北京城市图书馆,北京,中国

北京城市图书馆打造了一片既现代又经典永恒的天地,为北京丰富的文化和知识氛围提供了一处集学习、知识共享和社交等功能为一体的综合场所。在数字时代重塑图书馆的重要性为了让图书馆在21世纪重新焕发活力,设计师们对图书馆的外观、运行方式以及服务社区的方式提出了新的设想。为了重塑图书馆作为公共与知识生活重要支柱的作用,而不仅仅只是一座藏书楼,设计师将该建筑定位成学习、文化和社区中心。北京城市图书馆汲取了图书馆为满足其时代和地方需求而寻找创新对策的历史渊源,将开放式的思想交流和人际对话作为其核心宗旨。馆内还为展览、表演、会议和古籍修复等需求提供专用空间。

飞行保护头盔用TC4护目镜支架的热处理研究

为解决头盔用TC4合金护目镜支架强度低的问题,对其进行真空热处理,用金相显微镜、扫描电子显微镜等研究真空热处理工艺对护目镜支架显微组织及性能的影响。结果表明:在真空度为1×10^(-3)Pa下,1000℃保温20 min后淬火,合金发生相变,平均尺寸为2.6μm的等轴α相转变为宽度约为870 nm的细小片层α相,并弥散分布于β基体中,β晶粒平均尺寸约为260μm。相对原始组织,经真空热处理后,合金屈服强度和抗弯强度分别从1596、1942 MPa提高到1806、2170 MPa,分别提升13%、12%,这是因为纳米片层α相弥散分布的强化效应,显著提升了合金的强度等力学性能。

Effect of dietary supplement of inactivated Lactobacillus plantarum Ep-M 17 on growth performance,immune response,disease resistance,and intestinal microbiota in Penaeus vannamei

Our previous study found that feeding with Lactobacillus plantarum Ep-M17 could effectively affect the growth performance,immune response,and gut microbiota of Penaeus vannamei.However,high temperature and pressure during feed pelletizing is the main problem that can lead to a decrease in the activity of probiotics or cause their inactivation.Further investigation needs to investigate whether inactivated Ep-M17 can exert similar effects as live Ep-M17.Therefore,we evaluated the effects of inactivated L.plantarum Ep-M17 on growth performance,immune response,disease resistance,and gut microbiota in P.vannamei.Results show that adding inactivated Ep-M17 to the feed also promoted body weight gain and increased relative immune protection in shrimp.Also,histological examination revealed that the administration of inactivated Ep-M17 led to improvements in the density and distribution of microvilli in the intestines and enhancements in the abundance of B and R cells in the hepatopancreas.Additionally,the inactivated Ep-M17 supplementation resulted in increased activity levels of nutrient immune-related enzymes in both the shrimp hepatopancreas and intestines.Moreover,it stimulated the expression of Lvlec,PEN-3a,Crustin,LGBP,Lysozyme,and proPo genes in both the hepatopancreas and intestines.Furthermore,the inactivated Ep-M17 also increased bacterial diversity in the gut of shrimp and promoted the abundance of specific flora,facilitating the host organism’s metabolism and immunity to improve the disease resistance of shrimp.Therefore,supplementation of inactivated L.plantarum Ep-M17 in shrimp diets can exert similar effects as live L.plantarum Ep-M17 effectively improving growth performance,gut microbiota,immune response,and disease resistance in P.vannamei.

Continuous-Time Channel Prediction Based on Tensor Neural Ordinary Differential Equation

Channel prediction is critical to address the channel aging issue in mobile scenarios.Existing channel prediction techniques are mainly designed for discrete channel prediction,which can only predict the future channel in a fixed time slot per frame,while the other intra-frame channels are usually recovered by interpolation.However,these approaches suffer from a serious interpolation loss,especially for mobile millimeter-wave communications.To solve this challenging problem,we propose a tensor neural ordinary differential equation(TN-ODE)based continuous-time channel prediction scheme to realize the direct prediction of intra-frame channels.Specifically,inspired by the recently developed continuous mapping model named neural ODE in the field of machine learning,we first utilize the neural ODE model to predict future continuous-time channels.To improve the channel prediction accuracy and reduce computational complexity,we then propose the TN-ODE scheme to learn the structural characteristics of the high-dimensional channel by low-dimensional learnable transform.Simulation results show that the proposed scheme is able to achieve higher intra-frame channel prediction accuracy than existing schemes.

