Conjugated Nickel Phthalocyanine Derivatives for Heterogeneous Electrocatalytic H2 O2 Synthesis.

Electrocatalytic hydrogen peroxide (H2 O2 ) production has emerged as a promising alternative to the chemical method currently used in industry, due to its environmentally friendly conditions and potential for higher activity and selectivity. Heterogeneous molecular catalysts are promising in this regard, as their active site configurations can be judiciously designed, modified, and tailored with diverse functional groups, thereby tuning the activity and selectivity of the active sites. In this work, nickel phthalocyanine derivatives with various conjugation degrees are synthesized and identified as effective pH-universal electrocatalysts for H2 O2 production after heterogenized on nitrogen-decorated carbon, with increased conjugation degrees leading to boosted selectivity. This is explained by the regulated d-band center, which optimized the binding energy of the reaction intermediate, reducing the energy barrier for oxygen reduction and leading to optimized H2 O2 selectivity. The best catalyst, NiPyCN/CN, exhibits a high H2 O2  electrosynthesis activity with ≈95% of H2 O2 faradic efficiency in an alkaline medium, demonstrating its potential for H2 O2 production.

Enlarging the π-Conjugation of Cobalt Porphyrin for Highly Active and Selective CO2 Electroreduction.

Heterogeneous molecular catalysts have attracted considerable attention as carbon dioxide reduction reaction (CO2 RR) electrocatalysts. The π-electron system of conjugated ligands in molecular catalysts may play an important role in determining the activity. In this work, by enlarging π-conjugation through appending more aromatic substituents on the porphyrin ligand, altered π-electron system endows the as-prepared 5,10,15,20-tetrakis(4-(pyren-1-yl)phenyl)porphyrin CoII with high Faradaic efficiency (ca. 95 %) for CO production, as well as high turnover frequency (2.1 s-1 at -0.6 V vs. RHE). Density functional theory calculation further suggests that the improved electrocatalytic performance mainly originates from the higher proportion of Co d z 2 orbital and the CO2 π* orbital in the HOMO of the (Co-porphyrin-CO2 )- intermediate with larger π-conjugation, which facilitates the CO2 activation. This work provides strong evidence that π-conjugation perturbation is effective in boosting the CO2 RR.

Isolated FeN4 Sites for Efficient Electrocatalytic CO2 Reduction.

The construction of isolated metal sites represents a promising approach for electrocatalyst design toward the efficient electrochemical conversion of carbon dioxide (CO2). Herein, Fe-doped graphitic carbon nitride is rationally prepared by a simple adsorption method and is used as template to construct isolated FeN4 sites through a confined pyrolysis strategy, which avoids the agglomeration of metal atoms to particles during the synthesis process and thus provides abundant active sites for the CO2 reduction reaction. The isolated FeN4 sites lower the energy barrier for the key intermediate in the CO2 reduction process, leading to the enhanced selectivity for CO production with a faradaic efficiency of up to 93%.

A Planar, Conjugated N4 -Macrocyclic Cobalt Complex for Heterogeneous Electrocatalytic CO2 Reduction with High Activity.

Metal complexes have been widely investigated as promising electrocatalysts for CO2 reduction. Most of the current research efforts focus mainly on ligands based on pyrrole subunits, and the reported activities are still far from satisfactory. A novel planar and conjugated N4 -macrocyclic cobalt complex (Co(II)CPY) derived from phenanthroline subunits is prepared herein, and it delivers high activity for heterogeneous CO2 electrocatalysis to CO in aqueous media, and outperforms most of the metal complexes reported so far. At a molar loading of 5.93×10-8  mol cm-2 , it exhibits a Faradaic efficiency of 96 % and a turnover frequency of 9.59 s-1 towards CO at -0.70 V vs. RHE. The unraveling of electronic structural features suggests that a synergistic effect between the ligand and cobalt in Co(II)CPY plays a critical role in boosting its activity. As a result, the free energy difference for the formation of *COOH is lower than that with cobalt porphyrin, thus leading to enhanced CO production.

Two Ni/Co-substituted sandwich-type germanomolybdates based on an unprecedented trivacant polyanion [α-GeMo10O36]8.

Two Ni/Co-substituted sandwich-type germanomolybdates, {[M3(NH2-trz)6(H2O)6][M4(H2O)2(HGeMo10O36)2]}·nH2O (M = Ni2+ (1) and Co2+ (2), n = 10 (1) or 11 (2), NH2-trz = 4-amino-1,2,4-triazole), have been obtained under hydrothermal conditions. 1 and 2 represent the first trivacant Keggin germanomolybdates involving unprecedented [α-GeMo10O36]8- fragments and {M3O4} quasi-cubane building units. Both of them exhibit electrocatalytic behaviours for H2O2 reduction and photocatalytic properties for CO2 conversion.

Dynamic Video Stitching via Shakiness Removing.

