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Cropland productivity can be greatly improved to ensure national food security in China, particularly under the quantitative constraints of farmland resources. Among them, land consolidation can be an important way for the high cropland productivity in recent years. But, the spatial differentiation patterns of land consolidation can pose a great impact on cropland productivity in large-scale regions. Taking the Yangtze River Economic Zone as an example, this study aims to determine the impact of land consolidation on cropland productivity change using MODIS-EVI remote sensing data. The S-G filtering and threshold were used to extract the cropland productivity (i.e., single-crops productivity, the first and second season productivity of double crops) in the study area from 2001-2017. Then, 80 920 projects of land consolidation were collected (including land development, consolidation, and reclamation projects) with the location and attribute information using the national rural land consolidation monitoring and supervision system. The contribution rate of land consolidation was further analyzed for the cropland productivity in counties using a geographically weighted regression model, together with the spatial differentiation of the impact degree. Finally, the impact of land consolidation was spatially partitioned on the cropland productivity using the hierarchical clustering model. The optimization strategies of land consolidation were also proposed for each zone, according to the cropland utilization characteristics. The results showed that: 1) There was a significant spatial divergence trend of cropland productivity. Specifically, the productivity of single-crops and double-crops in the first and second seasons presented a decelerating increase, an accelerating increase, and an increase followed by a decrease, respectively, with the largest increase in the productivity in the upper reaches of the Yangtze River. There was a significant decrease in the productivity of the single-crops and the second season productivity of double-crops in the lower reaches; 2) The average contribution of land development, allocation, and reclamation to the change of single-crops productivity were 7.38%, 4.44%, and 2.80%, respectively; the average contribution to the change of first season productivity of double-crops were 6.21%, 5.04%, and 3.34%, respectively; and the average contribution to the change of second season productivity of double-crops were 7.10%, 7.15%, and 3.69%, respectively. 3) The Yangtze River economic belt was divided into the consolidation areas of the southwest mountain, the Sichuan basin, the southern hilly, and the lower Yangtze River plain, according to the cropland productivity and the impact mechanism of land consolidation. A better optimization was also provided for the land consolidation of each region. In addition, some findings were also needed to further explain: firstly, the land allocation was the least effective to promote cropland productivity improvement among all types of projects. The reason behind this issue can be expected to continue. Another phenomenon is that the second season productivity of double-crops was generally negatively correlated with the land consolidation indicators, has the implementation of land consolidation accelerated the phenomenon of “double to single”? What is the mechanism behind this phenomenon? Finally, it is very necessary to improve the efficiency of the causal inference using a geographically weighted regression model. [ABSTRACT FROM AUTHOR]

Sea buckthorn (Hippophaë rhamnoides L.) is well-known for its high content of flavonol glycosides (FGs), yet accurately determining the quantity of these nutrients present in the berries remains a challenge due to the significant variability of these nutrients and lack of reference standards. In this study, flavonol glycosides in sea buckthorn berries were identified and quantified using ultra-performance liquid chromatography Q-exactive high resolution mass spectrometry (UPLC-QE HRMS). The results showed that the total content of flavonol glycosides ranged from 39.5 to 240.2 mg/100 g fresh berries. The wild berries from Sichuan had remarkably high contents and unique profiles of flavonol glycosides. The main flavonol glycosides in all of the samples were isorhamnetin glycosides and quercetin glycosides, the predominant flavonol glycosides were different between different samples. The sPLS-DA statistical analysis indicated that cultivated and wild sea buckthorn can be distinguished based on their distinct composition and content of flavonol glycosides. The HCA clustered 16 high expression levels of FGs, which were revealed in a wild sample obtained from Sichuan. • High resolution and high sensitivity analysis was carried out on UPLC-QE HRMS. • 33 flavonol glycosides identified and quantified by UPLC-QE HRMS in sea buckthorn. • Differences of the flavonol glycosides between cultivated and wild samples were analyzed. • sPLS-DA analysis revealed clear distinction between cultivated and wild sea buckthorn. • High expression flavonol glycosides identified by hierarchical cluster analysis. [ABSTRACT FROM AUTHOR]

