Water rights trading planning and its application in water resources management: A water-ecology-food nexus perspective.

Nexus approach provides an effective perspective for implementing synergetic management of water resources. In this study, an interval two-stage chance-constrained water rights trading planning model under water-ecology-food nexus perspective (ITCWR-WEF) is proposed to analyze the interaction between water trading and water-ecology-food (WEF) nexus, which fills in the water resources management gaps from a novel nexus perspective. ITCWR-WEF incorporates hydrological simulation with soil and water assessment tool (SWAT), water rights configuration with interval two-stage chance-constrained programming (ITCP), and multi-criterion analysis with Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). The developed ITCWR-WEF is applied to a real case of Daguhe watershed, which has characteristics of water scarcity, food producing areas and fragile ecosystem. Initial water rights allocation is addressed before the trading. Mechanisms analysis is designed to reveal mutual effect of water rights trading and WEF nexus. Optimal water management scenario is identified through multi-criterion analysis. Results reveal that the mechanism of water rights trading with WEF nexus under low constraint-violation risk level of water availability and environment capacity is recommended to promote the rational water resources allocation to balance the economic goals, water environment and water supply security, as well as ecological and food water demand guarantees.

Metallofullertube: From Tubular Endohedral Structures to Properties.

Metallofullertubes are endohedral metallofullerenes with tubular fullerene cage possessing the segment of carbon nanotubes. Metallofullertubes have endohedral metal atom, fullerene cap and nanotube segment. Therefore, it is conceivable that this new kind of molecular materials would bring on many unexpected properties. In recent years, several pioneer metallofullertubes have been successfully reported, such as La2 @D5 (450)-C100 , Ce2 @D5 (450)-C100 , Sm2 @D3d (822)-C104 . Apart from the great effort to synthesize molecules and determine their structures, the physical and chemical properties of metallofullertubes are still waiting to be explored. In this minireview, we revisit the structures of reported metallofullertubes, and then we highlight their electronic and supramolecular properties. Finally, some perspectives for the development of metallofullertubes are also discussed.

Optimal design of two-dimensional water trading based on risk aversion for sustainable development of Daguhe watershed, China.

Water related problems, including water scarcity and pollution, have become increasingly urgent challenges especially in arid and semiarid regions. Two-dimensional water trading (2DWT) mechanism has been designed to unify the quantity and quality of water for relieving the water crisis. This study aims to develop a risk aversion optimization-two dimensional water trading model (RAO-2DWTM) for planning the regional-scale water resources management system (RWMS). This is the first attempt on planning RWMS through risk aversion optimization within the two-dimensional water trading framework. RAO-2DWTM cannot only support in-depth analysis regarding the effect of decision maker's preferences on system risk in different trading scenarios, but also reflect the interaction between water right trading and effluent trading, as well as disclose the optimal scheme of water resource management under uncertainties. Twenty four scenarios associated with different trading scenarios and robust levels are analyzed. The optimization scheme under the optimal risk control level is determined based on TOPSIS. Results revealed that 2DWT would bring high benefit with reduced risk cost, water deficit and emissions, implying the effectiveness of 2DWT mechanism. The results also disclosed that risk aversion behavior can mitigate water scarcity and pollution, as well as reduce risk cost, but may lead to some losses of system benefit. Consequently, decision makers should make trade-offs between system benefit and risk in identifying desired trading schemes.

A Metallofullertube of Ce2 @C100 with a Carbon Nanotube Segment: Synthesis, Single-Molecule Conductance and Supramolecular Assembly.