Stitching videos captured by hand-held mobile cameras can essentially enhance entertainment experience of ordinary users. However, such videos usually contain heavy shakiness and large parallax, which are challenging to stitch. In this paper, we propose a novel approach of video stitching and stabilization for videos captured by mobile devices. The main component of our method is a unified video stitching and stabilization optimization that computes stitching and stabilization simultaneously rather than does each one individually. In this way, we can obtain the best stitching and stabilization results relative to each other without any bias to one of them. To make the optimization robust, we propose a method to identify background of input videos, and also common background of them. This allows us to apply our optimization on background regions only, which is the key to handle large parallax problem. Since stitching relies on feature matches between input videos, and there inevitably exist false matches, we thus propose a method to distinguish between right and false matches, and encapsulate the false match elimination scheme and our optimization into a loop, to prevent the optimization from being affected by bad feature matches. We test the proposed approach on videos that are causally captured by smartphones when walking along busy streets, and use stitching and stability scores to evaluate the produced panoramic videos quantitatively. Experiments on a diverse of examples show that our results are much better than (challenging cases) or at least on par with (simple cases) the results of previous approaches.Stitching videos captured by hand-held mobile cameras can essentially enhance entertainment experience of ordinary users. However, such videos usually contain heavy shakiness and large parallax, which are challenging to stitch. In this paper, we propose a novel approach of video stitching and stabilization for videos captured by mobile devices. The main component of our method is a unified video stitching and stabilization optimization that computes stitching and stabilization simultaneously rather than does each one individually. In this way, we can obtain the best stitching and stabilization results relative to each other without any bias to one of them. To make the optimization robust, we propose a method to identify background of input videos, and also common background of them. This allows us to apply our optimization on background regions only, which is the key to handle large parallax problem. Since stitching relies on feature matches between input videos, and there inevitably exist false matches, we thus propose a method to distinguish between right and false matches, and encapsulate the false match elimination scheme and our optimization into a loop, to prevent the optimization from being affected by bad feature matches. We test the proposed approach on videos that are causally captured by smartphones when walking along busy streets, and use stitching and stability scores to evaluate the produced panoramic videos quantitatively. Experiments on a diverse of examples show that our results are much better than (challenging cases) or at least on par with (simple cases) the results of previous approaches.

Homography Propagation and Optimization for Wide-Baseline Street Image Interpolation.

Wide-baseline street image interpolation is useful but very challenging. Existing approaches either rely on heavyweight 3D reconstruction or computationally intensive deep networks. We present a lightweight and efficient method which uses simple homography computing and refining operators to estimate piecewise smooth homographies between input views. To achieve the goal, we show how to combine homography fitting and homography propagation together based on reliable and unreliable superpixel discrimination. Such a combination, other than using homography fitting only, dramatically increases the accuracy and robustness of the estimated homographies. Then, we integrate the concepts of homography and mesh warping, and propose a novel homography-constrained warping formulation which enforces smoothness between neighboring homographies by utilizing the first-order continuity of the warped mesh. This further eliminates small artifacts of overlapping, stretching, etc. The proposed method is lightweight and flexible, allows wide-baseline interpolation. It improves the state of the art and demonstrates that homography computation suffices for interpolation. Experiments on city and rural datasets validate the efficiency and effectiveness of our method.

Ionothermal syntheses and characterizations of new open-framework metal borophosphates.

Three new open-framework metal borophosphates, [Na(6)Co(3)B(2)P(5)O(21)Cl]·H(2)O (JIS-4), K(5)Mn(2)B(2)P(5)O(19)(OH)(2) (JIS-5), (NH(4))(8)[Co(2)B(4)P(8)O(30)(OH)(4)] (JIS-6), have been prepared under ionothermal conditions using ionic liquid 1-ethyl-3-methylimidazolium ([Emim]Br) as the solvent. They are the first examples of metalloborophosphate prepared by the ionothermal method. Their structures are determined by single-crystal X-ray diffraction. The 3-D open framework of JIS-4 is made of CoO(5)Cl octahedra, CoO(5) square pyramids, and PO(4) and BO(4) tetrahedra forming 12-ring channels along the [010] direction. It is noted that JIS-4 is the first 3-D open-framework structure in the family of borophosphate with the B/P ratio of 2/5, which features a borophosphate cluster anionic partial structure. Such cluster anionic partial structures connect with MnO(6) octahedra and MnO(5) trigonal bipyramids resulting in the formation of the 2-D layer structure of JIS-5 with the same B/P ratio as JIS-4. The 2-D layer structure of JIS-6 belongs to the largest family of borophosphate with a B/P ratio of 1/2 which features a unique 1-D chain anionic partial structure. Crystal data for JIS-4, orthorhombic, Pnma, a = 14.0638(8) Å, b = 9.8813(7) Å, c = 14.0008(10) Å, V = 1945.7(2) Å(3), and Z = 2; for JIS-5, monoclinic, P2(1)/n, a = 14.4939(3) Å, b = 9.2539(3) Å, c = 14.8031(4) Å, ß = 101.4600(10)°, V = 1945.88(9) Å(3), and Z = 4. For JIS-6, triclinic, P1, a = 9.6928(3) Å, b = 9.8747(3) Å, c = 10.0125(2) Å, α = 62.057(2)°, ß = 82.456(2)°, γ = 76.095(2)°, V = 821.60(4) Å(3), and Z = 1.

