Oolong tea presents notable variations in taste profile and aroma characteristics under different cultivation conditions, particularly across altitudes. However, systematic investigations into the altitude-induced differences in key taste compounds and aroma composition remain limited. In this study, we examined six oolong tea cultivars, comparing their taste-related chemical constituents and aroma profiles under high- and low-altitude cultivation. Sensory evaluation, high-performance liquid chromatography (HPLC) and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) were employed to characterize these differences. Sensory evaluation revealed that high-altitude oolong teas exhibited enhanced umami, sweetness, and floral intensity. In most cultivars, the levels of free amino acids, polyphenols, and soluble sugar were relatively higher under high-altitude conditions. HS-SPME-GC-MS identified 55 common volatile organic compounds (VOCs), with terpenes and esters comprising the largest number of compounds. Identification by partial least squares discriminant analysis (PLS-DA) combined with relative odor activity value (rOAV) screening yielded 22 candidate differential volatile organic compounds. Floral monoterpenes, including linalool, linalool oxide II and geraniol, were consistently higher in high-altitude teas, whereas most other volatiles varied primarily with cultivar rather than altitude. These chemical patterns are consistent with the sensory finding of stronger floral intensity in high-altitude samples. This study provides theoretical insights for cultivar selection and quality improvement of oolong tea grown in high-altitude regions.

Environmental regulation has become a central policy tool for reconciling the tensions between ecological sustainability and industrial development. Although most existing studies focus on its impact on green innovation or firm behavioral change, attention to how environmental regulation affects the structural resilience of manufacturing systems under external shocks remains limited. This paper constructs a balanced panel dataset covering 287 prefecture-level cities in mainland China from 2006 to 2021 to quantify the impact of environmental regulation intensity on the resilience of manufacturing development. Manufacturing resilience is assessed through a comprehensive indicator system, including the dimensions of adaptive capacity, recovery potential, and industrial continuity. The empirical results show that environmental regulation has a significant inhibitory effect on manufacturing resilience, and this effect is supported in a number of robustness analyses using instrumental variable estimation and lagged structural tests. Mechanism analysis suggests that, despite the overall negative effect, environmental regulations can indirectly enhance resilience performance by promoting industrial autonomy and digital transformation under certain conditions. Heterogeneity analysis further reveals that the negative effect is more pronounced in regions with higher regulatory intensity, in non-self-employed firms, in industries not subject to U.S. sanctions, and in eastern China. These findings suggest that the dynamic needs of the industrial system should be taken into account in the formulation of environmental policies, and that digital capacity building and autonomy upgrading should be the key paths to mitigate regulatory shocks.

Improving the quality of agriculture-related market entry is central to rural industrial upgrading, yet existing studies mainly measure entry quantity. The primary objective of this study is to assess whether the county-level business environment is associated with the structural quality of new agriculture-related entrants. Specifically, the study asks three questions: whether the association is positive; whether financial services, market connectivity, and human capital supply are consistent transmission channels; and whether the association varies with agricultural foundations, initial factor market conditions, and access to urban spillovers. Using Chinese business registration records and county-level socioeconomic data for 2010–2023, we construct a county–year panel and measure entry quality through capital quality, organizational quality, and value chain extension. Two-way fixed effects, double machine learning, fractional response models, robustness tests, and a supplementary instrumental variable diagnostic are applied. The preferred fixed effects estimate indicates that a 0.1 increase in the business environment index is associated with a 4.16 percentage point increase in the high-quality entry ratio; a one-standard-deviation increase corresponds to approximately 3.77 percentage points. The association remains positive under nonlinear and bounded-outcome specifications. Channel tests are consistent with financial, market connectivity, and human capital pathways, and the association is stronger in central and western counties, non-municipal districts, counties with stronger agricultural foundations, and counties with weaker initial financial and market conditions. Because the estimate becomes statistically insignificant after prefecture-by-year fixed effects are included, the findings are interpreted as robust conditional associations rather than definitive county-level causal effects.

The export expansion of wood forest products (WFPs) generates substantial socio-economic benefits. Unfortunately, the WFP manufacturing industry frequently experiences challenges in accessing finance and high financing costs. Since profit scramble between financial sector and real economy sectors has become a critical global concern, it is worth investigating how banking sector profits (BSPs) impact WFPs’ export margins, and whether a “financial concession” policy can mitigate or amplify this effect. Drawing on over four million trade records from China’s Customs Database and the United Nations Trade and Business Database, this study quantifies the WFPs’ export margins of 31 provinces in Mainland China to 184 countries during 2007–2022. Then it assesses the effects of regional BSP on the WFPs’ export margins. The results indicate that the extensive, intensive, and quantity margins of WFPs’ export exhibit an overall upward trend with fluctuations, while the price margin has shown steady growth since 2016. Regional BSP has significant negative effects on the extensive, intensive, and quantity margins. The observed upward trend of WFPs’ export margins implies that low BSP may facilitate export growth of WFPs. Further heterogeneity analysis indicates that the BSPs’ negative impact is more pronounced for labor-intensive WFPs’ exports. China’s “financial concession” policy effectively mitigates the BSPs’ adverse effects. Moderation effect analysis demonstrates that a larger number of bank institution outlets, a higher share of rural bank institution outlets, and the development of digital finance significantly reduce the BSPs’ negative effects.

High-altitude environments provide a favorable basis for tea quality formation, but suitable processing parameters for high-altitude Oolong Tea (HAOT, Camellia sinensis (L.) O. Kuntze) remain unclear. This study optimized key processing parameters for HAOT using a three-factor, three-level orthogonal design involving withering method, shaking intensity and standing time. Sensory evaluation, quantitative descriptive analysis (QDA), macro-compositions determination, headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS), multivariate statistics and correlation analysis were used to clarify quality differences and their chemical basis. Leaf anatomical observation showed that high-altitude fresh leaves had a thicker cuticle and more compact mesophyll structure, suggesting the need for targeted processing regulation. Range analysis indicated that shaking intensity had the largest R value for sensory scores, followed by withering method, whereas standing time showed a comparatively small R value. The favorable combination was combined withering, heavy shaking (6 rounds) and 60 min standing, hereafter referred to as FHM. FHM showed the highest floral and fruity aroma scores and produced a mellow, full-bodied taste with a sweet aftertaste. It also contained significantly higher flavonoid and soluble sugar levels than the other processing combinations. A total of 65 volatile organic compounds were detected, with terpenoids and esters as the dominant classes. ROAV analysis identified geraniol, linalool, β-ionone, (E)-nerolidol and benzaldehyde as representative major aroma-active compounds, while geraniol and linalool were especially prominent in FHM. Correlation analysis further linked flavonoids and soluble sugars with positive taste attributes, and linalool and geraniol with floral–fruity aroma. These results provide a practical basis for optimizing HAOT processing and improving product quality.