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71.
The development of ecological circular agriculture has been highly encouraged by the Chinese government to recycle agricultural wastes, reduce mineral fertilizer input, and protect the environment. Biogas slurry, a byproduct of biogas engineering developed in rural areas of China, could be used as N fertilizer for crop growth. The field experiments were conducted in 2014 and 2015 to study the plant growth responses and environmental impacts of applying biogas slurry to two-season Zizania aquatica Turcz. growth. The potential factors that restrict the rational use of biogas slurry were also clarified. Mineral N fertilizer can be completely or partly substituted by N fertilizer from biogas slurry to satisfy Z. aquatica plant growth. It was not at the cost of sacrificing yield, dry matter accumulation, N accumulation and physiological N use efficiency in the above-ground parts. However, the growth inhibition occurs when the N quantity in biogas slurry was 2 or 2.7 times higher than that of mineral N fertilizer. Vitamin C in non-shell swollen culms (as edible part) of Z. aquatica significantly increased after biogas slurry application. Biogas slurry application substantially increased the N concentrations, i.e., total N, NH4 +–N, and NO3 ?–N in floodwater and delayed the time to reach national discharge standards. However, biogas slurry application did not affect the N concentrations in percolating water compared with the treatment with mineral N fertilizer only. Applying biogass slurry did not generate potential pollution risks by trace elements (Cu, Zn, Pb, Cr, Cd, As, and Hg) in the non-shell swollen culm and soil, and did not increase the nitrate content in non-shell swollen culm. We found the NH4 +–N concentration in biogas slurry can account for 77–93% of total N and reflects the N level in biogas slurry to a great degree. Semi-quantitative color-based colorimetric methods possessing simple and fast characteristics should be developed to determine the NH4 +–N concentration with the purpose of promoting reasonable use of biogas slurry in area of crop cultivation. Otherwise, excessive use of biogas slurry can adversely affect crops and increase environmental risks.  相似文献   
72.
Eucalyptol (Euc) is a natural monoterpene with insecticide effects. Being highly volatile and sensitive to ambient conditions, its encapsulation would enlarge its application. Euc‐loaded conventional liposomes (CL), cyclodextrin/drug inclusion complex, and drug‐in‐cyclodextrin‐in‐liposomes (DCL) are prepared to protect Euc from degradation, reduce its evaporation, and provide its controlled release. The liposomal suspension is freeze‐dried using hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as cryoprotectant. The liposomes are characterized before and after freeze‐drying. The effect of Euc on the fluidity of liposomal membrane is also examined. A release study of Euc from delivery systems, in powder and reconstituted forms, is performed by multiple head extraction at 60 °C after 6 months of storage at 4 °C. CL and DCL suspensions are homogeneous, show nanometric vesicles size, spherical shape, and negative surface charge before and after freeze‐drying. Moreover, HP‐β‐CD does not affect the fluidity of liposomes. CL formulations present a weak encapsulation for Euc. The loading capacity of eucalyptol in DCL is 38 times higher than that in CL formulation. In addition, freeze‐dried DCL and HP‐β‐CD/Euc inclusion complex show a higher retention of eucalyptol than CL delivery system. Both carrier systems HP‐β‐CD/Euc and Euc‐loaded DCL decrease Euc evaporation and improve its retention. Practical Applications: Eucalyptol is a natural insecticide. It is highly volatile and poorly soluble in water. To enlarge its application, its encapsulation in three delivery systems (conventional liposomes, cyclodextrin/drug inclusion complex, combined system composed of cyclodextrin inclusion complex and liposome) is studied. In this paper it is proved that cyclodextrin/eucalyptol inclusion complex and eucalyptol‐in‐cyclodextrin‐in‐liposome are effective delivery systems for encalyptol encapsulation, retention, and release.  相似文献   
73.
Milkfat was separated into major chainlength fractions by solid-phase extraction. The effect on thermal behavior and texture of replacing both saturated and monounsaturated long-chain triglycerides from milkfat by long-chain monounsaturated triglycerides with an unsaturated fatty acid in thesn-2 position is reported. Increasing proportions of cocoa butter were added to fractions of short-to medium-chain triglycerides (C22−C44) and medium- to long-chain triglycerides (C36−C48) isolated from milkfat. Thermal behavior and texture of the mixtures were measured. Results indicated that long-chain monounsaturated triglycerides from cocoa butter enhanced co-crystallization and co-operative melting and did not induce polymorphic transitions upon crystallization and melting of the fractions. At 4°C, they acted as texture builder if present in proportions of more than 30%, whereas below this level, they acted as texture softeners. The effect of the long-chain monounsaturated triglycerides on the texture of fractions that melt at low temperature could not be predicted from the proportion of solid fat at that temperature. Presented at the 1995 AOCS Annual Meeting & Expo, San Antonio, Texas, May 1995.  相似文献   
74.
We recently demonstrated that daily whole egg consumption during moderate carbohydrate restriction leads to greater increases in plasma HDL-cholesterol (HDL-C) and improvements in HDL profiles in metabolic syndrome (MetS) when compared to intake of a yolk-free egg substitute. We further investigated the effects of this intervention on HDL composition and function, hypothesizing that the phospholipid species present in egg yolk modulate HDL lipid composition to increase the cholesterol-accepting capacity of subject serum. Men and women classified with MetS were randomly assigned to consume either three whole eggs (EGG, n = 20) per day or the equivalent amount of egg substitute (SUB, n = 17) throughout a 12-week moderate carbohydrate-restricted (25–30 % of energy) diet. Relative to other HDL lipids, HDL-cholesteryl ester content increased in all subjects, with greater increases in the SUB group. Further, HDL-triacylglycerol content was reduced in EGG group subjects with normal baseline plasma HDL-C, resulting in increases in HDL-CE/TAG ratios in both groups. Phospholipid analysis by mass spectrometry revealed that HDL became enriched in phosphatidylethanolamine in the EGG group, and that EGG group HDL better reflected sphingomyelin species present in the whole egg product at week 12 compared to baseline. Further, macrophage cholesterol efflux to EGG subject serum increased from baseline to week 12, whereas no changes were observed in the SUB group. Together, these findings suggest that daily egg consumption promotes favorable shifts in HDL lipid composition and function beyond increasing plasma HDL-C in MetS.  相似文献   
75.
