铜氨配离子结构与稳定性的理论研究

铜(Ⅱ)氨配离子是分析化学教学中配位平衡及配合物的分布特征部分较为经典的配离子之一。现行教材大多只给出了部分铜氨配离子的稳定常数,也并未解释铜氨配离子配位数与稳定性之间的关系。本文使用密度泛函理论,首先通过结构优化给出了铜氨配离子稳定性与配位数和结构的关系,而后进一步通过分析分子内部结构给出了一种回归结构本质的定性解释,既有助于改进教学效果,同时将理论计算应用于分析化学教学过程中,也可增加学生对理论计算的兴趣。

Viability of all-solid-state lithium metal battery coupled with oxide solid-state electrolyte and high-capacity cathode

Owing to the utilization of lithium metal as anode with the ultrahigh theoretical capacity density of 3860 mA h g^(-1)and oxide-based ceramic solid-state electrolytes(SE),e.g.,garnet-type Li7La_(3)Zr_(2)O_(12)(LLZO),all-state-state lithium metal batteries(ASLMBs)have been widely accepted as the promising alternatives for providing the satisfactory energy density and safety.However,its applications are still challenged by plenty of technical and scientific issues.In this contribution,the co-sintering temperature at 500℃is proved as a compromise method to fabricate the composite cathode with structural integrity and declined capacity fading of LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM).On the other hand,it tends to form weaker grain boundary(GB)inside polycrystalline LLZO at inadequate sintering temperature for LLZO,which can induce the intergranular failure of SE during the growth of Li filament inside the unavoidable defect on the interface of SE.Therefore,increasing the strength of GB,refining the grain to 0.4μm,and precluding the interfacial defect are suggested to postpone the electro-chemo-mechanical failure of SE with weak GB.Moreover,the advanced sintering techniques to lower the co-sintering temperature for both NCM-LLZO composite cathode and LLZO SE can be posted out to realize the viability of state-of-the-art ASLMBs with higher energy density as well as the guaranteed safety.

《操作系统原理》课程思政教学改革及案例设计

以课程思政重塑《操作系统原理》课程教学体系,将思政内容引入课堂教学,明确思政目标,通过无缝融入思政元素进行教学内容和教学环节设计,通过综合计算机操作系统的诞生与发展、进程同步、系统存储管理和文件系统的安全性等,从主要知识方面研究设计了一套可实施、符合我们国家对高校教育方法和目的期望的课程思政教学案例,将引导青年大学生拥有正确的价值取向,从多角度看待问题的逻辑能力和培养创新思维贯穿于整个课程教育的过程,充分展现教师爱岗敬业的教学激情与学生对课程学习的热情,促进学生自强自立、创新合作等优秀品质的形成,为计算机专业实现课程思政做出初步探索。

Hepatitis B virus X protein induces hepatic stem cell-like features in hepatocellular carcinoma by activating KDM5B

To determine the role of hepatitis B virus X protein (HBx), HBx in regulating hepatic progenitor cell (HPC)-like features in hepatocellular carcinoma (HCC) and the underlying molecular mechanisms.METHODSWe used a retrovirus vector to introduce wild type HBx or empty vector into HepG2 cells. We then used these cells to analyze cell proliferation, senescence, transformation, and stem-like features. Gene expression profiling was carried out on Affymetrix GeneChip Human U133A2.0 ver.2 arrays according to the manufacturer’s protocol. Unsupervised hierarchical clustering analysis and Class Comparison analysis were performed by BRB-Array Tools software Version 4.2.2. A total of 238 hepatitis B virus (HBV)-related HCC patients’ array data were used for analyzing clinical features.RESULTSThe histone demethylase KDM5B was significantly highly expressed in HBV-related HCC cases (P < 0.01). In HBV proteins, only HBx up-regulated KDM5B by activating c-myc. Hepatic stem cell (HpSC) markers (EpCAM, AFP, PROM1, and NANOG) were significantly highly expressed in KDM5B-high HCC cases (P < 0.01). KDM5B played an important role in maintaining HpSC-like features and was associated with a poor prognosis. Moreover, inhibition of KDM5B suppressed spheroid formation and cell invasion in vitro.CONCLUSIONHBx activates the histone demethylase KDM5B and induces HPC-like features in HCC. Histone demethylases KDM5B may be an important therapeutic target against HBV-related HCC cases.

