Detection of Cyanide in Pollution-free Livestock Product Breeding Water by Ion Chromatography

In order to verify the accuracy of ion chromatography for cyanide detection,optimization conditions were studied,and comparison was made for the detection results of cyanide between titration and isonicotinic acid pyrazolone spectrophotometry. The results showed that ion chromatography has good linearity and reproducibility,with the recovery rate of 95%-105% and the limit of detection of 0. 001 mg/L. This method is simple,rapid,safe,selective,and suitable for the determination of cyanide in pollution-free livestock product breeding water.

Greenhouse Production Technical Procedure for Pollution-free Food

This procedure specifies production area environment, production technology, prevention and control of plant diseases and insect pests, and production files of pollution-free foods by taking tomato as an example. This procedure is applicable to greenhouse production of pollution-free food in Shandong Province.

Occurrence and Pollution-free Control of Apolygus lucorum in Winter Jujube

In recent years, Apolygus htcorum has become the main pest of winter jujube. It sucks juice of young parts of winter jujube and causes falling of buds and flowers, leaf perforations, deformities and fall- off of fruits, leading to serious economic loss. Considering the occurrence characteristics and control problems, the distribution, occurrence regularity, damage characteristics and outbreak reasons of A. lucorum are overviewed and analyzed in this paper, and the pollution-free control measures are also put forward.

Evaluation on Heavy Metal Pollution of Soil in Pollution-free Agricultural Product Bases in Guangxi

Using data of 6 pollution-free agricultural product bases in Guangxi Zhuang Autonomous Region,this paper analyzed content of heavy metals,including arsenic(As),mercury(Hg),lead(Pb),cadmium(Cd),and chromium(Cr) in soil.After Pb,Cd,Cr,Hg and As content in soil is determined,it evaluated the pollution of soil using single factor pollution index method and Nemerow synthetic pollution index method in combination with evaluation standard of heavy metals in soil and grading standard for soil pollution.Analysis results indicate that As,Hg,Pb,Cd,Cr content is different in pollution-free agricultural product bases,but all conform to related standards and there is no standard exceeding problem.It is concluded that the quality of soil in pollution-free agricultural product bases is excellent,not polluted and completely meet requirements of evaluation standards,and suitable for developing pollution-free agricultural products.

Regional partitioning of agricultural non-point source pollution in China using a projection pursuit cluster model

A projection pursuit cluster（PPC） model was used to analyze the regional partitioning of agricultural non-point source pollution in China.The environmental factors impacting the agricultural non-point source pollution were compiled into a projection index to set up the projection index function.A novel optimization algorithm called Free search（FS） was introduced to optimize the projection direction of the PPC model.By making the appropriate improvements as we explored the use of the algorithm,it became simpler,and developed better exploration abilities.Thus,the multi-factor problem was converted into a single-factor cluster,according to the projection,which successfully avoided subjective disturbance and produced objective results.The cluster results of the PPC model mirror the actual regional partitioning of the agricultural non-point source pollution in China,indicating that the PPC model is a powerful tool in multi-factor cluster analysis,and could be a new method for the regional partitioning of agricultural non-point source pollution.

N Cycle, N Flow Trends in Japan, and Strategies for Reducing N_2O Emission and NO_3^- Pollution

To feed an increasing population, large amounts of chemical nitrogen fertilizer have been used to produce much of our food, feed and fiber thereby increasing nitrogen levels in soils, natural waters, crop residues, livestock wastes,and municipal and agricultural wastes, with national and international concern about its potential adverse effects on environmental quality and public health. To understand these phenomena and problems, first the nitrogen cycle and the environment are described. Then recent trends for nitrogen cycling through the food and feed system, N2O emissions from fertilized upland and paddy soils, and NO-3 pollution in ground water in Japan are reported. Finally, mitigation strategies in Japan for reducing N2O emission and NO-3 pollution are proposed, including nitrification inhibitors, controlled release fertilizers, utilization of plant species that could suppress nitrification, utilizing the toposequence, government policy, and appropriate agricultural practices. Of all the technologies presented, use of nitrification inhibitors and controlled release fertilizers are deemed the most important with further development of these aspects of technologies being expected. These practices, if employed worldwide, could help reduce the load, or environmental deterioration, on the Earth's biosphere.

