A Rapid Determination of 30 Prohibited Pesticide Residues in Lycii Fructus by UPLC-MS/MS

Prohibited pesticide residues have become one of the main factors affecting the quality and safety of Lycii Fructus,However,rarely studies focus on the rapid determination of these residues.Here,a total of 30 kinds of prohibited pesticide residues were determined by ultra-performance liquid chromatography tandem triple quadrupole mass spectrometry(UPLC-MS/MS)in five different process ways.Pretreatment methods,chromatographic separation and detection conditions in mass spectrometry were all optimized accordingly.Among the five different pretreatment methods,the first and third solid phase extraction failed to provide high recoveries of sulfosulfuron compounds(both lower than 60%).Recovery of chlorphenamidine by the Quick Easy Cheap Effective Rugged and Safe multiresidue method(QuEChERS)was lower than 60%,which did not meet the requirements of trace determination.The concentrations of 30 prohibited pesticides residues treated by straightforward and solid phase extraction showed good linearity in their corresponding ranges,with correlation coefficients over 0.99.The average recoveries of straightforward ranged from 78.13%to 110.9%,while RSD ranged from 1.3%to 16.9%,albeit poor purification was observed.The recovery yield from solid phase extraction was between 67.75%and 103.08%with RSD value from 0.8%to 14.0%,which met the requirements of trace determination,this method has good precision and stability.These results could be employed to other Traditional Chinese Medicines(TCMs)in detecting prohibited pesticide residues.

Contamination of Prohibited Substances in Various Food Products in Guangzhou, China

The use of antibiotics to maintain animal health has widely been practiced,for both therapeutic and prophylactic purposes.Along with the identification of serious adverse effects of some antibiotics on human and domestic animals[1],chloramphenicol.

Modifying current thin-film microextraction(TFME)solutions for analyzing prohibited substances:Evaluating new coatings using liquid chromatography

For identifying and quantifying prohibited substances,solid-phase microextraction(SPME)continues to arouse interest as a sample preparation method.However,the practical implementation of this method in routine laboratory testing is currently hindered by the limited number of coatings compatible with the ubiquitous high-performance liquid chromatography(HPLC)systems.Only octadecyl(C18)and polydimethylsiloxane/divinylbenzene ligands are currently marketed for this purpose.To address this situation,the present study evaluated 12 HPLC-compatible coatings,including several chemistries not currently used in this application.The stationary phases of SPME devices in the geometry of thin filmcoated blades were prepared by applying silica particles bonded with various functional ligands(C18,octyl,phenyl-hexyl,3-cyanopropyl,benzenesulfonic acid,and selected combinations of these),as well as unbonded silica,to a metal support.Most of these chemistries have not been previously used as microextraction coatings.The 48 most commonly misused substances were selected to assess the extraction efficacy of each coating,and eight desorption solvent compositions were used to optimize the desorption conditions.All samples were analyzed using an HPLC system coupled with triple quadrupole tandem mass spectrometry.This evaluation enables selection of the best-performing coatings for quantifying prohibited substances and investigates the relationship between extraction efficacy and the physicochemical characteristics of the analytes.Ultimately,using the most suitable coatings is essential for trace-level analysis of chemically diverse prohibited substances.

气相色谱-质谱联用法检测保健品中的违禁药物

This paper describes a method qualitative analysis of some prohibited drugs in functional food by gas chromatography-mass spectrometry.The result showed that ibuprofen,phenacetin,bendazol,voltaren,diazepam, nifendipinc,metoclopramide,indomethacin and 6 kinds of decomposition product were exist in the samples which we have tested.

中成药中违禁添加药物的液质联用仪测定研究

近年来不断有关于保健食品或植物提取药物中违禁添加合成药物的相关报道,其中包括各类兴奋剂、利尿剂、壮阳剂、厌食剂等几十种药物,为保护广大消费者的身体健康,有关国家都建立了相关的技术标准.在这一分析过程中,需要解决3个方面问题,一是药物的分析范围非常大,尤其是在极性、酸碱性差异非常大,如何能达到一次分析完成全谱的分析工作;二是药物含量限制差异巨大,有的仅有几个mg/kg;三是如何能准确地完成定性结论.……

Modified Cuckoo Search Algorithm to Solve Economic Power Dispatch Optimization Problems

A modified cuckoo search(CS) algorithm is proposed to solve economic dispatch(ED) problems that have nonconvex, non-continuous or non-linear solution spaces considering valve-point effects, prohibited operating zones, transmission losses and ramp rate limits. Comparing with the traditional cuckoo search algorithm, we propose a self-adaptive step size and some neighbor-study strategies to enhance search performance.Moreover, an improved lambda iteration strategy is used to generate new solutions. To show the superiority of the proposed algorithm over several classic algorithms, four systems with different benchmarks are tested. The results show its efficiency to solve economic dispatch problems, especially for large-scale systems.