FogMed:A Fog-Based Framework for Disease Prognosis Based Medical Sensor

Recently,an increasing number of works start investigating the combination of fog computing and electronic health(ehealth)applications.However,there are still numerous unresolved issues worth to be explored.For instance,there is a lack of investigation on the disease prediction in fog environment and only limited studies show,how the Quality of Service(QoS)levels of fog services and the data stream mining techniques influence each other to improve the disease prediction performance(e.g.,accuracy and time efficiency).To address these issues,we propose a fog-based framework for disease prediction based on Medical sensor data streams,named FogMed.This framework aims to improve the disease prediction accuracy by achieving two objectives:QoS guarantee of fog services and anomaly prediction of Medical data streams.We build a virtual FogMed environment and conduct comprehensive experiments on the public ECG dataset to validate the performance of FogMed.The experiment results show that it performs better than the cloud computing model for processing tasks with different complexities in terms of time efficiency.

Comparison of sampling schemes for spatial predictionof soil organic carbon in Northern China

Determining an optimal sample size is a key step in designing field surveys,and is particularly important for detecting the spatial pattern of highly variable properties such as soil organic carbon(SOC).Based on 550 soil sampling points in the nearsurface layer(0 to 20 cm)in a representative region of northern China's agro-pastoral ecotone,we studied effects of four interpolation methods such as ordinary kriging(OK),universal kriging(UK),inverse distance weighting(IDW)and radial basis function(RBF)and random subsampling(50,100,200,300,400,and 500)on the prediction accuracy of SOC estimation.When the Shannon's Diversity Index(SHDI)and Shannon's Evenness Index(SHEI)was 2.01 and 0.67,the OK method appeared to be a superior method,which had the smallest root mean square error(RMSE)and the mean error(ME)nearest to zero.On the contrary,the UK method performed poorly for the interpolation of SOC in the present study.The sample size of 200 had the most accurate prediction;50 sampling points produced the worst prediction accuracy.Thus,we used 200 samples to estimate the study area's soil organic carbon density(SOCD)by the OK method.The total SOC storage to a depth of 20 cm in the study area was 117.94 Mt,and its mean SOCD was 2.40 kg/m2.The SOCD kg/(C⋅m2)of different land use types were in the following order:woodland(3.29)>grassland(2.35)>cropland(2.19)>sandy land(1.55).

Multi-User File-Sharing Systems Based on LWE

Multi-user file-sharing plays an important role in the cloud storage.It allows different users to share files via the cloud.However,it usually faces many security issues because the cloud is usually public and semi-trusted.To overcome these issues,we propose multi-user file-sharing systems(MFS)in this paper.According to the date sources,we propose two frameworks of MFS based on the framework of proxy re-encryption(PRE),unique source(uni-source)MFS and multi-source MFS.We formalize the security models,which contain ciphertext security,secret key security and master secret security.With the frameworks,we propose two secure and efficient MFS schemes based on LWE,the uni-source MFS UM and the multi-source MFS MM.We prove that UM is secret key and ciphertext security,and MM is secret key,master secret and ciphertext security with the hardness assumptions of LWE and SIS.Furtherly,we prove they have some useful properties,such as non-interactive and anonymous.

酸碱滴定曲线的数学分析及其化学意义的探讨

酸碱滴定是化学专业教师及学生最为熟悉的基本实验,滴定曲线反映了整个中和反应的过程,对理解和掌握酸碱滴定十分重要。本文从三个基本假设出发,基于化学平衡思想,应用滴定过程中的电荷守恒与物料守恒关系,在一个参数不变与两个参数变动的初始条件下分别建立了电离度和pH与滴定分数之间的函数关系。通过对函数本身及其导函数进行数学分析,还原了酸碱滴定曲线;尝试利用两个初始条件在数学表达式中的位置及对函数的影响,定量验证了现有教材中对不同数量级初始浓度与不同强度的酸在滴定过程中所表现出差异的定性解释,进而对滴定曲线进行延拓,提出了一种滴定弱酸的可能方式。

Green Fabrication of Freestanding Piezoceramic Films for Energy Harvesting and Virus Detection

