Driving Factors behind Energy-Related Carbon Emissions in the U.S. Road Transport Sector: A Decomposition Analysis.

The U.S. is the second largest contributor to carbon emissions in the world, with its road transport sector being one of the most significant emission sources. However, few studies have been conducted on factors influencing the emissions changes for the U.S. from the perspective of passenger and freight transport. This study aimed to evaluate the carbon emissions from the U.S. road passenger and freight transport sectors, using a Logarithmic Mean Divisia Index approach. Emissions from 2008 to 2017 in the U.S. road transport sector were analysed and key findings include: (1) energy intensity and passenger transport intensity are critical for reducing emissions from road passenger transport, and transport structure change is causing a shift in emissions between different passenger transport modes; and (2) the most effective strategies to reduce carbon emissions in the road freight transport sector are to improve energy intensity and reduce freight transport intensity. Several policy recommendations regarding reducing energy and transport intensity are proposed. The results and policy recommendations are expected to provide useful references for policy makers to form carbon emissions reduction strategies for the road transport sector.

Recycling of Zinc-Carbon Batteries into MnO/ZnO/C to Fabricate Sustainable Cathodes for Rechargeable Zinc-Ion Batteries.

Acidic zinc-carbon dry batteries have been widely used in life because of their low cost. However, a great quantity of used batteries is discarded as refuse, which not only wastes resources but also leads to environmental contamination. To reuse spent batteries on a large scale, this study concerns a simple, effective, and sustainable strategy to turn them into MnO/ZnO/C composites. After a conventional leaching treatment followed by pyrolysis, the rust cathode materials can be reduced to MnO/ZnO/C. When serving as a rechargeable zinc-ion battery cathode, this electrode provides a maximum reversible capacity of around 362 mAh g-1 MnO ) and a rate capability of 191 mAh g-1 MnO at a high current rate of 1.20 A g-1 . Furthermore, ZnO gradually dissolves in the electrolyte with the increase of discharge cycles, replenishing the Zn2+ content in the electrolyte and further enhancing cycling stability (98.02 % after 500 cycles). The device also exhibits a remarkable energy density of 336.37 Wh kg-1 , low self-discharge rate, and can efficiently power a LED panel. This strategy offers an economical and facile route to convert zinc-carbon battery waste into useful materials for aqueous rechargeable zinc ion batteries.

A novel fluorescent biosensor for sequence-specific recognition of double-stranded DNA with the platform of graphene oxide.

A fluorescent biosensor for sequence-specific recognition of double-stranded DNA (dsDNA) was developed based upon the DNA hybridization between dye-labeled single-stranded DNA (ssDNA) and double-stranded DNA. The fluorescence of FAM-labeled single-stranded DNA was quenched when it adsorbed on the surface of graphene oxide (GO). Upon addition of the target dsDNA, a homopyrimidine·homopurine part of dsDNA on the Simian virus 40 (SV40) (4424-4440, gp6), hybridization occurred between the dye-labeled DNA and the target dsDNA, which induced the dye-labeled DNA desorbed from the surface of GO, and turned on the fluorescence of the dye. Under the optimum conditions, the enhanced fluorescence intensity was proportional to the concentration of target dsDNA in the range 40.0-260 nM, and the detection limit was found to be 14.3 nM alongside the good sequence selectivity.

[Spectral study on the interaction of [Cu(DPPZ)(L-Ser)]+ complex with DNA and its analytical application].

The characteristics of resonance light scattering (RLS), UV-visible absorption spectra and fluorescence spectra of [Cu(DPPZ)(L-Ser)]+ with DNA were studied and a RLS method for the determination of DNA was established. [Cu(DPPZ) (L-Ser)]+ could assemble on the surface of DNA through intercalation, and enhanced the RLS of DNA in the tris buffer of pH 7. 2. The maximum resonance light scattering peak appeared at 400 nm. Under the optimum conditions, the enhanced intensity of RLS was proportional to the concentration of DNA over the range of 0.42 - 4.2 ng x mL(-1), with a detection limit (3sigma/k) of 0.29 ng x mL(-1). The method was used for the determination of DNA samples with the recoveries between 97.8% and 106%.

Simultaneous voltammetric determination of epinephrine and acetaminophen using a highly sensitive CoAl-OOH/reduced graphene oxide sensor in pharmaceutical samples and biological fluids.

For this study, three novel types of sensors comprised of CoAl-layered double oxyhydroxide (CoAl-LDH), CoAl-LDH/reduced graphene oxide (rGO), and CoAl-OOH/rGO nanosheets were successfully fabricated on glassy carbon electrodes (GCEs) and employed for the electrochemical detection of epinephrine (EP) and acetaminophen (AC). Interestingly, we found that the CoAl-OOH/rGO/GCE was more suitable for the determination of EP and AC in contrast to the CoAl-LDH and CoAl-OOH/rGO sensors. Differential pulse voltammetry results revealed that the CoAl-OOH/rGO/GCE delivered excellent electrocatalytic activity. The sensitivities and detection limits for the simultaneous measurement of EP and AC were 12.2 µA µM-1 cm-2, 0.023 µM L-1, and 4.87 µA µM-1 cm-2, 0.058 µM L-1, respectively. Especially, the as-obtained CoAl-OOH/rGO/GCE was successfully utilized for the detection in pharmaceutical samples and biological fluids with satisfactory results. Owing to its outstanding electrocatalytic activity and superior sensitivity, the CoAl-OOH/rGO/GCE could be beneficial to construct a promising electrochemical sensor for the detection of EP and AC.

Sensitive and selective localized surface plasmon resonance light-scattering sensor for Ag+ with unmodified gold nanoparticles.

