WO_(3)/Zn_(0.5)Cd_(0.5)S S型异质结光催化产氢耦合有机物转化机理研究

开发新型纳米材料实现光催化产氢耦合有机物转化、提高太阳能到化学能的转换效率,在解决能源和环境危机方面具有巨大潜力。三元金属硫化物具有可调控的带隙和优异的可见光响应,在光催化分解水产氢方面引起了广泛关注。其中,Zn_(0.5)Cd_(0.5)S是一种带隙较窄、导带位置较高、耐光腐蚀的还原型光催化剂;然而,单一Zn_(0.5)Cd_(0.5)S中光生电子和空穴的复合率较高,只有少部分光生载流子参与光催化反应,导致量子效率较低而无法达到实际需求。WO_(3)是一种典型的氧化型光催化剂,具有较低的价带位置和较强的氧化能力,是与Zn_(0.5)Cd_(0.5)S耦合构建S型异质结的理想半导体。基于此,本文通过静电纺丝和水热方法将Zn_(0.5)Cd_(0.5)S纳米片垂直生长在WO_(3)纳米纤维上,制备了具有核壳结构的WO_(3)/Zn_(0.5)Cd_(0.5)S异质结。功函数的差异驱动Zn_(0.5)Cd_(0.5)S的电子转移到WO_(3)上,在界面处形成内建电场并使能带弯曲。通过原位光照X射线光电子能谱、电子顺磁共振和时间分辨荧光光谱分析,发现在内建电场、弯曲能带和库仑吸引力的作用下,WO_(3)导带上的光生电子迁移到Zn_(0.5)Cd_(0.5)S价带上并与其光生空穴复合,表明WO_(3)和Zn_(0.5)Cd_(0.5)S之间形成了S型异质结,实现了具有强氧化还原能力的载流子的高效分离。得益于独特的S型光催化机制以及反应物在催化剂表面的有效吸附与活化,没有贵金属助催化剂的情况下,WO_(3)/Zn_(0.5)Cd_(0.5)S异质结在产氢(715 μmol·g^(-1)·h^(-1))和乳酸转化为丙酮酸方面表现出增强的光催化活性,实现了光生电子和空穴的高效利用。原位漫反射傅里叶变换红外光谱和密度泛函理论计算揭示了光催化产氢和有机物转化的反应机理。本工作为设计和研究新型S型异质结光催化剂、实现高效产氢耦合有机物转化提供了新的见解。

可见光氧化还原协同镍催化构建C—S键偶联反应

在可见光和过渡金属镍协同催化体系中,可见光催化可以通过单电子氧化或还原过程推动过渡金属镍催化,又可以通过能量转移过程推动镍催化循环。这为传统过渡金属催化的偶联反应提供了更多可能性。同时,大多数光催化剂使用基于Ru和Ir金属的配合物,不仅价格昂贵,还会在工业生产中存在金属残留。本文开发了一种高效且经济的协同催化体剂(Nap)_(2)PXZ-bpy-Ni,以吩噁嗪为有机光催化剂,NiBr_(2)·DME为镍催化剂,联吡啶作为配体,通过Click的方式将光催化剂和联吡啶镍催化剂连接起来。实验结果表明:在1%(物质的量分数,下同)催化剂负载下反应12H,C—S键偶联产物收率可达73%~95%,实现了高效的催化效率并显示出较好的官能团适用性和底物普适性。最后通过自由基捕捉实验推测了该反应可能的机理。

人Corti's器扫描电镜观察

目的 了解正常人Corti’s器的超微结构特征。方法 用扫描电镜观察成年人和胎儿的Corti’s器。结果成人和胎儿Corti’s器基底圈内、外毛细胞排列规则,中圈和顶圈毛细胞排列不规则,内毛细胞以一排,外毛细胞以三排排列。可观察到列外的内、外毛细胞,四排排列和自然缺失的外毛细胞。外毛细胞粗大的静纤毛以及由于固定不及时引起的外毛细胞静纤毛气球样改变。结论 用扫描电镜观察成人和胎儿Corti’s器的精细结构,发现了毛细胞排列的基本规律和一些异常的形态。及时固定是保存Corti’s器结构完好的必要条件。

