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Adjuvant chemotherapy may improve outcome of patients with non-small-cell lung cancer with metastasis of intrapulmonary lymph nodes after systematic dissection of N1 nodes 被引量:2
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作者 Xing Wang Shi Yan +8 位作者 Yaqi Wang Xiang Li Chao Lyu Yuzhao Wang Jia Wang Shaolei Li lijian zhang Yue Yang Nan Wu 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2018年第6期588-595,共8页
Objective: Survival benefit of adjuvant chemotherapy(AC) of patients with intrapulmonary lymph node(IPLN)metastasis(level 12-14) needs investigation.We evaluated the impact of AC on patients whose metastatic nodes wer... Objective: Survival benefit of adjuvant chemotherapy(AC) of patients with intrapulmonary lymph node(IPLN)metastasis(level 12-14) needs investigation.We evaluated the impact of AC on patients whose metastatic nodes were limited to intrapulmonary levels after systematic dissection of N1 nodes.Methods: First,155 consective cases of lung cancer confirmed as pathologic N1 were collected and evaluated.Patients received systematic dissection of N2 and N1 nodes.For patients with IPLN metastasis,survival outcomes were compared between those receiving AC and those not receiving AC.Results: In this group,112 cases(72.3%) had IPLN metastasis and 55 cases(35.5%) had N1 involvement limited to level 13-14 without further disease spread to higher levels.Patients with IPLN involvement had a better prognosis than that of patients with hilar-interlobar involvement.For the intrapulmonary N1 group(level 12-14-positive,level 10-11-negative or unknown,n=112),no survival benefit was found between the AC group and nonAC group [5-year overall survival(OS): 54.6±1.6 vs.50.4±2.4 months,P=0.177].However,76 of 112 cases for whom harvesting of level-10 and level-11 nodes was done did not show cancer involvement in pathology reports(level 12-14-positive,level 10-11 both negative),oncologic outcome was better for patients receiving AC than those not receiving AC in this subgroup(5-year OS: 57.3±1.5 vs.47.1±3.2 months,P=0.002).Conclusions: Oncologic outcome may be improved by AC for patients with involvement of N1 nodes limited to intrapulmonary levels after complete examination of N1 nodes. 展开更多
关键词 INTRAPULMONARY LYMPH node METASTASIS ADJUVANT chemotherapy OUTCOME
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葡萄原花青素对H22肝癌移植瘤血管生成拟态的作用及其机制研究(英文)
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作者 Yunyan Luan Hongwei Xue +2 位作者 lijian zhang Ruyong Yao Hongsheng Yu 《The Chinese-German Journal of Clinical Oncology》 CAS 2014年第12期572-577,共6页
Objective: As a novel blood supply pattern, vasculogenic mimicry(VM) has attracted increasingly attention in recent years, which may partly compensate for the absence of feeding and facilitate tumor perfusion. However... Objective: As a novel blood supply pattern, vasculogenic mimicry(VM) has attracted increasingly attention in recent years, which may partly compensate for the absence of feeding and facilitate tumor perfusion. However, anti-angiogenic drugs have little effect on VM. The grape seed proanthocyanidins(GSPs), a kind of promising bioactive phytochemical, has shown anti-carcinogenesis and anti-angiogenic in several tumor models. However, GSPs regulation of VM and its possible mechanisms in a H22 hepatoma carcinoma model remain not clear. The aim of this study was to examine the effects of GSPs on proliferation and VM in a H22 hepatoma carcinoma model and to investigate the underlying mechanism. Methods: Seventy-five mice were divided into the control group and experimental groups treated with different concentration of GSPs. CD34-PAS dual staining was employed to identify the VM structure. The immunohistochemical staining for investigating the expression of VEGF, Eph A2 and MMP-2 protein was performed. Results: Treatment of the H22 model with Endostar(4 mg/kg), 50, 100, 200 mg/kg of the GSPs resulted in 6.87%, 17.81%, 27.43%, 53.52% inhibition in tumor growth, respectively. The mean weight of tumors were significantly lower in GSPs(100 mg/kg) and