Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since ...Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.展开更多
目的探究日间腹股沟疝无张力修补术后使用新型疝穿戴装置(HWD)和传统压迫方法对术后血清肿预防效果及生活质量影响的差异,以期发现可有效降低术后血清肿发生率及提高患者生活质量的临床途径。方法选取四川省人民医院日间手术中心2022年1...目的探究日间腹股沟疝无张力修补术后使用新型疝穿戴装置(HWD)和传统压迫方法对术后血清肿预防效果及生活质量影响的差异,以期发现可有效降低术后血清肿发生率及提高患者生活质量的临床途径。方法选取四川省人民医院日间手术中心2022年12月至2023年8月收治的125例腹股沟疝患者,均行腹腔镜下腹股沟疝无张力修补术,采用随机数字表法将纳入样本的腹股沟疝患者随机分成试验组与对照组。试验组术后穿戴HWD压迫术区体表投影处,对照组术后用盐袋常规压迫。随访并分析2组术后血清肿发生情况、疼痛视觉模拟量表(VAS)评分,使用卡罗莱纳舒适量表(CCS)评估生活质量,并调查HWD的使用满意度。结果2组患者在年龄、性别、疝类型等一般术前资料方面差异无统计学意义(P>0.05)。共有122例完成术后1周随访,随访率97.6%。其中试验组血清肿发生率为8.3%(5/60),对照组血清肿发生率为21.0%(13/62),差异有统计学意义(P<0.05)。术后1、3个月2组血清肿发生率差异无统计学意义(P>0.05)。随着术后时间延长,2组患者VAS评分均逐渐降低,其中试验组在术后2 h VAS评分低于对照组(P<0.05),术后1周VAS评分差异无统计学意义(P>0.05)。术后1周,2组患者的CCS评分均处于较低水平,且试验组低于对照组(P<0.05)。术后1周评估,HWD应用的总体满意度为91.6%(55/60)。结论在日间腹股沟疝无张力修补术后使用HWD较传统盐袋压迫方法,可以更好地降低血清肿发生率,减轻术后疼痛,提高生活质量,患者使用满意度较高。展开更多
We demonstrate coherent optical frequency dissemination over a distance of 972 km by cascading two spans where the phase noise is passively compensated for.Instead of employing a phase discriminator and a phase lockin...We demonstrate coherent optical frequency dissemination over a distance of 972 km by cascading two spans where the phase noise is passively compensated for.Instead of employing a phase discriminator and a phase locking loop in the conventional active phase control scheme,the passive phase noise cancellation is realized by feeding double-trip beat-note frequency to the driver of the acoustic optical modulator at the local site.This passive scheme exhibits fine robustness and reliability,making it suitable for long-distance and noisy fiber links.An optical regeneration station is used in the link for signal amplification and cascaded transmission.The phase noise cancellation and transfer instability of the 972-km link is investigated,and transfer instability of 1.1×10^(-19)at 10^(4)s is achieved.This work provides a promising method for realizing optical frequency distribution over thousands of kilometers by using fiber links.展开更多
Demand response has been intensively studied in recent years. It can motivate customers to change their consumption patterns according to the dynamic(time-varying) electricity price, which is considered to be the most...Demand response has been intensively studied in recent years. It can motivate customers to change their consumption patterns according to the dynamic(time-varying) electricity price, which is considered to be the most cost-effective and reliable solution for smoothing the demand curve. However, many existing schemes, based on users' demand request in each period, require users to consume their requested electricity exactly, which sometimes causes inconvenience and losses to the utility, because customers cannot always be able to consume the accurate electricity demand due to various personal reasons. In this paper, we tackle this problem in a novel approach. Instead of charging after consumption, we adopt the prepayment mechanism to implement power request. Furthermore, we propose a trading market running by the control center to cope with the users' dynamic demand. It is noteworthy that both users' original demand and trading records are protected against potential adversaries including the curious control center. Through the numerical simulation, we demonstrate that our scheme is highly efficient in both computation and communication.展开更多
文摘Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.