新生SD大鼠G418耳蜗Corti器离体损伤模型的建立

目的:建立毒性蛋白G418损坏新生大鼠耳蜗毛细胞的离体培养试验模型。方法:应用耳蜗基底膜分离取材技术,耳蜗器官离体培养技术和毛细胞免疫组化染色技术定量观察了G418对新生SD小鼠耳蜗毛细胞的损害。结果:G418对耳蜗毛细胞的有明显的损害,200μg/ml的终浓度,内外毛细胞均有不同程度损害,以外毛细胞为著。结论:G418可用于建立耳蜗Corti器离体损伤模型。

大型石化企业储罐VOC_(S)治理改造与节能应用探究

为减小因丁辛醇罐区储罐排放尾气引起的环境污染和其它安全隐患,通过对不同治理技术进行研究,择优应用冷却回收技术对含100%丁醛组分的醛储罐排放尾气进行回收。采用新型储罐密封技术对80%以上为丁醛的轻组分储罐、含60%左右丁醇的重组分储罐及含20%左右丁醇的杂醇储罐进行处理,以满足降低挥发性有机物量的目标,实现罐区尾气异味治理,有效减少现场异味,保护环境。

Numerical simulation of Corti stimulated by fluid in tunnel of Corti

In this paper, the effect of fluid in a tunnel of Corti （TC） on organ of Corti （OC） is studied. A three-dimensional OC model including basilar membrane （BM）, tectorial membrane （TM）, inner and outer hair cells （OHCs）, and reticular lamina （RL） is established by COMSOL. An initial pressure is applied to the fluid in the TC. The frequency response of the structure is analyzed, and the displacement of the BM is achieved. The results are in good agreement with the experimental data, confirming validity of the finite element model. Based on the model, the effect of fluid in the TC on the OC is studied. The results show that, when the pressure gradient is absent in the fluid, with the increase of the initial fluid pressure, the displacement of the BM increases. However, when the initial fluid pressure increases to a certain value, the increase rate of the displacement of the BM becomes very slow. The movement of the fluid amplifies the BM movement. Furthermore, the movement of the fluid can strengthen the movement of the OHCs and the shear movement of the stereocilia, especially in the vicinity of the characteristic frequency at which the amplification effect reaches a peak. Nevertheless, a pressure gradient in the fluid affects the BM movement.

Spectral Characterization of Colored Dissolved Organic Matter for Productive Inland Waters and Its Source Analysis

This study examined the spatiotemporal dynamics of colored dissolved organic matter （CDOM） and spectral slope （S）, and further to analyze its sources in three productive water supplies （Eagle Creek, Geist and Morse reservoirs） from Indiana, USA. The re- sults showed that he absorption coefficient aCDOM（440） ranged from 0.37 m-1 to 3.93 m-1 with an average of 1.89 ± 0.76 m-1 （±SD） for the aggregated dataset, and S varied from 0.0048 nm -1 to 0.0239 nm-1 with an average of 0.0108 ±0.0040 nmI. A significant relation- ship between S and aCDOM（440） can be fitted with a power equation （S = 0.013 × aCDOM（440）-0.42, R2 = 0.612）, excluding data from Geist Reservoir during high flow （12 April 2010） and the Morse Reservoir on 25 June 2010 due to a T-storm achieves even higher determina- tion coefficient （R2 = 0.842）. Correlation analysis indicated that aCDOM（440） has strong association with inorganic suspended matter （ISM） concentration （0.231 〈 R2 〈 0.786） for each of the field surveys, and this trend followed the aggregated datasets （R2 = 0.447, p 〈 0.001）. In contrast, chlorophyll-a was only correlated with aCDOM（440） in summer and autumn （0.081 〈 R2 〈 0.763）, indicating that CDOM is mainly from terrigenous sources in early spring and that phytoplankton contributed during the algal blooming season. The S value was used to characterize CDOM origin. The results indicate that the CDOM source is mainly controlled by hydrological varia- tions, while phytoplankton originated organic matter also closely linked with CDOM dynamics in three productive reservoirs.