p-STAT3和STING蛋白在胃癌组织中的表达及相关性

目的:检测胃癌组织和癌旁组织中p-STAT3和STING蛋白的表达情况,分析胃癌组织中p-STAT3和STING与Hp、分期、淋巴结转移等临床病理特征和预后的相关性,以及两者之间的关系。方法:将所选标本进行免疫组织化学染色,检测癌组织及癌旁组织中STING、p-STAT3的表达情况以及Hp感染情况。结果:胃癌组织中STING表达低于癌旁组织,p-STAT3表达高于癌旁组织,差异均有统计学意义。胃癌组织中STING表达与胃癌患者的预后呈正相关。STING表达量与分期和淋巴结转移存在负相关性。与年龄、性别、吸烟史、Hp感染均不相关。胃癌组织中p-STAT3表达与胃癌患者的预后呈负相关。p-STAT3与分期、淋巴结转移、Hp感染存在正相关性。p-STAT3的表达与年龄、性别、吸烟史之间无相关性。胃癌组织中p-STAT3表达和STING表达无相关性。结论:胃癌组织中STING的表达低于癌旁组织;STING高表达提示预后较好。胃癌组织中p-STAT3的表达高于癌旁组织;p-STAT3高表达提示预后不好。胃癌组织中STING和p-STAT3表达无相关性。

航空起动直流电机过热失效问题研究

直流起动电机作为发动机起动系统动力装置的核心部件,需在发动机假起动、冷运转和点火起动等工况下带动发动机转子至一定转速,且需具备在极端条件下具备多次连续起动的能力。现针对某起动直流电动机在发动机上连续起动出现冒烟的问题,提出了直流起动电机耐高温性能优化设计方法,并开展了仿真及试验验证。通过改善电机电磁参数,并选取性能更加优异的绝缘材料进行电机耐高温性能改善,优化后结果表明,定子绕组铜耗减少了30.4%,励磁绕组电流密度减少了30.9%;试验结果表明转子绕组的温度最高为210℃,温度降低110℃,定子绕组温度最高为154℃,温度降低106℃,满足电机工作最高温度要求。

Large Eddy Simulation of Gasoline-Air Mixture Explosion in Long Duct with Branch Structure

Gas explosion is a process involving complex hydrodynamics and chemical reactions.In order to investigate the interaction between the flame behavior and the dynamic overpressure resulting from the explosion of a premixed gasoline-air mixture in a confined space,a large eddy simulation(LES)strategy coupled with sub-grid combustion model has been implemented.The considered confined space consists of a long duct and four branches symmetrically distributed on both sides of the long duct.Comparisons between the simulated and experimental results have been considered with regard to the flame structure,flame speed and overpressure characteristics.It is shown that the explosion process can qualitatively be reproduced by the numerical simulation.Due to the branch structure,vortices are generated near the joint of the branch and long duct.Vortices rotate in opposite directions in the different branches.When the flame propagates into the branch,the flame front is influenced by the flow field structure and becomes more and more distorted.The overpressure displays a similar behavior in the two branches which have a different distance from the ignition point.It is finally shown that the overpressure change law can directly be put in relation with the shape of flame front.

Learning curve for a surgeon in robotic pancreaticoduodenectomy through a“G”-shaped approach:A cumulative sum analysis

BACKGROUND Robotic pancreaticoduodenectomy(RPD)can achieve similar surgical results to open and PD;however,RPD has a long learning curve and operation time(OT).To address this issue,we have summarized a surgical path to shorten the surgical learning curve and OT.AIM To investigate the effective learning curve of a“G”-shaped surgical approach in RPD for patients.METHODS A total of 60 patients,who received“G”-shaped RPD(GRPD)by a single surgeon in the First Hospital of Shanxi Medical University from May 2017 to April 2020,were included in this study.The OT,demographic data,intraoperative blood loss,complications,hospitalization time,and pathological results were recorded,and the cumulative sum(CUSUM)analysis was performed to evaluate the learning curve for GRPD.RESULTS According to the CUSUM analysis,the learning curve for GRPD was grouped into two phases:The early and late phases.The OT was 480±81.65 min vs 331±76.54 min,hospitalization time was 22±4.53 d vs 17±6.08 d,and blood loss was 308±54.78 mL vs 169.2±35.33 mL in the respective groups.Complications,including pancreatic fistula,bile leakage,reoperation rate,postoperative death,and delayed gastric emptying,were significantly decreased after this surgical technique.CONCLUSION GRPD can improve the learning curve and operative time,providing a new method for shortening the RPD learning curve.

