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18 results on '"Shenzhen Science and Technology Innovation Commission"'

2. Anthropogenic short-lived halogens increase human exposure to mercury contamination due to enhanced mercury oxidation over continents

Author

Shenzhen Science and Technology Innovation Commission, Natural Science Foundation of Guangdong Province, National Natural Science Foundation of China, Tsinghua Shenzhen International Graduate School, European Commission, Slovenian Research Agency, Research Grants Council (Hong Kong), Ministry of Earth Sciences (India), #NODATA#, Travnikov, Oleg [0000-0002-4413-0777], Li, Qinyi [0000-0002-5146-5831], Cuevas, Carlos A. [0000-0002-9251-5460], Fernandez, Rafael P. [0000-0002-4114-5500], Mahajan, Anoop S. [0000-0002-2909-5432], Wang, Shuxiao [0000-0001-9727-1963], Wang, Tao [0000-0002-4765-9377], Saiz-Lopez, A. [0000-0002-0060-1581], Fu, Xiao, Sun, Xianyi, Travnikov, Oleg, Li, Qinyi, Qin, Chuang, Cuevas, Carlos A., Fernandez, Rafael P., Mahajan, Anoop S., Wang, Shuxiao, Wang, Tao, Saiz-Lopez, A., Shenzhen Science and Technology Innovation Commission, Natural Science Foundation of Guangdong Province, National Natural Science Foundation of China, Tsinghua Shenzhen International Graduate School, European Commission, Slovenian Research Agency, Research Grants Council (Hong Kong), Ministry of Earth Sciences (India), #NODATA#, Travnikov, Oleg [0000-0002-4413-0777], Li, Qinyi [0000-0002-5146-5831], Cuevas, Carlos A. [0000-0002-9251-5460], Fernandez, Rafael P. [0000-0002-4114-5500], Mahajan, Anoop S. [0000-0002-2909-5432], Wang, Shuxiao [0000-0001-9727-1963], Wang, Tao [0000-0002-4765-9377], Saiz-Lopez, A. [0000-0002-0060-1581], Fu, Xiao, Sun, Xianyi, Travnikov, Oleg, Li, Qinyi, Qin, Chuang, Cuevas, Carlos A., Fernandez, Rafael P., Mahajan, Anoop S., Wang, Shuxiao, Wang, Tao, and Saiz-Lopez, A.

Abstract

Mercury (Hg) is a contaminant of global concern, and an accurate understanding of its atmospheric fate is needed to assess its risks to humans and ecosystem health. Atmospheric oxidation of Hg is key to the deposition of this toxic metal to the Earth's surface. Short-lived halogens (SLHs) can provide halogen radicals to directly oxidize Hg and perturb the budget of other Hg oxidants (e.g., OH and O3). In addition to known ocean emissions of halogens, recent observational evidence has revealed abundant anthropogenic emissions of SLHs over continental areas. However, the impacts of anthropogenic SLHs emissions on the atmospheric fate of Hg and human exposure to Hg contamination remain unknown. Here, we show that the inclusion of anthropogenic SLHs substantially increased local Hg oxidation and, consequently, deposition in/near Hg continental source regions by up to 20%, thereby decreasing Hg export from source regions to clean environments. Our modeling results indicated that the inclusion of anthropogenic SLHs can lead to higher Hg exposure in/near Hg source regions than estimated in previous assessments, e.g., with increases of 8.7% and 7.5% in China and India, respectively, consequently leading to higher Hg-related human health risks. These results highlight the urgent need for policymakers to reduce local Hg and SLHs emissions. We conclude that the substantial impacts of anthropogenic SLHs emissions should be included in model assessments of the Hg budget and associated health risks at local and global scales.

Published
2024

3. Quantum field theory with ghost pairs

Author

Ministerio de Ciencia e Innovación (España), Shenzhen Science and Technology Innovation Commission, SCOAP, Calcagni, Gianluca [0000-0003-2631-4588], Liu, Jiangfan, Modesto, Leonardo, Calcagni, Gianluca, Ministerio de Ciencia e Innovación (España), Shenzhen Science and Technology Innovation Commission, SCOAP, Calcagni, Gianluca [0000-0003-2631-4588], Liu, Jiangfan, Modesto, Leonardo, and Calcagni, Gianluca

Abstract

We explicitly show that general local higher-derivative theories with only complex conjugate ghosts and normal real particles are unitary at any perturbative order in the loop expansion. The proof presented here relies on integrating the loop energies on complex paths resulting from the deformation of the purely imaginary paths, when the external energies are continued from imaginary to real values. Contrary to the case of nonlocal theories, where the same integration path was first proposed, for the classes of theories studied here the same procedure is not analytic, but the resulting theory is unitary and unique when the complex ghosts are present in pairs. As an explicit application, a special class of higher-derivative super-renormalizable or finite gravitational and gauge theories turns out to be unitary at any perturbative order if we exclude the complex ghosts from the spectrum of the theory, as it is normally accepted for Becchi-Rouet-Stora-Tyutin (BRST) ghosts. Finally, we propose an analogy between confined gluons in quantum Yang-Mills theory and classical complex pairs in local higher-derivative theories. According to such interpretation, complex ghosts will not appear on shell as asymptotic states because confined in what is natural to name "ghostballs."