Tubular fullerenes can be considered as end-capped carbon nanotubes with accurate structure, which are promising nanocarbon materials for advanced single-molecule electronic devices. Herein, we report the synthesis and characterization of a metallofullertube Ce2 @D5 (450)-C100 , which has a tubular C100 cage with a carbon nanotube segment and two fullerene end-caps. As there are structure correlations between tubular Ce2 @D5 (450)-C100 and spherical Ce2 @Ih -C80 , their structure-property relationship has been compared by means of experimental and theoretical methods. Notably, single-molecule conductance measurement determined that the conductivity of Ce2 @D5 (450)-C100 was up to eight times larger than that of Ce2 @Ih -C80 . Furthermore, supramolecular assembly of Ce2 @D5 (450)-C100 and a [12]CPP nanohoop was investigated, and theoretical calculations revealed that metallofullertube Ce2 @D5 (450)-C100 adopted a "standing" configuration in the cavity of [12]CPP. These results demonstrate the special nature of this kind of metallofullertube.

Scandium Tetrahedron Supported by H Anion and CN Pentaanion inside Fullerene C80.

Endohedral metallofullerenes have greatly expanded the range of the fullerene family due to their nesting structure and unusual encapsulated clusters protected by a fullerene cage. Herein, we report a metallofullerene Sc4CNH@Ih-C80, which has a scandium tetrahedron supported by H and CN anions inside fullerene C80. Sc4CNH@Ih-C80 has a rare multilayer nesting structure, and the internal Sc4CNH is the most complex endohedral cluster disclosed to date. Sc4CNH@Ih-C80 has so many bonding types (metal-carbide, metal-nitride, and metal-hydride), which weave a polyhedron of Sc4CNH clusters. This work shows that the endohedral metallofullerenes have the potential to build inorganic nesting polyhedra that have distinctive architectures and unique electronic properties. Sc4CNH@Ih-C80 was synthesized by means of the arc-discharge method using scandium and graphite under the mixed atmosphere of hydrogen, nitrogen, and helium. It is the first time to disclose an unprecedented metal-hydride bond in a fullerene cage. This result shows that the endohedral fullerenes bearing hydrogen species can be synthesized by the arc-discharge technique under an atmosphere of hydrogen. This work demonstrates that a fullerene cage can be an ample carrier to encapsulate unusual cluster moieties.

Functional Metallofullerene Materials and Their Applications in Nanomedicine, Magnetics, and Electronics.

Endohedral metallofullerenes exhibit combined properties from carbon cages as well as internal metal moieties and have great potential in a wide range of applications as molecule materials. Along with the breakthrough of mass production of metallofullerenes, their applied research has been greatly developed with more and more new functions and practical applications. For gadolinium metallofullerenes, their water-soluble derivatives have been demonstrated with antitumor activity and unprecedented tumor vascular-targeting therapy. Metallofullerene water-soluble derivatives also can be applied to treat reactive oxygen species (ROS)-induced diseases due to their high antioxidative activity. For magnetic metallofullerenes, the internal electron spin and metal species bring about spin sensitivity, molecular magnets, and spin quantum qubits, which have many promising applications. Metallofullerenes are significant candidates for fabricating useful electronic devices because of their various electronic structures. This Review provides a summary of the metallofullerene studies reported recently, in the fields of tumor inhibition, tumor vascular-targeting therapies, antioxidative activity, spin probes, single-molecule magnets, spin qubits, and electronic devices. This is not an exhaustive summary and there are many other important study results regarding metallofullerenes. All of this research has revealed the irreplaceable role of metallofullerene materials.

Synthesis and Structural Studies of Two Paramagnetic Metallofullerenes with Isomeric C72 Cage.

We synthesized and isolated two paramagnetic metallofullerenes of La@C72 and Y@C72 with different fullerene cages, which were characterized by electron paramagnetic resonance (EPR) spectroscopy and theoretical calculations. DFT calculations disclosed two possible isomers of La/Y@C72 with C72- C2 and C72- C2v cages, both of which have similar thermodynamic stability and one pair of fused pentagons. Their paramagnetic properties were then studied by EPR spectroscopy, and the obtained EPR signals were analyzed with very different hyperfine coupling constants, revealing distinct electron spin distributions for these two species. Furthermore, the experimental coupling constants were compared with those of calculated coupling constants, and comparison results revealed that the produced La@C72 has a C72- C2v cage and Y@C72 has a C72- C2 cage. These studies illustrate that the electron spin can be used as a probe to identify metallofullerene structure due to the susceptibility of spin-metal couplings. The successful isolation and characterizations of La@C72 and Y@C72 with such a small C72 cage reveal their stability that is important for application as paramagnetic molecule materials.

