大模型赋能广播电视媒体深度融合

随着大模型时代的来临,越来越多的行业将生成式人工智能(AIGC)技术与企业的场景结合,进行数字化转型和产业升级。本文主要聚焦于媒体领域,探讨AIGC在媒体行业应用和发展的前景,并结合上海广播电视台、上海文化广播影视集团有限公司在AIGC方面的实践和案例,进一步对AIGC与媒体深度融合过程中存在的问题、挑战和机遇开展研究,作出思考。

铍针配合经络诊察治疗中风后肩痛临床观察

目的 观察中风后肩痛实施经络诊察配合铍针治疗的临床效果。方法 以2019年5月-2021年1月本院收治的60例中风后肩痛患者为研究对象,按照不同治疗方法分为两组(各组30例)。采取扶他林软膏治疗为对比组,采取经络诊察配合铍针治疗为实验组。比较两组ROM测量变化、VAS、FMA评分变化、总有效率及生存质量。结果两组对比治疗后ROM测量上举度、外展度、VAS、FMA等评分的数据后显示实验组更具优势,组间达到统计差异要求(P<0.05);但治疗前两组对比差异较小(P>0.05)。两组对比总有效率及生存质量各指标评分的数据后显示实验组更具优势,组间达到统计差异要求(P<0.05)。结论 中风后肩痛实施经络诊察配合铍针治疗的效果确切,既可对关节活动度和上肢功能予以显著改善,缓解患者疼痛症状,又可改善生存质量,可做进一步推广研究。

甲状腺乳头状癌中央区淋巴结转移的危险因素分析

目的探讨甲状腺乳头状癌(PTC)中央区淋巴结转移(CLNM)的危险因素。方法选取2016年8月—2018年12月在锦州医科大学附属第一医院行手术治疗的303例PTC患者临床资料,回顾性分析患者性别、年龄、体重指数(BMI)、肿瘤最大直径、肿瘤数量、肿瘤位置、被膜侵犯情况、甲状腺球蛋白抗体(TgAb)及促甲状腺激素(TSH)等因素对CLNM的影响。结果303例患者中,116例发生CLNM,总转移率为39.27%。单因素分析结果显示,性别、年龄、BMI、肿瘤最大直径、肿瘤数量、是否被膜侵犯及CLNM率比较,差异有统计学意义(P<0.05)。多因素Logistic回归分析显示,性别[O^R=0.454(95%CI:0.224,0.921)]、年龄[O^R=0.957(95%CI:0.936,0.978)]、肿瘤最大直径[O^R=1.438(95%CI:1.117,1.852)]及被膜侵犯[O^R=0.399(95%CI:0.230,0.691)]是PTC患者发生CLNM的危险因素。受试者工作特征曲线显示,年龄为45.5岁、肿瘤最大直径为0.75cm时约登指数最大,对应的曲线下面积分别为0.643和0.691,敏感性分别为0.620(95%CI:0.580,0.706)和0.695(95%CI:0.632,0.750),特异性分别为0.682(95%CI:0.580,0.706)和0.720(95%CI:0.632,0.750)。结论PTC发生CLNM与多个因素有关,当患者为男性、年龄<45.5岁、肿瘤最大直径≥0.75 cm及存在被膜侵犯时,CLNM发生可能性大,建议行中央区淋巴结清扫。

溧阳市台风“烟花”期间水库调度分析——以沙河、大溪水库为例

受台风“烟花”影响,2021年7月24日至28日,溧阳市普降大暴雨,局地特大暴雨,台风影响期间具有移动速度慢,滞留时间长,影响范围广等特点。台风带来的强降雨造成溧阳市境内主要水库及大部分河道均超警戒水位,以沙河、大溪2座大型水库为例,根据此次台风水文监测资料,分析了台风“烟花”影响期间暴雨特点、洪水特性,初步分析溧阳市台风期间水库调度工作,为今后台风影响期间的水库调度提供建议。