Published
2023

4. Neuronal lack of PDE7a disrupted working memory, spatial learning, and memory but facilitated cued fear memory in mice

Author

Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Science and Technology Innovation Commission, Ali, Tahir [0000-0002-2138-1303], He, Kaiwu [0000-0002-8131-5850], Gil, Carmen [0000-0002-3882-6081], Martínez, Ana [0000-0002-2707-8110], Liu, Zizhen, Li, Axiang, Ali, Tahir, He, Kaiwu, Gao, Ruyan, He, Liufang, Qiang, Hao, Li, Tao, Li, Ningning, García, Ana, Gil, Carmen, Martínez Gil, Ana, Lipina, Tatiana V., Li, Shupeng, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Science and Technology Innovation Commission, Ali, Tahir [0000-0002-2138-1303], He, Kaiwu [0000-0002-8131-5850], Gil, Carmen [0000-0002-3882-6081], Martínez, Ana [0000-0002-2707-8110], Liu, Zizhen, Li, Axiang, Ali, Tahir, He, Kaiwu, Gao, Ruyan, He, Liufang, Qiang, Hao, Li, Tao, Li, Ningning, García, Ana, Gil, Carmen, Martínez Gil, Ana, Lipina, Tatiana V., and Li, Shupeng

Abstract

Background: PDEs regulate cAMP levels which is critical for PKA activity-dependent activation of CREB-mediated transcription in learning and memory. Inhibitors of PDEs like PDE4 and Pde7 improve learning and memory in rodents. However, the role of PDE7 in cognition or learning and memory has not been reported yet., Methods:Therefore, we aimed to explore the cognitive effects of a PDE7 subtype, PDE7a, using combined pharmacological and genetic approaches., Results: PDE7a-nko mice showed deficient working memory, impaired novel object recognition, deficient spatial learning & memory, and contextual fear memory, contrary to enhanced cued fear memory, highlighting the potential opposite role of PDE7a in the hippocampal neurons. Further, pharmacological inhibition of PDE7 by AGF2.20 selectively strengthens cued fear memory in C57BL/6 J mice, decreasing its extinction but did not affect cognitive processes assessed in other behavioral tests. The further biochemical analysis detected deficient cAMP in neural cell culture with genetic excision of the PDE7a gene, as well as in the hippocampus of PDE7a-nko mice in vivo. Importantly, we found overexpression of PKA-R and the reduced level of pPKA-C in the hippocampus of PDE7a-nko mice, suggesting a novel mechanism of the cAMP regulation by PDE7a. Consequently, the decreased phosphorylation of CREB, CAMKII, eif2a, ERK, and AMPK, and reduced total level of NR2A have been found in the brain of PDE7a-nko animals. Notably, genetic excision of PDE7a in neurons was not able to change the expression of NR2B, BDNF, synapsin1, synaptophysin, or snap25., Conclusion: Altogether, our current findings demonstrated, for the first time, the role of PDE7a in cognitive processes. Future studies will untangle PDE7a-dependent neurobiological and molecular-cellular mechanisms related to cAMP-associated disorders.

Published
2023

5. The complete reference genome for grapevine (Vitis vinifera L.) genetics and breeding

Author

National Natural Science Foundation of China, National Key Research and Development Program (China), Shenzhen Science and Technology Innovation Commission, German Research Foundation, European Commission, Ministerio de Ciencia e Innovación (España), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Federal Ministry of Economics and Technology (Germany), Shi, Xiaoya, Cao, Shuo, Wang, Xu, Matus, José Tomás, Rustenholz, Camille, Cheng, Zong-Ming Max, Xiao, Hua, Zhou, Yongfeng, National Natural Science Foundation of China, National Key Research and Development Program (China), Shenzhen Science and Technology Innovation Commission, German Research Foundation, European Commission, Ministerio de Ciencia e Innovación (España), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Federal Ministry of Economics and Technology (Germany), Shi, Xiaoya, Cao, Shuo, Wang, Xu, Matus, José Tomás, Rustenholz, Camille, Cheng, Zong-Ming Max, Xiao, Hua, and Zhou, Yongfeng

Abstract

Grapevine is one of the most economically important crops worldwide. However, the previous versions of the grapevine reference genome tipically consist of thousands of fragments with missing centromeres and telomeres, limiting the accessibility of the repetitive sequences, the centromeric and telomeric regions, and the study of inheritance of important agronomic traits in these regions. Here, we assembled a telomere-to-telomere (T2T) gap-free reference genome for the cultivar PN40024 using PacBio HiFi long reads. The T2T reference genome (PN_T2T) is 69 Mb longer with 9018 more genes identified than the 12X.v0 version. We annotated 67% repetitive sequences, 19 centromeres and 36 telomeres, and incorporated gene annotations of previous versions into the PN_T2T assembly. We detected a total of 377 gene clusters, which showed associations with complex traits, such as aroma and disease resistance. Even though PN40024 derives from nine generations of selfing, we still found nine genomic hotspots of heterozygous sites associated with biological processes, such as the oxidation–reduction process and protein phosphorylation. The fully annotated complete reference genome therefore constitutes an important resource for grapevine genetic studies and breeding programs.

Published
2023

6. Renormalizability of nonlocal quantum gravity coupled to matter

Author

Ministerio de Ciencia e Innovación (España), Shenzhen Science and Technology Innovation Commission, Calcagni, Gianluca [0000-0003-2631-4588], Calcagni, Gianluca, Giacchini, Breno L., Modesto, Leonardo, de Paula Netto, Tibério, Rachwał, Lesław, Ministerio de Ciencia e Innovación (España), Shenzhen Science and Technology Innovation Commission, Calcagni, Gianluca [0000-0003-2631-4588], Calcagni, Gianluca, Giacchini, Breno L., Modesto, Leonardo, de Paula Netto, Tibério, and Rachwał, Lesław

Abstract

We extensively study the ultraviolet quantum properties of a nonlocal action for gravity nonminimally coupled to matter. The theory unifies matter and gravity in an action principle such that all the classical solutions of Einstein’s theory coupled to matter are also solutions of the nonlocal theory. At the quantum level, we show that the theory is power-counting super-renormalizable in even dimensions and finite in odd dimensions. A simple extension of the model compatible with the above properties is finite also in even dimensions.