GSPs(200 mg/kg) groups than in the control group(all P < 0.01). Similarly, compared with the control group, the number of VM channels were significantly reduced in GSPs(100 mg/kg) and GSPs(200 mg/kg) groups(all P < 0.01). Immunohistochemistry showed significant decreases in the expression levels of VEGF, Eph A2 and MMP-2 protein in GSPs(100 mg/kg) and GSPs(200 mg/kg) groups when compared with control group(all P < 0.001). Conclusion: This is the first report providing evidence that GSPs inhibit the VM structure by regulation of the VEGF/Eph A2/MMPs signaling pathway. Therefore, we concluded that GSPs has the potential of being a clinical anti-VM inhibitor. 展开更多
关键词 肿瘤血管生成 葡萄籽原花青素 拟态 血管内皮生长因子 肝移植 MMP-2 肿瘤模型 患者
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Development of Transient Electric Field Radiation Simulation Device during Gas Insulation Switch Operation
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作者 Wei Shen Sen Wang +6 位作者 Xuanxiang Zhao Haotian zhang Shuo Cao lijian zhang Hao Yang Xixiang Wang Lei Lei 《Energy Engineering》 EI 2022年第1期371-385,共15页
In gas insulation switch(GIS)substation,secondary devices such as linemonitoring devices are placed in the switching field,and these electronic devices are vulnerable to transient electromagnetic interference caused b... In gas insulation switch(GIS)substation,secondary devices such as linemonitoring devices are placed in the switching field,and these electronic devices are vulnerable to transient electromagnetic interference caused by switching operation.In order to facilitate the measurement and research of electromagnetic disturbance data under different working conditions,a simulation test device is developed in this paper,which can be used to simulate electromagnetic disturbance of GIS substation sensor and secondary device port under switch operation.A four-channel parallel gas switch was designed,and the main characteristic parameters of electromagnetic disturbance generated by the simulation device were measured by using high-frequency pulse power supply as the excitation source.The comparison between the measured waveform and the measured disturbance characteristic parameters of GIS substation shows that it is in good agreement with the measured waveform characteristics,conforms to the basic characteristics of damped oscillation wave,and can be used in the secondary equipment port disturbance voltage coupling characteristics,protection measures evaluation and assessment method research. 展开更多
关键词 GIS transient electric field radiation time-frequency characteristic TEM horn antenna
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Expression Profile of Epithelial Protein Lost in Neoplasm-Alpha (EPLIN-α) in Human Pulmonary Cancer and Its Impact on SKMES-1 Cells <i>in vitro</i>
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作者 Yinan Liu Andrew J. Sanders +1 位作者 lijian zhang Wen G. Jiang 《Journal of Cancer Therapy》 2012年第4期452-459,共8页
Epithelial Protein Lost in Neoplasm (EPLIN) is a cytoskeletal associated protein implicated in regulating actin dynamoics and cellular motility and whose expression is frequently downregulated in a number of human can... Epithelial Protein Lost in Neoplasm (EPLIN) is a cytoskeletal associated protein implicated in regulating actin dynamoics and cellular motility and whose expression is frequently downregulated in a number of human cancers. The current study examined the expression levels of EPLIN-α in a pulmonary cancer cohort and its association with clinical pathological factors using quantitative polymerase chain reaction. Additionally, EPLIN-α was over-expressed in the SKMES-1 pulmonary cancer cell line through transfection with a plasmid containing the expression sequence for EPLIN-α. The role of EPLIN-α was subsequently examined using a variety of in vitro functional assays. Decreased levels of EPLIN-α were seen in cancerous tissues compared to normal background tissue. Lower levels of EPLIN-α were also associated with higher TNM stage and nodal involvement. In vitro over-expression of EPLIN-α inhibited SKMES-1 growth rates (p = 0.05 vs. plasmid control) and motility (p = 0.002 vs. plasmid control), though did not have any significant effects on cell-matrix adhesion or cell invasion. Taken together, the current study indicates that lower levels of EPLIN-α may be associated with poorer prognosis and more advanced pulmonary cancer, where this molecule appears to play a suppressive role on cell growth and migration. 展开更多
