512 research outputs found
Study and Integrative Evaluation on the development of Circular Economy of Shaanxi Province
AbstractA kind of index system used for evaluating the circular economy development of Shaanxi province was built in this paper based on the circular economy development's content and some basic principles that should be followed by the system, along with the current status of the circular economy development of Shaanxi province. This system includes five aspects that are social and economic development, resource efficiency, resource recycling and reuse, environment protection, pollution reduction. By using this system and principal component analysis as well as analytic hierarchy process, we studied the circular economy development of Shaanxi Province. The results show that circular economy development in this province is in steady upward developing. Finally, some advices for accelerating the circular economy development of Shaanxi were prompted
Application of Indicators of Hydrologic Alteration to Ecological Hydrology in Trinity and Brazos River Basins
As the demand for water resources has been increasing all around the world, intense water appropriation has led to alterations of flow regimes over time. Changes in environmental flows have impaired beneficial functions of ecosystems. Thus, the protection of environmental instream flows to maintain healthy ecosystems has become more and more critical. The Texas Commission on Environmental Quality (TCEQ) has established environmental flow standards through a process established by the Texas Legislature in its 2007 Senate Bill 3 (SB3). The SB3 has expedited the process of developing methodologies and tools to analyze and quantify alterations in environmental flows. Furthermore, with the experts’ participation, the establishment of SB3 has helped lawmakers to improve regulations, laws, and water management practices.
This thesis applies the Indicators of Hydrologic Alteration (IHA) software and the TCEQ Water Availability Modeling (WAM) System allied with Hydrologic Engineering Center Data Storage System (HEC-DSS) to analyze and quantify flow conditions at 13 gaging stations in the Trinity River Basin and 20 gaging stations in the Brazos River Basins. The thesis focuses on three types of flows: observed flow, WAM naturalized flow, and WAM simulated regulated flow. The thesis explores long-term alterations in different types of flow characteristics in research areas, develops meaningful frequency metrics, and evaluates capabilities of different methodologies. The results reveal the differences and similarities of alterations in long-term flow characteristics in Trinity and Brazos River Basins. In addition, this thesis proves that the application of IHA is meaningful. Also, the use of the WAM System is fundamental in this thesis
Cryopreservation in Ophthalmology
Amniotic membranes (AMs) and corneas are critical materials in ocular surface reconstruction. AM has specific structures (e.g., basement and two types of cells with stemness characteristics: amniotic epithelial cells and amniotic mesenchymal cells), which contribute to its attractive physical and biological properties that make it fundamental to clinical application. The corneal endothelial cell is a vital part of the cornea, which can influence postoperative vision directly. However, widespread use of fresh AM and cornea has been limited due to their short use span and safety concerns. To overcome these concerns, different preservation methods have been introduced. Cryopreservation is distinguished from many preservation methods for its attractive advantages of prolonged use span, optimally retained tissue structure, and minimized infection risk. This review will focus on recent advances of cryopreserved AM and cornea, including different cryopreservation methods and their indications in ophthalmology
Structures and Stabilities of Carbon Chain Clusters Influenced by Atomic Antimony
The C-C bond lengths of the linear magnetic neutral CnSb, CnSb+ cations and CnSb− anions are within 1.255–1.336 Å, which is typical for cumulene structures with moderately strong double-bonds. In this report, we found that the adiabatic ionization energy (IE) of CnSb decreased with n. When comparing the IE~n relationship of CnSb with that of pure Cn, we found that the latter exhibited a stair-step pattern (n ≥ 6), but the IE~n relationship of CnSb chains took the shape of a flat curve. The IEs of CnSb were lower than those of corresponding pure carbon chains. Different from pure carbon chains, the adiabatic electron affinity of CnSb does not exhibit a parity effect. There is an even-odd alternation for the incremental binding energies of the open chain CnSb (for n = 