竞争环境下制造商的产品共享策略

传统制造商可以通过共享平台将产品出租给消费者,从而参与共享经济。提出了由两个制造商和一个共享平台组成的分析框架,研究产品共享对竞争环境下的制造商进入策略和定价策略优化。一方面,当高质量制造商与共享平台合作时,如果消费者租用高质量产品的感知质量大于购买低质量产品的感知质量,高质量制造商应在租赁价格适中时进入共享市场并从中获益。但是,如果消费者租用高质量产品的感知质量小于购买低质量产品的感知质量,那么两个制造商都会因为共享市场而蒙受损失。此时,高质量制造商不应该提供共享产品。因此,当高质量制造商进入共享市场时,应保持其质量优势。另一方面,当低质量制造商与共享平台合作时,低质量制造商只有在租赁价格适中的情况下才能从共享中获益。这意味着,当租赁高质量产品的感知质量小于购买低质量产品的感知质量时,低质量制造商会对提供产品共享更有兴趣。

Rational Design of Layered SnS2 on Ultralight Graphene Fiber Fabrics as Binder-Free Anodes for Enhanced Practical Capacity of Sodium-Ion Batteries

Generally,the practical capacity of an electrode should include the weight of non-active components such as current collector,polymer binder,and conductive additives,which were as high as 70 wt%in current reported works,seriously limiting the practical capacity.This work pioneered the usage of ultralight reduced graphene fiber(rGF)fabrics as conductive scaffolds,aiming to reduce the weight of nonactive components and enhance the practical capacity.Ultrathin SnS2 nanosheets/rGF hybrids were prepared and used as binder-free electrodes of sodium-ion batteries(SIBs).The interfused graphene fibers endow the electrode a porous,continuous,and conductive network.The in situ phase transformation from SnO2 to SnS2 could preserve the strong interfacial interactions between SnS2 and graphene.Benefitting from these,the designed binder-free electrode delivers a high specific capacity of 500 mAh g?1 after 500 cycles at a current rate of 0.5 A g?1 with almost 100%Coulombic efficiency.Furthermore,the weight percentage of SnS2 in the whole electrode could reach up to 67.2 wt%,much higher than that of common electrode configurations using Cu foil,Al foil,or carbon cloth,significantly highlighting the ultralight characters and advantages of the rGF fabrics for using as binder-free electrodes of SIBs.

Impacts of subsynchronous and supersynchronous frequency components on synchrophasor measurements

Phasor measurement units(PMU) are playing an increasingly important role in power system dynamic security monitoring and control. However, the wide-area deployments of the renewable energy sources and the high voltage direct current(HVDC) transmission bring a large number of inter-harmonics to the power grid, which may result in further power system security problems. The impacts of inter-harmonics on synchrophasor measurements are revealed. This paper derives the phasor expressions of the signal, which contains the fundamental component and the inter-harmonics. It is found that the inter-harmonics will lead to the subsynchronous oscillation of the phasor measurements. The frequency transmutation principle between the harmonic and the phasor oscillation is revealed. Then, the field PMU data recorded during a subsynchronous oscillation, which occurred in an area of China with a high concentration of wind farms and HVDC transmission lines, are studied. A geographical wiring diagram with the subsynchronous oscillation distribution depicts the severe consequences of the inter-harmonics. In addition, the correctness of the theoretical derivation and the possibility of the inter-harmonics monitoring are verified.

Service-oriented manufacturing:A literature review and future research directions

This study presents a systematic review of the literature on service-oriented manufacturing(SOM).Specifically,we focus on the impact of SOM on firm operating decisions,which distinguishes this work from previous reviews.This study proposes a classification framework for SOM research based on product flow,from its design to its final disposal.Although SOM has been studied for many years,most related research remains conceptual.Our criterion for choosing papers is that they must be relevant to practical problems.This review aims to provide readers a guide that will facilitate their search for papers in their field of interest.More importantly,we hope that this review can provide insightful managerial implications for SOM.

