希托夫法测定离子迁移数的影响因素探究

离子迁移数作为物理化学课程中电化学部分的一个重要概念,其测定实验被设置在多所高校的物理化学实验课程中。文献调研及过往教学实践表明,使用希托夫(Hittorf)法测定的离子迁移数,结果与文献值有较大出入。为了降低测定误差,以及探究测试结果的影响因素,本实验从溶液装液量控制、断液断电顺序、计算电量的数据来源三个方面进行改进,尽可能降低实验操作和浓度测定导致的误差,从而分析真正影响测试结果的因素。实验表明,当采用电流乘以时间作为电量的数据来源,且采用阴极区溶液计算离子迁移数时,所得结果更接近实验参考值。

Research on Risk Prevention and Resolution Strategies of College Network Ideology in the Context of the Internet

With the rapid development of the Internet,the network ideology of colleges and universities is facing severe challenges.This paper deeply analyzes the root of the risk of network ideology and makes a specific investigation of the status quo of network public opinion in colleges and universities.On this basis,the study explores and puts forward a series of targeted risk prevention and resolution strategies,aiming at providing a systematic solution for the network ideology security of colleges and universities.In this paper,with the combination of theory and practice as the path,we verify the effectiveness and applicability of the proposed strategy through the analysis of the implementation effect of the strategy.This study also provides theoretical support and practical guidance for the prevention and control of ideological risks and public opinion guidance in universities under the network environment,which has important practical significance.With the continuous progress of network technology,the threats to the network ideology of colleges and universities are increasing.For example,the spread of false information has become a serious problem affecting the security of college network ideology.

Quantitative micro-electrochemical study of duplex stainless steel 2205 in 3.5wt%NaCl solution

Duplex stainless steels(DSSs)are suffering from various localized corrosion attacks such as pitting,selective dissolution,crevice corrosion during their service period.It is of great value to quantitatively analyze and grasp the micro-electrochemical corrosion behavior and related mechanism for DSSs on the micrometer or even smaller scales.In this work,scanning Kelvin probe force microscopy(SKPFM)and energy dispersive spectroscopy(EDS)measurements were performed to reveal the difference between the austenite phase and ferrite phase in microregion of DSS 2205.Then traditional electrochemical impedance spectroscopy(EIS)and potentiodynamic polarization(PDP)tests were employed for micro-electrochemical characterization of DSS 2205 with different proportion phases inϕ40 andϕ10μm micro holes.Both of them can only be utilized for qualitative or semi-quantitative micro-electrochemical characterization of DSS 2205.Coulostatic perturbation method was employed for quantitative micro-electrochemical characterization of DSS 2205.What is more,the applicable conditions of coulostatic perturbation were analyzed in depth by establishing a detailed electrochemical interface circuit.A series of microregion coulostatic perturbations for DSS 2205 with different proportion phases inϕ10μm micro holes showed that as the austenite proportion increases,the corresponding polarization resistance of microregion increases linearly.

Assessing the cost reduction potential of CCUS cluster projects of coal-fired plants in Guangdong Province in China

Carbon capture, utilization, and storage (CCUS) have garnered extensive attention as a target of carbon neutrality in China. The development trend of international CCUS projects indicates that the cluster construction of CCUS projects is the main direction of future development. The cost reduction potential of CCUS cluster projects has become a significant issue for CCUS stakeholders. To assess the cost reduction potential of CCUS cluster projects, we selected three coal-fired power plants in the coastal area of Guangdong as research targets. We initially assessed the costs of building individual CCUS projects for each plant and subsequently designed a CCUS cluster project for these plants. By comparing individual costs and CCUS cluster project costs, we assessed the cost reduction potential of CCUS cluster projects. The results show that the unit emission reduction cost for each plant with a capacity of 300 million tonnes per year is 392.34, 336.09, and 334.92 CNY/tCO_(2). By building CCUS cluster project, it could save 56.43 CNY/tCO_(2) over the average cost of individual projects (354.45 CNY/tCO_(2)) when the total capture capacity is 9 million tonnes per year (by 15.92%). Furthermore, we conducted a simulation for the scenario of a smaller designed capture capacity for each plant. We found that as the capture scale increases, the cost reduction potential is higher in the future.