喀什地区甜瓜田间杂草3种病毒的检测及分析

2021年在新疆喀什地区伽师县和疏勒县厚皮甜瓜主产区随机采集了7科13种杂草的47份鲜样,采用RT-PCR法检测杂草带毒情况,分析杂草带毒率及病毒间的亲缘关系。结果表明:不同地点、不同种类杂草上的WMV、CMV、ZYMV检出率存在明显差异,伽师县WMV、CMV、ZYMV的检出率分别为5.77%、1.43%、32.19%,而疏勒县分别为17.14%、2.86%、7.14%;大部分杂草都携带病毒。杂草上的WMV、CMV和ZYMV存在较高的遗传变异。

The Mars orbiter magnetometer of Tianwen-1:in-flight performance and first science results

The Mars Orbiter MAGnetometer(MOMAG)is a scientific instrument onboard the orbiter of China’s first mission for Mars—Tianwen-1.Since November 13,2021,it has been recording magnetic field data from the solar wind to the magnetic pile-up region surrounding Mars.Here we present its in-flight performance and first science results,based on its first one and one-half months’data.Comparing these early MOMAG observations to the magnetic field data in the solar wind from NASA’s Mars Atmosphere and Volatile EvolutioN(MAVEN)mission,we report that the MOMAG magnetic field data are at the same level in magnitude,and describe the same magnetic structures with similar variations in three components.We recognize 158 clear bow shock(BS)crossings in these MOMAG data;their locations match well statistically with the modeled average BS.We also identify and compare five pairs of datasets collected when Tianwen-1’s orbiter and the MAVEN probe made simultaneous BS crossings.These BS crossings confirm the global shape of modeled BS,as well as the south-north asymmetry of the Martian BS.Two cases presented in this paper suggest that the BS is probably more dynamic at flank than near the nose.So far,MOMAG performs well,and provides accurate magnetic field vectors.MOMAG is continuously scanning the magnetic field surrounding Mars.Data from MOMAG’s measurements complement data from MAVEN and will undoubt edly advance our understanding of the plasma environment of Mars.

基于数字孪生的航空永磁发电稳压系统降阶模型分析研究

为适应下一代航空飞行器数字化研发的技术趋势,提高航空供电系统可靠性,降低生产周期和制造成本。本文以某型无人机用永磁发电稳压系统为例,基于ECE降阶算法提出了永磁同步发电机的一阶等效数字模型,利用器件级建模法建立了PWM稳压芯片SG1525模型,搭建了从引擎机械功率输入到永磁同步发电机AC-DC整流+BUCK稳压供电系统数字孪生仿真模型,其仿真速度较常规有限元算法具有跨数量级的提升,并可通过计算机采集试验台数据形成数据反馈,具有敏捷的“数字孪生”效果。同时将仿真值与试验值进行了对比,验证了数字孪生模型的有效性。本文的设计思想符合军用武器系统数字化设计技术发展趋势,其结论对新一代航空发电机及其稳压供电系统数字化研发具有一定的参考价值。

1,8-cineole ameliorates colon injury by downregulating macrophage M1 polarization via inhibiting the HSP90-NLRP3-SGT1 complex

Ulcerative colitis(UC)is characterized by chronic relapsing intestinal inflammation.Currently,there is no effective treatment for the disease.According to our preliminary data,1,8-cineole,which is the main active compound of Amomum compactum Sol.ex Maton volatile oil and an effective drug for the treatment of pneumonia,showed remarkable anti-inflammatory effects on colitis pathogenesis.However,its mechanism of action and direct targets remain unclear.This study investigated the direct targets and mechanism through which 1,8-cineole exerts its anti-inflammatory effects using a dextran sulfate sodium salt-induced colitis mouse model.The effects of 1,8-cineole on macrophage polarization were investigated using activated bone marrow-derived macrophages and RAW264.7 cells.In addition,1,8-cineole targets were revealed by drug affinity responsive target stability,thermal shift assay,cellular thermal shift assay,and heat shock protein 90(HSP90)adenosine triphosphatases(ATPase)activity assays.The results showed that 1,8-cineole exhibited powerful anti-inflammatory properties in vitro and in vivo by inhibiting the macrophage M1 polarization and protecting intestinal barrier function.Mechanistically,1,8-cineole directly interacted with HSP90 and decreased its ATPase activity,also inhibited nucleotide-binding and oligomerization domain-,leucine rich repeat-,and pyrin domain-containing 3(NLRP3)binding to HSP90 and suppressor of G-two allele of SKP1(SGT1)and suppressed NLRP3 inflammasome activation in macrophages.These results demonstrated that 1,8-cineole is a potential drug candidate for UC treatment.

