[Temporal and Spatial Characteristics of Net CO2 Emissions and Decoupling Analysis in Yangtze River Economic Belt].

Calculating the fossil energy consumption, revealing the temporal and spatial evolution characteristics of net CO2 emissions, and analyzing the decoupling effect between social development and net CO2 emissions in different regions of the Yangtze River Economic Belt (YREB) is crucial to support the different regions, allowing them to select their individual industrial development and carbon emission reduction path. The results showed that:① from 1999 to 2012, YREB became greener, the CO2 emission of the YREB increased by 2244.23 million tons, and the carbon sink increased by 148.07 million tons during the research period. ② From 2013 to 2018, the area of medium-high carbon sequestration (NPP>800 g·m-2, count for C) increased by 23.25%, compared with that from 1999-2012. ③ A highly decoupling effect between social development and net CO2 emissions was found in the downstream of the YREB. The highest decoupling cities in the upstream, midstream, and downstream accounted for 12%, 34%, and 54% of the highest decoupling cities in the YREB, respectively.

New Insight into CO2 Reduction to Formate by In Situ Hydrogen Produced from Hydrothermal Reactions with Iron.

To reveal the nature of CO2 reduction to formate with high efficiency by in situ hydrogen produced from hydrothermal reactions with iron, DFT calculations were used. A reaction pathway was proposed in which the formate was produced through the key intermediate species, namely iron hydride, produced in situ in the process of hydrogen gas production. In the in situ hydrogenation of CO2, the charge of H in the iron hydride was -0.135, and the Fe-H bond distance was approximately 1.537 Å. A C-H bond was formed as a transition state during the attack of Hδ- on Cδ+. Finally, a HCOO species was formed. The distance of the C-H bond was 1.107 Å. The calculated free energy barrier was 16.43 kcal/mol. This study may provide new insight into CO2 reduction to formate in hydrothermal reactions with metal.

Rh(III)-Catalyzed Tandem Reaction Access to (Quinazolin-2-yl)methanone Derivatives from 2,1-Benzisoxazoles and α-Azido Ketones.

A Rh(III)-catalyzed tandem reaction for the synthesis of (quinazolin-2-yl)methanone derivatives has been explored from 2,1-benzisoxazoles and α-azido ketones. The transformation involves Rh(III)-catalyzed denitrogenation of α-azido ketones, aza-[4 + 2] cycloaddition, ring opening, and dehydration aromatization processes. Notably, the aza-[4 + 2] cycloaddition of an imine rhodium complex intermediate with 2,1-benzisoxazoles is the key to this reaction.

Preparation and photophysical properties of thienothiophene functionalized difluoroboron bis-ß-diketonate complexes.

A series of six new thienothiophene functionalized difluoroboron bis-ß-diketonates were synthesized and characterized. Their photophysical properties were investigated by UV-vis absorption, fluorescence spectroscopy and the method of CIE chromaticity in solution and powders. The results showed that these difluoroboron complexes yielded a blue-green emission at 474-500 nm in DMF solution and emitted a green to yellow emission at 541-587 nm in powders. Especially, the complex 3c showed the stronger fluorescence intensity, much higher quantum yield (Φu = 0.89) in DMF solution and larger Stokes shifts (∆λstokes = 149 nm), longer lifetime value (τ = 3.54 ns) in powders as compared to other complexes. The CIE coordinate of the complex 3c was positioned in an ideal orange-yellow region of the chromaticity diagram. Meanwhile, their electrochemical properties were also studied by the cyclic voltammetry; the HOMO, LUMO energy levels and energy band gaps were determined from the onset oxidation and reduction potentials.

A highly sensitive fluorescent chemosensor for selective detection of zinc (II) ion based on the oxadiazole derivative.

A novel fluorescent chemosensor based on the oxadiazole, 2-(2-hydroxyphenyl)-5-(4-methoxyphenyl)-1,3,4-oxadiazole, was designed and synthesized. The interaction of the oxadiazole with different metal ions had been investigated through UV-vis absorption and fluorescence spectra in 9:1 (v/v) ethanol-water (pH=7.0) solution. The oxadiazole showed a pronounced fluorescence enhancement at 430nm upon addition of Zn2+ in aqueous solution, whereas it had no apparent interference from other metal ions. The results indicated that the oxadiazole possessed high selectivity and sensitivity to Zn2+ ion. The stoichiometric ratio between the oxadiazole and Zn2+ ion was calculated to be 2:1 by Job plot experiment, meanwhile their binding modes was confirmed by 1H NMR and mass spectrometry. Their association constant was determined to be 1.95×105M-1 and the detection limit for Zn2+ ion was 6.14×10-7mol/L.