Ho2O@C74: Ho2O Cluster Expands within a Small Non-IPR Fullerene Cage of C2(13333)-C74.

Steering the cluster configuration inside a fullerene cage has been one of most interesting topics in the field of fullerenes, since the physical property of a cluster fullerene may be modified accordingly. It has been well-recognized that the cluster configuration can be tuned via altering the cage size. Typically, the carbide cluster and the oxide cluster are experimentally seen to be curled up within a small fullerene cage whereas they are expanded in a large cage. In this work, a new oxide cluster fullerene Ho2O@ C2(13333)-C74 is prepared and isolated. The single-crystal X-ray diffraction (XRD) study reveals that the Ho2O cluster, however, expands within the small non-IPR cage of C2(13333)-C74 with a Ho-O-Ho angle of >170°, indicating that cluster configuration is highly related to the cage shape and cage structure as well. The DFT computation demonstrates that the cluster-to-cage electron-transfer obviously enhances the aromaticity of the motif containing the fused-pentagon pair and hence stabilizes the non-IPR cage of C2(13333)-C74. In addition, the electrochemical and magnetic properties of Ho2O@ C2(13333)-C74 are studied to further investigate the effect of endohedral Ho2O cluster.

Awaking N-hyperfine couplings in charged yttrium nitride endohedral fullerenes.

The electron spin properties of endohedral metallofullerene molecules have broad potential applications in quantum information and magnetic induction systems due to the high stability and sensitivity. Herein, we synthesized a series of Y3N@C2n (n = 40-44) molecules and studied the hyperfine structures of their anion radicals via ESR measurements and DFT calculations. N-Hyperfine couplings were clearly observed in the ESR spectra of charged Y3N@C80 and Y3N@C86 anion radicals, which are not found in the other metallofullerenes. The ESR results revealed size-dependent spin distributions and hyperfine structures, which are sensitive to subtle changes in the carbon cage and the configuration of the yttrium nitride cluster. BOMD cluster trajectories simulations indicated that the Y3N cluster almost rotates freely in neutral Y3N@C80 but there is a certain degree of limitation in the Y3N@C80 anion.

Steering Metallofullerene Electron Spin in Porous Metal-Organic Framework.

Paramagnetic endohedral fullerenes are ideal candidates for quantum information processing and high-density data storage due to their protected spins with particularly high stability. Herein, we report a solid spin system based on a paramagnetic metallofullerene Y2@C79N through incarcerating it into the cage-shaped pores of a metal-organic framework (MOF-177). In this kind of guest and host complex, the Y2@C79N molecules inside the pores of MOF crystal show axisymmetric paramagnetic property. It was found that the pores of MOF-177 crystal play an important role in dispersing the Y2@C79N molecules as well as in steering their electron spin. The group of arranged Y2@C79N molecules and their electron spins in MOF crystals are potential quantum bits for quantum information science and data storage. Moreover, this kind of solid spin system can be used as a probe for nanoscale nuclear magnetic resonance or for motion imaging of a single biomolecule.

Endohedral metallofullerenes based on spherical I(h)-C(80) cage: molecular structures and paramagnetic properties.

