A novel energy regeneration system for emulsion pump tests

Li Yilei,Zhu Zhencai,Chen Guoan,Cao Guohua 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.4

A novel energy regeneration system based on cylinders and a rectifier valve for emulsion pump tests is presented and studied. The overall structure and working principles of this system are introduced. Both simulation and experiments are carried out to investigate the energy regeneration feasibility and capability of this novel system. The simulation and experimental results validate that this system is able to save energy and satisfy the test requirement. The energy recovery coefficient and overall energy regeneration coefficient of the test bench are 0.785 and 0.214, respectively. Measures to improve these two coefficients are also given accordingly after analysis of power loss. This novel system brings a new method of energy regeneration for emulsion pump tests.

The Digital Transformation of Power Grid under the Background of Artificial Intelligence

Li Liu,Zhiqi Li,Sujuan Deng,Yilei Zhao,Yuening Wang 한국정보처리학회 2023 Journal of information processing systems Vol.19 No.3

Artificial intelligence (AI) plays a crucial role in the intelligent development of China’s power system. It is alsoan important part of the digital development of the power grid. The development of AI determines whether thedigital transformation of China’s power system can be successfully implemented. Therefore, this paperdiscusses the digital transformation of the power grid based on AI technologies. The author has established adigital evaluation index system to reflect the development of the power grid in one province. Both qualitativeand quantitative methods have been adopted in the analysis, which delves into the economic effectiveness,quality, and coordination of power grid development in the province in a comprehensive way. Results showthat, to meet the needs of the power grid’s digital transformation, the correlation coefficient between the powergrid’s development and the province’s overall coordination has been increasing in recent years.

The characteristic of Cu2ZnSnS4 thin film solar cells prepared by sputtering CuSn and CuZn alloy targets

Yilei Lu,Shurong Wang,Xun Ma,Xin Xu,Shuai Yang,Yaobin Li,Zhen Tang 한국물리학회 2018 Current Applied Physics Vol.18 No.12

Recent study shows that the main reason for limiting CZTS device performance lies in the low open circuit voltage, and crucial factor that could affect the Voc is secondary phases like ZnS existing in absorber layer and its interfaces. In this work, the Cu2ZnSnS4 thin film solar cells were prepared by sputtering CuSn and CuZn alloy targets. Through tuning the Zn/Sn ratios of the CZTS thin films, the crystal structure, morphology, chemical composition and phase purity of CZTS thin films were characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS) and Raman spectroscopy. The statistics data show that the CZTS solar cell with a ratio of Zn/Sn=1.2 have the best power convention efficiency of 5.07%. After HCl etching process, the CZTS thin film solar cell with the highest efficiency 5.41% was obtained, which demonstrated that CZTS film solar cells with high efficiency could be developed by sputtering CuSn and CuZn alloy targets.

Correlation Between New Cooperative Medical Scheme Policy Design and Catastrophic Medical Payment : Evidence From 25 Counties in Rural China

Zhang, Linxiu,Li, Shaoping,Yi, Hongmei,d’Intignano, Luisa Majnoni,Ding, Yilei SAGE Publications 2016 Asia-Pacific journal of public health Vol.28 No.1

<P>Few studies have examined the association between the New Cooperative Medical Scheme (NCMS) policy design and its achievement of providing financial protection to rural residents. This study collected data on NCMS policy design and health care spending from 25 counties and rural households in their catchment areas. It shows that on average, NCMS has a growing but small effect on the reduction of catastrophic medical payment (CMP) incidence. If outpatient spending can be reimbursed from an NCMS pooled account, the incidence of CMP before a reimbursement and that after a reimbursement will be reduced. Higher nominal reimbursement rate for inpatient spending at provincial hospitals is correlated with higher incidence of CMP before a reimbursement. Higher ceiling for annual reimbursement from NCMS is associated with lower incidence of CMP after a reimbursement. Thus, NCMS policy design can be improved to strengthen its effects on the reduction of CMP incidence.</P>

Measurement of Lateral and Interfacial Thermal Conductivity of Single- and Bilayer MoS₂ and MoSe₂ Using Refined Optothermal Raman Technique

Zhang, Xian,Sun, Dezheng,Li, Yilei,Lee, Gwan-Hyoung,Cui, Xu,Chenet, Daniel,You, Yumeng,Heinz, Tony F.,Hone, James C. American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.46

<P>Atomically thin materials such as graphene and semiconducting transition metal dichalcogenides (TMDCs) have attracted extensive interest in recent years, motivating investigation into multiple properties. In this work, we demonstrate a refined version of the optothermal Raman technique1,2 to measure the thermal transport properties of two TMDC materials, MoS<SUB>2</SUB> and MoSe<SUB>2</SUB>, in single-layer (1L) and bilayer (2L) forms. This new version incorporates two crucial improvements over previous implementations. First, we utilize more direct measurements of the optical absorption of the suspended samples under study and find values ∼40% lower than previously assumed. Second, by comparing the response of fully supported and suspended samples using different laser spot sizes, we are able to independently measure the interfacial thermal conductance to the substrate and the lateral thermal conductivity of the supported and suspended materials. The approach is validated by examining the response of a suspended film illuminated in different radial positions. For 1L MoS<SUB>2</SUB> and MoSe<SUB>2</SUB>, the room-temperature thermal conductivities are 84 ± 17 and 59 ± 18 W/(m·K), respectively. For 2L MoS<SUB>2</SUB> and MoSe<SUB>2</SUB>, we obtain values of 77 ± 25 W and 42 ± 13 W/(m·K). Crucially, the interfacial thermal conductance is found to be of order 0.1–1 MW/m<SUP>2</SUP> K, substantially smaller than previously assumed, a finding that has important implications for design and modeling of electronic devices.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-46/acsami.5b08580/production/images/medium/am-2015-085805_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b08580'>ACS Electronic Supporting Info</A></P>