Most electronics such as sensors,actuators and energy harvesters need piezoceramic films to interconvert mechanical and electrical energy.Transferring the ceramic films from their growth substrates for assembling electronic devices commonly requires chemical or physical etching,which comes at the sacrifice of the substrate materials,film cracks,and environmental contamination.Here,we introduce a van der Waals stripping method to fabricate large-area and freestanding piezoceramic thin films in a simple,green,and cost-effective manner.The introduction of the quasi van der Waals epitaxial platinum layer enables the capillary force of water to drive the separation process of the film and substrate interface.The fabricated lead-free film,Ba_(0.85)Ca_(0.15)Zr_(0.1)Ti_(0.9)O_(3)(BCZT),shows a high piezoelectric coefficient d_(33)=209±10 pm V−1 and outstanding flexibility of maximum strain 2%.The freestanding feature enables a wide application scenario,including micro energy harvesting,and covid-19 spike protein detection.We further conduct a life cycle analysis and quantify the low energy consumption and low pollution of the water-based stripping film method.

Optical transmitter module with hybrid integration of DFB laser diode and proton-exchanged LiNbO_(3)modulator chip

In this work,a hybrid integrated optical transmitter module was designed and fabricated.A proton-exchanged Mach–Zehnder lithium niobate(LiNbO_(3))modulator chip was chosen to enhance the output extinction ratio.A fiber was used to adjust the rotation of the polarization direction caused by the optical isolator.The whole optical path structure,including the laser chip,lens,fiber,and modulator chip,was simulated to achieve high optical output efficiency.After a series of process improvements,a module with an output extinction ratio of 34 dB and a bandwidth of 20.5 GHz(from 2 GHz)was obtained.The optical output efficiency of the whole module reached approximately 21%.The link performance of the module was also measured.

Traction Potential Analysis of Self-Propelled Seafloor Trencher Based on Mechanical Measurements in Bentonite Soil

Shear stress-displacement relationship model of soil is very important to predict the tractive performance of tracked vehicle. Most shear stress-displacement models were proposed for terrestrial field.However,they are not suit for soft seafloor with flow surface and high water content. Based on comprehensive analysis of seafloor soil shear deformation and track segment shear tests,a new empirical model of shear stressdisplacement relationship for saturated soft-plastic soil(SSP model) was proposed. To validate the SSP model and evaluate potential tractive force of self-propelled seafloor trencher,a test platform,where track segment shear test and drawbar pull test can be performed in seafloor soil substitute(bentonite water mixture),was built. Series of shear tests were carried out. Test results show that the SSP model can describe the mechanical behavior of track segment in seafloor soil substitute with good approximation. Through analyzing the main external forces,including environmental loads from seafloor soil and sea current applied to seafloor tracked trencher during the trenching process in a straight line,drawbar pull analysis model was deduced with the SSP model. A scale test model of seafloor tracked trencher was built,and the verification tests for drawbar pull analysis model were designed and carried out. Results of verification tests indicate that the drawbar pull analysis model was feasible and effective. The drawbar pull tests also indicated that the SSP model is valid from another side.

Head Orientation Stability of Underwater Snake-Like Robot Swimming

In prior research,the orientation of head of the snake-like robot is changed according to the sinusoidal wave. To solve this problem,we propose Central Pattern Generator( CPG)-based control scheme with head-controller to stabilize the head of the underwater snake-like robot. The advantage of the CPG-based control scheme with head-controller is that the head of the underwater snake-like robot is direct to the target orientation during swimming. The relation between CPG parameters and orientation stability of head is discussed.The adaptation of the proposed method to environment changes is tested. The influences of CPG parameters and hydrodynamic forces on the orientation offset of head are investigated. The target orientation( the input of headcontroller) with an experimental optimization is calculated through a convenient method. To prove the feasibility of the proposed methodology,the different swimming modes have been implemented in our simulation platform.The results show that the oscillation of head's orientation is inhibited effectively,and the proposed method has strong adaptation to environment and CPG parameters changes.

CRISPR/Cpf1–FOKI-induced gene editing in Gluconobacter oxydans

Gluconobacter oxydans is an important Gram-negative industrial microorganism that produces vitamin C and other products due to its efficient membrane-bound dehydrogenase system.Its incomplete oxidation system has many crucial industrial applications.However,it also leads to slow growth and low biomass,requiring further metabolic modification for balancing the cell growth and incomplete oxidation process.As a non-model strain,G.oxydans lacks efficient genome editing tools and cannot perform rapid multi-gene editing and complex metabolic network regulation.In the last 15 years,our laboratory attempted to deploy multiple CRISPR/Cas systems in different G.oxydans strains and found none of them as functional.In this study,Cpf1-based or dCpf1-based CRISPRi was constructed to explore the targeted binding ability of Cpf1,while Cpf1–FokI was deployed to study its nuclease activity.A study on Cpf1 found that the CRISPR/Cpf1 system could locate the target genes in G.oxydans but lacked the nuclease cleavage activity.Therefore,the CRISPR/Cpf1–FokI system based on FokI nuclease was constructed.Single-gene knockout with efficiency up to 100%and double-gene iterative editing were achieved in G.oxydans.Using this system,AcrVA6,the anti-CRISPR protein of G.oxydans was discovered for the first time,and efficient genome editing was realized.