Addressing Economic Dispatch Problem with Multiple Fuels Using Oscillatory Particle Swarm Optimization

Economic dispatch has a significant effect on optimal economical operation in the power systems in industrial revolution 4.0 in terms of considerable savings in revenue.Various non-linearity are added to make the fossil fuel-based power systems more practical.In order to achieve an accurate economical schedule,valve point loading effect,ramp rate constraints,and prohibited operating zones are being considered for realistic scenarios.In this paper,an improved,and modified version of conventional particle swarm optimization(PSO),called Oscillatory PSO(OPSO),is devised to provide a cheaper schedule with optimum cost.The conventional PSO is improved by deriving a mechanism enabling the particle towards the trajectories of oscillatory motion to acquire the entire search space.A set of differential equations is implemented to expose the condition for trajectory motion in oscillation.Using adaptive inertia weights,this OPSO method provides an optimized cost of generation as compared to the conventional particle swarm optimization and other new meta-heuristic approaches.

Sequential Approach with Matrix Framework for Various Types of Economic Thermal Power Dispatch Problems

This paper presents a sequential approach with matrix framework for solving various kinds of economic dispatch problems. The objective of the economic dispatch problems of electrical power generation is to schedule the committed generating units output so as to meet the required load demand while satisfying the system equality and inequality constraints. This is a maiden approach developed to obtain the optimal dispatches of generating units for all possible load demands of power system in a single execution. The feasibility of the proposed method is demonstrated by solving economic load dispatch problem, combined economic and emission dispatch problem, multiarea economic dispatch problem and economic dispatch problem with multiple fuel options. The proposed methodology is tested with different scale of power systems. The generating unit operational constraints are also considered. The simulation results obtained by proposed methodology for various economic dispatch problems are compared with previous literatures in terms of solution quality. Numerical simulation results indicate an improvement in total cost saving and hence the superiority of the proposed method is also revealed for economic dispatch problems.

Input Quantity and Distribution of Hexachlorocyclohexane (HCH) in the Jiaozhou Bay Waters

Based on data from the investigation in Jiaozhou bay waters in May, July and November in 1987, the distribution, source and seasonal variation of HCH in Jiaozhou Bay are analyzed. The results showed that in Jiaozhou bay HCH content was very low and less than 0.100 μg/L in this year, and better than the national Category I of the sea water quality standard, and the water quality about HCH was very clean;and that The seasonal variation of the HCH content in Jiaozhou bay waters has already vanished, namely, the seasonal variation of the HCH content in this year was not influenced by the rainfall, the runoffs or rivers. The horizontal distributions of the HCH content in the whole bay waters showed that the HCH content in the bay was not only directly input from both runoffs but also from rivers, the HCH source was area-source and came from land. The vertical distributions of the HCH content in the whole bay waters showed that the change of the HCH content at surface was not consistent with the corresponding one at bottom, and that the trend of the HCH distribution at surface was not consistent with that at bottom, and that only the HCH contents at surface and bottom were very close. From the year of four years ago of the prohibition (1979), to the prohibition year of HCH use (1983), and finally to the year after the four years of the prohibition (1987), The change of the HCH input into the bay waters unveiled that the by four years before the prohibition, the pollution of the HCH on land was very grave, and by four years after the prohibition, the HCH content in waters was very low, whose process represented that the process of human being having broken up the earth and the process of the earth having naturally restored. Therefore, Human being would consider not only for own benefits but also for the sustainable development of environment.

Food Prohibitions and Other Traditional Practices in Pregnancy: A Qualitative Study in Western Region of Ghana

Women all over the world are confronted with many difficult choices during pregnancy and child birth. Wrong choices often result in unfavorable outcomes for expectant mothers and their babies, a situation which is common in developing countries. Cultural practices, beliefs and taboos are often implicated in determining the care received by mothers during pregnancy and child birth which is an important determinant of maternal mortality. This study explored the traditional practices associated with pregnancy and childbirth in Shama District of the Western Region, Ghana. A qualitative study consisting of six focus group discussions of between eight and ten participants per group and eight in-depth interviews were held over a period of one month. The purpose was to explore local foods that are forbidden for pregnant women and why, herbal medicine use during pregnancy and child birth and reasons for choosing home or hospital delivery. The findings show that pregnant women are forbidden from taking nutritious foods such as snails, ripe plantain, okra and many others for fear of complications during pregnancy and child birth. Herbal medicines are frequently used by pregnant women and traditional birth attendants to induce labour, augment and control bleeding during labour. Traditional beliefs and practices as well as negative attitude of health workers are found to reduce health utilization by pregnant women. Health education concerning traditional practices that are detrimental to the health of pregnant women should be emphasized during ANC visits.