Published
2023

7. Gel transformation as a general strategy for fabrication of highly porous multiscale MOF architectures

Author

Research Grants Council (Hong Kong), Shenzhen Science and Technology Innovation Commission, Guangzhou Institute of Science and Technology, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Liu, Zhang, Lopez Navas, Javier, Han, Wei, Ibarra, M. Ricardo, Kwan, Joseph Kai Cho, Yeung, King Lun, Research Grants Council (Hong Kong), Shenzhen Science and Technology Innovation Commission, Guangzhou Institute of Science and Technology, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Liu, Zhang, Lopez Navas, Javier, Han, Wei, Ibarra, M. Ricardo, Kwan, Joseph Kai Cho, and Yeung, King Lun

Abstract

The structure and chemistry of metal–organic frameworks or MOFs dictate their properties and functionalities. However, their architecture and form are essential for facilitating the transport of molecules, the flow of electrons, the conduction of heat, the transmission of light, and the propagation of force, which are vital in many applications. This work explores the transformation of inorganic gels into MOFs as a general strategy to construct complex porous MOF architectures at nano, micro, and millimeter length scales. MOFs can be induced to form along three different pathways governed by gel dissolution, MOF nucleation, and crystallization kinetics. Slow gel dissolution, rapid nucleation, and moderate crystal growth result in a pseudomorphic transformation (pathway 1) that preserves the original network structure and pores, while a comparably faster crystallization displays significant localized structural changes but still preserves network interconnectivity (pathway 2). MOF exfoliates from the gel surface during rapid dissolution, thus inducing nucleation in the pore liquid leading to a dense assembly of percolated MOF particles (pathway 3). Thus, the prepared MOF 3D objects and architectures can be fabricated with superb mechanical strength (>98.7 MPa), excellent permeability (>3.4 × 10−10 m2), and large surface area (1100 m2 g−1) and mesopore volumes (1.1 cm3 g−1).