关键词 EPLIN-α PULMONARY CANCER Cell Migration ECIS
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Study on Robot Grasping System of SSVEP-BCI Based on Augmented Reality Stimulus 被引量:1
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作者 Shangen zhang Yuanfang Chen +2 位作者 lijian zhang Xiaorong Gao Xiaogang Chen 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2023年第2期322-329,共8页
Although notable progress has been made in the study of Steady-State Visual Evoked Potential(SSVEP)-based Brain-Computer Interface(BCI),several factors that limit the practical applications of BCIs still exist.One of ... Although notable progress has been made in the study of Steady-State Visual Evoked Potential(SSVEP)-based Brain-Computer Interface(BCI),several factors that limit the practical applications of BCIs still exist.One of these factors is the importability of the stimulator.In this study,Augmented Reality(AR)technology was introduced to present the visual stimuli of SSVEP-BCI,while the robot grasping experiment was designed to verify the applicability of the AR-BCI system.The offline experiment was designed to determine the best stimulus time,while the online experiment was used to complete the robot grasping task.The offline experiment revealed that better information transfer rate performance could be achieved when the stimulation time is 2 s.Results of the online experiment indicate that all 12 subjects could control the robot to complete the robot grasping task,which indicates the applicability of the AR-SSVEP-humanoid robot(NAO)system.This study verified the reliability of the AR-BCI system and indicated the applicability of the AR-SSVEP-NAO system in robot grasping tasks. 展开更多
关键词 Steady-State Visual Evoked Potential(SSVEP) Brain-Computer Interface(BCI) Augmented Reality(AR) ROBOT grasping system
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单源热蒸发制备阴离子比例可控的Sb_(2)(S,Se)_(3)薄膜用于高性能太阳能电池
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作者 高金祥 车波 +6 位作者 蔡慧玲 肖鹏 张立建 蔡志远 朱长飞 唐荣风 陈涛 《Science China Materials》 SCIE EI CAS CSCD 2023年第9期3415-3423,共9页
硒化锑(Sb_(2)(S,Se)_(3))因其高化学稳定性、绝佳光电特性和低成本等优势而成为一种有前途的光伏材料.在新兴的太阳能领域中,开发合适的材料加工方法控制元素比例,从而达到钝化Sb_(2)(S,Se)_(3)薄膜的深能级缺陷的目的,是基本需求也是... 硒化锑(Sb_(2)(S,Se)_(3))因其高化学稳定性、绝佳光电特性和低成本等优势而成为一种有前途的光伏材料.在新兴的太阳能领域中,开发合适的材料加工方法控制元素比例,从而达到钝化Sb_(2)(S,Se)_(3)薄膜的深能级缺陷的目的,是基本需求也是挑战.在此,我们开发了一种阴离子元素比例控制方法,通过烧结Sb,S和Se元素前体来调整Sb_(2)(S,Se)_(3)合金化合物中的阴离子摩尔比.我们可以相当精确地估计出,通过单源热蒸发过程蒸发预烧结Sb_(2)(S,Se)_(3)合金化合物而制备的单相Sb_(2)(S,Se)_(3)薄膜中的阴离子摩尔比.我们发现,获得的Sb_(2)(S,Se)_(3)薄膜可以基本保持前体合金化合物的阴离子元素比例,这为控制薄膜的组成提供了一个高效的方法.我们还证明了深层缺陷和定向晶体生长对S/Se原子比的依赖性,以及如何利用这种可调性来改善与光伏能源转换相关的载流子传输.通过引入低成本的CuPc掺杂的P3HT作为空穴传输层,实现了高效的Sb_(2)(S,Se)_(3)太阳能电池,功率转换效率达到8.25%.我们的研究提出了一种新的方法来制造金属硫化物半导体薄膜,并实现了Sb_(2)(S,Se)_(3)太阳能电池的性能改进. 展开更多
关键词 太阳能电池 功率转换效率 光伏材料 热蒸发 高化学稳定性 半导体薄膜 金属硫化物 材料加工
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Treatment of osteoporotic vertebral compressive fractures with percutaneous kyphoplasty and oral Zishengukang 被引量:13
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作者 Zhenjun Huang lijian zhang 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2012年第4期561-564,共4页
