自制土硝

自制土硝湖南娄底师范（４１７０００）彭秧锡土硝是黑火药的重要组成部分，其有效化学成份主要是硝酸钾（ＫＮＯ。）。我们可以利用硝士（主要含有ＫＮＯ３、Ｃａ（ＮＯ３）２和ＮａＣｌ）和草木灰（主要含Ｋ。ＣＯｓ）来制取。硝上存在于年久的土墙脚或猪、牛栏及厕所附...

稳态法测定馕坑硝土导热系数的研究

硝土是制作馕坑的基本材料,为了研究硝土的导热性能,在新疆戈壁滩上采集硝土,按传统使用硝土的方法制作成圆柱形试验模型,在试验模型的内部放置电加热装置,加热温度控制在200～220℃,当试验模型的内外温度达到稳定状态时测定硝土的导热系数.试验结果显示,在200～220℃条件下硝土的导热系数为（0.5726±0.0393） W/（m·℃）.

棚室简易无土栽培技术

无土栽培是指完全不用土壤,只用营养液供给营养,使作物正常生长,开花结果的一种方法。无土栽培不仅省去土壤耕作、施肥、灌水等活动、而且更重要的是可以克服土壤栽培中不易解决的水、空气和养分供应的矛盾。无土栽培的方式很多,如水培,沙培,砾培,锯末培,泥炭培等等。其中,较简易而又适宜目前棚室采用的方式是锯末袋栽法,现将其要点简介如下。(1)基质准备最好用黄杉和铁杉锯末,其些柏木末有毒、红松、落叶松及阔叶类树效果差,不宜用。

朴硝与芒硝

目前市售芒硝多为朴硝,药品色泽灰暗,掺杂砂土甚多,患者购回一般不经处理直接冲服或兑入汤剂服用。既有碍卫生,更易引起胃肠道不良反应,因朴硝是取天然产之不纯芒硝(俗称硝土)

人定胜天,那有鬼神——泸州市制硝火药厂安全生产1,295天

泸州市制硝火药厂是由2个手工生产社合并成的,现有职工68人,其中新工人56人,占总数的82.35％。这个厂以生产黑色火药为主,还生产土硝、火炮,有7个車间,分布于城区、蓝田、小市。厂子狹小,純系手工操作,技术落后,产品和原材料均屬易燃物品。合厂初期,职工中存在着各种阻碍安全生产的錯誤思想,給安全工作带来了很多困难。但是,在党的正确领导下,由于全体职工的努力,从1956年至现在的1,295天中。已经消灭了燃烧、爆炸、死亡、重伤和轻伤事故。劳动生产率由原来每人每天生产火药32斤提高到120斤,超額完成了生产任务。

BB肥到了该有国家标准的时候

BB肥标准的制定过程是一项系统工程,为了将标准制订得科学、可行,又有前瞻性,国家标准制定部门十分愿意接受来自政府管理、行业管理、检验单位、生产企业等各相关单位专家和朋友的指导和建议,希望通过大家的共同努力,来促进BB肥产业的规范发展。

Effects of long-term elevated CO_2 on N_2-fixing,denitrifying and nitrifying enzyme activities in forest soils under Pinus sylvestriformis in Changbai Mountain

A study was conducted to determine the effects of elevated CO2 on soil N process at Changbai Mountain in Jilin Province, northeastern China （42°24＂N, 128°06＂E, and 738 m elevation）. A randomized complete block design of ambient and elevated CO2 was established in an open-top chamber facility in the spring of 1999. Changpai Scotch pine （Pinus sylvestris var. sylvestriformis seeds were sowed in May, 1999 and CO2 fumigation treatments began after seeds germination. In each year, the exposure started at the end of April and stopped at the end of October. Soil samples were collected in June and August 2006 and in June 2007, and soil nitrifying, denitrifying and N2-fixing enzyme activities were measured. Results show that soil nitrifying enzyme activities （NEA） in the 5-10 cm soil layer were significantly increased at elevated CO2 by 30.3% in June 2006, by 30.9% in August 2006 and by 11.3% in June 2007. Soil denitrifying enzyme activities （DEA） were significantly decreased by elevated CO2 treatment in June 2006 （P 〈 0.012） and August 2006 （P 〈 0.005） samplings in our study; no significant difference was detected in June 2007, and no significant changes in N2-fixing enzyme activity were found. This study suggests that elevated CO2 can alter soil nitrifying enzyme and denitrifying enzyme activities.