Studies on Heavy Metal Pollution in Soil-Plant System:A Review

Heavy metal pollution in soil-plant system is of major environmental concern on a world scale and in China in particular with the rapid development of industry. The heavy metal pollution status in soil-plant system in China, the research progress on the bioavailability of heavy metals (affecting factors, extraction methods, free-ion activity model, adsorption model, multivariate regression model, Q-I relationship, and compound pollution), and soil remediation are reviewed in the paper. Future research and monitoring is also discussed.

Appraisal of pollution and health risks associated with coal mine contaminated soil using multimodal statistical and Fuzzy-TOPSIS approaches

The present study assesses the concentration,probabilistic risk,source classification,and dietary risk arising from heavy metal(HMs)pollution in agricultural soils affected by coal mining in eastern part of India.Analyses of soil and rice plant indicated significantly elevated levels of HMs beyond the permissible limit in the contaminated zones(zone 1:PbSoil:108.24±72.97,CuSoil:57.26±23.91,CdSoil:8.44±2.76,CrSoil:180.05±46.90,NiSoil:70.79±25.06 mg/kg;PbGrain:0.96±0.8,CuGrain:8.6±5.1,CdGrain:0.65±0.42,CrGrain:4.78±1.89,NiGrain:11.74±4.38 mg/kg.zone 2:PbSoil:139.56±69.46,CuSoil:69.89±19.86,CdSoil:8.95±2.57,CrSoil:245.46±70.66,NiSoil:95.46±22.89 mg/kg;PbGrain:1.27±0.84,CuGrain:7.9±4.57,CdGrain:0.76±0.43,CrGrain:8.6±1.58,NiGrain:11.50±2.46 mg/kg)compared to the uncontaminated zone(zone 3).Carcinogenic and non-carcinogenic health risks were computed based on the HMs concentration in the soil and rice grain,with Pb,Cr,and Ni identified as posing a high risk to human health.Monte Carlo simulation,the solubility-free ion activity model(FIAM),and severity adjusted margin of exposure(SAMOE)were employed to predict health risk.FIAM hazard quotient(HQ)values for Ni,Cr,Cd,and Pb were>1,indicating a significant non-carcinogenic risk.SAMOE(risk thermometer)results for contaminated zones ranged from low to moderate risk(CrSAMOE:0.05,and NiSAMOE:0.03).Fuzzy-TOPSIS and variable importance plots(from random forest)showed that Ni and Cr were mostly responsible for the toxicity in the rice plant,respectively.A self-organizing map for source classification revealed common origin for the studied HMs with zone 2 exhibiting the highest contamination.The positive matrix factorization model for the source apportionment identified coal mining and transportation as the predominant sources of HMs.Spatial distribution analysis indicated higher contamination near mining sites as compared to distant sampling sites.Consequently,this study will aid environmental scientists and policymakers controlling HM pollution in agricultural soils near coal mines.

基于F-B NCP函数的可行QP-free算法

本文得到一种可行QP-free算法,引入ε-有效集策略使得每次迭代只需求解规模较小的线性方程组得到迭代方向,且方程组只包含工作集中的约束,其规模较原问题大大减小,同时不进行弧搜索,从而降低了运算量.

Process for improving the ladle free- opening rate for high aluminum steel in continuous casting

Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are：sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.

Development of Debris-free Laser Plasma Sources for EUV Lithography in CIOMP

We have been developing debris-free laser plasma sources for EUV lithography since 1996. Two types of debris-free sources, such as cryogenic target and gas-puff target laser plasma sources, were designed and built up in CIOMP. EUV radiation spectra of the sources with a variety of targets have been obtained by different ways.

EXACT SOLUTION FOR RECTANGULAR SLAB WITH THREE EDGES SIMPLY-SUPPORTED AND OTHER FREE

In this paper,we give all-sided pastic analysis of the rectangular slab with three edges simply-supported and other free.Here we discuss the following four cases:(1)The uniformly distributedload over the area a slab.(2).A concentrated load act at midpoint of free edges slab.(3)A concen-trated load act at the center a slab.(4)The line load act along free edge of slab.