Published
2023

8. Roadmap on commercialization of metal halide perovskite photovoltaics

Author

Collaborative Research Fund (Hong Kong), Ningbo Institute of Materials Technology and Engineering, Zhejiang Provincial Natural Science Foundation, Shenzhen Science and Technology Innovation Commission, Ministry of Education and Science (Kazakhstan), Nazarbayev University, European Commission, Ministero dello Sviluppo Economico, Agence Nationale de la Recherche (France), Ministry of Science and Higher Education of the Russian Federation, National University of Singapore, Department of Energy (US), National Key Research and Development Program (China), National Natural Science Foundation of China, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, German Research Foundation, Generalitat Valenciana, Natural Science Foundation of Guangdong Province, Tibet Autonomous Region, Feng, Shien-Ping [0000-0002-3941-1363], Yip, Hin-Lap [0000-0002-5750-9751], Zhong, Yufei [0000-0001-9845-8607], Fong, Patrick W. K. [0000-0002-2460-4525], Li, Gang [0000-0001-8399-7771], Ng, Annie [0000-0002-5975-2499], Castriotta, Luigi Angelo [0000-0003-2525-8852], Matteocci, Fabio [0000-0001-7893-1356], Vesce, Luigi [0000-0003-3322-8688], Di Carlo, Aldo [0000-0001-6828-2380], Hou, Yi [0000-0002-1532-816X], Song, Zhaoning [0000-0002-6677-0994], Yan, Yanfa [0000-0003-3977-5789], Ng, Alan Man Ching [0000-0001-7081-8244], Richardson, Giles [0000-0001-6225-8590], Lira-Cantú, Mónica [0000-0002-3393-7436], Khenkin, Mark V. [0000-0001-9201-0238], Visoly-Fisher, Iris [0000-0001-6058-4712], Katz, Eugene A. [0000-0001-6151-1603], Vaynzof, Yana [0000-0002-0783-0707], Vidal, Rosario [0000-0001-7872-0620], Lin, Haoran [0000-0003-0625-8881], Wang, Shifeng [0000-0001-6169-2598], Djurišic, Aleksandra B. [0000-0002-5183-1467], Feng, Shien-Ping, Cheng, Yuanhang, Yip, Hin-Lap, Zhong, Yufei, Fong, Patrick W. K., Li, Gang, Ng, Annie, Chen, Cong, Castriotta, Luigi Angelo, Matteocci, Fabio, Vesce, Luigi, Saranin, Danila, Di Carlo, Aldo, Wang, Puqun, Wei Ho, Jian, Hou, Yi, Lin, Fen, Aberle, Armin G., Song, Zhaoning, Yan, Yanfa, Chen, Xu, Yang, Yang Michael, Syed, Ali Asgher, Ahmad, Ishaq, Leung, Tiklun, Wang, Yantao, Lin, Jing Yang, Ng, Alan Man Ching, Li, Yin, Ebadi, Firouzeh, Tress, Wolfgang, Richardson, Giles, Ge, Chuangye, Hu, Hanlin, Karimipour, Masoud, Baumann, Fanny, Tabah, Kenedy, Pereyra, Carlos, Raga, Sonia R., Xie, Haibing, Lira-Cantú, Mónica, Khenkin, Mark V., Visoly-Fisher, Iris, Katz, Eugene A., Vaynzof, Yana, Vidal, Rosario, Yu, Guicheng, Lin, Haoran, Weng, Shuchen, Wang, Shifeng, Djurišic, Aleksandra B., Collaborative Research Fund (Hong Kong), Ningbo Institute of Materials Technology and Engineering, Zhejiang Provincial Natural Science Foundation, Shenzhen Science and Technology Innovation Commission, Ministry of Education and Science (Kazakhstan), Nazarbayev University, European Commission, Ministero dello Sviluppo Economico, Agence Nationale de la Recherche (France), Ministry of Science and Higher Education of the Russian Federation, National University of Singapore, Department of Energy (US), National Key Research and Development Program (China), National Natural Science Foundation of China, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, German Research Foundation, Generalitat Valenciana, Natural Science Foundation of Guangdong Province, Tibet Autonomous Region, Feng, Shien-Ping [0000-0002-3941-1363], Yip, Hin-Lap [0000-0002-5750-9751], Zhong, Yufei [0000-0001-9845-8607], Fong, Patrick W. K. [0000-0002-2460-4525], Li, Gang [0000-0001-8399-7771], Ng, Annie [0000-0002-5975-2499], Castriotta, Luigi Angelo [0000-0003-2525-8852], Matteocci, Fabio [0000-0001-7893-1356], Vesce, Luigi [0000-0003-3322-8688], Di Carlo, Aldo [0000-0001-6828-2380], Hou, Yi [0000-0002-1532-816X], Song, Zhaoning [0000-0002-6677-0994], Yan, Yanfa [0000-0003-3977-5789], Ng, Alan Man Ching [0000-0001-7081-8244], Richardson, Giles [0000-0001-6225-8590], Lira-Cantú, Mónica [0000-0002-3393-7436], Khenkin, Mark V. [0000-0001-9201-0238], Visoly-Fisher, Iris [0000-0001-6058-4712], Katz, Eugene A. [0000-0001-6151-1603], Vaynzof, Yana [0000-0002-0783-0707], Vidal, Rosario [0000-0001-7872-0620], Lin, Haoran [0000-0003-0625-8881], Wang, Shifeng [0000-0001-6169-2598], Djurišic, Aleksandra B. [0000-0002-5183-1467], Feng, Shien-Ping, Cheng, Yuanhang, Yip, Hin-Lap, Zhong, Yufei, Fong, Patrick W. K., Li, Gang, Ng, Annie, Chen, Cong, Castriotta, Luigi Angelo, Matteocci, Fabio, Vesce, Luigi, Saranin, Danila, Di Carlo, Aldo, Wang, Puqun, Wei Ho, Jian, Hou, Yi, Lin, Fen, Aberle, Armin G., Song, Zhaoning, Yan, Yanfa, Chen, Xu, Yang, Yang Michael, Syed, Ali Asgher, Ahmad, Ishaq, Leung, Tiklun, Wang, Yantao, Lin, Jing Yang, Ng, Alan Man Ching, Li, Yin, Ebadi, Firouzeh, Tress, Wolfgang, Richardson, Giles, Ge, Chuangye, Hu, Hanlin, Karimipour, Masoud, Baumann, Fanny, Tabah, Kenedy, Pereyra, Carlos, Raga, Sonia R., Xie, Haibing, Lira-Cantú, Mónica, Khenkin, Mark V., Visoly-Fisher, Iris, Katz, Eugene A., Vaynzof, Yana, Vidal, Rosario, Yu, Guicheng, Lin, Haoran, Weng, Shuchen, Wang, Shifeng, and Djurišic, Aleksandra B.

Abstract

Perovskite solar cells (PSCs) represent one of the most promising emerging photovoltaic technologies due to their high power conversion efficiency. However, despite the huge progress made not only in terms of the efficiency achieved, but also fundamental understanding of the relevant physics of the devices and issues which affect their efficiency and stability, there are still unresolved problems and obstacles on the path toward commercialization of this promising technology. In this roadmap, we aim to provide a concise and up to date summary of outstanding issues and challenges, and the progress made toward addressing these issues. While the format of this article is not meant to be a comprehensive review of the topic, it provides a collection of the viewpoints of the experts in the field, which covers a broad range of topics related to PSC commercialization, including those relevant for manufacturing (scaling up, different types of devices), operation and stability (various factors), and environmental issues (in particular the use of lead). We hope that the article will provide a useful resource for researchers in the field and that it will facilitate discussions and move forward toward addressing the outstanding challenges in this fast-developing field.

Published
2023

9. Manipulating polaritons at the extreme scale in van der Waals materials

Author

Australian Research Council, Shenzhen Science and Technology Innovation Commission, National Natural Science Foundation of China, European Research Council, European Commission, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Office of Naval Research (US), Wu, Yingjie, Duan, Jiahua, Ma, Weiliang, Ou, Qingdong, Li, Peining, Alonso-González, Pablo, Caldwell, Joshua D., Bao, Qiaoliang, Australian Research Council, Shenzhen Science and Technology Innovation Commission, National Natural Science Foundation of China, European Research Council, European Commission, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Office of Naval Research (US), Wu, Yingjie, Duan, Jiahua, Ma, Weiliang, Ou, Qingdong, Li, Peining, Alonso-González, Pablo, Caldwell, Joshua D., and Bao, Qiaoliang

Abstract

Polaritons, originating from the interactions between photons and material excitations, have attracted attention because of their strong field compression and deeply subdiffractional scales. For practical applications, it is crucial to manipulate polaritons efficiently, but doing so has remained challenging because of the relatively poor tunability of traditional polaritonic media. Fortunately, in the past decade, polaritons hosted by van der Waals (vdW) materials have allowed new opportunities to tackle this difficulty. We review the state of the art in the manipulation of polaritons at the extreme scale in vdW materials. Benefiting from the large and expanding catalogue of vdW materials and associated architectures and techniques, more accessible manipulation strategies are expected, not only offering control of light at the nanoscale with new degrees of freedom, but also offering insight into nanophotonics, meta-optics, topological physics and quantum materials.