Efficient approach to 2-hydroxy-2,3-dihydrofuran derivatives and its application for the synthesis of novel 4-(1H-pyrazol-4-yl)pyridazines.

A highly efficient method for the synthesis of 2-hydroxy-2,3-dihydrofuran derivatives from 1,4-enediones and phenacyl pyridinium halides via a domino reaction has been developed. This is a simple and beneficial strategy for the construction of 2-hydroxy-2,3-dihydrofuran compounds from readily available starting materials under mild conditions. Moreover, the application of this reaction provides a straightforward and practical route for the synthesis of the novel 4-(1H-pyrazol-4-yl)pyridazine skeleton.

Highly efficient synthesis of 3a,6a-dihydrofuro[2,3-b]furans via a novel bicyclization.

A highly efficient method for the construction of 3a,6a-dihydrofuro[2,3-b]furan derivatives has been developed via a novel bicyclization, which is very valuable for the synthesis of fused furofuran compounds since it is time-saving and catalyst-free. Based on the bicyclization, a coupled domino strategy has been developed to directly construct 3a,6a-dihydrofuro[2,3-b]furan derivatives from methyl ketones.

[Diagnosis and treatment of cervicothoracic spinal fractures and dislocations in patients with ankylosing spondylitis].

OBJECTIVE: To discuss the pathological and clinical characteristics,methods of therapies and perioperative considerations of cervicothoracic spinal fractures and dislocations in patients with ankylosing spondylitis (AS). METHODS: Thirteen patients with ankylosing spondylitis and cervicothoracic spinal fractures and dislocations were treated from January 2001 to March 2009, including 11 males and 2 females,aged varied from 33 to 60 years (mean 46) in 11 males and from 36 to 59 years (mean 47.5) in 2 females respectively. The symptom duration of AS was from 12 to 27 years (means 14.5 years). The chief complains were pain around cervical part and shoulder blades, some accompanied with decrease of motor power and sensation in upper or lower limbs. Spine radiographs revealed a displaced fracture of cervicothoracic spine. Laboratory examination presented positive results of HLA-B27 test. Fusion of fracture and ASIA neurological function grade variation were observed. RESULT: A total of 13 patients, who underwent operation, were followed up for 12 to 43 months(means 35.6 months). There were 6 patients were treated with anterior cervical discectomy and fusion, 4 with anterior cervical corpectomy and fusion, 1 with laminectomy and fusion and 2 with combined anterior and posterior stabilisation. The bone fusion were observed after reduction of fractures and dislocations ultimately. Twelve patients acquired an improved neurological status in different degrees, and only one suffered from persistent neurological impairment loss. The complications occurred in 5 cases during perioperation. CONCLUSION: This study suggests that most cervicothoracic spinal fractures and dislocations in patients with AS are extremely unstable and require operations. If operative method is proper and operative process accurate, either anterior,posterior or combined approach can achieve good spinal myeloid functional recovery with low rates of operative complications occurrence, under the guidence of imaging manifestation.

Substituent effects control the self-association of molecular clips in the crystalline state.

We report the X-ray crystal structure of 11 molecular clips and analyze the influence of substituents (e.g., OMe, Me, and NO2) and their location on the observed crystal packing. Molecular clips 3a and 3b form tapelike structures in the crystal due to pi-pi interactions between the aromatic walls. Compounds 3d, 3eC, and 3fC form dimers driven by critical C-H...O interactions and then form tapes driven by pi-pi interactions in the crystal. These two building motifs, pi-pi and C-H...O interactions, can be used to rationalize the enantio- and diastereoselectivity observed in the X-ray crystal structures of the remaining five molecular clips. For example, the C-H...O interactions are found to dictate the formation of homochiral dimers in the structures of (+/-)-3eT and (+/-)-3fT and to control the diastereoselective formation of 6a2-6c2 dimeric motifs with internal p-dimethoxy-o-xylylene walls. Overall, the results suggest that substituent effects that induce even weak intermolecular interactions (e.g., C-H...O) can be used to reliably control crystal packing within glycoluril-based systems.