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。

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。

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.

The adsorptive properties of UiO-66 towards organic dyes: A record adsorption capacity for the anionic dye Alizarin Red S.

In order to decisively determine the adsorption selectivity of zirconium MOF(UiO-66) towards anionic versus cationic species, the adsorptive removal of the anionic dyes(Alizarin Red S.(ARS), Eosin(E), Fuchsin Acid(FA)and Methyl Orange(MO)) and the cationic dyes(Neutral Red(NR), Fuchsin Basic(FB), Methylene Blue(MB),and Safranine T(ST)) has been evaluated. The results clearly reveal a significant selectivity towards anionic dyes. Such an observation agrees with a plethora of reports of UiO-66 superior affinity towards other anionic species(Floride, PO_4^(3-), Diclofenac sodium, Methylchlorophenoxy-propionic acid, Phenols, CrO_4^(2-), SeO_3^(2-), and AsO_4^-). The adsorption process of ARS as an example has been optimized using the central composite design(CCD). The resultant statistical model indicates a crucial effect of both pH and sorbent mass. The optimum conditions were determined to be initial dye concentration 11.82 mg.L^(-1), adsorbent amount 0.0248 g, shaking time of 36 min and pH 2. The adsorption process proceeds via pseudo-second order kinetics(R^2= 0.999). The equilibrium data were fit to Langmuir and Tempkin models(R^2= 0.999 and 0.997 respectively). The results reveal an exceptional removal for the anionic dye(Alizarin Red S.) with a record adsorption capacity of400 mg·g^(-1). The significantly high adsorption capacity of UiO-66 towards ARS adds further evidence to the recently reported exceptional performance of MOFs in pollutants removal from water.

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 results 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 nm–1. A significant relationship 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 determination 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 variations, while phytoplankton originated organic matter also closely linked with CDOM dynamics in three productive reservoirs.

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.

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。

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。

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.

Quality Safety Standards of Organic Mango

This article conducts a brief analysis of the factors that affect the quality safety of organic mango, and discusses the organic production measures for improving the quality and quality safety of mango, including the choice of environment of place of origin, varieties and seedlings, fertilizers and fertilization, plant protection products and other production inputs. A test is carried out in 0.667 hm2 of base in Tianyang County, Baise City. Content of lead, arsenic and 14 kinds of pesticide residue such as BHC in the mango are not detected; the content of heavy metal such as mercury and cadmium is 0.001-0.006 mg/kg. Then the quality and quality safety indicators of organic mango are discussed, and finally the Guangxi local standards of organic mango products are developed.

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.

Prestack inversion identification of organic reef gas reservoirs of Permian Changxing Formation in Damaoping area, Sichuan Basin, SW China

Organic reef reservoirs in the platform margin of Kaijiang-Liangping trough in Damaoping area, Sichuan Basin are thin in single layer, fast in lateral variation, and have small P-impedance difference from the surrounding rock, it is difficult to identify and predict the reservoirs and fluid properties by conventional post-stack inversion. Through correlation analysis of core test data and logging P-S wave velocity, this work proposed a formula to calculate the shear wave velocity in different porosity ranges, and solved the issue that some wells in the study area have no S-wave data. AVO forward analysis reveals that formation porosity is the main factor affecting the variation of AVO type, the change of water saturation cannot affect the AVO type, but it has an effect on the change range of AVO. Through cross-plotting analysis of elastic parameters, it is found that fluid factor is a parameter sensitive to gas-bearing property of organic reef reservoir in the study area. By comparing results of post-stack impedance inversion, post-stack high frequency attenuation property, pre-stack simultaneous inversion and AVO anomaly analysis of angle gathers, it is found that the gas-bearing prediction of organic reef reservoirs by using fluid factor derived from simultaneous pre-stack inversion had the highest coincidence rate with actual drilling data. At last, according to the characteristics of fluid factor distribution, the favorable gas-bearing area of the organic reef reservoir in Changxing Formation was predicted, and the organic reef trap at the top of Changxing Formation in Block A of Damaoping area was sorted out as the next exploration target.

过渡金属催化有机硫化物C-S断裂反应的研究进展

有机硫化物广泛存在于石油、煤炭等自然资源中,具有丰富的资源储备。在石油炼制工业中,通常需要通过C-S断裂进行石油馏分的脱硫。其中,过渡金属催化的C-S断裂反应因具有效率高、条件温和、污染小等优点而备受研究者的关注。总结了过渡金属催化不同类型有机硫化物C-S断裂反应的最新进展,对Pd、Cu、Ni、Fe等催化体系的反应机理提出了见解,并对该类反应的发展前景进行了展望。

Assessment of the Influence of Sulfuric Acid/Hydrogen Peroxide Mixture on Organic Sulfur Reduction of High Sulfur Coals and Their Chemical Composition

One of the contaminants in coal is sulphur. The adverse impact of sulfur on coal, such as environmental pollution, degradation of steel quality, and reduction of coal’s thermal value, has led to the attention of sulfur separation methods in recent decades. Leaching (chemical dissolution) is one of the best methods for desulfurising coal, reducing sulfur in coal. In this study, hydrogen peroxide as an oxidising agent on sulfuric acid yield in reducing sulfur types of coal and chemical structure and the organic texture of high sulfur coal was investigated. The experiments were designed using a three-level response surface methodology with four duplicate points and 27 experiments. The independent variables studied were temperature, time, stirring speed and ratio of sulfuric acid to hydrogen peroxide. Dependent variables included reduction percentage of total, pyritic and organic sulfur. This study showed that 99.99% of total sulfur, 30.11% of pyritic sulfur and 69.08% of organic sulfur were reduced. These values were obtained at a temperature of 60&#176;C, time 120 min, stirring speed 200 rpm and 3:1 ratio of sulfuric acid to hydrogen peroxide. Significant changes were observed by infrared spectroscopy (FTIR) of the coal structure before and after desulphurisation. On the other hand, the studies showed no specific changes in the bonds related to the organic coal matrix. The results showed that this method could be used as a secure process for removing inorganic and organic sulfur without destroying the organic coal matrix.

Method and application of knowledge organization system for S&T literature

In the big data environment, the construction of massive S&T literature data resources needs intelligent technical assistance. With a focus on comparing the domestic and foreign knowledge organization systems and their applications, this article analyzes and summarizes the gaps in related researches and applications at home and abroad. A knowledge organization system framework for S&T literature data resources is presented in the article. Starting from the basic element of knowledge organization system, it also proposes and designs terminology-based analysis methods and technologies for S&T literature. Based on this framework, it proposes ideas and develops corresponding software tool to carry out relevant experiments. It gives an overview of theories and technologies method for future research.