Sequential organ failure assessment score is superior to other prognostic indices in acute pancreatitis

BACKGROUND Acute pancreatitis(AP)is a common surgical condition,with severe AP(SAP)potentially lethal.Many prognostic indices,including;acute physiology and chronic health evaluation II score(APACHE II),bedside index of severity in acute pancreatitis(BISAP),Glasgow score,harmless acute pancreatitis score(HAPS),Ranson’s score,and sequential organ failure assessment(SOFA)evaluate AP severity and predict mortality.AIM To evaluate these indices'utility in predicting severity,intensive care unit(ICU)admission,and mortality.METHODS A retrospective analysis of 653 patients with AP from July 2009 to September 2016 was performed.The demographic,clinical profile,and patient outcomes were collected.SAP was defined as per the revised Atlanta classification.Values for APACHE II score,BISAP,HAPS,and SOFA within 24 h of admission were retrospectively obtained based on laboratory results and patient evaluation recorded on a secure hospital-based online electronic platform.Data with<10%missing data was imputed via mean substitution.Other patient information such as demographics,disease etiology,and patient outcomes were also derived from electronic medical records.RESULTS The mean age was 58.7±17.5 years,with 58.7%males.Gallstones(n=404,61.9%),alcohol(n=38,5.8%),and hypertriglyceridemia(n=19,2.9%)were more common aetiologies.81(12.4%)patients developed SAP,20(3.1%)required ICU admission,and 12(1.8%)deaths were attributed to SAP.Ranson’s score and APACHE-II demonstrated the highest sensitivity in predicting SAP(92.6%,80.2%respectively),ICU admission(100%),and mortality(100%).While SOFA and BISAP demonstrated lowest sensitivity in predicting SAP(13.6%,24.7%respectively),ICU admission(40.0%,25.0%respectively)and mortality(50.0%,25.5%respectively).However,SOFA demonstrated the highest specificity in predicting SAP(99.7%),ICU admission(99.2%),and mortality(98.9%).SOFA demonstrated the highest positive predictive value,positive likelihood ratio,diagnostic odds ratio,and overall accuracy in predicting SAP,ICU admission,and mortality.SOFA and Ranson’s score demonstrated the highest area under receiver-operator curves at 48 h in predicting SAP(0.966,0.857 respectively),ICU admission(0.943,0.946 respectively),and mortality(0.968,0.917 respectively).CONCLUSION The SOFA and 48-h Ranson’s scores accurately predict severity,ICU admission,and mortality in AP,with more favorable statistics for the SOFA score.

Centennial-scale records of total organic carbon in sediment cores from the South Yellow Sea, China

Global carbon cycling is a significant factor that controls climate change.The centennial-scale variations in total organic carbon(TOC)contents and its sources in marginal sea sediments may reflect the influence of human activities on global climate change.In this study,two fine-grained sediment cores from the Yellow Sea Cold Water Mass of the South Yellow Sea were used to systematically determine TOC contents and stable carbon isotope ratios.These results were combined with previous data of black carbon and (210)~Pb dating from which we reconstructed the centennial-scale initial sequences of TOC,terrigenous TOC(TOC_(ter))and marine autogenous TOC(TOC_(mar))after selecting suitable models to correct the measured TOC(TOC_(cor)).These sequences showed that the TOC_(ter) decreased with time in the both cores while the TOC_(mar) increased,particularly the rapid growth in core H43 since the late 1960s.According to the correlation between the Huanghe(Yellow)River discharge and the TOC_(cor),TOC_(ter),or TOC_(mar),we found that the TOC_(ter) in the two cores mainly derived from the Huanghe River and was transported by it,and that higher Huanghe River discharge could strengthen the decomposition of TOC_(mar).The newly obtained initial TOC sequences provide important insights into the interaction between human activities and natural processes.