Published
2022

10. Negative reflection of nanoscale-confined polaritons in a low-loss natural medium

Author

Principado de Asturias, Australian Research Council, Australian National Fabrication Facility, National Science Foundation (US), Ministerio de Ciencia, Innovación y Universidades (España), Foundation for Polish Science, European Commission, Eusko Jaurlaritza, Ministerio de Ciencia e Innovación (España), Shenzhen Science and Technology Innovation Commission, Álvarez-Pérez, Gonzalo, Duan, Jiahua, Taboada-Gutiérrez, Javier, Ou, Qingdong, Nikulina, Elizaveta, Liu, Song, Edgar, James H., Bao, Qiaoliang, Giannini, V., Hillenbrand, Rainer, Martín-Sánchez, Javier, Nikitin, Alexey Y., Alonso-González, Pablo, Principado de Asturias, Australian Research Council, Australian National Fabrication Facility, National Science Foundation (US), Ministerio de Ciencia, Innovación y Universidades (España), Foundation for Polish Science, European Commission, Eusko Jaurlaritza, Ministerio de Ciencia e Innovación (España), Shenzhen Science and Technology Innovation Commission, Álvarez-Pérez, Gonzalo, Duan, Jiahua, Taboada-Gutiérrez, Javier, Ou, Qingdong, Nikulina, Elizaveta, Liu, Song, Edgar, James H., Bao, Qiaoliang, Giannini, V., Hillenbrand, Rainer, Martín-Sánchez, Javier, Nikitin, Alexey Y., and Alonso-González, Pablo

Abstract

Negative reflection occurs when light is reflected toward the same side of the normal to the boundary from which it is incident. This exotic optical phenomenon is not only yet to be visualized in real space but also remains unexplored, both at the nanoscale and in natural media. Here, we directly visualize nanoscale-confined polaritons negatively reflecting on subwavelength mirrors fabricated in a low-loss van der Waals crystal. Our near-field nanoimaging results unveil an unconventional and broad tunability of both the polaritonic wavelength and direction of propagation upon negative reflection. On the basis of these findings, we introduce a device in nano-optics: a hyperbolic nanoresonator, in which hyperbolic polaritons with different momenta reflect back to a common point source, enhancing the intensity. These results pave way to realize nanophotonics in low-loss natural media, providing an efficient route to control nanolight, a key for future on-chip optical nanotechnologies.

Published
2022

11. Spin excitations of individual magnetic dopants in an ionic thin film

Author

National Natural Science Foundation of China, Shenzhen Science and Technology Innovation Commission, Research Foundation - Flanders, KU Leuven, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Universidad del País Vasco, Eusko Jaurlaritza, European Commission, Li, Zhe, Delgado, Fernando, Du, Mei, He, Chen, Schouteden, Koen, Van Haesendonck, Chris, Janssens, Ewald, Arnau, Andrés, Lievens, Peter, Cerdá, Jorge I., National Natural Science Foundation of China, Shenzhen Science and Technology Innovation Commission, Research Foundation - Flanders, KU Leuven, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Universidad del País Vasco, Eusko Jaurlaritza, European Commission, Li, Zhe, Delgado, Fernando, Du, Mei, He, Chen, Schouteden, Koen, Van Haesendonck, Chris, Janssens, Ewald, Arnau, Andrés, Lievens, Peter, and Cerdá, Jorge I.

Abstract

Individual magnetic transition metal dopants in a solid host usually exhibit relatively small spin excitation energies of a few meV. Using scanning tunneling microscopy and inelastic electron tunneling spectroscopy (IETS) techniques, we have observed a high spin excitation energy around 36 meV for an individual Co substitutional dopant in ultrathin NaCl films. In contrast, the Cr dopant in the NaCl film shows much lower spin excitation energy around 2.5 meV. Electronic multiplet calculations combined with first-principles calculations confirm the spin excitation induced IETS, and quantitatively reveal the out-of-plane magnetic anisotropies for both Co and Cr. They also allow reproducing the experimentally observed redshift in the spin excitations of Co dimers and ascribe it to a charge and geometry redistribution.