Nucleic acid constituents are the main functional ingredients in edible fungi, therefore understanding the nucleic acid constituents of edible fungi often eaten on the table by the Chinese people is of significant value. In this study, Sichuan Provincial Center for Disease Control and Prevention collected 147 samples of edible fungi (including certain species that the Chinese often eat) from different parts of the Sichuan Basin. A new UPLC-QqQ/MS method has been developed to determine the 17 nucleic acid constituents in these 147 samples, including guanosine, adenosine, uridine, cytidine, inosine, thymidine, xanthosine dehydrate, 2′-deoxyguanosine, 2′-deoxyadenosine, 2′-deoxyuridine, 2′-deoxycytidine, 2′-deoxyinosine, guanosine 5′-monophosphate, adenosine 5′-monophosphate, uridine 5′-monophosphate, cytidine 5′-monophosphate, and inosine 5′-monophosphate. Finally, similarity assessment of the main edible fungus was performed using vectorial angle cosine method, and hierarchical cluster analysis was used to classify all the 147 samples. The results showed that some edible fungi have high similarities, especially in Lentinula edodes (Berk.) Pegler, the monogenic nucleotides content of which (55.84 ± 8.4 mg/100 g) is far greater than any other edible fungus, which is directly related to its taste. For quality control, this paper proposed to use the reference values of total nucleic acid compounds in edible fungi computed by percentile threshold method. This is the first time a comprehensive evaluation of nucleic acid constituents of different edible fungi of daily consumption was conducted for a large region, and the results is conducive to the quality evaluation and quality control of edible fungus. Unlabelled Image • Developed a new UPLC-/MS method for the determination of 17 nucleic acid constituents • The similarity was assessed by vectorial angle cosine and hierarchical cluster analysis. • The reference values of total nucleic acids in each species computed by percentile threshold method. • Can be applied for quality evaluation and quality control of edible fungus [ABSTRACT FROM AUTHOR]

Based on the radiated energy of 133 rock bursts monitored by a microseismic technique at the Jinping II hydropower station, in Sichuan province, China, we analyzed the advantages and disadvantages of qualitative classification methods for the rock burst intensity. Then, we investigated the characteristics, magnitude, and laws of the radiated energy, as well as the relationship between the rock burst radiated energy and intensity. Then, we selected the energy as an evaluation index for the rock burst intensity classification, and proposed a new rock burst intensity quantitative classification method, which utilized the hierarchical clustering analysis technique with the complete-linkage method. Next, we created a new set of criteria for the quantitative classification of the rock burst intensity based on radiated energy and surrounding rock damage severity. The new criteria classified the rock burst intensity into five levels: extremely intense, intense, moderate, weak, and none, and the common logarithms of the radiated energy of each level were >7 lg( E/J), >4 lg( E/J) and <7 lg( E/J), >2 lg( E/J) and <4 lg( E/J), >1 lg( E/J) and <2 lg( E/J), and <1 lg( E/J), respectively. Finally, we investigated the factors influencing the classification, and verified its feasibility and applicability via several practical rock burst examples. [ABSTRACT FROM AUTHOR]

• RSM was applied for optimizing the extraction process of minor curcuminoids. • MRM parameters including DP and CE for each curcuminoid were optimized. • The established method could discriminate turmeric samples from different origins. • This study was useful for discriminating other geo-authentic and non-authentic herbs. In this research, a three-step strategy was utilized for discriminating turmeric samples from different provinces and regions in China. Firstly, MRM-based UPLC-MS/MS method for chemical profiling of curcuminoids in turmeric samples was established. Then, response surface methodology was applied for optimizing the extraction process of targeted curcuminoids. Finally, multivariate analysis was conducted for systematic characterization of 66 curcuminoids in turmeric. Principal component analysis (PCA) and orthogonal projection to latent structure-discriminant analysis (OPLS-DA) revealed that turmeric samples from Sichuan and other regions could be classified into two distinct groups. Turmeric samples from the same group had similar curcuminoids content distribution. 25 differential curcuminoids were discovered through OPLS-DA, among which most curcuminoids were more abundant in Sichuan. Furthermore, turmeric samples from different provinces could be clearly discriminated based on hierarchical cluster analysis (HCA) using the screened differential curcuminoids. [ABSTRACT FROM AUTHOR]

• For the first time, GC×GC-TOFMS was used to classify strong aroma-type baijiu (SAB) from different regions. • The SAB samples from two different basins in China were clearly separated in PCA score plots. • The predictive ability of the PLS-DA model was excellent, correctly classifying 100% of the unknown SAB samples. • Twenty-three potential markers were identified using standard compounds. • The HCA result showed that the selected markers offered strong discrimination power. A metabolomics strategy was developed to differentiate strong aroma-type baijiu (SAB) (distilled liquor) from the Sichuan basin (SCB) and Yangtze-Huaihe River Basin (YHRB) through liquid–liquid extraction coupled with GC×GC-TOFMS. PCA effectively separated the samples from these two regions. The PLS-DA training model was excellent, with explained variation and predictive capability values of 0.988 and 0.982, respectively. As a result, the model demonstrated its ability to perfectly differentiate all the unknown SAB samples. Twenty-nine potential markers were located by variable importance in projection values, and twenty-four of them were identified and quantitated. Discrimination ability is closely correlated to the characteristic flavor compounds, such as acid, esters, furans, alcohols, sulfides and pyrazine. Most of the marker compounds were less abundant in the SCB samples than in the YHRB samples. The quantitated markers were further processed using hierarchical cluster analysis for targeted analysis, indicating that the markers had great discrimination power to differentiate the SAB samples. [ABSTRACT FROM AUTHOR]