A Fractional Drift Diffusion Model for Organic Semiconductor Devices

Because charge carriers of many organic semiconductors(OSCs)exhibit fractional drift diffusion(Fr-DD)transport properties,the need to develop a Fr-DD model solver becomes more apparent.However,the current research on solving the governing equations of the Fr-DD model is practically nonexistent.In this paper,an iterative solver with high precision is developed to solve both the transient and steady-state Fr-DD model for organic semiconductor devices.The Fr-DD model is composed of two fractionalorder carriers(i.e.,electrons and holes)continuity equations coupled with Poisson’s equation.By treating the current density as constants within each pair of consecutive grid nodes,a linear Caputo’s fractional-order ordinary differential equation(FrODE)can be produced,and its analytic solution gives an approximation to the carrier concentration.The convergence of the solver is guaranteed by implementing a successive over-relaxation(SOR)mechanism on each loop of Gummel’s iteration.Based on our derivations,it can be shown that the Scharfetter–Gummel discretization method is essentially a special case of our scheme.In addition,the consistency and convergence of the two core algorithms are proved,with three numerical examples designed to demonstrate the accuracy and computational performance of this solver.Finally,we validate the Fr-DD model for a steady-state organic field effect transistor(OFET)by fitting the simulated transconductance and output curves to the experimental data.

Effects of Organic Fertilizers Made from Distiller＇s Grains on the Growth and Development of Flue-cured Tobacco

Pot experiments were conducted to study the effects of different organic fertilizers made from distiller＇s grains on the physiological characteristics and growth of flue-cured tobacco. The results showed that the agronomic traits and biomass of flue-cured tobacco in the three treatments were higher than that of the control group,and the mixed application of different organic fertilizers made from distiller＇s grains and compound fertilizer could promote the growth and development of flue-cured tobacco significantly.

中耳局部应用氟嗪酸及庆大霉素对豚鼠Corti′s器及前庭终器的影响

本研究采用鼓室植管法，于正常豚鼠中耳局部连续应用氟嗪酸及庆大霉素溶液后，观察并比较了两种药液对内耳Ｃｏｒｔｉ′ｓ器及前庭终器的组织学影响。结果表明，氟嗪酸对内耳的感觉细胞无明显的影响，而庆大霉素则有严重的耳蜗毒性及前庭毒性。

Mechanical model of organ of Corti

According to the vibration characteristics of the organ of Corti （OC）, seven hypotheses are made to simplify the structure of the model, and a mechanical OC model is established. Using the variational principle, a displacement analytical expression is solved under a certain pressure. The results are in good agreement with experimental data, showing the validity of the formula. Combined with the damage caused by noise in clinic, it is found that the hardening of outer hair cells and outer stereocilia can lead to loss of hearing and generation of threshold shift. In addition, the results show that high frequency resonance occurs at the bottom of the basilar membrane （BM）, and low frequency resonance occurs at the top of the BM. This confirms the frequency selective characteristics of the BM. Further, using this formula can avoid interference of the envi- ronment and the technical level of the test personnel, and can evaluate performance of the OC objectively.

社会组织参与困境儿童社会支持网络构建的服务策略研究--以广州市S组织困境儿童服务项目为例

要妥善回应深化改革过程中困境儿童多元化的需求,须从困境儿童社会支持着手,通过发挥社会组织联动多元主体的作用来筑实困境儿童社会支持网络。研究聚焦S组织困境儿童服务实践策略,分析其回应需求的服务过程,旨在为社会组织参与构建困境儿童支持网络提供实务参考。研究发现,S组织在开展困境儿童服务时能够充分发挥枢纽平台优势,在一定程度上促进了儿童主体发展和多元主体参与,但组织存在建设局限性、服务内容与形式创新不足、服务不够规范、机制缺失等方面的问题。推动儿童福利事业发展的关键在于要坚持政府主导的公共服务供给格局,拓宽社会参与渠道和门槛,整合跨界创新力量,动员多元主体在困境儿童服务中积极投入服务和资源,强化其社会支持网络。

