Evolution of China's Role in the Structure of Global Carbon Emission Transfers:An Empirical Analysis Based on Network Governance

This paper reconsiders the roles of China and some developed countries in the network of carbon emission transfers via international trade in value added from a new perspective of network governance.Network search intensity(NSI)and the extended gravity model are used with cross-country panel data to analyze the mechanism of China's engagement in network governance of carbon emission transfers.The results show that from 2000 to 2009,China was a net exporter of carbon emissions,even though it shifted from the semi-periphery to the core in the network of carbon emissions embodied in imports.Meanwhile,NSI had a significant positive impact on carbon emissions embodied in exports.Given China's important role in the global production network and division of labor,NSI may also affect industrial structure and the quality of the ecological environment to a large extent.This study analyses the network governance mechanism of China's participation in global carbon transfers.The results suggest that the technical complexity of export products and product heterogeneity do not change the positive impact of NSI on carbon emissions.

Band Edge Emission Improvement by Energy Transfer in HybridⅢ-Nitride/Organic Semiconductor Nanostructure

GaN nanorods are fabricated using inductively coupled plasma etching with Ni nano-island masks. The poly [2- methoxy-5-（2-ethyl）hexoxy-l,4-phenylenevinylene] （MEH-PPV）/GaN-nanorod hybrid structure is fabricated by depositing the MEH-PPV film on the GaN nanorods by using the spin-coating process. In the hybrid structure, the spatial separation is minimized to achieve high-emciency non-radiative resonant energy transfer. Optical properties of a novel device consisting of MEH-PPV/GaN-nanorod hybrid structure is studied by analyzing photoluminescenee （PL） spectra. Compared with the pure GaN nanorods, the PL intensity of the band edge emission of GaN in the MEH-PPV/GaN-nanorods is enhanced as much as three times, and the intensity of the yellow band is suppressed slightly. The obtained results are analyzed by energy transfer between the GaN nanorods and the MEH-PPV. An energy transfer model is proposed to explain the phenomenon.

Investigation of energy transfer from pyrromethene dye to cresyl violet 670 in ethanol

In this paper, radiative and nonradiative energy transfer from laser dye pyrromethene 567 （PM567） and pyrromethene 580 （PM580） as donors to cresyl violet 670 （CV670） as acceptor in ethanol are investigated by using the steady-state emission measurement and the second harmonic generation （532 nm, ～ 13 ns） of a Q-switched Nd：YAG laser as the pumping source. The fluorescence intensity of the acceptor is improved due to the introduction of the donors, and the largest enhancement is obtained to be 128% in the PM567：CV670 dye mixture system. Energy transfer parameters, including the radiative and nonradiative energy transfer rate constants （KR and KNR）, critical distance （R0）, and half quenching concentration （[A]1/2） are investigated using the Stern–Volmer plots, and the acceptor concentration dependencies of radiative and nonradiative transfer efficiencies are also obtained. The values of KR for PM567：CV670 and PM580：CV670 systems are 2032.0×109 L·mol-1·s-1 and 2790.4×109 L·mol-1·s-1, respectively, and the values of corresponding KNR are 3.3×109 L·mol-1·s-1 and 4.2×109 L·mol-1·s-1, respectively. The results indicate that the dominant mechanism responsible for the energy transfer in the dye mixture systems is of the radiative type.

Analysis on CO2 Emissions Transferred from Developed Economies to China through Trade

Based on a global input-output model, this paper investigates the CO2 emission transfer between China and developed economies through trade. The results show that approximately 15-23 percent of China＇s production-based emissions during 1995-2009 were induced by the production of goods and services satisfying final demand in developed economies. Decomposition of emission transfers shows that trade of intermediate products played a significant role in emission transfer from developed economies to China. Most developed economies have consumption-based emission responsibilities that are higher than their production-based responsibilities, whereas China＇s consumption-based responsibility is significantly lower than its production-based responsibility. We argue that a fair and efficient carbon accounting approach should take CO 2 emission transfers from developed economies to developing economies into consideration. It is important that China and its developed trade partners cooperate in reducing emission transfers.

The construction of aggregation-induced charge transfer emission systems in aqueous solution directed by supramolecular strategy

Novel aggregation-induced charge transfer(CT) emission systems with long luminescence lifetime directed by supramolecular strategy have been successfully developed in water. The dimethylacridine-based electron donor(Br Ac) with excellent aggregation ability can co-aggregate with a triazine-based electron acceptor(TRZ) to form nanorods in water, which exhibit CT emission with long lifetime(τ = 0.92 μs).As for a similar electron donor(Qa Ac) with poor aggregation ability, water-soluble pillar[5]arene(WP5)can be introduced to promote the aggregation process, leading to the obvious CT emission with long lifetime(τ = 0.61 μs). In addition, structural modification of the acceptor with substituent groups possessing stronger electron-accepting capabilities will cause red-shift(about 50 nm) of the emission, which allows conveniently constructing long lifetime organic luminescent materials with different emission colors.

