Covariance-Adaptive Sequential Black-box Optimization for Diffusion Targeted Generation

Diffusion models have demonstrated great potential in generating high-quality content for images, natural language, protein domains, etc. However, how to perform user-preferred targeted generation via diffusion models with only black-box target scores of users remains challenging. To address this issue, we first formulate the fine-tuning of the targeted reserve-time stochastic differential equation (SDE) associated with a pre-trained diffusion model as a sequential black-box optimization problem. Furthermore, we propose a novel covariance-adaptive sequential optimization algorithm to optimize cumulative black-box scores under unknown transition dynamics. Theoretically, we prove a $O(\frac{d^2}{\sqrt{T}})$ convergence rate for cumulative convex functions without smooth and strongly convex assumptions. Empirically, experiments on both numerical test problems and target-guided 3D-molecule generation tasks show the superior performance of our method in achieving better target scores

DeltaEdit: Exploring Text-free Training for Text-Driven Image Manipulation

Text-driven image manipulation remains challenging in training or inference flexibility. Conditional generative models depend heavily on expensive annotated training data. Meanwhile, recent frameworks, which leverage pre-trained vision-language models, are limited by either per text-prompt optimization or inference-time hyper-parameters tuning. In this work, we propose a novel framework named \textit{DeltaEdit} to address these problems. Our key idea is to investigate and identify a space, namely delta image and text space that has well-aligned distribution between CLIP visual feature differences of two images and CLIP textual embedding differences of source and target texts. Based on the CLIP delta space, the DeltaEdit network is designed to map the CLIP visual features differences to the editing directions of StyleGAN at training phase. Then, in inference phase, DeltaEdit predicts the StyleGAN's editing directions from the differences of the CLIP textual features. In this way, DeltaEdit is trained in a text-free manner. Once trained, it can well generalize to various text prompts for zero-shot inference without bells and whistles. Code is available at https://github.com/Yueming6568/DeltaEdit.Comment: Accepted by CVPR2023. Code is available at https://github.com/Yueming6568/DeltaEdi

Assessing inequities in heat pump adoption across the U.S

Electrifying space heating is essential to reduce climate impacts in the building sector, and heat pumps have emerged as an energy-efficient and increasingly cost-effective solution. However, other clean energy technologies (e.g., rooftop solar) are less likely to be adopted in underserved communities, and thus policies incentivizing their adoption can be regressive. Unlike previously-studied technologies, the effects of heat pumps on energy bills may be positive or negative, and thus inequities in their adoption are context specific. Here we propose a framework for identifying inequities in heat pump adoption and map these inequities across the U.S. We find that households in communities of color and with high percentages of renters are adopting heat pumps at lower rates across the board, but differences are largest in areas where heat pumps are likely to reduce energy bills. Public policies must address these inequities to advance beneficial electrification and energy justice

Au/Pt and Au/Pt(3)Ni nanowires as self-supported electrocatalysts with high activity and durability for oxygen reduction

Novel Au/Pt and Au/Pt(3)Ni nanostructures consisting of Pt and Pt(3)Ni alloy nanodendrites grown on Au nanowires were synthesized, which exhibited high electrocatalytic activity and durability toward oxygen reduction when used as self-supported catalysts.NSFC[21131005, 21021061, 20925103, 20871100]; MOST of China[2011CB932403, 2009CB930703]; NSF of Fujian Province[2009J06005]; Fok Ying Tung Education Foundation[121011]; Key Scientific Project of Fujian Province[2009HZ0002-1]; China Postdoctoral Science Foundation[20100480716

Etching Growth under Surface Confinement: An Effective Strategy To Prepare Mesocrystalline Pd Nanocorolla