Nitrification and Denitrification Activities and N_2O Emission of Orchard Soils Cultivated for Different Periods of Time

[Objective] The aim was to investigate the differences in nitrification and denitrification activities and the N20 emission of orchard soils cultivated for different periods of time. [Method] Incubation experiment was conducted to determine the ni- trification and denitrification activities and N20 emission of three types of orchard soil samples that had been cultivated for 5, 12 and 20 years, respectively, by using the virgin soil sample as control. [Result] After 26 d of incubation, the nitrification rates of nitrogen fertilizer in the virgin soil sample and the orchard soil samples cultivated for 5, 12 and 20 years were 6.85%, 10.26%, 13.29% and 12.90%, respectively, which were positively correlated with content of soil organic matter, ammonium nitro- gen and total nitrogen （P〈0.05）, and negatively correlated with soil carbon-nitrogen ratio and pH value （P〈0.05）. The denitrification activities of these soil samples in- creased with the increase of cultivation years. The amount of nitrogen loss by deni- trification accounted for 0.01%-3.11% of the amount of fertilizer nitrogen, and had a positive correlation with the content of soil organic matter （P〈0.05）. The N20 emis- sions of orchard soil samples were higher than that of the virgin soil samples （P〈 0.05）. [Conclusion] In South China, the nitrification activity of orchard soil is relatively low, but it has a tendency to increase as the cultivation years increases; the denitri- fication activity is relatively high, and increases significantly with the increase of culti- vation years.

Moving Dynamics of Nitrate Nitrogen in Soil of Maize Field on Meadow Soil of Daling River Valley in Liaoning and Its Fertilization Controlling

The moving dynamics of nitrate nitrogen（NO3-N）in soil of maize field on meadow soil of Daling river valley in Liaoning and its rational fertilization controlling were discussed in this study by the designing of different kinds of N application methods.The results showed that the content of NO3-N in soil was increased with the amount of nitrogen fertilizer;At the same amount of nitrogen fertilizer,the content of NO3-N in soil showed a trend of chemical fertilizerstraw treatmentslow controlled release fertilizer.Based on the requirement of roots in different growth stages to nutrition,the migration directions of NO3-N could be regulated by each layer of soil.In the early growth stage,the NO3-N would move upward,while it moved downward in the late growth stage.Straw returning treatment could improve the keeping ability of soil to NO3-N and avoid the downward migration of NO3-N,as well as reduce the damage of groundwater pollution.The use of slow controlled release fertilizer had achieved the continuing releasing of nutrition.Moreover,the peak of nutrition releasing had been delayed for 30 d,which had met the requirement of nutrient supply in maturing stage.The yield of slow controlled release fertilizer treatment was the highest with the least accumulation of NO3-N and less negative influence on environment.The yield of straw returning treatment and chemical fertilizer treatment was closed to each other.

“三仙丹”的实验研究

“三仙丹”在中医外科临床上用途广泛,对人体表面皮肤或皮下软组织的炎症性病变有一定的疗效,有消毒、杀菌、促进机体组织的再生和伤口的愈合等作用。“三仙丹”见于《疡医大全》,由水银一两、火硝、白矾各一两二钱炼制而成。由于其中火硝不参加化学反应的杂质较多,而且较难购置,我们设想是否可用火硝的主要成分——硝酸钾取而代之。为了取得充分证据,我们分别将用火硝、硝酸钾二方进行炼制,并对含量测定、皮肤接触刺激性实验作了分析比较。兹将炼制方法,实验结果报告如下。一、实验材料与方法1.物料准备:铁锅2个,烧杯2个(1000ml),柴炭炉2个,柴炭,赤石脂。2.处方配制:甲组:水银10g、火硝10g、明矾10g。乙组:水银10g、硝酸钾(C.P)10g、明矾10g。

学会带出了一个卓有成效的乡镇企业

湖南省株洲市粘接学会,有一个跨省域的团体会员单位,它就是江西省宜春市的赣西化工厂.80年代初,地处湘赣边界革命老区的江西万载县慈化乡,一个专熬土硝供制鞭炮用的综合化工厂,因一场大火烧掉了产品和厂房.厂长葛银生带领十来个职工来到株洲市搞生产自救,在为南方动力机械公司处理污水工程中,结识了该公司粘接技术的专家、株洲市粘接学会理事长的张向宇高级工程师.二人都有志创业.经单位领导同意,张向宇来到200多公里外的贫困的慈化乡,

新植甘蔗对不同施用时期的肥料氮素的利用效果

方法同一设计的试验同时在邻近而不同的两种土类即 Clansthal 砂质土和 Rydalvale 粘质土进行。15N 标记的硫酸铵用量为84公斤 N/公顷,集中一次和分次施用,与15N 标记的硝酸钾（84公斤

