High-efficiency robust perovskite solar cells on ultrathin flexible substrates.

Wide applications of personal consumer electronics have triggered tremendous need for portable power sources featuring light-weight and mechanical flexibility. Perovskite solar cells offer a compelling combination of low-cost and high device performance. Here we demonstrate high-performance planar heterojunction perovskite solar cells constructed on highly flexible and ultrathin silver-mesh/conducting polymer substrates. The device performance is comparable to that of their counterparts on rigid glass/indium tin oxide substrates, reaching a power conversion efficiency of 14.0%, while the specific power (the ratio of power to device weight) reaches 1.96 kW kg(-1), given the fact that the device is constructed on a 57-μm-thick polyethylene terephthalate based substrate. The flexible device also demonstrates excellent robustness against mechanical deformation, retaining >95% of its original efficiency after 5,000 times fully bending. Our results confirmed that perovskite thin films are fully compatible with our flexible substrates, and are thus promising for future applications in flexible and bendable solar cells

Reducing Idleness in Financial Cloud via Multi-objective Evolutionary Reinforcement Learning based Load Balancer

In recent years, various companies started to shift their data services from traditional data centers onto cloud. One of the major motivations is to save operation costs with the aid of cloud elasticity. This paper discusses an emerging need from financial services to reduce idle servers retaining very few user connections, without disconnecting them from the server side. This paper considers this need as a bi-objective online load balancing problem. A neural network based scalable policy is designed to route user requests to varied numbers of servers for elasticity. An evolutionary multi-objective training framework is proposed to optimize the weights of the policy. Not only the new objective of idleness is reduced by over 130% more than traditional industrial solutions, but the original load balancing objective is slightly improved. Extensive simulations help reveal the detailed applicability of the proposed method to the emerging problem of reducing idleness in financial services.Comment: 17 pages, 13 figure

Stochastic Gradient Descent for Nonconvex Learning without Bounded Gradient Assumptions

Stochastic gradient descent (SGD) is a popular and efficient method with wide applications in training deep neural nets and other nonconvex models. While the behavior of SGD is well understood in the convex learning setting, the existing theoretical results for SGD applied to nonconvex objective functions are far from mature. For example, existing results require to impose a nontrivial assumption on the uniform boundedness of gradients for all iterates encountered in the learning process, which is hard to verify in practical implementations. In this paper, we establish a rigorous theoretical foundation for SGD in nonconvex learning by showing that this boundedness assumption can be removed without affecting convergence rates. In particular, we establish sufficient conditions for almost sure convergence as well as optimal convergence rates for SGD applied to both general nonconvex objective functions and gradient-dominated objective functions. A linear convergence is further derived in the case with zero variances.Comment: Accepted by IEEE Transactions on Neural Networks and Learning Systems. DOI: 10.1109/TNNLS.2019.295221

Study on Path Dependence in Enterprise Soft Power Promotion

In Enterprise Soft Power Promotion, the soft culture power of the promoting process, technological innovation, and system arrangements are two crucial issues. Technological innovation inherent to a certain degree of path dependence, and institutional change for business development has certain path dependence. The phenomenon is highlighted in the small and medium-sized enterprises and private enterprises, whose development will have both positive and negative effect. Then how to profit and avoid loss will directly affect the upgrade of soft culture power.Key words: Soft power; Path dependence; Technological innovation; System innovatio

Effectiveness and safety of co-administration of moxifloxacin with netilmicin in drug-resistant tuberculosis patients, and its impact on inflammatory factors and immune function

Purpose: To study the effectiveness and safety of co-administration of moxifloxacin with netilmicin in drug-resistant tuberculosis (TB) patients, and its impact on levels of inflammatory factors and immune function. Methods: We enrolled 100 patients with drug-resistant TB admitted to People’s Hospital of Rizhao between May 2017 and October 2019. The patients were randomly allocated to control group and study group, with 50 patients per group. The control group received moxifloxacin at a dose of 0.2 g t.i.d. for 6 months and the study group received netilmicin at a dose of 0.1 g t.i.d. plus. The response, incidence of adverse reactions, expression levels of inflammatory factors, immune function, and sputum-negative status after 2, 4 and 6 months of TB treatment were compared. Results: The study group showed markedly higher response than the control group (p < 0.05). Moreover, there were lower incidence of adverse effects in the study group than in the control group (p < 0.05). The expression levels of inflammatory factors were significantly lower in the study group, while the concentrations of CD3+, CD4+, and CD8+ were markedly higher (p < 0.05). After 2, 4 and 6 months of TB treatment, cases of sputum-negative conversion were significantly higher in the study group than in the control group (p < 0.05). Conclusion: Co-administration of moxifloxacin with netilmicin produces much higher effectiveness and safety than moxifloxacin monotherapy, decreases inflammatory factor levels and improves immune function in patients with drug-resistant TB