OPT-GAN: Black-Box Global Optimization via Generative Adversarial Nets

Black-box optimization (BBO) algorithms are concerned with finding the best solutions for problems with missing analytical details. Most classical methods for such problems are based on strong and fixed a priori assumptions, such as Gaussianity. However, the complex real-world problems, especially when the global optimum is desired, could be very far from the a priori assumptions because of their diversities, causing unexpected obstacles to these methods. In this study, we propose a generative adversarial net-based broad-spectrum global optimizer (OPT-GAN) which estimates the distribution of optimum gradually, with strategies to balance exploration-exploitation trade-off. It has potential to better adapt to the regularity and structure of diversified landscapes than other methods with fixed prior, e.g. Gaussian assumption or separability. Experiments conducted on BBO benchmarking problems and several other benchmarks with diversified landscapes exhibit that OPT-GAN outperforms other traditional and neural net-based BBO algorithms.Comment: M. Lu and S. Ning contribute equally. Submitted to IEEE transactions on Neural Networks and Learning System

Solution-processed blue/deep blue and white phosphorescent organic light emitting diodes (PhOLEDs) hosted by a polysiloxane derivative with pendant mCP (1, 3-bis(9-carbazolyl)benzene)

The synthesis and characterization is reported of an efficient polysiloxane derivative containing the 1,3-bis(9-carbazolyl)benzene (mCP) moiety as a pendant unit on the polysiloxane backbone. In comparison with mCP, the mCP-polysiloxane hybrid (PmCPSi) has significantly improved thermal and morphological stabilities with a high decomposition temperature (Td = 523 °C) and glass transition temperature (Tg = 194 °C). The silicon–oxygen linkage of PmCPSi prevents intermolecular π-stacking and ensures a high triplet energy level (ET = 3.0 eV). Using PmCPSi as a host, blue phosphorescent organic light emitting devices (PhOLEDs) effectively confine triplet excitons, with efficient energy transfer to the guest emitter and a relatively low turn-on voltage of 5.8 V. A maximum external quantum efficiency of 9.24% and maximum current efficiency of 18.93 cd/A are obtained. These values are higher than for directly analogous poly(vinylcarbazole) (PVK) based devices (6.76%, 12.29 cd/A). Good color stability over a range of operating voltages is observed. A two-component “warm-white” device with a maximum current efficiency of 10.4 cd/A is obtained using a blend of blue and orange phosphorescent emitters as dopants in PmCPSi host. These results demonstrate that well-designed polysiloxane derivatives are highly efficient hosts suitable for low-cost solution-processed PhOLEDs

Collaborative Optimized Operation Model of Multi-Character Distribution Network Considering Multiple Uncertain Factors and Demand Response

As many new devices and factors, such as renewable energy sources, energy storage (ESs), electric vehicles (EVs), and demand response (DR), flood into the distribution network, the characteristics of the distribution network are becoming complicated and diversified. In this study, a two-layer collaborative optimized operation model for the multi-character distribution network considering multiple uncertain factors is proposed to achieve optimal dispatching of ES and EV and obtain the optimal grid structure of the distribution network. Based on basic device models of distribution network, the upper layer distribution network reconfiguration (DNR) model is established and solved by the particle swarm optimization (PSO) based on the Pareto optimality and the Prim algorithm. Then, the lower layer optimal dispatching model of ES and EV is established and solved by the binary PSO. The upper layer model and the lower layer model are integrated to form the collaborative optimized operation model for the multi-character distribution network and solved by iterating the upper and lower layers continuously. A case study is conducted on the IEEE 33-bus system. The simulation results show that the total network loss and the voltage deviation are decreased by 15.66% and 15.52%, respectively, after optimal dispatching of ES and EV. The total network loss and the voltage deviation are decreased by 28.39% and 44.46%, respectively, after the DNR with distributed generation (DG) and EV loads with little impact on the average reliability of the power supply. The total network loss and the voltage deviation are decreased by 26.54% and 27.04%, respectively, after the collaborative optimized operation of the multi-character distribution network. The collaborative optimized operation of the distribution network can effectively reduce the total cost by 114.45%, which makes the system change from paying to gaining

Study on the adsorption mechanism and properties of silver-loaded zeolite for radioactive iodine

Due to the continuous development of nuclear energy, a large number of radioactive elements will be produced during the treatment of nuclear waste and spent fuel, and the typical representative is radioactive iodine. Adopt to adsorb the radioactive iodine in the waste gas, the self-made silver-loaded zeolite was used to dynamically adsorb the radioactive iodine containing waste gas in this study. The adsorption effect of silver-loaded zeolite under different adsorption conditions, such as different linear velocity, different adsorption temperature, different pressure drops, different filler layer depth and other factors were studied. By exploring the experimental results, it can be seen that changing the different linear velocity in the adsorption column has little effect on the saturated adsorption competence of zeolite, and will affect the saturated adsorption time; Changing the filling depth of zeolite in the adsorption column will change the resistance in the adsorption process, affect the length of saturated adsorption time, and lead to the increase of its adsorption competence with the increase of the depth; The adsorption temperature of zeolite was controlled by controlling the ambient temperature of the adsorption column. It can be seen that the optimal adsorption temperature of zeolite is 150 ℃; Change the intake air flow to control its pressure drop, it can be seen that the pressure drops increases, the adsorption effect increases, and the adsorption time is shortened. The results of zeolite adsorption show that its adsorption competence is 52.05 ∼ 220.71 mg/g. Compared with other adsorption materials, zeolite has stable adsorption effect and low cost. It is a promising adsorbent with good industrial application prospects

