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1.
基于千年生态系统评估对生态系统服务的分类方法,将天津市地下水生态系统服务功能划分为供给、调节、 支持和文化 4 个方面,以此为基础建立地下水生态系统服务价值评估指标体系,采用价值量评估方法构建货币化 的价值评估模型,对地下水生态系统服务价值进行测算,并重点分析南水北调中线工程通水前后天津市地下水生 态系统服务价值演变特征。结果表明:2008—2019 年,天津市地下水生态系统年均总服务价值为 83.71 亿元,其 中,南水北调中线工程通水前(2008—2014 年)为 69.81 亿元,通水后(2015—2019 年)为 103.18 亿元;通水后,地 下水调节服务价值、支持服务价值增大,供给服务价值减小;南水北调中线工程对地下水生态系统服务价值的贡 献呈增大趋势,由 2015 年 2.64 亿元增加至 2019 年 24.01 亿元。  相似文献   
2.
Food Science and Biotechnology - The objective of this study was to develop a non-fermented probiotic milk that maintains its physicochemical properties, microbial properties, antioxidant activity,...  相似文献   
3.
基于历史实测降水数据与全球气候模型预估数据,使用 Morlet 小波方法分析滇中引水工程水源区与受水区 降水序列的周期变化和未来的降水趋势。同时,采用 Copula 函数计算历史时期(1960—2021 年)与未来时期 (2022—2100 年)水源区与受水区降水丰枯异步或丰枯同步的概率。结果表明:1960—2021 年降水序列存在 26~39?a、18~25?a、4~7?a 的 3 类时间尺度的周期变化,2022—2100 年降水序列存在 38~55?a、18~30?a、5~12?a 的 3 类时间尺度的周期变化,降水量呈现“多—少—多”的循环交替,预计未来 10~20?a 将持续处于降水较多的时期; 过去 62?a,水源区和受水区降水丰枯异步频率 36.4%,同期丰水年频率为 25.3%,同期枯水年频率小于 30%,水源区 和受水区具有水量互补的引水条件,两区域之间存在着水量补偿特征;与历史丰枯遭遇对比,未来降水量丰枯同 步频率均呈现减小的趋势,丰枯异步呈现增加的趋势,同枯和源枯受丰的频率减少,未来有利于调水的降水丰枯 组合概率平均增加 3.75%;在近、中、远期预估中,从 SSP1-2.6 情景过渡到 SSP5-8.5 情景,SSP5-8.5 情景下降水量 丰枯异步频率比 SSP1-2.6 情景大,说明水源区与受水区的降水区域差异变大,降水时空差异更加显著。通过对滇 中引水工程水源区与受水区降水量丰枯遭遇的综合分析、定量评估和模拟预测,为滇中引水工程水资源调度协同 一体化提供数据支撑及参考依据。  相似文献   
4.
The structural diversity of polyphenols and the inherent limitations of current extraction techniques pose a challenge to extract polyphenols using a simple and green method. Hence, in this study, a method was developed to simultaneously fractionate multiple classes of polyphenols by only varying ethanol-water solutions. Honeybush tea, which is rich in polyphenols, was selected as a model for this study. Solvent extraction followed by solid-phase extraction (SPE) was developed to obtain a polyphenol-rich fraction from six honeybush samples. Based on a gradient elution programme (10%, 30%, 50%, 70% and 90% (v/v) ethanol-water solution) of SPE, the Strata X cartridge showed a better recovery of most targeted polyphenols under 0.9 mL of the drying volume and 1 mL min−1 of the dispensing speed. The elution programme for fractionating most polyphenols was as follows: single elution with 50% ethanol, followed by twice elution with 70% ethanol. The antioxidant capacity was used to analyse the differences among the polyphenol-rich fractions from six honeybush samples. Principal component analysis (PCA) revealed that unfermented C. genistoides (GG) has the greatest antioxidant capacity among the honeybush species studied. Additionally, mangiferin, isomangiferin and vicenin-2 were the main contributors to the antioxidant capacity in six honeybush fractions according to the correlation study.  相似文献   
5.
Food Science and Biotechnology - The fourth industrial revolution represented by big data and artificial intelligence (AI), already had a significant impact on the food industry. In this review,...  相似文献   
6.