磷化镍电催化氧析出活性的来源:原位电化学氧化和Cr掺杂实现高催化性能

锌-空气电池(ZnABs)因其高理论能量密度和环境友好的优势而被认为是下一代电子产品的理想能源器件.然而,由于缺乏高效且经济适用的电催化剂,限制了其广泛应用.过渡金属磷化物(TMP)因其独特的物理化学性质而被认为是最有前途的催化剂.因此,本文采用表面工程和设计多金属位点的策略,设计合成了(Ni_(1-x)Cr_(x))_(2)P(0≤x≤0.15)材料.研究发现,该材料在氧析出反应(OER)的初始阶段甚至催化剂的活化过程就已发生了原位电化学氧化,最终转变为具有高效OER活性的Cr-NiOOH.通过密度泛函理论(DFT)计算并结合实验表征,揭示了表面工程、多金属活性中心和原位相变能够协同调谐催化剂的电子结构,从而显著地提升OER催化性能.当将(Ni_(0.90)Cr_(0.10))2P组装成可充电ZnAB时,其可在5 m A cm^(-2)的电流密度下稳定循环208 h且循环时过电位无明显变化.当被应用于柔性固态ZnAB时,该电池可以高效且平稳地为可穿戴电子设备供电.

Study on RNAi-based herbicide for Mikania micrantha

The invasive plant Mikania micrantha Kunth(M.micrantha)from South America poses a significant threat to the stability and biodiversity of ecosystems.However,an effective and economical method to control M.micrantha is still lacking.RNA interference(RNAi)has been widely studied and applied in agriculture for trait improvement.Spray-induced gene silencing(SIGS)can produce RNAi silencing effects without introducing heritable modifications to the plant genome and is becoming a novel nontransformation strategy for plant protection.In this study,the genes encoding chlorophyll a/b-binding proteins were selected as targets of RNAi,based on high-throughput sequencing of M.micrantha transcriptome and bioinformatic analyses of sequence specificity.Three types of RNAi molecules,double-stranded RNA,RNAi nanomicrosphere,and short hairpin RNA(shRNA),with their corresponding short interfering RNA sequences were designed and synthesized for SIGS vector construction,from which each RNAi molecule was transcribed and extracted to be sprayed on M.micrantha leaves.Whereas water-treated control leaves remained green,leaves treated with RNAi molecules turned yellow and eventually wilted.Quantitative real-time PCR showed that the expression levels of target genes were significantly reduced in the RNAi-treated groups compared with those of the control,suggesting that all three types of RNAi herbicides effectively silenced the endogenous target genes,which are essential for the growth of M.micrantha.We also found that shRNA showed better silencing efficiency than the other two molecules.Taken together,our study successfully designed three types of RNAi-based herbicides that specifically silenced endogenous target genes and controlled the growth of M.micrantha.Moreover,we identified a gene family encoding chlorophyll a/b-binding proteins that is important for the growth and development of M.micrantha and could serve as potential targets for controlling the spread of M.micrantha.

Short-term forecasts and long-term mitigation evaluations for the COVID-19 epidemic in Hubei Province,China

As an emerging infectious disease,the 2019 coronavirus disease(COVID-19)has developed into a global pandemic.During the initial spreading of the virus in China,we demonstrated the ensemble Kalman filter performed well as a short-term predictor of the daily cases reported in Wuhan City.Second,we used an individual-level network-based model to reconstruct the epidemic dynamics in Hubei Province and examine the effectiveness of non-pharmaceutical interventions on the epidemic spreading with various scenarios.Our simulation results show that without continued control measures,the epidemic in Hubei Province could have become persistent.Only by continuing to decrease the infection rate through 1)protective measures and 2)social distancing can the actual epidemic trajectory that happened in Hubei Province be reconstructed in simulation.Finally,we simulate the COVID-19 transmission with non-Markovian processes and show how these models produce different epidemic trajectories,compared to those obtained with Markov processes.Since recent studies show that COVID-19 epidemiological parameters do not follow exponential distributions leading to Markov processes,future works need to focus on non-Markovian models to better capture the COVID-19 spreading trajectories.In addition,shortening the infectious period via early case identification and isolation can slow the epidemic spreading significantly.