A Shape-Memory Deployable Subsystem with a Large Folding Ratio in China’s Tianwen-1 Mars Exploration Mission

Once China’s Tianwen-1 Mars probe arrived in a Mars orbit after a seven-month flight in the deep cold space environment,it would be urgently necessary to monitor its state and the surrounding environment.To address this issue,we developed a flexible deployable subsystem based on shape memory polymer composites(SMPC-FDS)with a large folding ratio,which incorporates a camera and two temperature telemetry points for monitoring the local state of the Mars orbiter and the deep space environment.Here,we report on the development,testing,and successful application of the SMPC-FDS.Before reaching its Mars remote-sensing orbit,the SMPC-FDS is designed to be in a folded state with high stiffness;after reaching orbit,it is in a deployed state with a large envelope.The transition from the folded state to the deployed state is achieved by electrically heating the shape memory polymer composites(SMPCs);during this process,the camera on the SMPC-FDS can capture the local state of the orbiter from multiple angles.Moreover,temperature telemetry points on the SMPC-FDS provide feedback on the environment temperature and the temperature change of the SMPCs during the energization process.By simulating a Mars on-orbit space environment,the engineering reliability of the SMPC-FDS was comprehensively verified in terms of the material properties,structural dynamic performance,and thermal vacuum deployment feasibility.Since the launch of Tianwen-1 on 23 July 2020,scientific data on the temperature environment around Tianwen-1 has been successfully acquired from the telemetry points on the SMPCFDS,and the local state of the orbiter has been photographed in orbit,showing the national flag of China fixed on the orbiter.

Optical image encryption algorithm based on a new four-dimensional memristive hyperchaotic system and compressed sensing

Some existing image encryption schemes use simple low-dimensional chaotic systems, which makes the algorithms insecure and vulnerable to brute force attacks and cracking. Some algorithms have issues such as weak correlation with plaintext images, poor image reconstruction quality, and low efficiency in transmission and storage. To solve these issues,this paper proposes an optical image encryption algorithm based on a new four-dimensional memristive hyperchaotic system(4D MHS) and compressed sensing(CS). Firstly, this paper proposes a new 4D MHS, which has larger key space, richer dynamic behavior, and more complex hyperchaotic characteristics. The introduction of CS can reduce the image size and the transmission burden of hardware devices. The introduction of double random phase encoding(DRPE) enables this algorithm has the ability of parallel data processing and multi-dimensional coding space, and the hyperchaotic characteristics of 4D MHS make up for the nonlinear deficiency of DRPE. Secondly, a construction method of the deterministic chaotic measurement matrix(DCMM) is proposed. Using DCMM can not only save a lot of transmission bandwidth and storage space, but also ensure good quality of reconstructed images. Thirdly, the confusion method and diffusion method proposed are related to plaintext images, which require both four hyperchaotic sequences of 4D MHS and row and column keys based on plaintext images. The generation process of hyperchaotic sequences is closely related to the hash value of plaintext images. Therefore, this algorithm has high sensitivity to plaintext images. The experimental testing and comparative analysis results show that proposed algorithm has good security and effectiveness.

高速永磁起发电机SVPWM可控升压整流策略及其对铁耗的影响

传统的高速永磁起发电机(HSPMSG)一般采用三相桥式不控整流将输出交流电压变换为直流电压。采用这种整流方式得到的直流电压无法升高且不稳定,当需要输出较高的稳定直流电压时往往不能满足要求。因此本文利用Maxwell和Simplorer以及Simulink三款软件的联合仿真实现了HSPMSG的可控升压整流,总结了该整流系统对起发电机铁心损耗及转子涡流损耗的影响规律。结果表明SVPWM整流时会产生大量高次谐波,大幅增加了电机的铁心损耗及转子涡流损耗,且载波频率和幅值也会影响起发电机损耗大小。本文的结论对高温高速永磁起发电机的设计及转子温升计算具有有效的参考价值。

