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Floods are common natural disasters in Asia. Flood datasets from 48 countries in Asia were collected to investigate the spatiotemporal distribution and influencing factors, using the Mann–Kendall trend test and the Spearman’s rank correlation. These results show that flood occurrences and damages increased significantly in Asia, with the mortality rates and deaths decreasing. Southern and Eastern Asia are flood vulnerable regions, with Central Asia being the least flood-occurrence region, and China and India are also flood-prone countries with a largest population and land area in Asia. Least flood disasters occurred in Bahrain, Cyprus, Brunei Darussalam and Singapore, with a smaller population and land area. The spatial disparities of flood disasters were positively influenced by population and land area, and negatively influenced by urbanization rate and per capita GDP. The largest proportion of flood disasters were discovered in riverine floods, followed by flash floods, with coastal floods being the least. The highest and second-highest mortality rates were observed in flash floods and coastal floods, which showed decreasing trends, and the mortality rate of riverine floods was the lowest, with an increasing trend. The rain was the main triggering origin of floods, and tropical cyclone contributed to the second, followed by snowmelt, convective storms, and dam-break flows. This analysis can help to provide a useful insight into the formulation of flood risk maps, disaster mitigation measures and emergency management.

The accurate characterization of near-field flow dynamics from urban surface to sewer system is essential for the design of urban drainage systems and the risk identification of urban floods. Motivated by the observation that the vortex flow structure was evident around the grate inlet during urban flood events, a physical model was used to measure flow features and investigate the drainage capacity of grate inlets. Detailed flow velocity fields and flow motions in the vicinity of the grate inlet are presented in both horizontal and vertical directions. It is found that there exists a critical threshold of water depth at [Formula: see text], where the flow regime transforms from weir flow to orifice flow for the tested grate inlet. In addition, flow accelerates significantly near the grate inlet and the vortex flow feature is obviously enhanced from the surface layer to the bottom layer in the region of the grate inlet. With the decrease in discharge capacity, vortex flow structure and turbulence kinetic energy were intensified significantly. Overall, this work demonstrates the near-field flow dynamics of grate inlets and the experimental datasets could also be helpful for the design of drainage systems and the validation of numerical modeling in various urban flood events.

Street inlets play a key role in intercepting surface runoff into underground drainage systems, which can reduce the hazard degree during urban flood events. An accurate calculation of the discharge capacity of street inlets is vitally important in numerically modelling urban floods and managing flood resilience. A series of laboratory experiments were combined with a theoretical analysis in this study to investigate the conveyance characteristics of a typical street grate inlet. A large-scale laboratory platform was constructed, consisting of an upper-layer model street and an underground measuring system installed with a V-notch weir structure. A model street inlet was used to connect the upper and underground layers, which had a complete drainage structure including: an inlet grate, a drain box, and a connection tube. A total of 78 experimental runs were conducted using this laboratory platform, and the discharges intercepted by the grate inlet were measured for a range of incoming water depths and flow velocities, where the approaching Froude number varied from 0.05 to 0.89. These experimental results showed that the drainage pattern of the street inlet was converted from weir flow to orifice flow after the drain box was fully pressurized. In addition, a power function was derived between the relative drainage velocity through the inlet and the approaching Froude number, based on the method of dimensional analysis, and a unified formula was proposed to calculate the discharge capacity of street inlets. The corresponding coefficients in the formula were calibrated using the laboratory measurements. The unified discharge capacity formula was verified using other experimental results obtained from previous studies, and the results indicated that the calculated results using the unified formula agreed well with these measurements, with the regression coefficients of R2 > 0.90. Therefore, the unified formula for discharge capacity of street inlets obtained from the study reported herein has a high predictive accuracy, which can be used in numerical modelling and risk management of urban floods.

The discovery of photo-assisted diazonium activation toward gold(I) oxidation greatly extended the scope of gold redox catalysis by avoiding the use of a strong oxidant. Some practical issues that limit the application of this new type of chemistry are the relative low efficiency (long reaction time and low conversion) and the strict reaction condition control that is necessary (degassing and inert reaction environment). Herein, an alternative photo-free condition has been developed through Lewis base induced diazonium activation. With this method, an unreactive Au(I) catalyst was used in combination with Na2CO3 and diazonium salts to produce a Au(III) intermediate. The efficient activation of various substrates, including alkyne, alkene and allene was achieved, followed by rapid Au(III) reductive elimination, which yielded the C-C coupling products with good to excellent yields. Relative to the previously reported photo-activation method, our approach offered greater efficiency and versatility through faster reaction rates and broader reaction scope. Challenging substrates such as electron rich/neutral allenes, which could not be activated under the photo-initiation conditions (

An efficient synthesis of substituted cyclopentenes through gold/gallium-catalyzed annulation of 1,3-dicarbonyl compounds and cyclopropylacetylenes is achieved. This tandem reaction consists of a gold-catalyzed Nakamura reaction, a catalytic dienol–enone tautomerization, and a gallium-catalyzed vinylcyclopropane (VCP) rearrangement.