文摘目的探究日间腹股沟疝无张力修补术后使用新型疝穿戴装置(HWD)和传统压迫方法对术后血清肿预防效果及生活质量影响的差异,以期发现可有效降低术后血清肿发生率及提高患者生活质量的临床途径。方法选取四川省人民医院日间手术中心2022年12月至2023年8月收治的125例腹股沟疝患者,均行腹腔镜下腹股沟疝无张力修补术,采用随机数字表法将纳入样本的腹股沟疝患者随机分成试验组与对照组。试验组术后穿戴HWD压迫术区体表投影处,对照组术后用盐袋常规压迫。随访并分析2组术后血清肿发生情况、疼痛视觉模拟量表(VAS)评分,使用卡罗莱纳舒适量表(CCS)评估生活质量,并调查HWD的使用满意度。结果2组患者在年龄、性别、疝类型等一般术前资料方面差异无统计学意义(P>0.05)。共有122例完成术后1周随访,随访率97.6%。其中试验组血清肿发生率为8.3%(5/60),对照组血清肿发生率为21.0%(13/62),差异有统计学意义(P<0.05)。术后1、3个月2组血清肿发生率差异无统计学意义(P>0.05)。随着术后时间延长,2组患者VAS评分均逐渐降低,其中试验组在术后2 h VAS评分低于对照组(P<0.05),术后1周VAS评分差异无统计学意义(P>0.05)。术后1周,2组患者的CCS评分均处于较低水平,且试验组低于对照组(P<0.05)。术后1周评估,HWD应用的总体满意度为91.6%(55/60)。结论在日间腹股沟疝无张力修补术后使用HWD较传统盐袋压迫方法,可以更好地降低血清肿发生率,减轻术后疼痛,提高生活质量,患者使用满意度较高。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12103059,12033007,12303077,and 12303076)the Fund from the Xi’an Science and Technology Bureau,China(Grant No.E019XK1S04)the Fund from the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.1188000XGJ).
文摘We demonstrate coherent optical frequency dissemination over a distance of 972 km by cascading two spans where the phase noise is passively compensated for.Instead of employing a phase discriminator and a phase locking loop in the conventional active phase control scheme,the passive phase noise cancellation is realized by feeding double-trip beat-note frequency to the driver of the acoustic optical modulator at the local site.This passive scheme exhibits fine robustness and reliability,making it suitable for long-distance and noisy fiber links.An optical regeneration station is used in the link for signal amplification and cascaded transmission.The phase noise cancellation and transfer instability of the 972-km link is investigated,and transfer instability of 1.1×10^(-19)at 10^(4)s is achieved.This work provides a promising method for realizing optical frequency distribution over thousands of kilometers by using fiber links.
基金supported by the National Natural Science Fund for Distinguished Young Scholars(52025015)the National Natural Science Foundation of China(52271010,52201162,52130105,52101181)+1 种基金the Natural Science Foundation of Tianjin City(21JCZDJC00510)China Postdoctoral Science Foundation(2022M712344)。
基金supported by the National Key Research and Development Plan of China under Grant No.2016YFB0800301the Fund of Science and Technology on Communication Networks Laboratory under Grant No.KX162600024Youth Innovation Promotion Association CAS under Grant No.2016394
文摘Demand response has been intensively studied in recent years. It can motivate customers to change their consumption patterns according to the dynamic(time-varying) electricity price, which is considered to be the most cost-effective and reliable solution for smoothing the demand curve. However, many existing schemes, based on users' demand request in each period, require users to consume their requested electricity exactly, which sometimes causes inconvenience and losses to the utility, because customers cannot always be able to consume the accurate electricity demand due to various personal reasons. In this paper, we tackle this problem in a novel approach. Instead of charging after consumption, we adopt the prepayment mechanism to implement power request. Furthermore, we propose a trading market running by the control center to cope with the users' dynamic demand. It is noteworthy that both users' original demand and trading records are protected against potential adversaries including the curious control center. Through the numerical simulation, we demonstrate that our scheme is highly efficient in both computation and communication.