科尔沁沙地防沙治沙实践与生态可持续修复浅议

地处中国北方农牧交错带东南端的科尔沁沙地,本应是水草丰美的疏林草地景观,然而脆弱的生态环境基质条件叠加气候变化与不合理的人类活动影响,使其成为现代沙漠化最严重的区域之一。在中国防沙治沙的实践进程中,科尔沁沙地率先实现了沙漠化逆转,但在全球变化背景下该区的防沙治沙形势依然严峻。本文重点梳理了科尔沁沙地在过去几十年防沙治沙中形成的独具特色的治理模式及成效,归纳了科尔沁沙地歼灭战攻坚行动启动以来各省区的行动方案,探讨分析了新时代防沙治沙面临的主要问题与挑战,并针对性地提出了生态可持续修复的对策建议,以期为科尔沁沙地生态环境高水平保护修复与经济社会高质量发展提供科技支撑。

半干旱区典型沙地生态环境演变特征及沙漠化防治建议

沙地作为陆地生态系统重要组成,具有独特的结构和功能。中国北方半干旱、半湿润区的农牧交错带沙地生态环境经历了快速的人类活动正负向干扰过程,集中体现在“破坏利用”和“保护恢复利用”两个阶段。粗放式发展模式引发了一系列诸如土地沙漠化、水资源过度利用及生态失衡等问题。选取科尔沁沙地、毛乌素沙地、浑善达克沙地及呼伦贝尔沙地(四大沙地)作为研究对象,梳理了半干旱区典型沙地自然要素的地域分异特征、沙漠化土地时空演变过程及其驱动力、植被-土壤特征协同演变等方面的文献和研究成果;根据气候变化和人类活动影响下脆弱生态系统土地沙漠化态势及其治理现状认为,未来亟须在政策主导下的沙区人地关系协调发展和基于区域水量平衡的生态恢复及植被稳定性等方面加强研究,科学推进科尔沁、浑善达克两大沙地歼灭战等重点生态工程建设,促进半干旱沙区生态-经济-社会的可持续发展。

The impact of perception bias for cardiovascular disease risk on physical activity and dietary habits

Objective:Cardiovascular disease(CVD)remains a significant public health challenge in China.Accurateperception of individual CVD risk is crucial for timely intervention and preventive strategies.This studyaimed to determine the alignment between CVD risk perception levels and objectively calculated CVDrisk levels,then investigate the disparity in physical activity and healthy diet habits among distinct CVDrisk perception categories.Methods:From March to August 2022,a cross-sectional survey was conducted in Zhejiang Province usingconvenience sampling.Participants aged between 20 and 80 years,without prior diagnosis of CVD wereincluded.CVD risk perception was evaluated with the Chinese version of the Attitude and Beliefs aboutCardiovascular Disease Risk Perception Questionnaire,while objective CVD risk was assessed through thePrediction for Atherosclerotic Cardiovascular Disease Risk(China-PAR)model.Participants’demographicinformation,self-reported physical activity,and healthy diet score were also collected.Results:A total of 739 participants were included in the final analysis.Less than a third of participants(29.2%)accurately perceived their CVD risk,while 64.5%over-perceived it and 6.2%under-perceived it.Notably,half of the individuals(50.0%)with high CVD risk under-perceived their actual risk.Compared tothe accurate perception group,individuals aged 60e80 years old(OR=6.569),currently drinking(OR=3.059),and with hypertension(OR=2.352)were more likely to under-perceive their CVD risk.Meanwhile,participants aged 40-<60 years old(OR=2.462)and employed(OR=2.352)were morelikely to over-perceive their risk.The proportion of individuals engaging in physical activity was lowest inthe under-perception group,although the difference among the three groups was not statistically significant(X^(2)=2.556,P=0.278).In addition,the proportion of individuals practicing healthy diet habitswas also lowest in the under-perception group,and a significant statistical difference was observedamong the three groups(X^(2)=10.310,P=0.006).Conclusion:Only a small proportion of participants accurately perceived their CVD risk,especially amongthose with high actual CVD risk.Individuals in the under-perceived CVD risk group exhibited the lowestrates of physical activity engagement and healthy diet adherence.Healthcare professionals should prioritize implementing personalized CVD risk communication strategies tailored to specific subgroups toenhance the accuracy of risk perception.