Fluorescence active fused-triazole was developed as a ligand in gold(I) cation coordination. The coordination ability was evaluated using NMR and fluorescence emission. Our previously reported N-2-aryl-triazoles, though gave good emission, could not form stable complexes with gold cations. A new N-fused-triazole (NFT) derivative was prepared and the ligand indicated good fluorescence emission, and formed strong coordination with gold cations. Both ligand and complex were characterized by X-ray crystallography. Fluorescence properties of various gold complexes (with different primary ligands) were evaluated, which suggested the feasibility of using fluorescence emission as potential tools for future mechanistic investigation.

Gold-catalyzed oxidative cross-coupling of alkynes to unsymmetrical diynes has been achieved for the first time. A N,N-ligand (1,10-Phen) and PhI(OAc)2 were identified as crucial factors to promote this transformation, giving the desired cross-coupled conjugated diynes in excellent heteroselectivity (>10:1), in good to excellent yields, and with large substrate tolerability.

An unexpected ligand effect was discovered in the silver(I)-catalyzed alkyne activation. For both aldehyde-alkyne-amine (A3) condensation and intermolecular alkyne hydroamination, the type B complex (P:Ag=1:1) effectively promoted the reaction, while no reaction occurred with either no ligand or excess ligands under the identical conditions.

Gold-catalyzed O-vinylation of cyclic 1,3-diketones has been achieved for the first time, which provides direct access to various vinyl ethers. A catalytic amount of copper triflate was identified as the significant additive in promoting this transformation. Both aromatic and aliphatic alkynes are suitable substrates with good to excellent yields.

An efficient synthesis of substituted cyclopentenes through gold/gallium-catalyzed annulation of 1,3-dicarbonyl compounds and cyclopropylacetylenes is achieved. This tandem reaction consists of a gold-catalyzed Nakamura reaction, a catalytic dienol–enone tautomerization, and a gallium-catalyzed vinylcyclopropane (VCP) rearrangement.

Extensive studies suggest direct links between cholesteryl ester transfer protein (CETP), high-density lipoproteins-cholesterol level and cardiovascular diseases. Many therapeutic approaches are aimed at the CETP. A series of N, N-disubstituted-trifluoro-3-amino-2-propanol analogues are among the most highly potent and selective inhibitors of CETP described to date. For in-depth investigation into the structural and chemical features responsible for exploring the binding pocket of these compounds, as well as for the binding recognition mechanism concerned, we performed a series of automated molecular docking operations. Moreover, the docking results were quite robust as further validated by molecular dynamics. The docking results reveal that the binding site mainly consists of two hydrophobic regions (P1 and P2 site) which are able to accommodate the lipophilic arms of the compounds investigated. Val421 in P1 site and Met194 in P2 site could be considered to be two important residues in forming the two hydrophobic regions. The presence of residues Phe197 and Phe463 in P2 site may be responsible for the binding recognition through π-π stacking interactions. The hydrophobic 3-phenoxy substituent may be important in creating the preferable inhibitive capability for increasing the binding potency. The hydrophobic character of the tetrafluoroethoxybenzyl group at position 3 displays better hydrophobicity than a shorter hydrophobic substituent. An interaction model of CETP-inhibitors is derived that can be successfully used to explain the different biologic activities of these inhibitors. It is anticipated that the findings reported here may provide very useful information or clues for designing effective drugs for the therapeutic treatment of CETP-related cardiovascular diseases.

Gold-catalyzed oxidative cross-coupling of alkynes to unsymmetrical diynes has been achieved for the first time. A N,N-ligand (1,10-Phen) and PhI(OAc)2 were identified as crucial factors to promote this transformation, giving the desired cross-coupled conjugated diynes in excellent heteroselectivity (>10:1), in good to excellent yields, and with large substrate tolerability.

A gold-catalyst with an electron-deficient phosphite as the ancillary ligand is found to exclusively promote the carbophilic chemoselective addition of arenes, hetarenes and 1,3-diketones to α-aryldiazoesters.

The first gold-catalyzed Markovnikov addition of sulfinic acids to terminal alkynes is presented.

This Ag-catalysis is based on a strong ligand effect requiring a ratio of BINAP:Ag of 1:2 for excellent yields and moderate enantioselectivities.

The chemoselective addition of arenes and 1,3-diketones to α-aryldiazoesters was achieved through ligand-controlled gold catalysis. Unlike a dirhodium catalyst (which promotes C(sp3)-H insertion and cyclopropanation) and a copper catalyst (which catalyzes O-H and N-H insertions), the gold catalyst with an electron-deficient phosphite as the ancillary ligand exclusively gave the carbophilic addition product, thus representing a new and efficient approach to form "carbophilic carbocations", which selectively react with carbon nucleophiles.

A general method for the synthesis of α-substituted vinyl sulfones makes use of a combination of a triazole gold complex and gallium triflate. This efficient CS bond formation between simple terminal alkynes and sulfinic acids provides access to various α-substituted vinyl sulfones.