微小RNA通过SIRT1调控小鼠耳蜗老化HEI-OC1细胞凋亡的研究

目的构建小鼠耳蜗毛细胞株HEI-OC1(house ear institute-organ of Corti 1)老化模型,探索微小RNA-96(miR-96)可否通过SIRT1调控老化HEI-OC1凋亡。方法CCK-8筛选D-半乳糖浓度。流式细胞仪检测细胞凋亡,Western blot检测p53、p38、caspase-3蛋白表达。q RT-PCR检测miR-96、SIRT1 mRNA表达,Western blot检测SIRT1蛋白表达。miR-96模拟物转染HEI-OC1细胞,qRT-PCR检测miR-96、SIRT1 mRNA表达,Western blot检测SIRT1、caspase-3蛋白表达。结果HEI-OC1细胞在15 mg/ml D-半乳糖条件下培养72 h后,凋亡较对照组显著增加(P<0.01),且p53、p38(P<0.05)及caspase-3(P<0.0001)蛋白表达明显增加。老化组miR-96与SIRT1 mRNA和蛋白表达均明显减低(P<0.05)。miR-96过表达后,SIRT1 mRNA及蛋白较对照组表达升高,caspase-3蛋白表达降低(P<0.05)。结论老化HEI-OC1细胞中miR-96、SIRT1 mRNA与蛋白的表达均下降。miR-96可通过上调SIRT1抑制HEI-OC1细胞的凋亡。miR-96、SIRT1可能成为保护老年性聋耳蜗毛细胞的作用靶点。

Group Purchasing Organizations (GPOs) in the U.S.: Development and Reform

Objective To study the characteristics, specific functions and policy improvement process of the Group Purchasing Organizations (GPOs) in the U.S. and to provide references for drug group purchasing practices in China. Methods Domestic and foreign relevant literatures, websites were reviewed or searched to analyze the functions and policy improvement process of the GPOs in the U.S. so as to provide references for drug group purchasing practices in China. Results and Conclusion As a third party in the U.S. GPOs has formed a relatively integrated business process and projects service system after long-term development. Supported by corresponding policies and industrial regulations, GPOs have made a great contribution to control the growth of medical and healthcare expenses and improve the efficiency of medical institutions, and its development experience can enlighten the practices in China.

双酚S对秀丽隐杆线虫精子生成相关基因表达的影响

目的:探讨双酚S对模式生物秀丽隐杆线虫精子生成相关基因表达的影响。方法:根据双酚S的急性毒性试验结果确定本研究剂量为0、3、30、300μmol/L,对同步化至L4期的线虫进行24 h暴露,测定其子代数目并用实时荧光定量PCR(qPCR)检测akt-1、swm-1、try-5、spe-4、spe-6基因表达水平。结果:秀丽隐杆线虫于双酚S中暴露24 h后,其半数致死浓度(LC50)为2773.672μmol/L;与对照组相比,暴露后的L4期秀丽隐杆线虫在双酚S剂量为3、30、300μmol/L时子代数目均显著降低(P<0.05或P<0.01);akt-1 mRNA在3μmol/L时的表达水平升高(P<0.05);swm-1、try-5、spe-4、spe-6 mRNA在30和300μmol/L时表达水平均升高(P<0.05或P<0.01)。结论:双酚S对秀丽隐杆线虫精子生成相关基因表达有影响。

Short-term influence of anaerobically-digested and conventional swine manure, and N fertilizer on organic C and N, and available nutrients in two contrasting soils