抗短路直流发电系统一体化拓扑设计与研究

交流发电机作为直流供电系统的能量来源,后端需要进行整流变换后输出直流电,为提高28 V直流供电系统的集成度,本文研究了将小型交流发电机与整流变换器结构一体化的新型设计方案,基于产品的电路-磁路进行联合仿真,同时针对发电机体系和电子元器件耐温程度不同、耐滑油程度不同的固有问题,设计了密封电气衔接结构。产品集成了发电、整流及稳压,输出功率440 W,重量1.4 kg,实现了28 V直流供电系统轻量化、小型化设计,为后续28 V小型直流供电系统提供了一种新方案。

智能播音主持的发展趋势与前沿

本文从智能文创视角研究播音主持等有声语言传播活动,探析智能播音主持的发展趋势与前沿。通过梳理智能播音主持的发展现状,尤其是不同阶段的代表产品,如机器替人的“智能播音”、人机协同的“智能主播”、数实融合的“智能形态”。面对来自数字人伦、市场纬度、文化层面等的困难,本文希望探究智能播音主持面临的机遇与挑战,并提出对策建议。

Transcription factor OsWRKY11 induces rice heading at low concentrations but inhibits rice heading at high concentrations

The heading date of rice is a crucial agronomic characteristic that influences its adaptability to different regions and its productivity potential.Despite the involvement of WRKY transcription factors in various biological processes related to development,the precise mechanisms through which these transcription factors regulate the heading date in rice have not been well elucidated.The present study identified OsWRKY11 as a WRKY transcription factor which exhibits a pivotal function in the regulation of the heading date in rice through a comprehensive screening of a clustered regularly interspaced palindromic repeats(CRISPR)-CRISPR-associated nuclease 9 mutant library that specifically targets the WRKY genes in rice.The heading date of oswrky11 mutant plants and OsWRKY11-overexpressing plants was delayed compared with that of the wild-type plants under short-day and long-day conditions.Mechanistic investigation revealed that OsWRKY11 exerts dual effects on transcriptional promotion and suppression through direct and indirect DNA binding,respectively.Under normal conditions,OsWRKY11 facilitates flowering by directly inducing the expression of OsMADS14 and OsMADS15.The presence of elevated levels of OsWRKY11 protein promote formation of a ternary protein complex involving OsWRKY11,Heading date 1(Hd1),and Days to heading date 8(DTH8),and this complex then suppresses the expression of Ehd1,which leads to a delay in the heading date.Subsequent investigation revealed that a mild drought condition resulted in a modest increase in OsWRKY11 expression,promoting heading.Conversely,under severe drought conditions,a significant upregulation of OsWRKY11 led to the suppression of Ehd1 expression,ultimately causing a delay in heading date.Our findings uncover a previously unacknowledged mechanism through which the transcription factor OsWRKY11 exerts a dual impact on the heading date by directly and indirectly binding to the promoters of target genes.

韧性城市背景下历史建筑的防火韧性重塑--以浙江胜利剧院消防提升项目为例

随着城市化进程的进一步加快,我国的城市现代化程度在不断提升,但在城市发展的一些中心区域,由于受技术革新、政策变化及维保缺失等复杂因素的影响,部分历史建筑的防火韧性已远远无法达到现代韧性城市的要求,给建筑单体乃至城市片区均带来了非常大的火灾隐患。以杭州历史建筑浙江胜利剧院的活化利用项目为例,通过全面分析其现存的消防安全隐患,提出消防安全提升的目标和策略,从而采取相应措施重塑其防火韧性,希望探索出一条韧性城市发展背景下历史建筑的活化更新之路。

中国企业和中国管理向何处去?

当下,世界处于百年未有之大变局,英国脱欧,美国退群,G7吵架,国际政治经济似乎正在形成美英、中俄、欧日的大三角格局;同时,美国挑起的贸易战、科技战,使美国在中国人眼前失去光环,美国在中国人心目中的地位可能再也回不到从前。如果被迫和美国经贸、科技、教育进行切割,中国企业和中国管理将向何处去?赵向阳博士的《大变局下的中国管理:以英美为师,转向与德日同行》一文(以下简称《转向》文),提出了有见地的道路选项之一。