A UV-B-responsive glycosyltransferase,OsUGT706C2,modulates flavonoid metabolism in rice

Although natural variations in rice flavonoids exist, and biochemical characterization of a few flavonoid glycosyltransferases has been reported, few studies focused on natural variations in tricin-lignan-glycosides and their underlying genetic basis. In this study, we carried out metabolic profiling of tricin-lignan-glycosides and identified a major quantitative gene annotated as a UDPdependent glycosyltransferase OsUGT706C2 by metabolite-based genome-wide association analysis. The putative flavonoid glycosyltransferase OsUGT706C2 was characterized as a flavonoid 7-O-glycosyltransferas in vitro and in vivo. Although the in vitro enzyme activity of OsUGT706C2 was similar to that of OsUGT706D1, the expression pattern and induced expression profile of OsUGT706C2 were very different from those of OsUGT706D1. Besides, OsUGT706C2 was specifically induced by UV-B. Constitutive expression of OsUGT706C2 in rice may modulate phenylpropanoid metabolism at both the transcript and metabolite levels. Furthermore, overexpressing OsUGT706C2 can enhance UV-B tolerance by promoting ROS scavenging in rice. Our findings might make it possible to use the glycosyltransferase OsUGT706C2 for crop improvement with respect to UVB adaptation and/or flavonoid accumulation, which may contribute to stable yield.

Creep-Induced Phase Instability and Microstructure Evolution of a Nearly Lamellar Ti–45Al–8.5Nb–(W, B, Y) Alloy

Microstructure degradation and stress-induced transformation of a high Nb-containing TiAl alloy with nearly lamellar microstructure during creep were investigated.Tensile creep experiments were performed at 800,850 and 900℃ under 150 MPa in air.Microstructures before and after creep tests were examined using scanning and transmission electron microscopy(SEM and TEM).Dislocations within the lamellar structure andβo(ω)region and twin intersection in massiveγgrains were investigated.Dislocation sliding played a critical role in the deformation ofωo phase,which preferentially occurred on the(0002)ωo plane.Possible deformation mechanisms were revealed.A stress-inducedγ→α2 phase transformation took place during the creep test at 850 and 900℃.α2 lamella could directly decompose into theωo phase at 850℃.The instability of high-temperature microstructure can weaken the creep resistance and promote the plastic deformation of the lamellar matrix,thus could be detrimental to the creep properties.The correlations between creep properties and microstructure instability were discussed.

连续锁边外翻缝合在肝移植肝动脉吻合中的应用(附视频)

肝移植已被广泛应用于治疗各种不可逆性急慢性肝病。经过几十年的持续稳步发展,肝移植技术逐渐成熟和稳定。然而,肝动脉并发症仍是导致肝移植术后移植物失功和受者死亡的主要原因[1,2,3]。采用快速、牢固及可靠的动脉吻合方法可减少肝动脉并发症、移植物失功和再次肝移植的发生风险,对挽救肝移植受者生命具有重要意义。本研究通过回顾性分析江西省人民医院接受经典原位肝移植的受者临床资料,探讨连续锁边外翻缝合技术在缩短动脉吻合时间,增强吻合的牢固性以及在处理直径不匹配动脉吻合方面的特点和优势,现报道如下。

High-efficiency Gaussian key reconciliation in continuous variable quantum key distribution

Efficient reconciliation is a crucial step in continuous variable quantum key distribution. The progressive-edge-growth(PEG) algorithm is an efficient method to construct relatively short block length low-density parity-check(LDPC) codes. The qua-sicyclic construction method can extend short block length codes and further eliminate the shortest cycle. In this paper, by combining the PEG algorithm and quasi-cyclic construction method, we design long block length irregular LDPC codes with high error-correcting capacity. Based on these LDPC codes, we achieve high-efficiency Gaussian key reconciliation with slice recon-ciliation based on multilevel coding/multistage decoding with an efficiency of 93.7%.