Two-particle dark state cooling of a nanomechanical resonator

The steady-state cooling of a nanomechanical resonator interacting with three coupled quantum dots is studied. General conditions for the cooling to the ground state with single and two-electron dark states are obtained. The results show that in the case of the interaction of the resonator with a single-electron dark state, no cooling of the resonator occurs unless the quantum dots are not identical. The steady-state cooling is possible only if the energy state of the quantum dot coupled to the drain electrode is detuned from the energy states of the dots coupled to the electron source electrode. The detuning has the effect of unequal shifting of the effective dressed states of the system that the cooling and heating processes occur at different frequencies. For the case of two electrons injected to the quantum dot system, the creation of a two-particle dark state is established to be possible with spin-antiparallel electrons. The results predict that with the two-particle dark state, an effective cooling can be achieved even with identical quantum dots subject of an asymmetry only in the charging potential energies coupling the injected electrons. It is found that similar to the case of the single-electron dark state, the asymmetries result in the cooling and heating processes to occur at different frequencies. However, an important difference between the single and two-particle dark state cases is that the cooling process occurs at significantly different frequencies. This indicates that the frequency at which the resonator could be cooled to its ground state can be changed by switching from the one-electron to the two-electron Coulomb blockade process.Comment: Published versio

Non-classical non-Gaussian state of a mechanical resonator via selectively incoherent damping in three-mode optomechanical systems

We theoretically propose a scheme for the generation of a non-classical single-mode motional state of a mechanical resonator (MR) in the three-mode optomechanical systems, in which two optical modes of the cavities are linearly coupled to each other and one mechanical mode of the MR is optomechanically coupled to the two optical modes with the same coupling strength simultaneously. One cavity is driven by a coherent laser light. By properly tuning the frequency of the weak driving field, we obtain engineered Liouvillian superoperator via engineering the selective interaction Hamiltonian confined to the Fock subspaces. In this case, the motional state of the MR can be prepared into a non-Gaussian state, which possesses the sub-Poisson statistics although its Wigner function is positive.Comment: 6 pages, 5 figure

Superfluid and magnetic states of an ultracold Bose gas with synthetic three-dimensional spin-orbit coupling in an optical lattice

We study ultracold bosonic atoms with the synthetic three-dimensional spin-orbit (SO) coupling in a cubic optical lattice. In the superfluidity phase, the lowest energy band exhibits one, two or four pairs of degenerate single-particle ground states depending on the SO-coupling strengths, which can give rise to the condensate states with spin-stripes for the weak atomic interactions. In the deep Mott-insulator regime, the effective spin Hamiltonian of the system combines three-dimensional Heisenberg exchange interactions, anisotropy interactions and Dzyaloshinskii-Moriya interactions. Based on Monte Carlo simulations, we numerically demonstrate that the resulting Hamiltonian with an additional Zeeman field has a rich phase diagram with spiral, stripe, vortex crystal, and especially Skyrmion crystal spin-textures in each xy-plane layer. The obtained Skyrmion crystals can be tunable with square and hexagonal symmetries in a columnar manner along the z axis, and moreover are stable against the inter-layer spin-spin interactions in a large parameter region.Comment: 9 pages, 4 figures; title modified, references and discussions added; accepted by PR

SC-TVP Green Practice Initiative in China’s Logistics Market Based on Case Analysis

In the era of circular economy, the concept of sustainable development has attracted more and more attention. With the development of cross-border e-commerce, the demand for logistics services has continued to surge, and the pressure on them to provide sustainable services has risen sharply. In 2020, China officially put forward the “double carbon” strategic goal, and green logistics has become the new direction of industry development, in line with the concept of sustainable development. However, the actual impact of green logistics practice on China’s sustainable logistics services is unknown. This paper aims to study the current situation and results of green logistics practice through data analysis and case analysis, including green design, green transportation, green management and other indicators. Based on the case analysis in this paper, the SC-TVP model is constructed to provide an effective green logistics practice framework, with a view to improving the management level of green logistics, promoting the development of enterprises, and providing some reference for the logistics development in the post-epidemic era

Screening Key Indicators for Acute Kidney Injury Prediction Using Machine Learning

Acute kidney injury is a common critical disease with a high mortality. The large number of indicators in AKI patients makes it difficult for clinicians to quickly and accurately determine the patient’s condition. This study used machine learning methods to filter key indicators and use key indicator data to achieve advance prediction of AKI so that a small number of indicators could be measured to reliably predict AKI and provide auxiliary decision support for clinical staff. Sequential forward selection based on feature importance calculated by XGBoost was used to screen out 17 key indicators. Three machine learning algorithms were used to make predictions, namely, logistic regression (LR), decision tree, and XGBoost. To verify the validity of the method, data were extracted from the MIMIC III database and the eICU-CRD database for 1,009 and 1,327 AKI patients, respectively. The MIMIC III database was used for internal validation, and the eICU-CRD database was used for external validation. For all three machine learning algorithms, the prediction performance from using only the key indicator dataset was very close to that from using the full dataset. The XGBoost algorithm performed the best, and LR was the next best. The decision tree performed the worst. The key indicator screening method proposed in this study can achieve a good predictive performance while streamlining the number of indicators

