocrude oil derived from a continuous reactor stored at 4 °C in an N₂ atmosphere condition remained relatively unchanged, which enables the scheduling of oil refining production.

In order to make the process more sustainability and more efficient in co-digestion of kitchen waste (KW) and cow manure (CM), the effect of pH controlling at initial fermentation time (I), first gas stagnation time (A), and combination of both times (C) were investigated. Five pH values (6.5, 7.0, 7.5, 8.0 and 8.5) were set in each case to find out the optimal way of pH regulation with the consideration of changes in biogas and methane production, volatile solid (VS) reduction, and lag-phase time. The results show that adjusting pH of the co-digestion system could significantly improve biogas production except when pH was set to 6.5 in groups I and A. Adjusting pH twice (group C) could increase the system stability. When pH value was set to 7.5 twice, highest methane production (16501.10 mL), the highest methane yield of 287.64 mL/g VS_added, and a relatively short lag-phase time (27.3d) were obtained by C^7.5.

Chemical composition evaluation and pyrolysis behavior of biomass tar: Pyrolysis experiment and kinetic studies