1–16) and CnSb+ (n = 1–10, when n > 10, the incremental binding energies of odd (n) chain of CnSb+ are larger than adjacent clusters). The difference in the incremental binding energies between the even and odd chains of both CnSb and pure Cn diminishes with the increase in n. The incremental binding energies for CnSb- anions do not exhibit a parity effect. For carbon chain clusters, the most favorable binding site of atomic antimony is the terminal carbon of the carbon cluster because the terminal carbon with a large spin density bonds in an unsaturated way. The C-Sb bond is a double bond with Wiberg bond index (WBI) between 1.41 and 2.13, which is obviously stronger for a carbon chain cluster with odd-number carbon atoms. The WBI of all C-C bonds was determined to be between 1.63 and 2.01, indicating the cumulene character of the carbon chain. Generally, the alteration of WBI and, in particular, the carbon chain cluster is consistent with the bond length alteration. However, the shorter C-C distance did not indicate a larger WBI. Rather than relying on the empirical comparison of bond distance, the WBI is a meaningful quantitative indicator for predicting the bonding strength in the carbon chain
The role of landscape evolution in the genetic diversification of a stream fish Sarcocheilichthys parvus from Southern China
Sarcocheilichthys parvus (Cypriniformes: Gobionidae) is a stream fish which is endemic to sub-tropical coastal drainages in southern China, thus offering a valuable model for understanding how genetic divergence arises in stream-adapting freshwater fishes in this region. Using the mitochondrial Cyt b gene, integrative analyses of phylogeny, population demography, and ancestral area and paleo-drainage reconstructions are carried out to explicitly explore the role of landscape evolution in genetic diversification of S. parvus. The time-calibrated phylogeny of S. parvus indicates the splitting of two major lineages (A and B) at ∼3.66 Ma. Lineage A inhabits the Poyang Lake sub-drainage of the middle Yangtze River, Han River and Pearl River, and can be split into two sub-lineages (A-I and A-II), where sub-lineage A-II can be further sub-divided into three infra-sub-lineages (A-IIa, A-IIb and A-IIc). Except for the infra-sub-lineage A-IIc, which is restricted to the Han River and Pearl River, the other sub-lineages and infra-sub-lineages live exclusively in the Poyang Lake sub-drainage. Lineage B lives in the lower Yangtze River, Qiantang River, Jiaojiang River and Ou River, displaying close genetic relationships among the drainages. Rapid population expansion has occurred since the Late Pleistocene. Our findings indicate that the splitting of lineages A and B could be attributed to geographic isolation due to the Zhe–Min Uplift, acting as a biogeographic barrier before the late Early Pleistocene. Furthermore, the strong genetic divergence within Lineage A could be explained by the isolation role of the Nanling Mountains and Poyang Lake acting as an ecological barrier; while the lack of phylogenetic structure within Lineage B may have been the result of paleo-drainage connections or episodic freshwater connections during the eustatic low stand of sea level in the late Middle–Late Pleistocene
Food–energy–water nexus optimization brings substantial reduction of urban resource consumption and greenhouse gas emissions
Urban sustainability is a key to achieving the UN sustainable development goals (SDGs). Secure and efficient provision of food, energy, and water (FEW) resources is a critical strategy for urban sustainability. While there has been extensive discussion on the positive effects of the FEW nexus on resource efficiency and climate impacts, measuring the extent to which such synergy can benefit urban sustainability remains challenging. Here, we have developed a systematic and integrated optimization framework to explore the potential of the FEW nexus in reducing urban resource demand and greenhouse gas (GHG) emissions. Demonstrated using the Metropolis Beijing, we have identified that the optimized FEW nexus can reduce resource consumption and GHG emissions by 21.0 and 29.1%, respectively. These reductions come with increased costs compared to the siloed FEW management, but it still achieved a 16.8% reduction in economic cost compared to the business-as-usual scenario. These findings underscore the significant potential of FEW nexus management in enhancing urban resource efficiency and addressing climate impacts, while also identifying strategies to address trade-offs and increase synergies
Opposing effects on two phases of defense responses from concerted actions of HSC70 and BON1 in Arabidopsis
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