Fullerenes are carbon cages assembled from fused hexagons andpentagons that have closed networks and conjugated π systems. The curve of the fullerene structure requires that the constituent carbon atoms take on a pyramidal shape and produces extra strain energy. However, the highly symmetrical geometry of the fullerene decreases the surface tension in these structures, so highly symmetrical fullerenes are usually very stable. For example, C60 with icosahedral symmetry (Ih) is the most stable fullerene molecule. However, another highly symmetrical fullerene, Ih-C80, is extremely unstable. The reason for this difference is the open-shell electronic structure of Ih-C80, which has a 4-fold degenerate HOMO occupied by only two electrons. Predictably, once the degenerate HOMO of Ih-C80 accepts six more electrons, it forms a closed-shell electronic structure similar to Ih-C60 and with comparable stability. Because the hollow structure of fullerenes can encapsulate metal atoms and those internal metals can transfer electrons to the fullerene cage, the encapsulation of metal clusters may provide an ideal technique for the stabilization of the Ih-C80 fullerenes. In this Account, we focus on the molecular structures and paramagnetic properties of spherical Ih-C80 endohedral fullerenes encaging a variety of metal moieties, such as metal atoms (Mn), metal nitride (M3N), metal carbide (MnC2), metal carbonitride (M3CN), and metal oxides (M4Om). We introduce several types of endohedral metallofullerenes such as Sc4C2@Ih-C80, which exhibits a Russian-doll-like structure, and Sc3CN@Ih-C80, which encapsulates a planar metal carbonitride cluster. In addition, we emphasize the paramagnetic properties of Ih-C80-based metallofullerenes, such as Sc3C2@Ih-C80, Y2@C79N, and M3N@Ih-C80, to show how those spin-active species can present a controllable paramagnetism. This Account highlights an inspiring molecular world within the spherical Ih-C80 cages of various metallofullerenes.

Metallofullerenes encaging mixed-metal clusters: synthesis and structural studies of Gdx Ho3-x N@C80 and Gdx Lu3-x N@C80.

Metallofullerenes of Gdx Ho3-x N@C80 and Gdx Lu3-x N@C80 encapsulating mixed-metal nitride clusters were synthesized. Spectroscopic characterization of Gdx Ho3-x N@C80 and Gdx Lu3-x N@C80 was employed to reveal their structural and vibrational properties. The structural properties of these species were analyzed by using theoretical calculations. The studies of Gdx Ho3-x N@C80 and Gdx Lu3-x N@C80 laid the foundations for these species to be used as multifunctional molecules.

[Research progress of the role of non-coding RNA in hyperoxia-induced acute lung injury].

Hyperoxia-induced acute lung injury (HALI) is an important complication of clinical oxygen therapy, which is mainly characterized by acute respiratory distress syndrome (ARDS) in adults and broncho-pulmonary dysplasia (BPD) in infants. HALI seriously affects the prognosis and quality of life of patients, so it has received more and more attention. However, the pathogenesis of HALI is complex and unclear, and there is no clear treatment method at present. Non-coding RNA (ncRNA) is an important type of functional RNA transcriptome. Due to the lack of effective open reading frame, ncRNA does not have the function of coding proteins. However, ncRNA can still regulate gene expression at multiple levels and affect the occurrence and development of many diseases. In recent years, a large number of in vitro and in vivo studies have shown that ncRNA is involved in the pathogenesis of HALI and is of great significance. This article reviews the expression and significance of ncRNA in HALI, in order to provide new diagnosis and treatment ideas for the prevention and treatment of HALI.

Estimation of Weight and Body Measurement Model for Pigs Based on Back Point Cloud Data.