Published
2022

12. Synthesis process and thermoelectric properties of n-type tin selenide thin films

Author

Bo Li, Ping Fan, Fu Li, Zhuanghao Zheng, Jingting Luo, Cao Li, Wenting Wang, College of Physics and Energy, Shenzhen University, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Tsinghua University [Beijing] (THU), JCYJ20150827165038323, Shenzhen Science and Technology Innovation Commission, JCYJ20170818142740568, Shenzhen Science and Technology Innovation Commission, JCYJ20160422102622085, Shenzhen Science and Technology Innovation Commission, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Annealing (metallurgy), Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, Tungsten, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Crystallinity, thermal evaporation, Seebeck coefficient, Thermoelectric effect, Materials Chemistry, [CHIM]Chemical Sciences, Thin film, Mechanical Engineering, Tin selenide, Metals and Alloys, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Thermoelectric materials, 0104 chemical sciences, tin selenide, chemistry, Mechanics of Materials, thermoelectric property, 0210 nano-technology
Abstract

International audience; Tin selenide (SnSe) is a very promising thermoelectric material, but there are few reports related to the thermoelectric properties of its thin films, especially for n-type SnSe. In this work, n-type SnSe thin films were synthesized via thermal evaporation using powdered SnSe that was prepared directly by mechanical alloying. It was found that the crystallinity of the films gradually improved and the closer the elemental ratio of Sn and Se was to a ratio of 11 with increasing the current through the tungsten boat during the thermal evaporation of the SnSe precursor from 100 to 130 A. Further, the thin films obtained at 120 A show the highest power factor (0.13 μW/mK2) of all the samples fabricated in this study. The samples were then annealed, and the thermoelectric properties of the films were enhanced as this step improved their crystallinities. A Seebeck coefficient of over 100 μV/K could be achieved with an annealing time of 4 h. Combined with a recorded electrical conductivity of 47 S/cm, a maximum power factor of 120 μW/mK2 at 473 K has been obtained for the annealed film with n-type conductive characteristics; this is nearly six times higher than that reported for polycrystalline n-type bulk SnSe at the same temperature. © 2018 Elsevier B.V.

Published
2018

13. Spin excitations of individual magnetic dopants in an ionic thin film

Author

Zhe Li, Fernando Delgado, Mei Du, Chen He, Koen Schouteden, Chris Van Haesendonck, Ewald Janssens, Andres Arnau, Peter Lievens, Jorge I Cerda, National Natural Science Foundation of China, Shenzhen Science and Technology Innovation Commission, Research Foundation - Flanders, KU Leuven, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Universidad del País Vasco, Eusko Jaurlaritza, and European Commission

Subjects
scanning tunneling microscopy, General Materials Science, Condensed Matter Physics, magnetic dopants, spin excitation
Abstract

Individual magnetic transition metal dopants in a solid host usually exhibit relatively small spin excitation energies of a few meV. Using scanning tunneling microscopy and inelastic electron tunneling spectroscopy (IETS) techniques, we have observed a high spin excitation energy around 36 meV for an individual Co substitutional dopant in ultrathin NaCl films. In contrast, the Cr dopant in the NaCl film shows much lower spin excitation energy around 2.5 meV. Electronic multiplet calculations combined with first-principles calculations confirm the spin excitation induced IETS, and quantitatively reveal the out-of-plane magnetic anisotropies for both Co and Cr. They also allow reproducing the experimentally observed redshift in the spin excitations of Co dimers and ascribe it to a charge and geometry redistribution., This research was supported by the National Natural Science Foundation of China (91961102, 11704057), the Shenzhen fundamental research funding (JCYJ20190806112206698), the starting funding from HIT Shenzhen (HA45001082), and the Research Foundation Flanders (G0D56.19N and G0A05.19N) and by the KU Leuven Research Council (C14/22/103). Financial support by the following Projects: RTI2018-097895-B-C41, PID2019-109539GB-C41 and PID2019-103910GB-I00, funded by MCIN/AEI/10.13039/501100011033/ and FEDER Una manera de hacer Europa, as well as GIU18/138 by Universidad del País Vasco UPV/EHU; IT-1246-19, IT986-16 and IT-1260-19 by Gobierno Vasco, is gratefully acknowledged.

Published
2022

14. Negative reflection of nanoscale-confined polaritons in a low-loss natural medium

Author

Gonzalo Álvarez-Pérez, Jiahua Duan, Javier Taboada-Gutiérrez, Qingdong Ou, Elizaveta Nikulina, Song Liu, James H. Edgar, Qiaoliang Bao, Vincenzo Giannini, Rainer Hillenbrand, Javier Martín-Sánchez, Alexey Yu Nikitin, Pablo Alonso-González, Principado de Asturias, Australian Research Council, Australian National Fabrication Facility, National Science Foundation (US), Ministerio de Ciencia, Innovación y Universidades (España), Foundation for Polish Science, European Commission, Eusko Jaurlaritza, Ministerio de Ciencia e Innovación (España), and Shenzhen Science and Technology Innovation Commission