Oil and Gas Policies in the World’s Major Countries

Revolutionary adjustments were made to the global energy structure in 2017.For the first time,OPEC cooperated with non-OPEC countries to reach an agreement on production curtailment in order to stabilize the oil and gas market.On the one hand,host countries have introduced various fiscal and tax incentive policies to attract investment in the oil and gas industry;on the other,the lack of fiscal revenue has been made up for and the low-carbon environmental protection policy supported by imposing a value-added tax and environmental protection tax.Major consumers have introduced a timetable for the sales prohibition of fuel vehicles and supported the development of new energy vehicles with fiscal and taxation policies.However,from the perspective of the full life cycle,the promotion of electric vehicles is only conducive to partially improving the environment and is not the optimal choice for national energy structure optimization.Electric vehicles will have real significance for environmental protection only after clean electric power is solved.As such,implementing the sales prohibition of fuel vehicles with administrative power goes against market discipline.

COCA Context Feature-Based Study of Near-Synonymous Verbs——A Case Study of Forbid and Prohibit

English near-synonyms pose a great challenge for English learners and they often feel confused about them.This paper draws on the research findings of the distinction of synonymous pair:forbid and prohibit based on COCA(Corpus of Contemporary American English)corpus online.The result shows that for collocation,forbid may be used to collocate with the infinitive(to do)oring participle,while prohibit often collocates with the preposition from.After register analysis,it is found that prohibit is more for⁃mal than forbid.As for semantic prosody,forbid is associated with neutral collocates,whereas prohibit appears to suggest a more negative semantic prosody.Detailed comparison and contrast about the two verbs can thus help English learners grasp the differenc⁃es of English synonyms accurately.

Optimal power flow calculation in AC/DC hybrid power system based on adaptive simplified human learning optimization algorithm

This paper employs an efficacious analytical tool,adaptive simplified human learning optimization(ASHLO)algorithm,to solve optimal power flow(OPF)problem in AC/DC hybrid power system,considering valve-point loading effects of generators,carbon tax,and prohibited operating zones of generators,respectively.ASHLO algorithm,involves random learning operator,individual learning operator,social learning operator and adaptive strategies.To compare and analyze the computation performance of the ASHLO method,the proposed ASHLO method and other heuristic intelligent optimization methods are employed to solve OPF problem on the modified IEEE 30-bus and 118-bus AC/DC hybrid test system.Numerical results indicate that the ASHLO method has good convergent property and robustness.Meanwhile,the impacts of wind speeds and locations of HVDC transmission line integrated into the AC network on the OPF results are systematically analyzed.

An improved chaotic hybrid differential evolution for the short-term hydrothermal scheduling problem considering practical constraints

Short-term hydrothermal scheduling(STHTS) is a non-linear and complex optimization problem with a set of operational hydraulic and thermal constraints. Earlier, this problem has been addressed by several classical techniques; however, due to limitations such as non-linearity and non-convexity in cost curves, artificial intelligence tools based techniques are being used to solve the STHTS problem. In this paper an improved chaotic hybrid differential evolution(ICHDE) algorithm is proposed to find an optimal solution to this problem taking into account practical constraints. A self-adjusted parameter setting is obtained in differential evolution(DE) with the application of chaos theory, and a chaotic hybridized local search mechanism is embedded in DE to effectively prevent it from premature convergence. Furthermore, heuristic constraint handling techniques without any penalty factor setting are adopted to handle the complex hydraulic and thermal constraints. The superiority and effectiveness of the developed methodology are evaluated by its application in two illustrated hydrothermal test systems taken from the literature. The transmission line losses, prohibited discharge zones of hydel plants, and ramp rate limits of thermal plants are also taken into account. The simulation results reveal that the proposed technique is competent to produce an encouraging solution as compared with other recently established evolutionary approaches.

A symmetric aqueous redox flow battery based on viologen derivative

Due to the diversity and feasibility of structural modification for organic molecules,organic-based redox flow batteries(ORFBs)have been widely investigated,especially in aqueous solution under neutral circumstance.In this work,a symmetric aqueous redox flow battery(SARFB)was rationally designed by employing a bipolar redox active molecule(N,N’-dimethyl-4,4-bipyridinium diiodide,MVI2)as both cathode and anode materials and combining with an anion exchange membrane.For one MVI2 flow battery,MV2+/MV·+and I-/I3-serve as the redox couples of anode and cathode,respectively.The MVI2 battery with a working voltage of 1.02 V exhibited a high voltage efficiency of 90.30%and energy efficiency of 89.44%after 450 cycles,and crossover problem was prohibited.The comparable conductivity of MVI2 water solution enabled to construct a battery even without using supporting electrolyte.Besides,the bipolar character of MVI2 battery with/without supporting electrolyte was investigated in the voltage range between-1.2 V and 1.2 V,showing excellent stable cycling stability during the polarity-reversal test.