A novel localized surface plasmon resonance (LSPR) light-scattering sensor for Ag(+) was developed with unmodified gold nanoparticles (AuNPs), based upon the specific recognition property of Ag(+) with a cytosine-cytosine mismatched base pair. The addition of Ag(+) induced the oligonucleotide 5'-TAC ATA CAT ACT ATC TAT CTA-3' to be desorbed from the surface of the AuNPs, resulting in the aggregation of AuNPs, accompanied by a dramatic enhancement of the LSPR light-scattering intensity. The enhancement of LSPR light-scattering intensity was proportional to the concentration of Ag(+) in the range of 0.13-1.12 µM, with a limit of detection of 62.0 nM. The results were also proved by a colorimetric method. Furthermore, this method can provide satisfactory results for the determination of Ag(+) in water samples and industrial products.

[Spectrometric study on the interaction of doxepin hydrochloride and fast green and its application].

The characteristics of resonance light scattering and absorption spectra of doxepin hydrochloride with fast green were investigated, and a new analytical method for doxepin hydrochloride was described. In the buffer solution of pH 4.0, doxepin hydrochloride can strengthen the signal of resonance light scattering of fast green. The effective factors, including the order of addition of the reagents, acidity and kinds of the buffers, and concentration of fast green were investigated. Under the optimum conditions, the scattering peaks of the system are at 344 and 486 nm, while the maximum is at 344 nm. The enhanced intensity of RLS is proportional to the concentration of doxepin hydrochloried in the range of 8.75 x 10(-3)-4.88 x 10(-2) mg x mL(-1). The detection limit for doxepin hydrochloried is 1.72 x 10(-5) mg x mL(-1). The relative standard deviation obtained from eleven determinations for a 0.025 mg x mL(-1) standard solution of doxepin hydrochloried is 1.4%. The method was applied to the determination of doxepin hydrochloric in pharmaceutical preparations. The results were compared with those obtained by the reference method, and t-test showed no significant difference between the two methods.

One-step analysis of glucose and acetylcholine in water based on the intrinsic peroxidase-like activity of Ni/Co LDHs microspheres.

In the present study, a simple strategy was developed for Ni/Co layered double hydroxides (LDHs) as a substitute for natural peroxidase. The obtained Ni/Co LDHs exhibited ease of preparation, low-cost, and water-solubility; importantly, this material showed high catalytic activity in neutral pH solutions (phosphate buffer, Tris-HCl buffer, and even water). Benefitting from Ni/Co LDHs having a similar pH and temperature with specificity oxidase, such as glucose oxidase, choline oxidase, acetylcholinesterase, etc., a novel one-step method for a biosensor was developed in water. Glucose detection was selected as an application model system to evaluate the performance of this method, which showed a linear detection range from 0.5 µM to 100 µM with a detection limit (DL) of 0.1 µM. We also extended the one-step method to detect acetylcholine (ACh) by taking advantage of the specific catalytic reaction of acetylcholinesterase (AChE) and choline oxidase (ChOx). The linear detection range was from 10 µM to 150 µM with the DL of 1.62 µM. The proposed method had ease of operation, simple steps, and was rapid for glucose and ACh detection in real samples. On the basis of these advantages and virtues, Ni/Co LDHs could become attractive nanozymes in biotechnology and bioassays, and create a great influence on the next generation of enzyme mimetic systems.

The peroxidase and oxidase-like activity of NiCo2O4 mesoporous spheres: Mechanistic understanding and colorimetric biosensing.

The synthesized NiCo2O4 mesoporous spheres (MS) displayed intrinsic peroxidase and oxidase-like activity were firstly reported. The catalytic mechanism of the oxidase-like activity of NiCo2O4 MS was analyzed in detail using the electron spin resonance (ESR) method. It is found that NiCo2O4 MS could directly oxidize 3,3',5,5'-tetramethylbenzidine (TMB) but did not produce 1O2 and ·OH. And the mechanism of the peroxidase-like activity of NiCo2O4 MS was also verified that the oxidation of TMB stemmed from not only ·OH but also 1O2. Based on the NiCo2O4 MS showed excellent peroxidase-like activity over a broad temperature range, especially at normal body temperature, a detection tool was designed for glucose determination in diabetics' serum samples. And this detection method based on NiCo2O4 MS gave a lower limit of detection than the method using Co3O4 NPs and NiO NPs, as the single-component oxides of NiCo2O4. Our study may open up the possibility to make a great influence on the next generation of enzyme mimetics system.

Gold nanoparticles-based colorimetric investigation of triplex formation under weak alkalic pH environment with the aid of Ag+.

A novel colorimetric method for investigating triplex formation between oligonucleotide modified Au nanoparticles (AuNPs) under weak alkalic pH environment is developed based upon the specific recognition property of Ag+ with CGC triads. Oligonucleotide 5'-SH-T12-CTTCTTTCCTTTCTTC-3' (oligo-1) is modified on the surface of AuNPs. Upon addition of oligonucleotide 5'-GAAGAAAGGAAAGAAG-3' (oligo-2), triplex formation between oligo-1 modified AuNPs occurred at pH 8.0 with the aid of Ag+, triggers the aggregation of AuNPs, accompany with the solution color change from red to purple. The melting temperature demonstrates a 31 °C increase for the triplex DNA compose of 10 T•A∘T triads and 6 C•G∘C triads upon addition of Ag+, the disassociation constant (Kd) between Ag+ and C•G∘C triads is 3.6 µM. Moreover, triplex formation between AuNPs depending on Ag+ can be used to recognize Ag+ ion with the naked eye, as well as UV-vis absorption spectroscopy.