Experimental measurement of the quantum geometric tensor using coupled qubits in diamond

Geometry and topology are fundamental concepts, which underlie a wide range of fascinating physical phenomena such as topological states of matter and topological defects. In quantum mechanics, the geometry of quantum states is fully captured by the quantum geometric tensor. Using a qubit formed by an NV center in diamond, we perform the first experimental measurement of the complete quantum geometric tensor. Our approach builds on a strong connection between coherent Rabi oscillations upon parametric modulations and the quantum geometry of the underlying states. We then apply our method to a system of two interacting qubits, by exploiting the coupling between the NV center spin and a neighboring $^{13}$C nuclear spin. Our results establish coherent dynamical responses as a versatile probe for quantum geometry, and they pave the way for the detection of novel topological phenomena in solid state

Robust strategies in nuclear-targeted cancer therapy based on functional nanomaterials

Nucleus, as the machinery for genome transcription, play prominent roles to support the fundamental cel-lular functions, the destruction of any of these specific parts would significantly modulate the cell function. Therefore, troumendous drug delivery systems with enhanced nucleus targeting ability have been studied for nucleus-related disease regulation. The purpose of this review is to sort out the fundamental nuclear tar-geting strategy, especially the active mechanism of various nuclear targeting ligands and their extensive applications based on cancer targeting therapy. Various nuclear targeting ligands are first introduced to understand their nuclear entry mechanism. Next, to overcome biological barriers and avoid the serum pro-tein absorption, diverse robust delivery strategies based on different nuclear targeting ligands are dis-cussed. Moreover, other sophisticated carrier systems with enhanced nuclear entry, while without nuclear targeting ligands are also assembled. At the end the challenges and future opportunities in the field of nuclear targeting nanotherapeutics are tentatively proposed, to speed up their clinical translation. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/)

Structural and mechanistic insights into the biosynthesis of CDP-archaeol in membranes

The divergence of archaea, bacteria and eukaryotes was a fundamental step in evolution. One marker of this event is a major difference in membrane lipid chemistry between these kingdoms. Whereas the membranes of bacteria and eukaryotes primarily consist of straight fatty acids ester-bonded to glycerol-3-phosphate, archaeal phospholipids consist of isoprenoid chains ether-bonded to glycerol-1-phosphate. Notably, the mechanisms underlying the biosynthesis of these lipids remain elusive. Here, we report the structure of the CDP-archaeol synthase (CarS) of Aeropyrum pernix (ApCarS) in the CTP- and Mg(2+)-bound state at a resolution of 2.4 Å. The enzyme comprises a transmembrane domain with five helices and cytoplasmic loops that together form a large charged cavity providing a binding site for CTP. Identification of the binding location of CTP and Mg(2+) enabled modeling of the specific lipophilic substrate-binding site, which was supported by site-directed mutagenesis, substrate-binding affinity analyses, and enzyme assays. We propose that archaeol binds within two hydrophobic membrane-embedded grooves formed by the flexible transmembrane helix 5 (TM5), together with TM1 and TM4. Collectively, structural comparisons and analyses, combined with functional studies, not only elucidated the mechanism governing the biosynthesis of phospholipids with ether-bonded isoprenoid chains by CTP transferase, but also provided insights into the evolution of this enzyme superfamily from archaea to bacteria and eukaryotes.Cell Research advance online publication 29 September 2017; doi:10.1038/cr.2017.122

Research on the Integration of Prefabricated Building and BIM Based on Bibliometrics

Analyzing the literature in the field of prefabricated building and BIM integration is helpful to promote the development of prefabricated building informatization. Using the Web of Science core collection database as the data source, this study screened relevant literatures at home and abroad from 2000 to 2020. CiteSpace and VOSviewer were used to conduct visual analysis on the characteristics of published articles, research hotspots and evolution trends based on bibliometrics. The results show that the related literature heat in this field will continue to increase in China in the future. Design and management have become the focus and trend of current scholars in this field. Exploring all kinds of development obstacles has become a new research hotspot in the past two years

Risk Network Evaluation of Prefabricated Building Projects in Underdeveloped Areas: A Case Study in Qinghai

Prefabricated building projects (PBPs) face more risks than traditional construction projects, especially in underdeveloped areas. This study takes Qinghai Province as a study case. Social network analysis (SNA) is adopted to develop a risk network of PBPs, and nine core risk factors and five key risk relationships are identified. Risk effect detection reveals the effectiveness of risk response strategies. The research shows that PBPs in underdeveloped areas are still in the early stage of development, and developers generally lack a leading role. There are prominent problems in the design stage of PBPs, so the stakeholders pay special attention to them. In underdeveloped regions, the development of PBPs must rely on the strong promotion of the government. Limited by natural and economic conditions, the market mechanism of PBPs in underdeveloped areas is not perfect, and policy regulation greatly affects the spread of the risk network. Therefore, local governments need to actively introduce corresponding supportive policies and mobilize the enthusiasm of stakeholders. This is the first study to consider the risk within the life cycle of PBPs in underdeveloped plateau areas. This study expands the research system of risk management of PBPs and provides valuable risk response strategies for the stakeholders