Influence of 10-(6-plastoquinonyl) decyltriphenylphosphonium on free-radical homeostasis in the heart and blood serum of rats with streptozotocin-induced hyperglycemia

BACKGROUND It is known that under conditions of tissue tolerance to insulin,observed during type 2 diabetes mellitus(DM2),there is an increased production of reactive oxygen species.Moreover,the free radicals can initiate lipid peroxidation(LPO)in lipoprotein particles.The concentration of LPO products can influence the state of insulin receptors,repressing their hormone connection activity,which is expressed as a reduction of the glucose consumption by cells.It is possible that reduction in glucose concentration during administration of 10-(6-plastoquinonyl)decyltriphenylphosphonium(SkQ1)to rats with DM2 may be related to the antioxidant properties of this substance.AIM To establish the influence of SkQ1 on free-radical homeostasis in the heart and blood serum of rats with streptozotocin-induced hyperglycemia.METHODS To induce hyperglycemia,rats were fed a high-fat diet for 1 mo and then administered two intra-abdominal injections of streptozotocin with a 7-d interval at a 30 mg/kg of animal weight dose with citrate buffer equal to pH 4.4.SkQ1 solution was administered intraperitoneally at a 1250 nmol/kg dose per day.Tissue samples were taken from control animals,animals with experimental hyperglycemia,rats with streptozotocin-induced glycemia that were administered SkQ1 solution,animals housed under standard vivarium conditions that were administered SkQ1,rats that were administered intraperitoneally citrate buffer equal to pH 4.4 once a week during 2 wk after 1-mo high-fat diet,and animals that were administered intraperitoneally with appropriate amount of solution without SkQ1(98%ethanol diluted eight times with normal saline solution).To determine the intensity of free radical oxidation and total antioxidant activity,we used the biochemiluminescence method.Aconitate hydratase(AH),superoxide dismutase,and catalase activities were estimated using the Hitachi U-1900 spectrophotometer supplied with software.The amount of citrate was determined by means of the Natelson method.Real-time polymerase chain reaction was carried out using an amplifier ANK-32.RESULTS It was found that the mitochondrial-directed antioxidant elicits decrease of biochemiluminescence parameter values that increase by pathology as well as the levels of primary products of LPO,such as diene conjugates and carbonyl compounds,which indicate intensity of free radical oxidation.At the same time,the activity of AH,considered a crucial target of free radicals,which decreased during experimental hyperglycemia,increased.Apparently,increasing activity of AH influenced the speed of citrate utilization,whose concentration decreased after administering SkQ1 by pathology.Moreover,the previously applied antioxidant during hyperglycemia influenced the rate of antioxidant system mobilization.Thus,superoxide dismutase and catalase activity,as well as the level of gene transcript under influence of SkQ1 at pathology,were changing to the direction of control groups values.CONCLUSION According to the results of performed research,SkQ1 can be considered a promising addition to be included in antioxidant therapy of DM2.

中国自由贸易试验区是否抑制了环境污染——来自中国281个城市的实证研究

加快建设贸易强国,提高对外开放水平,是推进高水平对外开放进而实现高质量发展的重大课题。然而,贸易引致而来的环境问题不容忽视,如何有效防治环境污染,推动绿色发展,成为高质量发展中亟须解决的问题之一。本文以自由贸易试验区作为“准自然实验”,利用2005—2019年中国城市的面板数据,通过双重差分法探究贸易与环境的关系。研究发现:自贸区能够显著抑制片区所在城市的环境污染,该结论在考虑内生性问题以及多种稳健性检验后依然成立;自贸区通过优化地区产业结构、提高地区绿色创新能力以及促进地区经济集聚三个作用渠道来抑制地区环境污染;自贸区对地区环境污染的抑制作用存在地理、行政异质性,中西部城市和副省级以上城市的抑制环境污染效应更显著;自贸区在抑制环境污染方面具有空间溢出效应,能够对邻近地区的环境污染起到显著的遏制作用;在抑制环境污染方面,自贸区与“一带一路”倡议之间存在联动作用。本文为丰富自贸区的政策内涵、实现贸易与环境双赢发展提供了新思路。