OBJECTIVE:To observe the therapeutic effect of percutaneous kyphoplasty(PKP) and oral Zishengukang(ZSGK) for the treatment of osteoporotic vertebral compression fractures(OVCFs).METHODS:Seventy patients were randomly ... OBJECTIVE:To observe the therapeutic effect of percutaneous kyphoplasty(PKP) and oral Zishengukang(ZSGK) for the treatment of osteoporotic vertebral compression fractures(OVCFs).METHODS:Seventy patients were randomly divided into a control group(PKP group) and an experimental group(PKP plus ZSGK group).The 35 patients in the experimental group were prescribed 6 g oral ZSGK three times a day for 90 days after PKP.Visual analog pain scale(VAS),Oswestry functional score,vertebral height and Cobb's angle were recorded and compared before treatment and at one week,one month and three months after treatment.RESULTS:Vertebral height and Cobb's angle significantly improved and VAS and Oswestry functional score were significantly lower in both groups after PKP than pre-operatively(P<0.01).Three months after treatment,VAS and Oswestry functional score in the experimental group were lower than controls(P<0.05),even though vertebral height and Cobb's angle were comparable(P>0.05).CONCLUSION:PKP combined with oral ZSGK provide superior short-term and long-term symptom control after OVCF than PKP alone. 展开更多
关键词 治疗效果 压缩性 疏松性 成形 骨折 骨质 VAS 视觉模拟
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Quantum-enhanced stochastic phase estimation with the Su(1,1)interferometer 被引量:2
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作者 KAIMIN ZHENG MINGHAO MI +6 位作者 BEN WANG LANG XU LIYUN HU SHENGSHUAI LIU YANBO LOU JETAI JING lijian zhang 《Photonics Research》 SCIE EI CSCD 2020年第10期1653-1661,共9页
Quantum stochastic phase estimation has many applications in the precise measurement of various physical parameters.Similar to the estimation of a constant phase,there is a standard quantum limit for stochastic phase ... Quantum stochastic phase estimation has many applications in the precise measurement of various physical parameters.Similar to the estimation of a constant phase,there is a standard quantum limit for stochastic phase estimation,which can be obtained with the Mach-Zehnder interferometer and coherent input state.Recently,it has been shown that the stochastic standard quantum limit can be surpassed with nonclassical resources such as squcezed light.However,practical methods to achieve quantum enhancement in the stochastic phase estimation remain largely unexplored.Here we propose a method utilizing the SU(1,1)interferometer and coherent input states to cstimate a stochastic optical phase.As an example,we investigate the Ornstcin-Uhlenback stochastic phase.We analyze the performance of this method for three key estimation problems:prediction,tracking,and smoothing.The results show significant reduction of the mean square error compared with the Mach-Zehnder interferometer under the same photon number flux inside the interferometers.In particular,we show that the method with the SU(1,1)interferometer can achieve fundamental quantum scaling,achieve stochastic Heisenberg scalinga and surpass the precision of the canonical measurement. 展开更多
关键词 STOCHASTIC ESTIMATION QUANTUM
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Novel phenyl-urea derivatives as dual-target ligands that can activate both GK and PPARγ 被引量:1
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作者 lijian zhang Kang Tian +9 位作者 Yongqiang Li Lei Lei Aifang Qin Lijuan zhang Hongrui Song Lianchao Huo Lijing zhang Xiaofeng Jin Zhufang Shen Zhiqiang Feng 《Acta Pharmaceutica Sinica B》 SCIE CAS 2012年第6期588-597,共10页
A series of novel phenyl-urea derivatives which can simultaneously activate gluco kinase(GK)and peroxisome proliferator-activated receptorγ(PPARγ)was designed and prepared,and their activation of GK and PPARγ was e... A series of novel phenyl-urea derivatives which can simultaneously activate gluco kinase(GK)and peroxisome proliferator-activated receptorγ(PPARγ)was designed and prepared,and their activation of GK and PPARγ was evaluated.The structure--activity relationships of these compounds are also described.Three compounds showed potent ability to activate both GK and PPARγ.The possible binding mode of one of these compounds with GK and PPARγ were predicted by molecular docking simulation. 展开更多
关键词 Type 2 diabetes GK activators PPARγagonists Dual action
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Quantum verification of NP problems with single photons and linear optics 被引量:1
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作者 Aonan zhang Hao Zhan +5 位作者 Junjie Liao Kaimin Zheng Tao Jiang Minghao Mi Penghui Yao lijian zhang 《Light(Science & Applications)》 SCIE EI CAS CSCD 2021年第9期1750-1760,共11页