Pulmonary endothelium-targeted nanoassembly of indomethacin and superoxide dismutase relieves lung inflammation

Lung inflammation is an essential inducer of various diseases and is closely related to pulmonary-endothelium dysfunction.Herein,we propose a pulmonary endothelium-targeted codelivery system of anti-inflammatory indomethacin(IND)and antioxidant superoxide dismutase(SOD)by assembling the biopharmaceutical SOD onto the“vector”of rod-like pure IND crystals,followed by coating with anti-ICAM-1 antibody(Ab)for targeting endothelial cells.The codelivery system has a 237 nm diameter in length and extremely high drug loading of 39%IND and 2.3%SOD.Pharmacokinetics and biodistribution studies demonstrate the extended blood circulation and the strong pulmonary accumulation of the system after intravenous injection in the lipopolysaccharide(LPS)-induced inflammatory murine model.Particularly,the system allows a robust capacity to target pulmonary endothelium mostly due to the rod-shape and Ab coating effect.In vitro,the preparation shows the synergistic antiinflammatory and antioxidant effects in LPS-activated endothelial cells.In vivo,the preparation exhibits superior pharmacodynamic efficacy revealed by significantly downregulating the inflammatory/oxidative stress markers,such as TNF-a,IL-6,COX-2,and reactive oxygen species(ROS),in the lungs.In conclusion,the codelivery system based on rod-like pure crystals could well target the pulmonary endothelium and effectively alleviate lung inflammation.The study offers a promising approach to combat pulmonary endothelium-associated diseases.

Novel ultra-wideband fluorescence material:Defect state control based on nickel-doped semiconductor QDs embedded in inorganic glasses

In recent years,the development of an environmentally friendly quantum dots(QDs)embedded luminous solid by a simple method has attracted considerable attention.In this study,semiconductor ZnS QDs were successfully prepared in an inorganic matrix of amorphous glass,which yielded beneficial broadband emission in the long-wavelength region of the visible range.The strong red emission belonged to the defect state energy level of the ZnS QDs,which could be enhanced by incorporation of nickel ions into the fixed matrix to regulate the defects state.The novel material had a small self-absorption,wide excitation and emission ranges,and thus potential applications in light-conversion devices,luminescent solar concentrators,and solar cell cover glasses.

Multiple Trajectories of Cereal Consumption and Their Associations with Type 2 Diabetes in Chinese Adults-China,1997-2018

Summary What is already known about this topic?Consuming refined grains,specifically white rice,elevates the risk of developing type 2 diabetes(T2D).Conversely,incorporating whole grains into the diet is linked to a reduced risk.What is added by this report?This study employed a novel multi-trajectory modeling technique to account for the intercorrelations among various cereal consumption patterns.

Development of high-resolution multiple-SNP arrays for genetic analyses and molecular breeding through genotyping by target sequencing and liquid chip

Genotyping platforms,as critical supports for genomics,genetics,and molecular breeding,have been well implemented at national institutions/universities in developed countries and multinational seed companies that possess high-throughput,automatic,large-scale,and shared facilities.In this study,we integrated an improved genotyping by target sequencing(GBTS)system with capture-in-solution(liquid chip)technology to develop a multiple single-nucleotide polymorphism(mSNP)approach in which mSNPs can be captured from a single amplicon.From one 40K maize mSNP panel,we developed three types of markers(40K mSNPs,251K SNPs,and 690K haplotypes),and generated multiple panels with various marker densities(1K–40K mSNPs)by sequencing at different depths.Comparative genetic diversity analysis was performed with genic versus intergenic markers and di-allelic SNPs versus non-typical SNPs.Compared with the one-amplicon-one-SNP system,mSNPs and within-mSNP haplotypes are more powerful for genetic diversity detection,linkage disequilibrium decay analysis,and genome-wide association studies.The technologies,protocols,and application scenarios developed for maize in this study will serve as a model for the development of mSNP arrays and highly efficient GBTS systems in animals,plants,and microorganisms.

Intracellular codelivery of anti-inflammatory drug and anti-miR 155 to treat inflammatory disease

Atherosclerosis(AS) is a lipid-driven chronic inflammatory disease occurring at the arterial subendothelial space. Macrophages play a critical role in the initiation and development of AS. Herein,targeted codelivery of anti-miR 155 and anti-inflammatory baicalein is exploited to polarize macrophages toward M2 phenotype, inhibit inflammation and treat AS. The codelivery system consists of a carrier-free strategy(drug-delivering-drug, DDD), fabricated by loading anti-miR155 on baicalein nanocrystals,named as baicalein nanorods(BNRs), followed by sialic acid coating to target macrophages. The codelivery system, with a diameter of 150 nm, enables efficient intracellular delivery of anti-miR155 and polarizes M1 to M2, while markedly lowers the level of inflammatory factors in vitro and in vivo. In particular, intracellular fate assay reveals that the codelivery system allows for sustained drug release over time after internalization. Moreover, due to prolonged blood circulation and improved accumulation at the AS plaque, the codelivery system significantly alleviates AS in animal model by increasing the artery lumen diameter, reducing blood pressure, promoting M2 polarization, inhibiting secretion of inflammatory factors and decreasing blood lipids. Taken together, the codelivery could potentially be used to treat vascular inflammation.