A three-year (2006-2008) field experiment was conducted at Swift Current and Star City in Saskatchewan to determine the short-term in-fluence of land-applied anaerobically digested swine manure (ADSM), conventionally treated swine manure (CTSM) and N fertilizer on total organic C (TOC), total organic N (TON), light fraction organic C (LFOC), light fraction organic N (LFON) and pH in the 0 - 7.5 and 7.5 - 15 cm soil layers, and ammonium-N, nitrate-N, extractable P, exchangeable K and sulphate-S in the 0 - 15, 15 - 30, 30 - 60, 60 - 90 and 90 - 120 cm soil layers. Treatments included spring and autumn applications of CTSM and ADSM at a 1x rate (10,000 and 7150 L·ha-1, respectively) applied each year, a 3x rate (30,000 and 21,450 L·ha-1, respectively) applied once at the beginning of the experiment, plus a treatment receiving commercial fertilizer (UAN at 60 kg·N·ha-1·yr-1) and a zero-N control. There was no effect of swine manure rate, type and application time on soil pH. Mass of TOC and TON in the 15 cm soil layer increased significantly with swine manure application compared to the control, mainly at the Swift Current site, with greater increases from 3x rate than 1x rate (by 2.21 Mg·C·ha-1 and 0.167 Mg·N·ha-1). Compared to the control, mass of LFOC and LFON in the 15 cm soil layer increased with swine manure application at sites, with greater increases from 3x rate than 1x rate (by 287 kg·C·ha-1 and 26 kg·N·ha-1 at Star City, and by 194 kg·C·ha-1 and 19·kg·N ha-1 at Swift Current). Mass of TOC and TON in soil layer was tended to be greater with ADSM than CTSM, but mass of LFOC and LFON in soil was greater with CTSM than ADSM. Mass of TOC, TON, LFOC and LFON in soil also increased with annual N fertilizer application compared to the control (by 3.2 Mg·C·ha-1 for TOC, 0.195 Mg·N·ha-1 for TON, 708 kg·C·ha-1 for LFOC and 45 kg·N·ha-1 for LFON). In conclusion, our findings suggest that the quantity and quality of organic C and N in soil can be affected by swine manure rate and type, and N fertilization even after three years, most likely by influencing inputs of C and N through crop residue, and improve soil quality.

N/S codoping modification based on the metal organic frameworkderived carbon to improve the electrochemical performance of different energy storage devices

Carbon-based materials have become a research hotspot in the field of energy storage devices in recent years due to their abundant resources,low cost,and environmental friendliness.However,the low capacity and poor high rate performance still constitute great challenges.Metal organic framework-derived carbon has been widely researched because of its high porosity,tunable structure,and good conductivity.In this work,N/S codoped hierarchical porous carbon microspheres were prepared by a high-temperature heat treatment and atomic doping process using a zinc-based organic framework as the precursor.When used as a potassium-ion battery anode,it has a high reversible specific capacity(435.7 mAh g^(-1)),good rate performance(133.5 mAh g^(-1)at 10,000 m A g^(-1)),and long-term cycling stability(73.2%capacity retention after the 2500th cycle).The potassium storage mechanism of the derived carbon was explained by various electrochemical analysis methods and microstructure characterization techniques,and the relationship between the structural characteristics and electrochemical properties was researched.In a supercapacitor,the porous carbon material exhibits a specific capacitance of 307.2 F g^(-1)at a current density of 0.2 A g^(-1)in a KOH aqueous solution and achieves a retention rate of 99.88%after 10,000 cycles.The assembled symmetric supercapacitor device delivers a high energy density of 6.69 Wh kg^(-1),with a corresponding power density of 2500 W kg^(-1).In addition,density functional theory calculations further confirmed that N/S codoping can improve the adsorption capacities of potassium and hydroxyl ions in the derived carbon.

The Function,Future and Support Elements of Farmer Cooperative Economy Organization

The nature of farmer cooperative economy organization( known as FCEO) determines the fact that the economic effects of farmer cooperative economy organization are as important as its social effects. Many experts,however,now would only focus on its economic function, and either neglect or weaken its social influence. Therefore,this paper introduces the theoretical foundation of the farmer cooperative economy organization,and studies the nature of cooperative economics. Based on those typical cases,the future of cooperative organization and four supporting elements were put forward in this paper.