通讯作者地址: Zheng, NF (通讯作者),Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] etching growth strategy was developed to prepare corolla-like Pd mesocrystals consisting of unidirectionally aligned, well-spaced, and connected ultrathin (1.8-nm-thick) Pd nanosheets. The combined use of CO and Fe(3+) is critical to the successful synthesis of the branched corolla-like Pd mesocrystals. While CO functions as the surface-confining agent to allow anisotropic growth of the 1.8-nm-thick Pd nanosheets as branches, Fe(3+) etches the Pd seeds at the early stage of the reaction to induce formation of the branched structure. Inheriting the unique properties of 1.8-nm-thick Pd nanosheets, the as-prepared Pd mesocrystals display well-defined surface plasmon resonance absorption in the near-infrared region, a high electrochemically active surface area, and a significant photothermal effect when irradiated with a near-infrared laser. Owing to the presence of internal voids and increased apparent thickness, the Pd mesocrystals also exhibit several features superior to those of single-domain Pd nanosheets, making them promising for electrocatalysis and cancer photothermal therapy applications.NSFC 21131005 21021061 20925103 20871100 Fok Ying Tung Education Foundation 121011 MOST of China 2011CB932403 2009CB930703 NSF of Fujian Province 2009J06005 Key Scientific Project of Fujian Province 2009HZ0002-

Amine-Assisted Synthesis of Concave Polyhedral Platinum Nanocrystals Having {411} High-Index Facets

通讯作者地址: Zheng, NF (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] surfaces of a face-centered cubic metal (e.g., Pd, Pt) have a high density of low-coordinated surface atoms and therefore possess enhanced catalysis activity in comparison with low-index faces. However, because of their high surface energy, the challenge of chemically preparing metal nanocrystals having high-index facets remains. We demonstrate in this work that introducing amines as the surface controller allows concave Pt nanocrystals having {411} high-index facets to be prepared through a facile wet-chemical route. The as-prepared Pt nanocrystals display a unique octapod morphology with {411} facets. The presence of high-index {411} exposed facets endows the concave Pt nanocrystals with excellent electrocatalytic activity in the oxidation of both formic acid and ethanol.NSFC 21021061 20925103 20923004 20871100 Fok Ying Tung Education Foundation 121011 MOST of China 2011CB932403 2009CB930703 NFFTBS J1030415 NSF of Fujian Province 2009J06005 Key Scientific Project of Fujian Province 2009HZ0002-

A graphene-platinum nanoparticles-ionic liquid composite catalyst for methanol-tolerant oxygen reduction reaction

通讯作者地址: Tan, YM (通讯作者),Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 3. Hunan Normal Univ, Coll Chem & Chem Engn, Minist Educ China, Key Lab Chem Biol & Tradit Chinese Med Res, Changsha 410081, Hunan, Peoples R China 电子邮件地址: [email protected] report here that graphene-supported Pt nanoparticles impregnated with the ionic liquid [MTBD][bmsi] which is more oxygen-philic and less methanol-philic than the exterior aqueous solution can exhibit both enhanced electrocatalytic activity and excellent methanol tolerance for oxygen reduction reaction.MOST of China 2011CB932403 2009CB930703 NSF of China 21131005 21021061 20925103 Fok Ying Tung Education Foundation 121011 NSF of Fujian 2009J06005 China Postdoctoral Science Foundation 2010048071

Carbon Monoxide-Assisted Synthesis of Single-Crystalline Pd Tetrapod Nanocrystals through Hydride Formation

通讯作者地址: Zheng, NF (通讯作者),Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 3. Xiamen Univ, Dept Phys, Xiamen 361005, Peoples R China 电子邮件地址: [email protected]; [email protected] monoxide can adsorb specifically on Pd(111) to induce the formation of unique Pd nanostructures. In the copresence of CO and H-2 single-crystalline Pd tetrapod nanocrystals have now been successfully prepared. The Pd tetrapods are enclosed by (111) surfaces and are yielded through hydride formation. Density functional theory calculations revealed that the formation of PdHx in the presence of H, reduces the binding energy of CO on Pd and thus helps to decrease the CO coverage during the synthesis, which is essential to the formation of the PdHx tetrapod nanocrystals. In addition to tetrapod nanocrystals, tetrahedral nanocrystals were also produced in the copresence of CO and H-2 when the reaction temperature was ramped to further lower the CO coverage. Upon aging in air, the as-prepared PdHx nanocrystals exhibited a shape-dependent hydrogen releasing behavior. The conversion rate of PdHx tetrapod nanocrystals into metallic Pd was faster than that of tetrahedral nanocrystals.MOST of China 2011CB932403 2009CB930703 NSFC 21131005 21021061 20925103 20973139 21133004 Fok Ying Tung Education Foundation 121011 Fundamental Research Funds for the Central Universitie