A controllable superconducting electromechanical oscillator with a suspended membrane

We fabricate a microscale electromechanical system, in which a suspended superconducting membrane, treated as a mechanical oscillator, capacitively couples to a superconducting microwave resonator. As the microwave driving power increases, nonmonotonic dependence of the resonance frequency of the mechanical oscillator on the driving power has been observed. We also demonstrate the optical switching of the resonance frequency of the mechanical oscillator. Theoretical models for qualitative understanding of our experimental observations are presented. Our experiment may pave the way for the application of a mechanical oscillator with its resonance frequency controlled by the electromagnetic and/or optical fields, such as a microwave-optical interface and a controllable element in a superqubit-mechanical oscillator hybrid system.Comment: 8 pages,4 figure

Epidemiology of multimorbidity in China and implications for the healthcare system: cross-sectional survey among 162,464 community household residents in southern China

<b>Background</b> China, like other countries, is facing a growing burden of chronic disease but the prevalence of multimorbidity and implications for the healthcare system have been little researched. We examined the epidemiology of multimorbidity in southern China in a large representative sample. The effects of multimorbidity and other factors on usual source of healthcare were also examined. <p></p> <b>Methods</b> We conducted a large cross-sectional survey among approximately 5% (N = 162,464) of the resident population in three prefectures in Guangdong province, southern China in 2011. A multistage, stratified random sampling was adopted. The study population had many similar characteristics to the national census population. Interviewer-administered questionnaires were used to collect self-report data on demographics, socio-economics, lifestyles, healthcare use, and health characteristics from paper-based medical reports. <p></p> <b>Results</b> More than one in ten of the total study population (11.1%, 95% confidence interval (CI) 10.6 to 11.6) had two or more chronic conditions from a selection of 40 morbidities. The prevalence of multimorbidity increased with age (adjusted odds ratio (aOR) = 1.36, 95% CI 1.35 to 1.38 per five years). Female gender (aOR = 1.70, 95% CI 1.64 to 1.76), low education (aOR = 1.26, 95% CI 1.23 to 1.29), lack of medical insurance (aOR = 1.79, 95% CI 1.71 to 1.89), and unhealthy lifestyle behaviours were independent predictors of multimorbidity. Multimorbidity was associated with the regular use of secondary outpatient care in preference to primary care. <p></p> <b>Conclusions</b> Multimorbidity is now common in China. The reported preferential use of secondary care over primary care by patients with multimorbidity has many major implications. There is an urgent need to further develop a strong and equitable primary care system

GhABP19, a Novel Germin-Like Protein From Gossypium hirsutum, Plays an Important Role in the Regulation of Resistance to Verticillium and Fusarium Wilt Pathogens

Germin-like proteins (GLPs) are water-soluble plant glycoproteins belonging to the cupin superfamily. The important role of GLPs in plant responses against various abiotic and biotic stresses, especially pathogens, is well validated. However, little is known about cotton GLPs in relation to fungal pathogens. Here, a novel GLP gene was isolated from Gossypium hirsutum and designated as GhABP19. The expression of GhABP19 was upregulated in cotton plants inoculated with Verticillium dahliae and Fusarium oxysporum and in response to treatment with jasmonic acid (JA) but was suppressed in response to salicylic acid treatment. A relatively small transient increase in GhABP19 was seen in H2O2 treated samples. The three-dimensional structure prediction of the GhABP19 protein indicated that the protein has three histidine and one glutamate residues responsible for metal ion binding and superoxide dismutase (SOD) activity. Purified recombinant GhABP19 exhibits SOD activity and could inhibit growth of V. dahliae, F. oxysporum, Rhizoctonia solani, Botrytis cinerea, and Valsa mali in vitro. To further verify the role of GhABP19 in fungal resistance, GhABP19-overexpressing Arabidopsis plants and GhABP19-silenced cotton plants were developed. GhABP19-transgenic Arabidopsis lines showed much stronger resistance to V. dahliae and F. oxysporum infection than control (empty vector) plants did. On the contrary, silencing of GhABP19 in cotton conferred enhanced susceptibility to fungal pathogens, which resulted in necrosis and wilt on leaves and vascular discoloration in GhABP19-silenced cotton plants. The H2O2 content and endogenous SOD activity were affected by GhABP19 expression levels in Arabidopsis and cotton plants after inoculation with V. dahliae and F. oxysporum, respectively. Furthermore, GhABP19 overexpression or silencing resulted in activation or suppression of JA-mediated signaling, respectively. Thus, GhABP19 plays important roles in the regulation of resistance to verticillium and fusarium wilt in plants. These modulatory roles were exerted by its SOD activity and ability to activate the JA pathway. All results suggest that GhABP19 was involved in plant disease resistance