Quantum computing is seeking to realize hardware-optimized algorithms for application-related computational tasks.NP(nondeterministic-polynomial-time)is a complexity class containing many important but intractable pro... Quantum computing is seeking to realize hardware-optimized algorithms for application-related computational tasks.NP(nondeterministic-polynomial-time)is a complexity class containing many important but intractable problems like the satisfiability of potentially conflict constraints(SAT).According to the well-founded exponential time hypothesis,verifying an SAT instance of size n requires generally the complete solution in an O(n)-bit proof.In contrast,quantum verification algorithms,which encode the solution into quantum bits rather than classical bit strings,can perform the verification task with quadratically reduced information about the solution in O~(Õ−−√n)qubits.Here we realize the quantum verification machine of SAT with single photons and linear optics.By using tunable optical setups,we efficiently verify satisfiable and unsatisfiable SAT instances and achieve a clear completeness-soundness gap even in the presence of experimental imperfections.The protocol requires only unentangled photons,linear operations on multiple modes and at most two-photon joint measurements.These features make the protocol suitable for photonic realization and scalable to large problem sizes with the advances in high-dimensional quantum information manipulation and large scale linear-optical systems.Our results open an essentially new route toward quantum advantages and extend the computational capability of optical quantum computing. 展开更多
关键词 QUANTUM OPTICS verify
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High-fidelity,low-latency polarization quantum state transmissions over a hollow-core conjoined-tube fiber at around 800 nm 被引量:1
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作者 Xinyu Chen Wei Ding +8 位作者 Ying-Ying Wang Shou-Fei Gao Feixiang Xu Huichao Xu Yi-Feng Hong Yi-Zhi Sun Pu Wang Yan-Qing Lu lijian zhang 《Photonics Research》 SCIE EI CAS CSCD 2021年第4期460-470,共11页
Hollow-core fiber(HCF)promises to unify air-borne light propagation and non-line-of-sight transmission,thus holding great potential for versatile photonics-based quantum information applications.The early version of H... Hollow-core fiber(HCF)promises to unify air-borne light propagation and non-line-of-sight transmission,thus holding great potential for versatile photonics-based quantum information applications.The early version of HCF based on photonic-bandgap guidance has not proven itself a reliable quantum channel because of the poor modal purity in both spatial and polarization domains,as well as significant difficulty in fabrication when the wavelength shifts to the visible region.In this work,based on the polarization degree of freedom,we demonstrate high-fidelity(∼0.98)single-photon transmission and distribution of entangled photons over a 36.4 m hollow-core conjoined-tube fiber(CTF)by using commercial silicon single-photon avalanche photodiodes.Our CTF realizes the combined merits of low loss,high spatial modal purity,low polarization degradation,and low chromatic dispersion.We also demonstrate single-photon low-latency(∼99.96%speed of light in vacuum)transmission,paving the way for extensive uses of HCF links in versatile photonics-based quantum information processing. 展开更多
关键词 POLARIZATION FIBER QUANTUM
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Enhanced photon communication through Bayesian estimation with an SNSPD array 被引量:1
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作者 XIANG LI JINGROU TAN +16 位作者 KAIMIN ZHENG LABAO zhang lijian zhang WEIJI HE PENGWEI HUANG HAOCHEN LI BIAO zhang QI CHEN RUI GE SHUYA GUO TAO HUANG XIAOQING JIA QINGYUAN ZHAO XUECOU TU LIN KANG JIAN CHEN PEIHENG WU 《Photonics Research》 SCIE EI CSCD 2020年第5期637-641,共5页