巧用创新渡难关——新四军军事工业回忆

1943年到1945年,抗日战争,不断取得胜利。前线对弹药的需求不但数量大,要求也高了,除缴获敌伪大批武器弹药经过及时修理,运到部队使用外,用黑火药的炮弹已远远不能适应前线的要求。于是我们将生产的八二、六〇两种炮弹改装成梯恩梯炸药。梯恩梯炸药威力大。但当时华东地区没有一家军工厂能生产它,怎么办?全班同志研究决定,将缴获来的日本、美国、蒋介石制造的迫击炮哑弹拆卸,掏出弹体内的炸药,装在我们自己造的迫击炮弹体内,送往前方消灭敌人。

Engineering behavior and sedimentation behavior of lead contaminated soil-bentonite vertical cutoff wall backfills

Soil-bentonite （SB） vertical slurry cutoff wall is a useful treatment for urban industrial contaminated sites. Due to the clay-heavy metal interaction, significant changes would occur in the engineering behavior of SB cutoff walls. However, previous study is limited to kaolinitic soils or montmorillonitic soils along using solidum chloride and/or calcium chloride as target contaminant. In this work, a series of oedometer tests were conducted to investigate the effects of lead （Pb） on the compressibility and the permeability of kaolin-bentonite （KB） mixtures, a simplified model of in-situ SB cutoff wall backfills. In addition, sedimentation tests were conducted to interpret the mechanism controlling the change of compressibility and permeability from the perspective of soil fabric. The Pb-contaminated KB mixtures for oedometer tests and sedimentation tests were prepared with bentonite contents of 0, 5%, 10%, and 15% by dry mass, and they were mixed with pre-determined volume of lead nitrate solution based on designed Pb concentration and solid-to-solution ratio. The Pb concentration was controlled as 0, 0.1, 0.5, 1.0, 5.0, 10, and 50 mg/g with a solid-to-solution ratio of approximate 0.5. The prepared KB mixtures with bentonite contents of 0, 5%, and 10% were chosen for the sedimentation tests. They were freeze-dried and mixed with DDI with a solid-to-solution ratio of 10 g/100 mL. The results indicate that pH, compressibility, and permeability of KB mixture changed considerably with respect to Pb concentration. It is concluded that the fabric of KB mixture, depending on the particle-particle interaction subjected to different ranges of pH and Pb concentration, governs the sedimentation behavior and permeability. The results of liquid limit （WE） cannot be explained in terms of the sedimentation behavior since it is only ionic-dependent.

Geospatial Mapping of Soil Nitrate-Nitrogen Distribution Under a Mixed-Land Use System

Mapping the spatial distribution of soil nitrate-nitrogen （NO3=N） is important to guide nitrogen application as well as to assess environmental risk of NO3-N leaching into the groundwater. We employed univariate and hybrid geostatistical methods to map the spatial distribution of soil NO3-N across a landscape in northeast Florida. Soil samples were collected from four depth increments （0-30, 30-60, 60-120 and 120-180 cm） from 147 sampling locations identified using a stratified random and nested sampling design based on soil, land use and elevation strata. Soil NO3-N distributions in the top two layers were spatially autocorrelated and mapped using lognormal kriging. Environmental correlation models for NO3-N prediction were derived using linear and non-linear regression methods, and employed to develop NO3-N trend maps. Land use and its related variables derived from satellite imagery were identified as important variables to predict NO3-N using environmental correlation models. While lognormal kriging produced smoothly varying maps, trend maps derived from environmental correlation models generated spatially heterogeneous maps. Trend maps were combined with ordinary kriging predictions of trend model residuals to develop regression kriging prediction maps, which gave the best NO3-N predictions. As land use and remotely sensed data are readily available and have much finer spatial resolution compared to field sampled soils, our findings suggested the efficacy of environmental correlation models based on land use and remotely sensed data for landscape scale mapping of soil NO3-N. The methodologies implemented are transferable for mapping of soil NO3-N in other landscapes.