自贸试验区如何促进绿色发展——基于环境污染视角的实证研究

有效减少环境污染是绿色发展的前提,也是实现绿色发展的关键。基于2009—2020年中国257个地级及以上城市的面板数据,采用多期双重差分法研究自贸试验区试点政策对城市环境污染的影响,构建中介效应模型分析产业结构高级化和绿色技术创新的具体作用,同时运用空间杜宾模型检验自贸试验区试点的设立对环境污染的影响是否具有空间辐射效应。研究结果表明:自贸试验区试点政策有利于减少城市环境污染;自贸试验区试点政策从产业结构高级化和绿色技术创新这两个途径改善了城市环境状况;自贸区试点政策对环境污染的改善具有显著的空间辐射作用。

ICP-MS测定无公害农产品土壤样中的铅·镉

[目的]简便快速测定无公害农产品土壤样中铅(Pb)、镉(Cd)的含量。[方法]采用湿法消解样品,在硝酸介质中用电感耦合等离子体质谱仪(ICP-MS)测定Pb、Cd的含量。[结果]在最佳测定条件下,Pb、Cd的质量分数分别在1.70～1000.00mg/kg、0.05～100.00mg/kg范围内呈线性关系。相对标准偏差分别小于3.4%和5.2%。[结论]该法具有简便快速、检出限低等特点,可满足土壤样中Pb、Cd的测定。

温度升高和游离余氯对泥蚶的氧化胁迫效应

为了研究核电站温排水污染对水生动物长期胁迫的影响,实验通过室内模拟核电站温排水的游离余氯残留和温升效应,研究了不同温度和不同游离余氯浓度耦合下对泥蚶的氧化胁迫效应。设置水温为19和29℃,游离余氯浓度分别为0.33和6.66 mg/L,进行为期20 d的胁迫实验。结果显示:①单一温升条件下,温度升高可以显著影响泥蚶ROS水平。温度越高,ROS水平越高。②0.33 mg/L浓度组泥蚶ROS水平和DNA损伤在第20天时显著升高,19和29℃下分别为对照组的2.2、2.9倍和1.8、2.2倍;细胞活性、SOD活性、ATP酶活性均下降;6.66 mg/L浓度组ROS水平在第20天时显著上升,19和29℃下分别为对照组的6.2、3.6倍,DNA损伤增加,细胞活性、血细胞吞噬率和ATP酶活性下降,SOD酶活性在第20天、29℃时降至最小值(36.4±8.4)U/(mg·prot)。③双因素方差分析结果显示,水温和游离余氯对泥蚶ROS水平、DNA损伤、血细胞吞噬活性、ATP酶活性具有显著交互作用。研究表明,游离余氯能够显著增加泥蚶ROS水平和DNA损伤,温度升高和游离余氯复合暴露对泥蚶造成更大的胁迫压力,影响了其机体内氧化响应相关生理过程,余氯排放海域夏季相比冬季会对泥蚶产生更大的氧化胁迫。本研究可为温度升高和游离余氯复合污染中的海洋生物氧化胁迫毒性研究提供参考,并且为生态风险评估提供科学依据。

（K1，4；2）-图的闭包和周长

针对（K1,4；2）-图这一新的图类，证明了以下结论：1）设G是δ≥5且K1∨P4-free的（K1,4；2）-图，则c（G）=c（cl（G））；2）设G是δ≥5且T3-free的（K1,4；2）-图，则c（G）=c（cl（G））．

(K_(1,4);2)-图的3-闭包中的路

对(K1,4;2)-图,证明它的3-闭包的一个性质。G为{K1∨P5,T3}-free或K1∨P4-free的(K1,4;2)图,x,a,b为G中不同三点,x为G中局部3-连通的适宜点,G′由G在点x局部完备所得。若G′中有长为l的(a,b)-路,则G中有长为l的(a,b)-路。

无公害蔬菜栽培和病虫害防治技术分析

蔬菜富含多种营养成分,是日常生活不可缺少的必需品。在蔬菜种植过程中为了降低病虫害的发病率和负面影响,提高蔬菜产量,通常会使用农药和化肥,但有时会出现农药残留等现象。随着人们对健康的关注度越来越高,对蔬菜的安全性也提出了更高的要求,因此对无公害蔬菜的需求越来越大,因此可加大无公害蔬菜的种植面积,通过科学手段提高蔬菜产量。该文简要分析了无公害蔬菜的栽培技术和病虫害防治技术,以供相关专业人员参考。