Collaborative Optimized Operation Model of Multi-Character Distribution Network Considering Multiple Uncertain Factors and Demand Response

As many new devices and factors, such as renewable energy sources, energy storage (ESs), electric vehicles (EVs), and demand response (DR), flood into the distribution network, the characteristics of the distribution network are becoming complicated and diversified. In this study, a two-layer collaborative optimized operation model for the multi-character distribution network considering multiple uncertain factors is proposed to achieve optimal dispatching of ES and EV and obtain the optimal grid structure of the distribution network. Based on basic device models of distribution network, the upper layer distribution network reconfiguration (DNR) model is established and solved by the particle swarm optimization (PSO) based on the Pareto optimality and the Prim algorithm. Then, the lower layer optimal dispatching model of ES and EV is established and solved by the binary PSO. The upper layer model and the lower layer model are integrated to form the collaborative optimized operation model for the multi-character distribution network and solved by iterating the upper and lower layers continuously. A case study is conducted on the IEEE 33-bus system. The simulation results show that the total network loss and the voltage deviation are decreased by 15.66% and 15.52%, respectively, after optimal dispatching of ES and EV. The total network loss and the voltage deviation are decreased by 28.39% and 44.46%, respectively, after the DNR with distributed generation (DG) and EV loads with little impact on the average reliability of the power supply. The total network loss and the voltage deviation are decreased by 26.54% and 27.04%, respectively, after the collaborative optimized operation of the multi-character distribution network. The collaborative optimized operation of the distribution network can effectively reduce the total cost by 114.45%, which makes the system change from paying to gaining

Mitochondrial ROS-Modulated mtDNA: A Potential Target for Cardiac Aging

Mitochondrial DNA (mtDNA) damage is associated with the development of cardiovascular diseases. Cardiac aging plays a central role in cardiovascular diseases. There is accumulating evidence linking cardiac aging to mtDNA damage, including mtDNA mutation and decreased mtDNA copy number. Current wisdom indicates that mtDNA is susceptible to damage by mitochondrial reactive oxygen species (mtROS). This review presents the cellular and molecular mechanisms of cardiac aging, including autophagy, chronic inflammation, mtROS, and mtDNA damage, and the effects of mitochondrial biogenesis and oxidative stress on mtDNA. The importance of nucleoid-associated proteins (Pol γ), nuclear respiratory factors (NRF1 and NRF2), the cGAS-STING pathway, and the mitochondrial biogenesis pathway concerning the development of mtDNA damage during cardiac aging is discussed. Thus, the repair of damaged mtDNA provides a potential clinical target for preventing cardiac aging

Structure Evolution of Poly(3-hexylthiophene) on Si Wafer and Poly(vinylphenol) Sublayer

The structure evolution of P3HT thin films on Si wafer and PVPh covered Si wafer during heating, thermal annealing, and melt recrystallization processes has been studied in detail using X-ray analysis techniques. The effect of substrate on the crystallization behavior and interface structure of P3HT films was explored. For the P3HT films deposited on the Si substrate, it was found that the stability of P3HT crystals is orientation dependent. The crystals oriented with <i>b</i>-axis normal to the substrate, that is, a face-on molecular orientation, are less stable than those with the <i>a</i>-axis arranged normal to the substrate (side-on molecular orientation). Thermal annealing temperature plays an important role in the molecular structure of P3HT including crystal structure, film thickness, and surface roughness. After annealing at relatively high temperature, new crystals form during the cooling process accompanied by the shrinking of <i>a</i>-axis. Moreover, the melt recrystallization favors the formation of more stable P3HT crystals with side-on molecular orientation. The PVPh substrate does not affect the crystallization behavior of solution cast P3HT significantly but inhibits the formation of P3HT crystal with face-on molecular orientation. However, the interfacial morphology of P3HT and PVPh changes by annealing at elevated temperature. The P3HT/PVPh interface changes from a sharply defined one into a diffused one at around 160 °C. The PVPh sublayer inhibits the melt recrystallization of P3HT to some extent, leading to a slight expansion of the <i>a</i>-axis

C-Eval: A Multi-Level Multi-Discipline Chinese Evaluation Suite for Foundation Models

New NLP benchmarks are urgently needed to align with the rapid development of large language models (LLMs). We present C-Eval, the first comprehensive Chinese evaluation suite designed to assess advanced knowledge and reasoning abilities of foundation models in a Chinese context. C-Eval comprises multiple-choice questions across four difficulty levels: middle school, high school, college, and professional. The questions span 52 diverse disciplines, ranging from humanities to science and engineering. C-Eval is accompanied by C-Eval Hard, a subset of very challenging subjects in C-Eval that requires advanced reasoning abilities to solve. We conduct a comprehensive evaluation of the most advanced LLMs on C-Eval, including both English- and Chinese-oriented models. Results indicate that only GPT-4 could achieve an average accuracy of over 60%, suggesting that there is still significant room for improvement for current LLMs. We anticipate C-Eval will help analyze important strengths and shortcomings of foundation models, and foster their development and growth for Chinese users.Comment: Website: https://cevalbenchmark.co