Conversion of Natural Ecosystems to Cropland Increases the Soil Net Nitrogen Mineralization and Nitrification in Tibet

A comparative study was conducted to determine the NH4+ and NO3- concentrations in soil profiles and to examine the net nitrogen (N) mineralization and nitrification in adjacent forest, grassland, and cropland soils on the Tibetan Plateau. Cropland soil showed significantly higher inorganic N concentrations in soil profiles compared with forest and grassland soils. NO3- -N accounted for 70%–90% of inorganic N in cropland soil, while NH4+ -N was the main form of inorganic N in forest and grassland soils. The average net N mineralization rate at 0–20 cm depth was approximately twice in cropland soil (1.48 mg kg-1 d-1) as high as in forest (0.83 mg kg-1 d-1) or grassland soil (0.72 mg kg-1 d-1). Cropland showed strong net nitrification, with the net rate almost equal to the total net N mineralization. Urea addition stimulated soil respiration, particularly in forest soil. Most urea-N, however, remained as NH4+ in forest and grassland soils, while NO3- was the main form of inorganic N to increase in cropland soil. Higher rates of net nitrification in cropland soils suggest that land use change on the Tibetan Plateau may lead to high N losses through nitrate leaching.

Nitrogen recovery and nitrate leaching of controlled release nitrogen fertilizer in irrigated paddy soil

Ordinary high nitrogen fertilizer often results in nitrate (NO3--N) leaching and low recovery. Microplot and field plot experiments were conducted to determine the effect of controlled release nitrogen fertilizer (CRNF) on reco very and nitrate leaching on paddy soils. During two early rice cropping seasons (2002 and 2003), a single basal application of CRNF at 90 kg N ha-1 increased grain yields by 7.7%to 11.6%compared with two applications of urea. Estimated by the difference method fertilizer N recovery of CRNF (mean 76.3%) was 38.9 pe rcentage point higher than that of urea (mean 37.4%); estimated by 15N isotope method (mean 49.6%) CRNF (mean 67.1%) was 35.9 percentage point higher than ur ea (mean 31.2%). NO3--N leaching losses were 9.19 and 6.70 kg ha-1 for urea and CRNF, respectively. NO3--N leaching during the early rice cropping season was 27.1 %lower from CRNF than from two applications of urea. These losses repr esent 10.2%and 7.4%of applied urea-N and CRNF-N. Results from this study ind icate that CRNF improves N recovery and reduces NO3--N leaching and increases rice yield.

Decreased Soil Nitrification Rate with Addition of Biochar to Acid Soils

This study was conducted to investigate the effects of mixed biochar on the nitrification rate in acidic soils. A15 N tracer experiment with(15 NH4)2 SO4 was conducted to determine the nitrification rates of 4 acidic agricultural soils with p H 4.03-6.02 in Yunnan Province, Southern China. The accumulation of15 N-NO3-and nitrification rates decreased with the addition of biochar at the end of incubation, suggesting that biochar could be a nitrification inhibitor in acidic fertilized soil. Nitrification rates in soil with p H 4.03 were evidently lower than those in soil with p H 4.81-6.02 with or without biochar. Decreased nitrification rates were detected in the acidic soils with biochar. Soil p H controlled nitrification more than biochar in certain strongly acidic soils.

Crop Yield,N Uptake and Nitrates in a Fluvo-Aquic Soil Profile

The effects of different chemical fertilizer combinations (N, P and K) oncrop yield, N uptake and nitrate distribution and accumulation to a depth of 100 cm were studied ina cinnamon fluvo-aquic soil profile (Beijing) with a continuous winter wheat-summer maize croppingsystem for nine years. The experiment consisted of 7 treatments: no fertilizer control (CK); Nalone, N in combination with K (NK), P (NP), and P and K (NPK and N1PK); and P and K in combinationwithout N (PK). The rate of N was 150 kg ha^(-1) for the N treatments except Treatment N1PK withhigher N rate (195 kg ha^(-1)), and the rates of P (P_2O_5) and K (K2O) were 75 and 37.5 kg ha^(-1),respectively. The applications of N combined with P and K (NK, NP and NPK) resulted in higher cropyields than a single application of N. The yields followed the order: NPK > NP > N1PK > PK > NK > N> CK for winter wheat, and NPK > N1PK > NP > NK > N > PK > CK for summer maize. Supplement of N withP or K, or both P and K resulted in a higher average N uptake of the two crops, which was in adecreasing order NPK > NP > N1PK > NK > N > PK > CK. The combinations also increased apparent Nrecovery more than N alone and CK. The nitrate content in the profile was thus reduced more in thecombination treatments. The nitrate accumulation in the soil profiles followed the order: N > NK >N1PK > NPK > NP > CK > PK. Higher N uptake by the adequately fertilized crops (Treatment NPK)reduced nitrate accumulation in the profile and thus reduced nitrate leaching. The optimum N:P:Kratio was thus of paramount importance in increasing yields and N uptake of crops and reducingnitrate leaching losses.