Laser communication using photons should consider not only the transmission environment’s effects,but also the performance of the single-photon detector used and the photon number distribution.Photon communication ba... Laser communication using photons should consider not only the transmission environment’s effects,but also the performance of the single-photon detector used and the photon number distribution.Photon communication based on the superconducting nanowire single-photon detector(SNSPD)is a new technology that addresses the current sensitivity limitations at the level of single photons in deep space communication.The communication’s bit error rate(BER)is limited by dark noise in the space environment and the photon number distribution with a traditional single-pixel SNSPD,which is unable to resolve the photon number distribution.In this work,an enhanced photon communication method was proposed based on the photon number resolving function of four-pixel array SNSPDs.A simulated picture transmission was carried out,and the error rate in this counting mode can be reduced by 2 orders of magnitude when compared with classical optical communication.However,in the communication mode using photon-enhanced counting,the four-pixel response amplitude for counting was found to restrain the communication rate,and this counting mode is extremely dependent on the incident light intensity through experiments,which limits the sensitivity and speed of the SNSPD array’s performance advantage.Therefore,a BER theoretical calculation model for laser communication was presented using the Bayesian estimation algorithm in order to analyze the selection of counting methods for information acquisition under different light intensities and to make better use of the SNSPD array’s high sensitivity and speed and thus to obtain a lower BER.The counting method and theoretical model proposed in this work refer to array SNSPDs in the deep space field. 展开更多
关键词 COMMUNICATION PHOTON ESTIMATION
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一种硫醇/胺方法将金属氧化物转换为器件级金属硫属化物(英文)
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作者 张童 张立建 +4 位作者 尹奕炜 江晨辉 李诗昂 朱长飞 陈涛 《Science China Materials》 SCIE EI CSCD 2019年第6期899-906,共8页
利用分子前驱体溶液制备金属硫属化物薄膜在器件领域具有广泛的应用前景.本文利用巯基乙醇和乙醇胺这种新型硫醇/胺溶剂,溶解很多价格便宜的金属氧化物和氢氧化物,如Cu_2O, ZnO, SnO, In(OH)_3, GeO_2, Cd(OH)_2, MnO, PbO, Bi_2O_3, Sb... 利用分子前驱体溶液制备金属硫属化物薄膜在器件领域具有广泛的应用前景.本文利用巯基乙醇和乙醇胺这种新型硫醇/胺溶剂,溶解很多价格便宜的金属氧化物和氢氧化物,如Cu_2O, ZnO, SnO, In(OH)_3, GeO_2, Cd(OH)_2, MnO, PbO, Bi_2O_3, Sb_2O_3.通过添加硫脲和硒粉作为硫源和硒源后可以制得相应的二元金属硫化物、硒化物.此方法还可用来制备纯物相的带隙可调的三元CuSbSe_(2-x)Sx和四元Cu_2ZnSnSe_4.我们用这种方法合成的Sb_2S_3平面异质结太阳电池光电转化效率可高达到4.39%.这项研究提供了一种制备二元、三元、四元器件级金属硫属化物薄膜的普适性方法. 展开更多
关键词 金属氧化物 硫属化物 器件级 乙醇胺 硫醇 In(OH)3 Cd(OH)2 异质结太阳电池
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Improving the precision of optical metrology by detecting fewer photons with biased weak measurement
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作者 Peng Yin Wen-Hao zhang +13 位作者 Liang Xu Ze-Gang Liu Wei-Feng Zhuang Lei Chen Ming Gong Yu Ma Xing-Xia ng Peng Gong-Chu Li Jin-Shi Xu Zong-Quan Zhou lijian zhang Geng Chen Chuan-Feng Li Guang-Can Guo 《Light(Science & Applications)》 SCIE EI CAS CSCD 2021年第6期1070-1077,共8页
In optical metrological protocols to measure physical quantities,it is,in principle,always beneficial to in crease photon number n to improve measurement precision.However,practical constraints prevent the arbitrary i... In optical metrological protocols to measure physical quantities,it is,in principle,always beneficial to in crease photon number n to improve measurement precision.However,practical constraints prevent the arbitrary increase of n due to the imperfections of a practical detector,especially when the detector response is dominated by the saturation effect.In this work,we show that a modified weak measurement protocol,namely,biased weak measurement significantly improves the precision of optical metrology in the presence of saturation effect.This method detects an ultra-small fraction of photons while main tains a considerable amount of metrological information.The biased pre-coupling leads to an additi onal reduction of photons in the post-selection and gene rates an extinction point in the spectrum distribution,which is extremely sensitive to the estimated parameter and difficult to be saturated.Therefore,the Fisher information can be persistently enhanced by increasing the photon number.In our magnetic-sensing experiment,biased weak measurement achieves precision approximately one order of magnitude better than those of previously used methods.The proposed method can be applied in various optical measurement schemes to remarkably mitigate the detector saturation effect with low-cost apparatuses. 展开更多