Subjects
Multidisciplinary
Abstract

7 pags., 4 figs., Negative reflection occurs when light is reflected toward the same side of the normal to the boundary from which it is incident. This exotic optical phenomenon is not only yet to be visualized in real space but also remains unexplored, both at the nanoscale and in natural media. Here, we directly visualize nanoscale-confined polaritons negatively reflecting on subwavelength mirrors fabricated in a low-loss van der Waals crystal. Our near-field nanoimaging results unveil an unconventional and broad tunability of both the polaritonic wavelength and direction of propagation upon negative reflection. On the basis of these findings, we introduce a device in nano-optics: a hyperbolic nanoresonator, in which hyperbolic polaritons with different momenta reflect back to a common point source, enhancing the intensity. These results pave way to realize nanophotonics in low-loss natural media, providing an efficient route to control nanolight, a key for future on-chip optical nanotechnologies., G.Á.-P. and J.T.-G. acknowledge support through the Severo Ochoa Program from the Government of the Principality of Asturias (grant numbers PA-20-PF-BP19-053 and PA-18-PF-BP17-126, respectively). Q.O. acknowledges support from the Australian Research Council (ARC; CE170100039 and DE220100154). This work was performed in part at the Melbourne Centre for Nanofabrication (MCN) in the Victorian Node of the Australian National Fabrication Facility (ANFF). hBN crystal growth was supported by the National Science Foundation award number CMMI 1538127. V.G. acknowledges the Ministerio de Ciencia, Innovación y Universidades through the grant MELODIA (PGC2018-095777-B-C21). V.G. thanks the “ENSEMBLE 3–Centre of Excellence for nanophotonics, advanced materials and novel crystal growth-based technologies” project (GA no. MAB/2020/14) carried out within the International Research Agendas program of the Foundation for Polish Science cofinanced by the European Union under the European Regional Development Fund and the European Union’s Horizon 2020 research and innovation programme Teaming for Excellence (GA no. 857543) for support of this work. R.H. acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities (national project RTI2018-094830-B-100 and the project MDM-2016-0618 of the María de Maeztu Units of Excellence Program) and the Basque Government (grant no. IT1164-19). J.M.-S. acknowledges financial support from the Ramón y Cajal Program of the Government of Spain and FSE (RYC2018-026196-I) and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation grant number PID2019-110308GA-I00). A.Y.N. acknowledges the Spanish Ministry of Science and Innovation (grants MAT201788358-C3-3-R and PID2020-115221GB-C42) and the Basque Department of Education (grant PIBA-2020-1-0014). P.A.-G. acknowledges support from the European Research Council under starting grant no. 715496, 2DNANOPTICA and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation grant number PID2019-111156GB-I00). Q.B. acknowledges the support from Shenzhen Nanshan District Pilotage Team Program (LHTD20170006).

Published
2022

15. Manipulating polaritons at the extreme scale in van der Waals materials

Author

Yingjie Wu, Jiahua Duan, Weiliang Ma, Qingdong Ou, Peining Li, Pablo Alonso-González, Joshua D. Caldwell, Qiaoliang Bao, Australian Research Council, Shenzhen Science and Technology Innovation Commission, National Natural Science Foundation of China, European Research Council, European Commission, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), and Office of Naval Research (US)

Subjects
General Physics and Astronomy
Abstract

Polaritons, originating from the interactions between photons and material excitations, have attracted attention because of their strong field compression and deeply subdiffractional scales. For practical applications, it is crucial to manipulate polaritons efficiently, but doing so has remained challenging because of the relatively poor tunability of traditional polaritonic media. Fortunately, in the past decade, polaritons hosted by van der Waals (vdW) materials have allowed new opportunities to tackle this difficulty. We review the state of the art in the manipulation of polaritons at the extreme scale in vdW materials. Benefiting from the large and expanding catalogue of vdW materials and associated architectures and techniques, more accessible manipulation strategies are expected, not only offering control of light at the nanoscale with new degrees of freedom, but also offering insight into nanophotonics, meta-optics, topological physics and quantum materials., This work was supported by the Australian Research Council (ARC, CE170100039 and DE220100154) and Shenzhen Nanshan District Pilotage Team Program (LHTD20170006). P.L. acknowledges support from the National Natural Science Foundation of China (grant no. 62075070) and the Innovation Fund of WNLO. P.A.-G. acknowledges support from the European Research Council under starting grant no. 715496, 2DNANOPTICA and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation grant no. PID2019-111156GB-I00). J.D.C. acknowledges support from the Office of Naval Research, grant no. N000142212035.

Published
2022

16. Neuronal lack of PDE7a disrupted working memory, spatial learning, and memory but facilitated cued fear memory in mice

Author

Zizhen Liu, Axiang Li, Tahir Ali, Kaiwu He, Ruyan Gao, Liufang He, Hao Qiang, Tao Li, Ningning Li, Ana M. Garcia, Carmen Gil, Ana Martinez, Tatiana V. Lipina, Shupeng Li, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Science and Technology Innovation Commission, Ali, Tahir [0000-0002-2138-1303], He, Kaiwu [0000-0002-8131-5850], Gil, Carmen [0000-0002-3882-6081], Martínez, Ana [0000-0002-2707-8110], Ali, Tahir, He, Kaiwu, Gil, Carmen, and Martínez, Ana

Subjects
Pharmacology, Cyclic Nucleotide Phosphodiesterases, Type 7, Brain-Derived Neurotrophic Factor, Spatial Learning, Synaptophysin, PDE7a, Working memory, Fear, Contextual and cued fear memory, AMP-Activated Protein Kinases, Hippocampus, Mice, Inbred C57BL, Mice, Memory, Short-Term, Memory, Animals, Calcium-Calmodulin-Dependent Protein Kinase Type 2, Biological Psychiatry, Spatial learning & memory
Abstract

