Multishelled NiO Hollow Spheres Decorated by Graphene Nanosheets as Anodes for Lithium-Ion Batteries with Improved Reversible Capacity and Cycling Stability

Graphene-based nanocomposites attract many attentions because of holding promise for many applications. In this work, multishelled NiO hollow spheres decorated by graphene nanosheets nanocomposite are successfully fabricated. The multishelled NiO microspheres are uniformly distributed on the surface of graphene, which is helpful for preventing aggregation of as-reduced graphene sheets. Furthermore, the NiO/graphene nanocomposite shows much higher electrochemical performance with a reversible capacity of 261.5 mAh g−1 at a current density of 200 mA g−1 after 100 cycles tripled compared with that of pristine multishelled NiO hollow spheres, implying the potential application in modern science and technology

Study on Subjective Evaluation of Acoustic Environment in Urban Open Space Based on “Effective Characteristics”

With the continuous expansion of urban scale with dense population and traffic and the gradual improvement of residents’ requirements for environmental quality, the traditional evaluation method relying on acoustic energy is not enough to reflect the feelings of urban crowds about acoustic environment quality. The acoustic environment quality evaluation method based on human subjective perception has gradually become one of the research focuses in the field of environmental noise control. In recent years, various subjective and objective acoustic characteristic parameters have been introduced into the study of acoustic environment assessment in the global literature. However, the extraction of “effective characteristics” from a large number of physical and psychoacoustic characteristics contained in acoustic signals and the creation of a scientific and efficient subjective evaluation model have always been key technical problems in the field of acoustic environment evaluation. Based on subjective human perceptions, the overall acoustic environment quality evaluation of urban open spaces is studied in this paper. Based on the “effective characteristic” parameters and the subjective characteristic proposed in the previous research, including equivalent continuous A-weighted sound pressure level (LA), the difference between median noise and ambient background noise (L50 − L90), Sharpness (Sh), as well as satisfaction (Sat), the multivariable linear regression algorithm is used to further study the intrinsic correlation between the proposed “effective characteristics” and subjective perception. Then, a satisfaction evaluation model of the acoustic environment based on “effective characteristics” is built in this paper. Furthermore, the soundwalk evaluation experiment and the MATLAB numerical simulation experiment are carried out, which verify that the prediction accuracy of the proposed model is more than 92%, the consistency of satisfaction level is more than 88%, as well as the changes in the values of Sh and L50 − L90 have a significant impact on the satisfaction prediction of the proposed model. It shows that the proposed “effective characteristics” more comprehensively describe the quality level of the regional acoustic environment in urban open space compared with a single LA index, and the proposed acoustic environment satisfaction evaluation model based on “effective characteristics” has significant accuracy superiority and regional applicability

Multilayer Hybrid Deep-Learning Method for Waste Classification and Recycling

This study proposes a multilayer hybrid deep-learning system (MHS) to automatically sort waste disposed of by individuals in the urban public area. This system deploys a high-resolution camera to capture waste image and sensors to detect other useful feature information. The MHS uses a CNN-based algorithm to extract image features and a multilayer perceptrons (MLP) method to consolidate image features and other feature information to classify wastes as recyclable or the others. The MHS is trained and validated against the manually labelled items, achieving overall classification accuracy higher than 90% under two different testing scenarios, which significantly outperforms a reference CNN-based method relying on image-only inputs

Synthesis, Structures, and Reactivity of Cyclometalated Complexes Formed by Insertion of Alkynes into M–C (M = Ir and Rh) Bonds