Experimental study on total dissolved gas supersaturation in water

More and more high dams have been constructed and operated in China. The total dissolved gas （TDG） supersaturation caused by dam discharge leads to gas bubble disease or even death of fish, Through a series of experiments, the conditions and requirements of supersaturated TDG generation were examined in this study. The results show that pressure （water depth）, aeration, and bubble dissolution time are required for supersaturated TDG generation, and the air-water contact area and turbulence intensity are the main factors that affect the generation rate of supersaturated TDG. The TDG supersaturation levels can be reduced by discharging water to shallow shoals downstream of the dam or using negative pressure pipelines. Furthermore, the TDG supersaturation levels in stilling basins have no direct relationship with those in reservoirs. These results are of great importance for further research on the prediction of supersaturated TDG generation caused by dam discharge and aquatic protection.

Research on Parameter Collaborative Configuration of DC Circuit Breaker and DC Fault Current Limiter

Fault current suppression is the key technology to ensure the safe operation of the DC power distribution system. In order to realize the parameter collabora-tive configuration of the DC circuit breaker and the DC current limiter and improve the fault current suppression capability, the fault current suppression mechanism of the DC power distribution system is revealed based on the circuit model. Then, based on the mathematical model of the DC breaker, the characteristic parameters of DC breaking are extracted, and then the influence of different characteristic parameters on the breaking characteristics of fault current is studied. Finally, the mathematical model of the collaborative process between DC circuit breaker and DC current limiter is established. The charac-teristic parameters of fault current collaborative suppression are extracted. The coupling effects of different characteristic parameters on the fault current col-laborative suppression are studied. The principle of collaborative configuration of DC circuit breaker and DC current limiter is proposed, and the collaborative suppression ability of DC circuit breaker and DC current limiter to fault current is fully exploited to ensure the safe and reliable operation of the DC power distribution system.

Research of simulation and experiment on arc characteristics of gas mechanical switch

An arc is the high-temperature discharge plasma produced in the opening process of mechanical switches,which directly affects the breaking capability of a hybrid DC circuit breaker.According to the physical mechanism of an electric arc,the construction of an arc model for simulation analysis is an important technical means in the electrical field.In this study,based on the theory of magneto hydrodynamics(MHD),a gas mechanical switch model of a natural commutation DC circuit breaker with a compound gap is established.The arc motion process under different conditions is simulated and calcu-lated.The influence of different initial pressures,different opening speeds,and different striking currents on the arc voltage characteristics is analysed.The results show that the larger the gas pressure,the smaller the arc volume and the higher the arc voltage.The faster the opening speed,the longer the arc and the higher the arc voltage;with the increase of the current,the arc voltage increases rapidly at a low current,while the arc voltage increases slowly at a high current.

Structural insights into the activation initiation of full-length mGlu1

Dear Editor,Glutamate is the main excitatory neurotransmitter in the human brain,and it exerts diverse responses through ionotropic glutamate receptors(iGluRs)and metabotropic glutamate receptors(mGluRs)(Nakanishi and Masu,1994).mGluRs are members of the C family of GPCRs,and are divided into three groups based on G protein coupling,sequence homology,and ligand selectivity(Stansley and Conn,2019).mGlu1 and mGlu5 belong to group I and predominantly couple to Gq/11.

Planning and analysis of the demonstration project of the MVDC distribution network in Zhuhai

The DC distribution system is an important development direction of the distribution system,which can improve the reliability and the quality of the power supply,and support the new energy,the energy storage,the electric vehicles,and the flexible access of AC and DC loads to grid.To realize the demonstration application of the DC distribution technology,China's first demonstration project of the medium voltage DC distribution network will be built in Zhuhai,Guangdong Province to support the construction of the city energy internet.First,this paper analyzes the demand of the DC distribution network project,and puts forward the construction content and construction target.Then,it designs and analyzes the electrical connection mode,system operation mode,and startup and shutdown mode of the DC distribution network,and proposes the overall project construction plan.Finally,it conducts the specific project design and analysis,which mainly in elude the selection of equipment such as inverters,DC transformers and DC circuit breakers,the design and analysis of the DC control and protection system,the design and analysis of the overvoltage protection and the configuration scheme of the lightning arrester,and analysis of the system transient characteristics.The design and analysis of the engineering program is a combination of China's distribution network engineering practice and technical characteristics,which lays a solid foundation for the advancement of the DC power distribution technology in China,and has reference value and demonstration effect for the design and construction of other projects.