Atomically thin p–n junctions with van der Waals heterointerfaces

Lee, Chul-Ho,Lee, Gwan-Hyoung,van der Zande, Arend M.,Chen, Wenchao,Li, Yilei,Han, Minyong,Cui, Xu,Arefe, Ghidewon,Nuckolls, Colin,Heinz, Tony F.,Guo, Jing,Hone, James,Kim, Philip Nature Publishing Group, a division of Macmillan P 2014 Nature nanotechnology Vol.9 No.9

Semiconductor p–n junctions are essential building blocks for electronic and optoelectronic devices. In conventional p–n junctions, regions depleted of free charge carriers form on either side of the junction, generating built-in potentials associated with uncompensated dopant atoms. Carrier transport across the junction occurs by diffusion and drift processes influenced by the spatial extent of this depletion region. With the advent of atomically thin van der Waals materials and their heterostructures, it is now possible to realize a p–n junction at the ultimate thickness limit. Van der Waals junctions composed of p- and n-type semiconductors—each just one unit cell thick—are predicted to exhibit completely different charge transport characteristics than bulk heterojunctions. Here, we report the characterization of the electronic and optoelectronic properties of atomically thin p–n heterojunctions fabricated using van der Waals assembly of transition-metal dichalcogenides. We observe gate-tunable diode-like current rectification and a photovoltaic response across the p–n interface. We find that the tunnelling-assisted interlayer recombination of the majority carriers is responsible for the tunability of the electronic and optoelectronic processes. Sandwiching an atomic p–n junction between graphene layers enhances the collection of the photoexcited carriers. The atomically scaled van der Waals p–n heterostructures presented here constitute the ultimate functional unit for nanoscale electronic and optoelectronic devices.

CDH17 nanobodies facilitate rapid imaging of gastric cancer and efficient delivery of immunotoxin

Jingbo Ma,Xiaolong Xu,Chunjin Fu,Peng Xia,Ming Tian,Liuhai Zheng,Kun Chen,Xiaolian Liu,Yilei Li,Le Yu,Qinchang Zhu,Yangyang Yu,Rongrong Fan,Haibo Jiang,Zhifen Li,Chuanbin Yang,Chengchao Xu,Ying Long,J 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: It is highly desirable to develop new therapeutic strategies for gastric cancer given the low survival rate despite improvement in the past decades. Cadherin 17 (CDH17) is a membrane protein highly expressed in cancers of digestive system. Nanobody represents a novel antibody format for cancer targeted imaging and drug delivery. Nanobody targeting CHD17 as an imaging probe and a delivery vehicle of toxin remains to be explored for its theragnostic potential in gastric cancer. Methods: Naïve nanobody phage library was screened against CDH17 Domain 1-3 and identified nanobodies were extensively characterized with various assays. Nanobodies labeled with imaging probe were tested in vitro and in vivo for gastric cancer detection. A CDH17 Nanobody fused with toxin PE38 was evaluated for gastric cancer inhibition in vitro and in vivo. Results: Two nanobodies (A1 and E8) against human CDH17 with high affinity and high specificity were successfully obtained. These nanobodies could specifically bind to CDH17 protein and CDH17-positive gastric cancer cells. E8 nanobody as a lead was extensively determined for tumor imaging and drug delivery. It could efficiently co-localize with CDH17-positive gastric cancer cells in zebrafish embryos and rapidly visualize the tumor mass in mice within 3 h when conjugated with imaging dyes. E8 nanobody fused with toxin PE38 showed excellent anti-tumor effect and remarkably improved the mice survival in cell-derived (CDX) and patient-derived xenograft (PDX) models. The immunotoxin also enhanced the anti-tumor effect of clinical drug 5-Fluorouracil. Conclusions: The study presents a novel imaging and drug delivery strategy by targeting CDH17. CDH17 nanobodybased immunotoxin is potentially a promising therapeutic modality for clinical translation against gastric cancer.

Bright visible light emission from graphene

Kim, Young Duck,Kim, Hakseong,Cho, Yujin,Ryoo, Ji Hoon,Park, Cheol-Hwan,Kim, Pilkwang,Kim, Yong Seung,Lee, Sunwoo,Li, Yilei,Park, Seung-Nam,Shim Yoo, Yong,Yoon, Duhee,Dorgan, Vincent E.,Pop, Eric,Hein Nature Publishing Group 2015 Nature nanotechnology Vol.10 No.8

Graphene and related two-dimensional materials are promising candidates for atomically thin, flexible and transparent optoelectronics. In particular, the strong light–matter interaction in graphene has allowed for the development of state-of-the-art photodetectors, optical modulators and plasmonic devices. In addition, electrically biased graphene on SiO<SUB>2</SUB> substrates can be used as a low-efficiency emitter in the mid-infrared range. However, emission in the visible range has remained elusive. Here, we report the observation of bright visible light emission from electrically biased suspended graphene devices. In these devices, heat transport is greatly reduced. Hot electrons (∼2,800 K) therefore become spatially localized at the centre of the graphene layer, resulting in a 1,000-fold enhancement in thermal radiation efficiency. Moreover, strong optical interference between the suspended graphene and substrate can be used to tune the emission spectrum. We also demonstrate the scalability of this technique by realizing arrays of chemical-vapour-deposited graphene light emitters. These results pave the way towards the realization of commercially viable large-scale, atomically thin, flexible and transparent light emitters and displays with low operation voltage and graphene-based on-chip ultrafast optical communications.