A new opportunity for the emerging tellurium semiconductor: making resistive switching devices

Abstract: The development of the resistive switching cross-point array as the next-generation platform for high-density storage, in-memory computing and neuromorphic computing heavily relies on the improvement of the two component devices, volatile selector and nonvolatile memory, which have distinct operating current requirements. The perennial current-volatility dilemma that has been widely faced in various device implementations remains a major bottleneck. Here, we show that the device based on electrochemically active, low-thermal conductivity and low-melting temperature semiconducting tellurium filament can solve this dilemma, being able to function as either selector or memory in respective desired current ranges. Furthermore, we demonstrate one-selector-one-resistor behavior in a tandem of two identical Te-based devices, indicating the potential of Te-based device as a universal array building block. These nonconventional phenomena can be understood from a combination of unique electrical-thermal properties in Te. Preliminary device optimization efforts also indicate large and unique design space for Te-based resistive switching devices

Immunity duration of a recombinant adenovirus type-5 vector-based Ebola vaccine and a homologous prime-boost immunisation in healthy adults in China: fi nal report of a randomised, double-blind, placebo-controlled, phase 1 trial

Background The 2013–15 Ebola virus disease epidemic in west Africa greatly accelerated the development of Ebola vaccine. We aimed to analyse the immune persistence induced by one shot of an adenovirus type-5 vector-based Ebola virus vaccine up to 6 months and the eff ect of boosting with a homologous vector in healthy adults in China. Methods In a randomised, double-blind, placebo-controlled, phase 1 clinical trial in one site in Jiangsu Province, China, 120 healthy adults aged 18–60 years received an initial dose of intramuscular adenovirus type-5 Ebola virus vaccine of 4·0 × 10¹⁰ viral particles, 1·6 × 10¹¹ viral particles, or placebo, and were followed up to day 168. Participants were subsequently re-recruited to receive a booster dose of the same vaccine or placebo, in the same dose, at month 6. Women who were pregnant, breastfeeding, or planned to become pregnant during the next month were excluded. Randomisation was conducted by computer-generated block randomisation. Randomisation data were unmasked for interim analysis of the data obtained between days 0–28 but not disclosed to participants or site staff . Safety and immunogenicity analysis were done on the intention-to-treat population. We aimed to assess the safety profi le of the experimental vaccine and the immunity responses to a single-dose immunisation or a homologous prime-boost regimen. Primary outcomes were Ebola glycoprotein-specifi c ELISA antibody responses 28 days post-boost and the occurrences of adverse reactions post-boost. The original trial and the extended booster study were registered with ClinicalTrials.gov, numbers NCT02326194 and NCT02533791, respectively. Findings Between Dec 28, 2014, and Jan 9, 2015, we enrolled 210 volunteers. 90 participants were not randomised due to not meeting inclusion criteria (61), meeting exclusion criteria (4), or withdrawal of consent (25). 120 people were randomly assigned to receive intramuscular Ebola vaccine at 4·0 × 10¹⁰ viral particles (low dose, n=40), Ebola vaccine at 1·6 × 10¹¹ viral particles (high dose, n=40), or placebo (n=40, in two groups of 20). After prime vaccination, the geometric mean titer (GMT) of ELISA EC90 peaked at 682·7 (95% CI 424·3–1098·5) in the low-dose vaccine group and 1305·7 (970·1–1757·2) in the high-dose vaccine group at day 28, and then fell gradually through the next a few months to 575·5 (394·8–838·8) in the high-dose vaccine group and 197·9 (107·9–362·7) in the low-dose vaccine group at day 168. No specific response was recorded in the placebo group with a GMT of 5·0. Of the 120 participants involved in the initial trial, ten participants declined to participate, and 110 were included in the boost immunisation: 38 received the low dose, 35 received the high dose, and 37 received the placebo. At day 28 after boost vaccination, the ELISA EC90 titres rapidly rose to 6110 (95% CI 4705–7935) in the low-dose group and to 11825 (8904–15705) in the high dose group. 78 of 110 participants reported at least one solicited adverse reaction within the fi rst 7 days after booster administration. Both of the groups who received vaccine showed signifi cantly higher incidence of mild or moderate solicited adverse reactions than did the placebo group. Interpretation The adenovirus 5-vectored Ebola vaccine of 1·6 × 10¹¹ viral particles was highly immunogenic and safe. The lower dose of 4·0 × 10¹⁰ viral particles was also safe, but immunogenicity seemed to be more vulnerable to the pre-existing immunity of adenovirus 5. A homologous priming-boosting regimen with adenovirus type-5 Ebola vaccine at 6 months interval was able to elicit greater antibody responses with longer duration. These results support an immunisation strategy to implement a booster injection for a more durable protection against Ebola virus disease