Atmospheric pollution of agriculture-oriented cities in Northeast China: A case in Suihua

Agriculture-oriented cities in Northeastern China have experienced frequent atmospheric pollution events.Deeper understandings of the pollution characteristics,haze causes and effects of management on local air quality are crucial for conducting integrated management approaches for the sustainable development of agriculture-oriented cities.Taking a typical agriculture-dominant city(i.e.,Suihua)in Northeast China,we analyzed in detail the characteristics and causes of atmospheric pollution and evaluated the straw-burning prohibition using multisource data.The results showed a clear temporal pattern of air quality index(AQI)on an annual scale(i.e.,2015-April 2019),with two typical pollution periods occurring in late autumn and early spring.The large areas of concentrated straw burning at local and regional scales accounted for the first period(i.e.,October and November),while dust emissions and farming disturbances comprised the second period.The interannual variation in pollution periods among these years was large,showing similar trends from 2015 to 2017 and the postponed late-autumn pollution period in 2018.Our evaluation has shown that the prohibition effect of straw burning significantly improved air quality in 2018,with a reduction of 59%±88%in the PM2.5 concentrations in October and November compared to 2015–2017.However,From October to April of the following year,the improvement effect was not significant due to postponement of straw burning to February or March.Our analysis also highlighted the roles of meteorological conditions,Therefore,combined with the promotion of straw utilization,scientifically prescribed burning considering the burning amount and location,meteorological conditions and regional transportation should be implemented.

Multi-place physics and multi-place nonlocal systems

Multi-place nonlocal systems have attracted attention from many scientists.In this paper,we mainly review the recent progresses on two-place nonlocal systems(Alice-Bob systems)and four-place nonlocal models.Multi-place systems can firstly be derived from many physical problems by using a multiple scaling method with a discrete symmetry group including parity,time reversal,charge conjugates,rotations,field reversal and exchange transformations.Multiplace nonlocal systems can also be derived from the symmetry reductions of coupled nonlinear systems via discrete symmetry reductions.On the other hand,to solve multi-place nonlocal systems,one can use the symmetry-antisymmetry separation approach related to a suitable discrete symmetry group,such that the separated systems are coupled local ones.By using the separation method,all the known powerful methods used in local systems can be applied to nonlocal cases.In this review article,we take two-place and four-place nonlocal nonlinear Schr?dinger(NLS)systems and Kadomtsev-Petviashvili(KP)equations as simple examples to explain how to derive and solve them.Some types of novel physical and mathematical points related to the nonlocal systems are especially emphasized.

Exact Solutions of an Alice-Bob KP Equation

An Alice-Bob Kadomtsev-Petviashivili(ABKP) equation with shifted-parity(■_s^x parity with a shift for the space variable x) and delayed time reversal(■d, time reversal with a delay) symmetries is investigated. The multi-soliton solutions with three arbitrary even or odd functions are found from the ■_s^x■_d symmetry reductions of a coupled local KP system. The result shows that for the ABKP equation with ■_s^x■_d nonlocality, the odd numbers of solitons are prohibited.The solitons of the ABKP must be paired. For the ABKPⅡ equation, there exists a critical value of wave numbers for the existence of paired solitons. For the ABKPI equation, there are two types of 'breather' excitations. A lump solution of the ABKPI may possess four, five or six leaves.

A fine-grained access control model for relational databases

Fine-grained access control (FGAC) must be supported by relational databases to satisfy the requirements of privacy preserving and Internet-based applications.Though much work on FGAC models has been conducted,there are still a number of ongoing problems.We propose a new FGAC model which supports the specification of open access control policies as well as closed access control policies in relational databases.The negative authorization is supported,which allows the security administrator to specify what data should not be accessed by certain users.Moreover,multiple policies defined to regulate user access together are also supported.The definition and combination algorithm of multiple policies are thus provided.Finally,we implement the proposed FGAC model as a component of the database management system (DBMS) and evaluate its performance.The performance results show that the proposed model is feasible.

Should Tsinghua University Prohibit Kindergartens From Using Its Name?

China’s prestigious Tsinghua University, which was established in 1911, has recently filed several lawsuits against kindergartens that use the two Chinese characters Qinghua(current spelling of Tsinghua in roman alphabet), representing Tsinghua(the old spelling of the same two Chinese characters).