Measuring Topological Charges of Optical Vortices with Multi-Singularity Using a Cylindrical Lens

We present a simple method to measure the topological charges of optical vortices with multiple singularities. Using a cylindrical lens, a vortex beam can decay into a light field distribution with multiple separated dark holes, whose number just equals the topological charge of the input beam. This conclusion is then verified via experiments and numerical simulations of the propagation of vortex beams with multiple singulaxities. This method is also reliable to measure the topological charges of broadband vortex beams with different distributions of singularities, which does not resort to multiple beam interferometrie experiments.

Controllably Coupling Superconducting Charge and Flux Qubits by Using Nanomechanical Resonator

We propose an effective mechanism to couple superconducting charge and flux qubits by using a quantized nanomechanical resonator. The coupling between the charge and flux qubits can be controlled by the external flux of the charge qubit. Under the strong coupling limR, an iSWAP gate can be generated by this scheme. The experimental feasibility in our scheme is also presented.

Probing the fractional topological charge of a vortex light beam by using dynamic angular double slits

Vortex beams with fractional topological charge(FTC) have many special characteristics and novel applications.However, one of the obstacles for their application is the difficulty of precisely determining the FTC of fractional vortex beams. We find that when a vortex beam with an FTC illuminates a dynamic angular double slit(ADS), the far-field interference patterns that include the information of the FTC of the beam at the angular bisector direction of the ADS vary periodically. Based on this property, a simple dynamic ADS device and data fitting method can be used to precisely measure the FTC of a vortex light beam with an error of less than 5%.

Co-doping method used to improve the charge transport balance in solution processed OLEDs

In this paper, co-doping method is used to improve the current efficiency of solution-processed organic light-emitting diodes(OLEDs). By changing the ratio of two thermally activated delayed fluorescent(TADF) emitters, we studied the performance of device and its mechanism. A solution processed OLED with a structure of indium tin oxide(ITO, 150 nm)/PEDOT:PSS(30 nm)/CBP:4 Cz IPN-x%:4 Cz PN-y%(30 nm)/TPBi(40 nm)/Li F(1 nm)/Al(100 nm) was fabricated. The current efficiencies of 26.6 cd/A and 26.4 cd/A were achieved by the devices with dopant ratio of 6% 4 Cz IPN:2% 4 Cz PN and 2% 4 Cz IPN:6% 4 Cz PN in emitting material layer(EML), respectively. By investigating the tendency of current density change in devices with different doping ratio, we suggested that the enhancement of the current efficiency should be due to the charge transport balance improvement induced by assist dopant in EML.

Transmission Use of System Charging for Differentiating Long-term Impacts from Various Generation Technologies

This paper proposes a novel transmission use of system(TUoS)charging method,which is able to 1)acknowledge the trade-offs between short-run congestion cost and long-run investment cost when justifying economic network investment,2)identify the impacts of different generation technologies on congestion cost and network investment,and 3)translate these impacts into economically efficient TUoS tariffs that differentiate generation technologies.An incremental capacity change from a generator will impact the congestion costs at each branch,which is then translated into the impacts on investment time horizons.The difference in the present values with and without the incremental change for a branch is its long-run incremental cost(LRIC).The final TUoS tariff for this generator is the sum of all LRIC triggered by its capacity increment.The proposed method is demonstrated on a modified IEEE 14-bus system to show its effectiveness over the traditional approach.Results show that it can provide cost-reflective TUoS tariffs for different generation technologies at the same sites by examining their respective impacts on congestion and investment.It thus can incentivize appropriate generation expansion to reduce congestion costs and ultimately network investment cost.

Tax distortions in cross-border flows of intangible assets

The phenomenon of global fragmented production and associated trade in intermediate products,including intangible assets,has changed how economists study globalization and how new public policies are shaped.Understanding cross-border flows of disembodied knowledge,often associated with intellectual property(IP),is essential for analyzing how modern economies operate.Available data to document these international IP-related knowledge flowsdnamely cross-border payments for IPdare distorted by various factors.Tax planning by multinational enterprises has seriously distorted the measurement of cross-border IP flows,affecting national measurements of imports,exports,GDP,and productivity.The tax-induced mismeasurement could be more than 35% of global charges for use of intellectual property,and greater for individual countries,particularly high-taxrate countries.International initiatives to address the effects of tax base erosion,profit shifting,and other statistical initiatives on global value chains will improve future measurements of cross-border IP flows,improving the understanding of both the creation and uses of IP.