Spontaneous crystallization of a new chiral open-framework borophosphate in the ionothermal system.

We present the spontaneous crystallization of a new chiral open-framework borophosphate in an ionothermal system. Its structure contains a three-dimensional (3D) anionic framework with intersecting 12-ring channels formed by interweaving helical chains.

Bis[diaquabis(2,2-bipyridine N,N'-dioxide-kappa2O,O')cobalt(II)] xi-octamolybdate dihydrate.

The title organic-inorganic hybrid compound, [Co(C(10)H(8)N(2)O(2))(2)(H(2)O)(2)](2)[Mo(8)O(26)].2H(2)O, consists of [Co(bpdo)(2)(H(2)O)(2)](2+) (bpdo is 2,2-bipyridine N,N'-dioxide) and xi-[Mo(8)O(26)](4-) groups in a 2:1 ratio, plus two water solvent molecules. The independent Co atom in the cation is coordinated by four O atoms from two bpdo ligands and two water molecules, in a distorted octahedral geometry. The counter-anions, built up around a symmetry center, are linked by solvent water molecules through O-H...O hydrogen bonds to generate two-dimensional layers, which are in turn linked by coordinated water molecules from the cationic units through further O-H...O hydrogen bonds, forming a three-dimensional supramolecular structure.

Theoretical study on photophysical properties of phenolpyridyl boron complexes.

Organoboron complexes have potential application in organic light-emitting devices (OLEDs). Our group has synthesized four phenolpyridyl boron complexes (Inorg. Chem. 2006, 45, 2788), which can function as an electron transport materials (ETM), white and blue emitters, and exhibit high efficiency and stability. To reveal the relationship between the properties and structures of these functional materials, theoretical analysis of spectral properties and electronic structures of these complexes was systematically characterized with the B3LYP and 6-31G* basis set. The calculated absorption and emission spectra of these systems are in good agreement with the experimental ones. It is clear seen that these transitions are charge transferred along 2,6-bis(2-hydroxyphenyl)pyridyl boron moiety, and the contribution of boron atom in these compounds to the main transition orbitals is vanishingly small. The substitution of methyl and methoxyl for hydrogen does not change the absorption wavelengths and transition natures, but influences the radioactive efficiencies and electron transport properties, which are observed and discussed in detail. Furthermore, large red shifts of fluorescence are caused by replacing the hydrogen with CN or NO2 groups, which indicates that they are potential candidates as green-light-emitting materials. These results are favorable to further understanding the photophysical properties of this kind of complexes.

Ichthyotoxic ARF after fish gallbladder ingestion: a large case series from Vietnam.

Fish gallbladders are consumed in rural areas of Asia as a traditional medicine to improve symptoms of arthritis, decreased visual acuity, and impotence. Consumption of large amounts of this traditional medicine can result in systemic toxicities; in particular, acute renal failure. We reviewed records of all admissions to Cho Ray Hospital (Ho Chi Minh City, Vietnam) between January 1995 and December 2000 after this ingestion. Clinical courses and outcomes were similar in 16 of 17 patients. Within hours, patients experienced profuse vomiting (n = 16) and diarrhea (n = 15). All developed acute renal failure, with a mean serum creatinine concentration of 14.7 +/- 3.9 mg/dL (1,299.5 +/- 344.8 micromol/L). Four patients administered intravenous fluid (IVF) developed extracellular fluid volume overload, as did 1 patient not administered IVF. Time to peak creatinine concentration was 8.6 +/- 3.0 days, which was accompanied by decreased urine volume (174.7 +/- 161.6 mL/24 h). Blood pressure remained normal, with a mean arterial pressure of 91 +/- 12 mm Hg. Twelve patients required renal replacement therapy. A mean of 1.9 +/- 1.1 hemodialysis sessions was performed per patient. Sixteen patients recovered renal function; 1 patient died of fulminant hepatic failure. Kidney biopsies showed features of acute tubular injury. Acute renal failure after fish gallbladder ingestion is characterized by a failure to respond to IVF, an 8.6-day interval to peak creatinine level, frequent need for dialysis therapy, and findings on renal biopsy consistent with acute tubular necrosis. Acute renal failure after fish gallbladder ingestion has an excellent prognosis. However, death from fulminant hepatic failure can occur.