Reactions of three aryl-substituted phosphines with [Cp*MCl₂]₂ (M = Ir and Rh) have been carried out in the presence of sodium acetate. Aryl-substituted phosphine is cyclometalated readily to give the corresponding five-membered metallacycle complex via an intramolecular activation of C­(sp²)–H or C­(sp³)–H bond. Competition reaction indicates that the aromatic C­(sp²)–H bond is more likely to be activated than C­(sp³)–H bond under the same conditions. As representatives of cyclometalated complexes containing an M–C­(sp²) bond, cycloiridated complex <b>1</b> and cyclorhodated complex <b>3</b> reacted with DMAD to afford corresponding seven-membered cyclometalated complexes <b>13</b> and <b>14</b> via 1,2-insertion of alkyne into M–C bond. However, the reaction of <b>1</b> with diphenylacetylene or phenylacetylene resulted in five-membered and six-membered doubly cycloiridated complexes <b>15</b> or <b>16</b>, the formation of which presumably went through the vinylidene rearrangement of alkynes followed by 1,1-insertion; while the reaction of <b>3</b> with diphenylacetylene or phenylacetylene mainly gave normal seven-membered cyclorhodated complexes <b>17</b> or <b>18</b> by 1,2-insertion. For two representatives of cyclometalated complexes comprising an M–C­(sp³) bond, cycloiridated complex <b>4</b> and cyclorhodated complex <b>6</b> reacted with DMAD to form corresponding seven-membered cyclometalated complexes <b>20</b> and <b>21</b> by 1,2-insertion. Interestingly, the reactions of <b>4</b> and <b>6</b> with phenylacetylene generated six-membered metallacycle complexes <b>22</b> and <b>23</b>, and a plausible formation pathway is the similar 1,1-insertion of vinylidene ligand into the M–C bond followed by the isomerization of the C–C double bond. Molecular structures of five-membered cyclometalated complexes <b>4</b> and <b>5</b> and insertion products <b>13</b>, <b>15</b>–<b>19</b>, <b>21</b>, and <b>22</b> were determined by X-ray diffraction

Synthesis, Structures, and Reactivity of Cyclometalated Complexes Formed by Insertion of Alkynes into M–C (M = Ir and Rh) Bonds

Reactions of three aryl-substituted phosphines with [Cp*MCl₂]₂ (M = Ir and Rh) have been carried out in the presence of sodium acetate. Aryl-substituted phosphine is cyclometalated readily to give the corresponding five-membered metallacycle complex via an intramolecular activation of C­(sp²)–H or C­(sp³)–H bond. Competition reaction indicates that the aromatic C­(sp²)–H bond is more likely to be activated than C­(sp³)–H bond under the same conditions. As representatives of cyclometalated complexes containing an M–C­(sp²) bond, cycloiridated complex <b>1</b> and cyclorhodated complex <b>3</b> reacted with DMAD to afford corresponding seven-membered cyclometalated complexes <b>13</b> and <b>14</b> via 1,2-insertion of alkyne into M–C bond. However, the reaction of <b>1</b> with diphenylacetylene or phenylacetylene resulted in five-membered and six-membered doubly cycloiridated complexes <b>15</b> or <b>16</b>, the formation of which presumably went through the vinylidene rearrangement of alkynes followed by 1,1-insertion; while the reaction of <b>3</b> with diphenylacetylene or phenylacetylene mainly gave normal seven-membered cyclorhodated complexes <b>17</b> or <b>18</b> by 1,2-insertion. For two representatives of cyclometalated complexes comprising an M–C­(sp³) bond, cycloiridated complex <b>4</b> and cyclorhodated complex <b>6</b> reacted with DMAD to form corresponding seven-membered cyclometalated complexes <b>20</b> and <b>21</b> by 1,2-insertion. Interestingly, the reactions of <b>4</b> and <b>6</b> with phenylacetylene generated six-membered metallacycle complexes <b>22</b> and <b>23</b>, and a plausible formation pathway is the similar 1,1-insertion of vinylidene ligand into the M–C bond followed by the isomerization of the C–C double bond. Molecular structures of five-membered cyclometalated complexes <b>4</b> and <b>5</b> and insertion products <b>13</b>, <b>15</b>–<b>19</b>, <b>21</b>, and <b>22</b> were determined by X-ray diffraction