Development and prospect of direct‐current circuit breaker in China

The direct‐current circuit breaker(DCCB)is the most ideal choice for DC fault isolation in DC grids.Despite a late start,China's research and development on the DCCB have made outstanding achievements.This article provides a brief glance of current China's DCCB development status.It begins by sorting out the technical route according to the topology of DCCB.Then it systematically summarises both mechanical and hybrid DCCBs with focussing on the aspects of topology structure and principle,key technology and characteristics,prototype development and application.It is apparent that Chinese scientists and engineers confronted the worldwide problem of large capacity DC breaking,and put forward a comprehensive solution which consists of an innovative topology structure based on coupled negative voltage circuit,breaking throughs on the key technologies such as highly controllable and reliable fault current commutation,millisecond‐level ultra‐fast and efficient electromagnetic repulsion mechanism,high tolerance and high stability power electronic switch,low residual voltage and fast response energy consumption device,etc.The article states that the world's first set of hybrid high‐voltage(HV)DCCB,and the first set of mechanical HV DCCB have been developed.These DCCBs will soon be deployed to the DC grids which have the highest voltage levels therefore require the strongest breaking capacity.These achievements are leading the world in the development and application of DCCB.The article also discusses the overall development trends of DCCB in the areas of new topologies,key techno-logical breakthroughs and application scenarios,etc.These discussions serve as references for DCCB's future technological advancement and its ever‐expanding applications.

Precise multi‐dimensional temperature‐rise characterisation of switchgear based on multi‐conditional experiments and LPTN model for high‐capacity application

As the power load increases, the capacity of switchgear becomes larger so the problem of overheating of switchgears becomes more significant. Whether the switchgears operate safely and reliably affects the reliability and economy of the entire power system. Different methods have been tried to study the thermal problems of switch-gears. However, there are few experimental studies on the switchgear entity. In this study, a series of temperature rise tests were carried out on medium‐voltage high‐ca-pacity switchgear to explore laws of temperature rise. First, five groups of multi‐con-ditional experiments were carried out including changes of the load current, ventilation conditions and loop resistance. Then, multi‐dimensional temperature‐rise characterisa-tion was analysed based on the experimental results and the relating theory. Finally, a circuit‐based lumped‐parameter thermal network (LPTN) model was developed by analysing the heat dissipation in switchgear and used to determine the steady‐state temperature distribution of the switchgear. The model is verified by comparing the simulation results with the experimental results.

Effects of eggshell addition on calcium-deficient acid soils contaminated with heavy metals

In this study, effects of water conditions （flooded, wet, or dry） and eggshell dosages （0, 0.1, 1.0, and 10.0 g/kg soil, respectively） on pH variation, content of unavailable state of heavy metals, form of heavy metals, and available nutritious element calcium （Ca） in acid soils contaminated with heavy metals were investigated, respectively. The soil samples were continuously cultivated indoors and analyzed by toxicity characteristic leaching procedure and community bureau of reference （BCR） sequential extraction procedure. The results showed that the addition of eggshell could effectively improve the pH of acid soil and increase it to neutral level. Moreover, the contents of unavailable state of heavy metals Cu, Zn, and Cd increased significantly. Furthermore, when the soil was cultivated under the flooded condition with 1.0 g/kg eggshell, the unavailable state ofCu, Zn, and Cd increased the most, and these heavy metals were transformed into residual state. On the other hand, the amount of available state of Ca increased to 432.19 from 73.34 mg/kg with the addition of 1.0 g/kg eggshell, which indicated that the addition of eggshell dramatically improved the available state of Ca. Therefore, eggshell could ameliorate the soil environment as it led to the decrease of available heavy metals and improvement of fertilization effectively. In a word, this study indicates that the addition of eggshell would be a new potential method for remediation of acid field soils contaminated with heavy metals.