12 p.-5 fig., Background: PDEs regulate cAMP levels which is critical for PKA activity-dependent activation of CREB-mediated transcription in learning and memory. Inhibitors of PDEs like PDE4 and Pde7 improve learning and memory in rodents. However, the role of PDE7 in cognition or learning and memory has not been reported yet., Methods:Therefore, we aimed to explore the cognitive effects of a PDE7 subtype, PDE7a, using combined pharmacological and genetic approaches., Results: PDE7a-nko mice showed deficient working memory, impaired novel object recognition, deficient spatial learning & memory, and contextual fear memory, contrary to enhanced cued fear memory, highlighting the potential opposite role of PDE7a in the hippocampal neurons. Further, pharmacological inhibition of PDE7 by AGF2.20 selectively strengthens cued fear memory in C57BL/6 J mice, decreasing its extinction but did not affect cognitive processes assessed in other behavioral tests. The further biochemical analysis detected deficient cAMP in neural cell culture with genetic excision of the PDE7a gene, as well as in the hippocampus of PDE7a-nko mice in vivo. Importantly, we found overexpression of PKA-R and the reduced level of pPKA-C in the hippocampus of PDE7a-nko mice, suggesting a novel mechanism of the cAMP regulation by PDE7a. Consequently, the decreased phosphorylation of CREB, CAMKII, eif2a, ERK, and AMPK, and reduced total level of NR2A have been found in the brain of PDE7a-nko animals. Notably, genetic excision of PDE7a in neurons was not able to change the expression of NR2B, BDNF, synapsin1, synaptophysin, or snap25., Conclusion: Altogether, our current findings demonstrated, for the first time, the role of PDE7a in cognitive processes. Future studies will untangle PDE7a-dependent neurobiological and molecular-cellular mechanisms related to cAMP-associated disorders., This work was supported by the Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions No: 2022SHIBS0004: Basic research and free exploration project of Shenzhen Science and technology innovation Commission (JCYJ20190808113007570).

Published
2022

17. Chiral CdSe nanoplatelets as an ultrasensitive probe for lead ion sensing

Author

Ruxue Li, Liu Yuhui, Junjie Hao, Yiwen Li, Jiagen Li, Junzi Li, Xiao Wei Sun, Jiaji Cheng, Zikang Tang, Rui Chen, Tingchao He, Marie-Hélène Delville, Xi Zhu, Xiongbin Wang, Jun Miao, Yan Jun Liu, Department of Electrical and Electronic Engineering, Southern University of Science and Technology of China (SUSTech), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), College of Physics and Energy, Shenzhen University, School of Materials Science and Engineering, Hubei University, The Institute of Applied Physics and Materials Engineering, University of Macau (UMac), Department of Materials Science and Engineering, School of Science and Engineering, The Chinese University of Hong Kong [Hong Kong], and This work is supported by the National Natural Science Foundation of China (11574130) and the Shenzhen Science and Technology Innovation Commission (project no. KQJSCX20170726145748464, JCYJ20150930160634263, JCYJ20170302142433007, JCYJ20170818103918295 and KQTD2015071710313656).

Subjects
Detection limit, Photoluminescence, Materials science, business.industry, Chiral ligand, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Polarization (waves), 01 natural sciences, 0104 chemical sciences, Ion, Metal, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, visual_art, visual_art.visual_art_medium, Optoelectronics, Molecule, General Materials Science, Density functional theory, 0210 nano-technology, business
Abstract

International audience; As opposed to traditional photoluminescence and ultra-violet based optical sensing, we present here a sensing system based on resolved optically active polarization with promising applications. It is based on the ultrathin CdSe nanoplatelets (NPLs) when modified with either L or D-cysteine molecules (L/D-cys) as bio-to-nano ligands. The chiral ligand transfers its chiroptical activity to the achiral nanoplatelets with an anisotropy factor of ∼10−4, which unlocks the chiral excitonic transitions and allows lead ion detection with a limit of detection (LOD) as low as 4.9 nM. Simulations and modelling based on time-dependent density functional theory (TD-DFT) reveal the chiral mechanism of L/D-cys capped CdSe NPLs. The presented CD-based sensing system illustrates an alternative possibility of using chiral CdSe NPLs as competitive chiral sensors for heavy metal ion detection.

Published
2019

18. Study on the effects of catalysts on the immobilization efficiency and mechanism of heavy metals during the microwave pyrolysis of sludge

Author

Rui Ma, Junle Qu, Lin Fang, Junhao Lin, Xiaofei Huang, Yilin Liu, Peixin Zhang, Xianghua Zhang, Shichang Sun, Shenzhen University, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), JCYJ20170818093116044, Shenzhen Science and Technology Innovation Commission, 2017YFC0703201, 827-000037, 2015A030310395, Natural Science Foundation of Guangdong Province, 51708357, NSFC, National Natural Science Foundation of China, Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)

Subjects
Pollution, 020209 energy, media_common.quotation_subject, Inorganic chemistry, chemistry.chemical_element, 02 engineering and technology, Zinc, 010501 environmental sciences, 01 natural sciences, Chemical reaction, Sludge, Ferric Compounds, Catalysis, Immobilization efficiency, Chromium, Metals, Heavy, 0202 electrical engineering, electronic engineering, information engineering, [CHIM]Chemical Sciences, Microwaves, Waste Management and Disposal, Dissolution, 0105 earth and related environmental sciences, media_common, Sewage, chemistry, Heavy metals, 13. Climate action, Leaching (metallurgy), Catalyst, Pyrolysis, Microwave pyrolysis
Abstract

International audience; In order to enhance the immobilization of heavy metals in the bio-char during microwave pyrolysis, the immobilization efficiency and mechanism of heavy metals in the microwave pyrolysis of sludge with different alkaline catalysts were explored. Results showed that the leaching concentrations of heavy metals reduced greatly after pyrolysis, which were lower when catalyzed by CaO than those of Fe2O3. CaO was more favorable for the immobilization of Cr, Cu, Zn, Pb and Ni while Fe2O3 was more favorable for Cd. Different species distributions of heavy metals in the bio-char affected the leaching concentrations. Adding catalyst could significantly reduce the ecological risks of heavy metals in the bio-char, and CaO (RI = 15.17–20.43) had a better performance than Fe2O3 (RI = 16.88–21.79). When catalyzed by CaO, the formation of pores and co-crystal compounds in the bio-char determined the immobilization efficiencies of heavy metals. © 2018 Elsevier Ltd

Published
2018

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