Organic crystal-based flexible smart materials

Although the famous brittle characteristics of molecular crystals are unfavorable when they are used as flexible smart materials (FSMs), an increasing number of organic crystal-based FSMs have been reported recently. This breaks the perception of their stiff and brittle properties and promises a bright future for basic research and practical applications. Crystalline smart materials present considerable advantages over polymer materials under certain circumstances, rendering them potential candidates for certain applications, such as rapidly responsive actuators, ON/OFF switching, and microrobots. In this review, we summarize the recent developments in the field of organic crystal-based FSMs, including the derivatives of azobenzene, diarylethene, anthracene, and olefin. These organic crystal-based FSMs can bend, curl, twist, deform, or respond otherwise to external stimuli, such as heat or light. The detailed mechanisms of their smart behaviors are discussed with their potential applications in exciting intelligent fields. We believe this review could provide guidelines toward future fabrication and developments for novel organic crystal-based FSMs and their advanced smart applications.Agency for Science, Technology and Research (A*STAR)National Research Foundation (NRF)Submitted/Accepted versionHuang Y, Gong Q, and Yu J acknowledge the AME Programmatic Funding Scheme of Cyber Physiochemical Interfaces (CPI) project (#A18A1b0045) and Singapore National Research Foundation Fellowship (NRF-NRFF11-2019-0004). Huang Y is thankful for the start-up funds of the Youth Talent Support Program from Xi’an Jiaotong University

Policy Framework for Prefabricated Buildings in Underdeveloped Areas: Enlightenment from the Comparative Analysis of Three Types of Regions in China

Prefabricated buildings (PBs) are vigorously promoted for their many advantages. However, obvious regional differences exist in the development of PBs in China, and underdeveloped areas significantly lag behind other areas. Regional “tactics” have a more direct effect on the development of PBs than national “strategies”. A targeted analysis of PB policies in underdeveloped areas in China is lacking in current research. Therefore, the aim of this study was to construct a comprehensive policy framework to help underdeveloped areas improve PB policies to develop PBs. In this study, we constructed a three-dimensional policy framework based on the content analysis method and policy instrument theory. Through a comparative analysis of 137 PB policies in three representative regions, 547 policy content codes were obtained, and reliability and validity tests were completed. The results indicate that (1) underdeveloped areas should focus on improving the number of policies rather than the accuracy in the early stages of development of PBs; (2) underdeveloped areas should focus on mandatory policy instruments (MPIs) supplemented by incentive policy instruments (IPIs) and social policy instruments (SPIs) rather than a balanced use of various policy instruments; and (3) underdeveloped areas should adjust the policy layout of the whole life cycle, and stakeholders should pay attention to the construction willingness of developers and the demands of consumers and seek policy support in the operation and maintenance stages, as well as during the demolition and recovery stages. In this study, we systematically analyzed the focus of PB policies for different stages and stakeholders and proposed an application strategy of policy instruments, contributing to the improvement of the PB policy system and the narrowing of regional development gaps with respect to PBs

Characterization and Analysis of Corrosion Resistance of Rubber Materials for Downhole Tools in a High-Stress Environment with Coupled H₂S-CO₂

In the process of constructing deep natural gas wells in Sichuan and Chongqing, gas wells encounter various technical challenges such as high temperature, high pressure, and a corrosive environment containing H2S and CO2. The corrosion of rubber materials in these acidic environments can easily lead to seal failure in downhole tools. To better investigate the corrosion resistance of rubber materials in acidic environments, we utilized a dynamic cyclic corrosion experimental device capable of simulating the service conditions experienced by downhole tools under high-temperature, high-pressure multiphase flow. Corrosion-resistance tests were conducted on fluororubbers (FKM) 1, 2, 3, and HNBR (hydrogenated nitrile-butadiene rubber) under acidic conditions (80 °C and 160 °C), along with sealing corrosion tests on O-rings. These tests aimed to analyze the mechanical properties, hardness, and corrosion resistance before and after exposure to acid media as well as the sealing performance of O-rings. Ultimately, our goal was to identify suitable rubber materials for acidic pressure environments. Experimental results revealed that all four types of rubber exhibited decreased elongation at break after undergoing corrosion testing; however, fluororubber 3 demonstrated significant susceptibility to temperature effects while the other three types showed minimal impact from temperature variations. Fluororubber 1 and fluororubber 3 displayed substantial deformation levels whereas mechanical properties greatly deteriorated for fluororubber 2. Overall, HNBR showcased superior comprehensive performance