Embodied carbon emissions in China-US trade

China-US trade holds great significance for the world’s political and economic landscape.Since 2018,the US government has imposed additional tariffs on Chinese exports on the grounds of the US trade deficit with China.However,the transfer of pollutants embodied in trade and the differences in environmental costs between China and the US have not been widely recognized.In this study,we quantify the embodied carbon emissions(the"virtual"emissions associated with trade and consumption)in China-US trade by constructing a carbon dioxide emissions inventory and a multiregional input-output model.The study shows that the US benefits from a trade surplus of environmental costs by importing energy-intensive and pollutionintensive products from China,which increases China’s environmental pollution and abatement costs.In 2017,288 Mt CO2 emissions were associated with products produced in China but finally consumed in the US,and only 46 Mt CO2 were associated with the US products that were consumed in China.From this perspective,China-US trade results in a net transfer of 242 Mt CO2 per year from the US to China,accounting for approximately 5%of the total CO2 emissions in the US.More importantly,for Chinese products exported to the US,the carbon emissions embodied in one unit of economic value amount to 0.92 kg/$(RMB:USD=6.8:1),but for US products exported to China,the carbon emissions embodied in one unit of economic value amount to 0.53 kg/$,which means China will incur environmental costs that are 74%higher than those of the US while enjoying the same economic benefits.This environmental trade deficit has burdened China with higher environmental costs than economic benefits.To address this environmental trade deficit,China should actively promote further industrial upgrading and energy structure adjustment and increase investment in innovation and R&D,thereby increasing the value added per unit of export products and reducing the environmental cost of producing export products.

Influence of(FeO+Ti O_2) abundance on the microwave thermal emissions of lunar regolith

One of the essential controls on the microwave thermal emissions(MTE) of the lunar regolith is the abundance of Fe O and TiO_2, known as the(Fe O+Ti O_2) abundance(FTA). In this paper, a radiative transfer simulation is employed first to study the change in the brightness temperature(T_B) with FTA under a range of frequencies and surface temperatures. Then, we analyze the influence of FTA on the MTE of the lunar regolith using microwave sounder(CELMS) data from the Chang'E-2 lunar orbiter, Clementine UV-VIS data, and lunar samples recovered from the Apollo and Surveyor projects. We conclude that:(1) FTA strongly influences the MTE of the lunar regolith, but it is not the decisive control, and(2) FTA decreases slightly with depth. This research plays an essential role in appropriately inverting CELMS data to obtain lunar regolith parameters.

Enhanced 1.8 μm emission in Er^(3+)/Tm^(3+) co-doped lead silicate glasses under different excitations for near infrared laser

A detailed study of the fluorescence emission properties and energy transfer mechanism in Er^（3＋）/Tm^（3＋） co-doped lead silicate glasses was reported. Enhanced near infrared 1.8 μm and visible up-conversion emissions were investigated under 808 and 980 nm excitations, respectively. The energy transfer mechanism between Er^（3＋） and Tm^（3＋） was analyzed according to the absorption spectra, the emission spectra and the level structures of Er^（3＋） and Tm^（3＋）. The energy transfer efficiency between Er^（3＋） and Tm^（3＋） reached 68.1% in the Er^（3＋）/Tm^（3＋） co-doped lead silicate glasses when pumped by 808 nm laser diode. Based on the absorption spectra, the Judd-Ofelt parameters, spontaneous emission probability, absorption and emission cross sections, gain coefficients were calculated and analyzed. It was found that the calculated emission cross section and the maximum gain coefficient around 1.8 μm were 4.9×10^（–21）cm^2 and 1.12 cm^（–1）, respectively. These results indicated that the Er^（3＋）/Tm^（3＋） co-doped lead-silicate glasses had potential application in near infrared lasers.

D-A structured high efficiency solid luminogens with tunable emissions： Molecular design and photophysical properties

Fabrication of efficient solid luminogens with tunable emission is both fundamentally significant and technically important. Herein, based on our previous strategy for the construction of efficient and multifunctional solid luminogens through the combination of diverse aggregation-induced emission （ALE） units with other functional moieties, a group of luminophores with electron donor-acceptor （D-A） structure and typical intramolecular charge transfer （ICT） characteristics, namely CZ-DCDPP, DPA-DCDPP and DBPA-DCDPP were synthesized and investigated. The presence of twisting and AlE-active 2,3- dicyano-S,6-diphenylpyrazine （DCDPP） moiety endows them highly emissive in the solid states, whereas the introduction of arylamines with varied electron-donating capacity and different conjugation render them with tunable solid emissions from green to red. While CZ-DCDPP and DPA-DCDPP solids exhibit distinct mechanochromism, both DPA-DCDPP and DBPA-DCDPP solids can generate efficient red emission. Owing to their high efficiency, remarkable thermal and morphological stabilities and moreover red emission, they are promising for diverse optoelectronic and biological applications.

Thermal Energy-Driven Solid-State Molecular Rotation Monitored by Real-Time Emissive Color Switching

Inspired by nature’s molecular machines,the scientific research on solid-state molecular rotors is of great interest yet remains largely unexplored.Herein,we report a unique example of a thermal energydriven stimuli-responsive solid-state molecular rotor,which features an o-carborane moiety as a rotor that directly transduces the surrounding thermal energy into molecular rotations in the crystalline state.Its rotation is confirmed by X-ray diffraction.

Photoluminescence properties and effect of Bi^(3+) dopant of Eu^(3+) and Dy^(3+) co-doped Sr_3V_2O_8

Photoluminescence properties of Sr 2.5 Dy 1/3-x Eu x V 2 O 8（x=0,0.06,0.12,0.18,0.24,0.33） were investigated.The excitation spectra included a broad band in the short wavelength region and several sharp lines in the longer wavelength region,and the spectral origin were discussed.The emission spectra were measured in two different exciting ways,i.e.,exciting the VO 4 group at 270 nm and the Eu 3＋ ion at 398 nm,respectively,and the energy transferring process was reasonably suggested.Furthermore,multi-color emission could be achieved in Sr 2.5 Dy 1/3-x Eu x V 2 O 8,indicating that the studied samples had potential applications in the white light emitting diodes.Further investigation showed that reducing the concentration of Eu 3＋ and Dy 3＋ and introducing Bi 3＋ as a sensitizer ion greatly enhanced the emission intensity.