Pig farming is a crucial sector in global animal husbandry. The weight and body dimension data of pigs reflect their growth and development status, serving as vital metrics for assessing their progress. Presently, pig weight and body dimensions are predominantly measured manually, which poses challenges such as difficulties in herding, stress responses in pigs, and the control of zoonotic diseases. To address these issues, this study proposes a non-contact weight estimation and body measurement model based on point cloud data from pig backs. A depth camera was installed above a weighbridge to acquire 3D point cloud data from 258 Yorkshire-Landrace crossbred sows. We selected 200 Yorkshire-Landrace sows as the research subjects and applied point cloud filtering and denoising techniques to their three-dimensional point cloud data. Subsequently, a K-means clustering segmentation algorithm was employed to extract the point cloud corresponding to the pigs' backs. A convolutional neural network with a multi-head attention was established for pig weight prediction and added RGB information as an additional feature. During the data processing process, we also measured the back body size information of the pigs. During the model evaluation, 58 Yorkshire-Landrace sows were specifically selected for experimental assessment. Compared to manual measurements, the weight estimation exhibited an average absolute error of 11.552 kg, average relative error of 4.812%, and root mean square error of 11.181 kg. Specifically, for the MACNN, incorporating RGB information as an additional feature resulted in a decrease of 2.469 kg in the RMSE, a decrease of 0.8% in the MAPE, and a decrease of 1.032 kg in the MAE. Measurements of shoulder width, abdominal width, and hip width yielded corresponding average relative errors of 3.144%, 3.798%, and 3.820%. In conclusion, a convolutional neural network with a multi-head attention was established for pig weight prediction, and incorporating RGB information as an additional feature method demonstrated accuracy and reliability for weight estimation and body dimension measurement.

Quantifying the mutual effects of water trading and systematic water saving in a water-scarce watershed of China.

In this study, a conjunctive water management model based on interval stochastic bi-level programming method (CM-ISBP) is proposed for planning water trading program as well as quantifying mutual effects of water trading and systematic water saving. CM-ISBP incorporates water resources assessment with soil and water assessment tool (SWAT), systematic water-saving simulation combined with water trading, and interval stochastic bi-level programming (ISBP) within a general framework. Systematic water saving involves irrigation water-saving technologies (sprinkler irrigation, micro-irrigation, low-pressure pipe irrigation), enterprise water-saving potential and water-saving subsidy. The CM-ISBP is applied to a real case of a water-scarce watershed (i.e. Dagu River watershed, China). Mutual effects of water trading and water-saving activities are simulated with model establishment and quantified through mechanism analysis. The fate of saved water under the systematic water saving is also revealed. The coexistence of the two systems would increase system benefits by [11.89, 12.19]%, and increase the water use efficiency by [40.04, 40.46]%. Thus mechanism that couples water trading and water saving is optimal and recommended according to system performance.

Theoretical Study on a Supramolecular Dimeric Structure Constructed by Metallofullerene Y3N@C80 and Figure-of-Eight Nanoring.

A new supramolecular complex with a dimeric structure (2Y3N@C80⊂OPP) constructed by metallofullerene Y3N@Ih-C80 and figure-of-eight molecular nanoring of oligoparaphenylene (OPP) was investigated using dispersion-corrected density functional theory (DFT-D3). The interactions between the Y3N@Ih-C80 guest and the OPP host were studied theoretically at the B3LYP-D3/6-31G(d)∼SDD level. By analyzing geometric characteristics and host-guest binding energies, it is revealed that the OPP is an ideal host molecule for the Y3N@Ih-C80 guest. Typically, the OPP can well induce the orientation of the endohedral Y3N cluster on the plane of nanoring. Meanwhile, the configuration of the dimeric structure demonstrates that OPP presents excellent elastic adaptability and shape flexibility during the encapsulation of Y3N@Ih-C80. Highly accurate binding energy suggests that 2Y3N@C80⊂OPP (∼-443.82 kJ mol-1 at the ωB97M-V/def2-QZVPP level of theory) is an extremely stable host-guest complex. Thermodynamic information indicates that the formation of the 2Y3N@C80⊂OPP dimer is thermodynamically spontaneous. Furthermore, electronic property analysis reveals that this dimeric structure has a strong electron-attracting ability. Energy decomposition and real-space function analyses of host-guest interactions reveal the characteristics and nature of the noncovalent interactions in the supramolecules. These results provide theoretical support for the design of new host-guest systems based on metallofullerene and nanoring.

Embedded nano spin sensor for in situ probing of gas adsorption inside porous organic frameworks.