Effect of Li＋ ion concentration on upconversion emission and temperature sensing behavior of La2O3：Er3＋ phosphors

The effects of Li~＋ co-doping concentration on the structure, upconversion luminescence and temperature sensing behavior of Er^（3＋）：La_2O_3 phosphors were investigated. X-ray diffraction and scanning electron microscopy observations reveal that Li~＋ ion co-doping can change the lattice parameter of La_2O_3 host and increase the particle size of the samples. The optical investigation shows that co-doping of Li~＋ ions can enhance the upconversion emission of Er^（3＋） ions in La_2O_3 matrix effectively. Most importantly, the temperature sensing sensitivity of the samples is found to be dependent on Li~＋ co-doping concentration,when the emission intensity ratio of the（~2H_（11/2）→~4 I_（15/2）） and（~4 S_（3/2）→~4 I_（15/2）） transitions of Er^（3＋） is chosen as the thermometric index. Both of the optimum upconversion luminescence and temperature sensing sensitivity are obtained for 7 mol% Li~＋ co-doped sample. When the Li~＋ concentration is beyond 7 mol%,both the quenching in upconversion intensity and the degradation of temperature sensitivity are observed, which may be due to the serious distortion in local crystal field around Er^（3＋） ions caused by the excess Li~＋ ions.

Trends in Adult Cooking Salt Intake--China, 1991−2018

What is already known about this topic?Sodium intake in China is among the highest in the world,the main source of which in adults is salt added during cooking.In 2012,the national average cooking salt intake was 10.5 g/d.What is added by this report?In 2018,median cooking salt intake was 6.3 g/d,which has decreased compared to that in 1991.The northsouth gap in cooking salt intake was closing over time.What are the implications for public health practice?Effective policies and interventions need to be sustained and intensified to lower cooking salt intake,thus achieving the recommended level of sodium and total salt intake.

Empowering perovskite PbTiO_(3) nanoparticles with enhanced up-conversion luminescence and thermal sensitivity by introducing Er^(3+) dopant

Up-convertion(UC)perovskite Er^(3+)-doped Pb TiO3(Er-PTO)nanoparticles with green and red emissions were synthesized via the hydrothermal method.The UC properties were manipulated by adjusting the concentration of Er^(3+) ions dopant.The green emission intensity was decreased as the doping concentration increased from 1% to 4%(mole fraction),whereas the red emission intensity was increased.The influences of Er^(3+) ions on the temperature-sensing performance were further investigated.The results demonstrated that Er-PTO nanoparticles with doping 1% Er^(3+) ions possessed a sensitivity of3.1×10^(-3) K^(-1) at 475 K,presenting a high potential in optical heating devices.

Upconversion luminescence, intrinsic optical bistability,and optical thermometry in Ho3+/Yb3+: BaMoO4 phosphors

Ho^3+/Yb^3+: BaMoO4 phosphors with different concentrations were fabricated by a gel combustion method.The upconversion(UC) luminescence, intrinsic optical bistability, and the corresponding mechanisms were reported for the present system. The optical thermometric properties based on red(^5F5→^5I8) and green(^5F4/^5S2→^5I8) emissions were studied. The sensing sensitivities could be tuned by manipulating the cooperative energy transfer process. The highest absolute sensitivity was 99 × 10^-4 K^-1 at 573 K, which is larger than that of many previous UC materials.

Broadening and enhancing 2.7 μm emission spectra in Er/Ho co-doped oxyfluoride germanosilicate glass ceramics by imparting multiple local structures to rare earth ions

Er/Ho co-doped oxyfluoride germanosilicate glass and glass ceramics are prepared and compared. The results indicate that the glass consists of SiO_4 and GeO_4 structural units, while the network of the glass ceramics consists of SiO_4, GeO_4, and GeO_6 units together with NaYF_4 nanocrystals. The presence of multiple local structures in glass ceramics creates a range of dipole environments, which is beneficial to the broadening of 2.7 μm emission.Two other reasons are attributed to the broadening of 2.7 μm emission in glass ceramics: the energy-level splitting of Er^(3+) and the enhancement of the Ho^(3+):~5I_6→~5I_7 transition in NaYF_4 nanocrystals.