关键词 effect. METROLOGY SATURATION
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Quantum-limited localization and resolution in three dimensions
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作者 BEN WANG LIANG XU +1 位作者 JUN-CHI LI lijian zhang 《Photonics Research》 SCIE EI CAS CSCD 2021年第8期1522-1530,共9页
As a method to extract information from optical systems,imaging can be viewed as a parameter estimation problem.The fundamental precision in locating one emitter or estimating the separation between two incoherent emi... As a method to extract information from optical systems,imaging can be viewed as a parameter estimation problem.The fundamental precision in locating one emitter or estimating the separation between two incoherent emitters is bounded below by the multiparameter quantum Cramér-Rao bound(QCRB).Multiparameter QCRB gives an intrinsic bound in parameter estimation.We determine the ultimate potential of quantum-limited imaging for improving the resolution of a far-field,diffraction-limited optical field within the paraxial approximation.We show that the quantum Fisher information matrix(QFIm)in about one emitter’s position is independent on its true value.We calculate the QFIm of two unequal-brightness emitters’relative positions and intensities;the results show that only when the relative intensity and centroids of two-point sources,including longitudinal and transverse directions,are known exactly,the separation in different directions can be estimated simultaneously with finite precision.Our results give the upper bounds on certain far-field imaging technology and will find wide use in applications from microscopy to astrometry. 展开更多
关键词 ESTIMATION QUANTUM DIRECTIONS
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Direct characterization of coherence of quantum detectors by sequential measurements
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作者 Liang Xu Huichao Xu +4 位作者 Jie Xie Hui Li Lin Zhou Feixiang Xu lijian zhang 《Advanced Photonics》 EI CSCD 2021年第6期38-47,共10页
The quantum properties of quantum measurements are indispensable resources in quantum information processing and have drawn extensive research interest.The conventional approach to revealing quantum properties relies ... The quantum properties of quantum measurements are indispensable resources in quantum information processing and have drawn extensive research interest.The conventional approach to revealing quantum properties relies on the reconstruction of entire measurement operators by quantum detector tomography.However,many specific properties can be determined by a part of the matrix components of the measurement operators,which makes it possible to simplify the characterization process.We propose a general framework to directly obtain individual matrix elements of the measurement operators by sequentially measuring two noncompatible observables.This method allows us to circumvent the complete tomography of the quantum measurement and extract the required information.We experimentally implement this scheme to monitor the coherent evolution of a general quantum measurement by determining the off-diagonal matrix elements.The investigation of the measurement precision indicates the good feasibility of our protocol for arbitrary quantum measurements.Our results pave the way for revealing the quantum properties of quantum measurements by selectively determining the matrix components of the measurement operators. 展开更多
关键词 direct tomography quantum measurement weak measurement sequential measurement COHERENCE
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