刘楠   《中国园林》2020,36(5):53
20世纪80年代,瑞典农业科学大学风景园林系教授罗朗·古斯塔文森在阿尔纳普校区创建风景实验室,融汇三脉斯堪的纳维亚风景园林的历史源流,即农林、早期自然保护与城市公园,系统性、全尺度地探索一片幼林地风景的创造性管理。风景实验室将林地规划为多林分组合,作为营林、风景园林设计与教学,以及公共游览的同一场所,因循植物景观的自然形态与活态结构,善用林室氛围景观,实践一种协同营林、生态保育和风景审美效用的管理式设计,为发展多用途城市林地提供创新实验场所。在风景实验室教研组发表的项目论文与报告书等文献资料的基础上,说明主要实验原则与方法,解析创造性管理的风景园林设计主线,简述由风景实验室延伸出的设计概念与项目。  相似文献   
76.
Single cell solid oxide fuel cells using Ni-YSZ and Co-YSZ anodes were tested in H2, CH4, H2S/H2 and H2S/CH4 fuel mixtures. Their performance was found to quickly degrade in dry CH4 due to carbon deposition and lifting of the anode from the electrolyte. In contrast, hydrogen or methane containing H2S showed an increase in exchange current densities when compared to H2,M/YSZ/LSM,air systems (M = Ni or Co) despite having less optimal anode microstructure. Conversion from metal to metal-sulfide in the presence of H2S produced large, dense metal-sulfide particles surrounded by YSZ, thus decreasing the triple-phase boundary. Furthermore, CoS-based anodes showed phase segregation and densification toward the electrolyte. Despite this, long-term testing at ηa = 0.5 V of the H2S/CH4,CoS-YSZ/YSZ/LSM,air system showed no signs of degradation of the anode over a 6-day period. Only after removal of H2S from the H2S/CH4 stream did the CoS-anode reduce back to Co, signifying H2S is required to maintain the metal-sulfide active anode.  相似文献   
77.
Project portfolio management (PPM) bridges strategy and project management. Traditional research in PPM has primarily investigated the rational, top-down and structural aspects of strategizing. By doing so, it has failed to focus on the underlying practices that are triggered by the strategy and how these practices frame strategy implementation. Practice-based research provides a methodological lens to explore the reality of strategic enactment through the project portfolio. Practice-based perspectives are under-represented in PPM research; therefore the aim of this paper is to provide an agenda for further practice-based research in PPM. Central to this agenda is a concern with various aspects of practice, including its discursivity, representation, dynamic capabilities, leadership and materiality.  相似文献   
78.
Resilience in river ecosystems requires that organisms must persist in the face of highly dynamic hydrological and geomorphological variations. Disturbance events such as floods and droughts are postulated to shape life history traits that support resilience, but river management and conservation would benefit from greater understanding of the emergent effects in communities of river organisms. We unify current knowledge of taxonomic‐, phylogenetic‐, and trait‐based aspects of river communities that might aid the identification and quantification of resilience mechanisms. Temporal variations in river productivity, physical connectivity, and environmental heterogeneity resulting from floods and droughts are highlighted as key characteristics that promote resilience in these dynamic ecosystems. Three community‐wide mechanisms that underlie resilience are (a) partitioning (competition/facilitation) of dynamically varying resources, (b) dispersal, recolonization, and recruitment promoted by connectivity, and (c) functional redundancy in communities promoted by resource heterogeneity and refugia. Along with taxonomic and phylogenetic identity, biological traits related to feeding specialization, dispersal ability, and habitat specialization mediate organism responses to disturbance. Measures of these factors might also enable assessment of the relative contributions of different mechanisms to community resilience. Interactions between abiotic drivers and biotic aspects of resource use, dispersal, and persistence have clear implications for river conservation and management. To support these management needs, we propose a set of taxonomic, phylogenetic, and life‐history trait metrics that might be used to measure resilience mechanisms. By identifying such indicators, our proposed framework can enable targeted management strategies to adapt river ecosystems to global change.  相似文献   
79.
Oxidation of Metals - The present work focuses on the intergranular oxidation of Alloy 600 and its weld material Alloy 82 after exposure in simulated primary water at 340–360 °C...  相似文献   
80.
The orexin system is responsible for regulating the sleep-wake cycle. Suvorexant, a dual orexin receptor antagonist (DORA) is approved by the FDA for the treatment of insomnia disorders. Herein, we report the optimization efforts toward a DORA, where our starting point was (5-methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-pyrrolidin-1-yl}methanone ( 6 ), a compound which emerged from our in-house research program. Compound 6 was shown to be a potent, brain-penetrating DORA with in vivo efficacy similar to suvorexant in rats. However, shortcomings from low metabolic stability, high plasma protein binding (PPB), low brain free fraction (fu brain), and low aqueous solubility, were identified and hence, compound 6 was not an ideal candidate for further development. Our optimization efforts addressing the above-mentioned shortcomings resulted in the identification of (4-chloro-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-methyl-2-[5-(2-trifluoromethoxy-phenyl)-4H-[1,2,4]triazol-3-yl]-pyrrolidin-1-yl}l-methanone ( 42 ), a DORA with improved in vivo efficacy compared to 6 .  相似文献   
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