Park  Jieun  Kim  Junghun  Hyun  Sinjae  Lee  Jongmin 《Magma (New York, N.Y.)》2022,35(5):719-732
Magnetic Resonance Materials in Physics, Biology and Medicine - This study aims to compare an electrocardiogram (ECG)-gated four-dimensional (4D) phase-contrast (PC) magnetic resonance imaging...  相似文献   
7.

Hydrological drought is assessed through river flow, which depends on river runoff and water withdrawal. This study proposed a framework to project future hydrological droughts considering agricultural water withdrawal (AWW) for shared socioeconomic pathway (SSP) scenarios. The relationship between AWW and potential evapotranspiration (PET) was determined using a deep belief network (DBN) model and then applied to estimate future AWW using projections of the twelve global climate models (GCMs). 12 GCMs were bias-corrected using the quantile mapping method, climate variables were generated, and river flow was estimated using the soil and water assessment tool (SWAT) model. The standardized runoff index (SRI) was used to project the changes in hydrological drought characteristics. The results revealed a higher occurrence of severe droughts in the future. Droughts would be more frequent in the near future (2021–2060) than in the far future (2061–2100) and more severe when AWW is considered. Droughts would also be more severe for SSP5-8.5 than for SSP2-4.5. The study revealed that the increased PET due to rising temperatures is the primary cause of the increased drought frequency and severity. The AWW will accelerate the drought severities in the future in the Yeongsan River basin.

  相似文献   
8.
The aim of this study was to determine the effects of tumbling at different post-mortem times on the proteolytic features and quality attributes of beef loins (M. longissimus lumborum). Loins (n = 12) were cut into 4 sections and assigned to tumbling at 1, 6 or 11 days post-mortem or non-tumbled control. Upon tumbling, additional ageing was applied to a common post-mortem time of 16 days. In general, tumbling had no considerable impacts on water-holding ability of samples. Tumbling resulted in an immediate decrease in shear force values (WBSF) of beef samples. Tumbling at 1 day post-mortem with no ageing had similar WBSF compared to the non-tumbled controls at 16 days (P > 0.05). With ageing, tumbling increased amounts of protein degradation, myofibrillar fragmentation and calpain-1 autolysis of samples. These results suggest that early post-mortem tumbling coupled with ageing can synergistically impact the tenderness development of beef loins and shorten the necessary ageing period.  相似文献   
9.
Here we report a transparent dual-phase ZnO·2.7Al2O3 ceramic. The composite is pore-free and consists of thin nanosheets with a spinel phase and a hexagonal phase, while the two phases match closely in both lattice and refractive index. Such features result in excellent optical transmittance (maximum value >80% in the visible spectrum) at comparable phase volume. This work may provide a new thought for the rational structural design of optical nanocomposites.  相似文献   
10.
Coptidis Rhizoma is the dried rhizome from the Coptis chinensis Franch. that has been shown to have a number of beneficial pharmacological properties including antioxidant, anti-inflammatory, and anti-cancer effects. However, the anti-cancer effects of Coptidis Rhizoma on hepatocellular carcinoma (HCC) remain unclear. In this study, we investigated the anti-cancer properties of Coptidis Rhizoma ethanol extract (CR) in HCC Hep3B cells and in a xenograft mouse model. Our results showed that the CR significantly inhibited cell growth and induced apoptosis in Hep3B cells through increased expression of Bcl-2 associated x-protein (Bax) and cleavage of poly-ADP ribose polymerase (PARP), reduced expression of Bcl-2, and activated caspases. CR also increased the generation of intracellular reactive oxygen species (ROS), which caused a loss of mitochondrial membrane potential (MMP, ΔΨm) and activation of the mitochondria-mediated intrinsic apoptosis pathway. Moreover, N-acetylcysteine (NAC), a ROS inhibitor, markedly blocked the effects of CR on apoptotic pathways. CR also induced the expression of light chain 3 (LC3)-I/II, a key autophagy regulator, whereas CR-mediated autophagy was significantly suppressed by NAC. In addition, pre-treatment with NAC perfectly attenuated the inhibition of cell invasion and migration of CR-stimulated Hep3B cells. Furthermore, oral administration of CR suppressed Hep3B tumor growth in xenograft mice without toxicity, alterations to body weight, or changes in hematological and biochemical profiles. Taken together, our findings suggest that CR has anti-tumor effects that result from ROS generation, and may be a potential pharmacological intervention for HCC.  相似文献   
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