Spin-based sensors have attracted considerable attention owing to their high sensitivities. Herein, we developed a metallofullerene-based nano spin sensor to probe gas adsorption within porous organic frameworks. For this, spin-active metallofullerene, Sc3C2@C80, was selected and embedded into a nanopore of a pyrene-based covalent organic framework (Py-COF). Electron paramagnetic resonance (EPR) spectroscopy recorded the EPR signals of Sc3C2@C80 within Py-COF after adsorbing N2, CO, CH4, CO2, C3H6, and C3H8. Results indicated that the regularly changing EPR signals of embedded Sc3C2@C80 were associated with the gas adsorption performance of Py-COF. In contrast to traditional adsorption isotherm measurements, this implantable nano spin sensor could probe gas adsorption and desorption with in situ, real-time monitoring. The proposed nano spin sensor was also employed to probe the gas adsorption performance of a metal-organic framework (MOF-177), demonstrating its versatility. The nano spin sensor is thus applicable for quantum sensing and precision measurements.

Structure and single-molecule conductance of two endohedral metallofullerenes with large C88 cage.

Endohedral metallofullerenes are capable of holding peculiar metal clusters inside the carbon cage. Additionally, these display many chemical and physical properties originating from the complexation between the metal clusters and carbon cages, which could be acquired for wide applications. In this study, two metallofullerenes (Ce2O@C88 and Ce3N@C88) with an identical large C88-D2(35) cage, and their molecular structures and single-molecule conductance properties were investigated comparatively. Characterizations of UV-vis-NIR absorption spectroscopy, Raman spectroscopy, and DFT calculations were employed to determine the geometries and electronic structures of Ce2O@C88 and Ce3N@C88. These molecules revealed varied energy gaps, structural parameters, vibrational modes, and molecular frontier orbitals. Although the two metallofullerenes have an identical cage isomer of C88-D2(35), their different endohedral clusters can influence their structures and physicochemical properties. Furthermore, the single-molecule conductance properties were measured using the scanning tunneling microscopy break junction technique (STM-BJ). The experimental results revealed that Ce2O@C88 has a higher conductance than Ce3N@C88 and C60. This revealed the cluster-dependent electron transportation as well as the significant research value of metallofullerenes with large carbon cages. These results provide guidance for fabricating single-molecule electronic devices.

Controllable fabrication of iron oxide/oxyhydroxide with diverse nanostructures and their excellent performance in visible light induced photocatalytic degradation of rhodamine B.

Alpha-FeOOH and alpha-Fe2O3 with diverse morphologies (sea hedgehog-like, array-like, nanorod-like and nanoparticle-like) were synthesized through a simple and facile solvent-mediated method. The products with different morphologies can be prepared by adjusting the concentration of ferrous ions, reaction temperature and the pH value of the reaction solution in the rationally designed synthesis routes. All the products had a high BET surface area and exhibited an excellent catalytic ability in visible light induced degradation of rhodamine B.

A density functional theory investigation for the open-shell metal-carbide endofullerene Lu3C2@C88(D2:35) and closed-shell metal-nitride endofullerene Lu3N@C88(D2:35).

By means of the density functional theory calculations, two C88(D2:35)-based endohedral fullerenes, Lu3C2@C88(D2:35) and Lu3N@C88(D2:35) which encapsulate tri-lutetium carbide and tri-lutetium nitride cluster were investigated. For the cores in Lu3C2@C88 and Lu3N@C88, the trivalent C2 and N respectively template a butterfly-shaped endohedral moiety and a planar tri-lutetium cluster within the same D2-symmetric C88 cage. Moreover, Lu3N@C88 - D2 has a closed-shell electronic structure but for LuC3C2@C88 - D2, it owns an unpaired electron mainly localized on the internal Lu3C2 cluster. These results clearly showed that the core unit C2(3) as well as N3- play an important role in constructing molecular structures and electronic features of metallofullerenes. Furthermore, the electrochemical redox potentials, and vibrational frequencies of the two endofullerenes agree well with our experimental results. The electronic structures, ionization energies, electron affinities, inner clusters' dynamic motions of them have been predicted to further disclose the characters of these two metallofullerenes.