Micromorphology and quality attributes of the loess derived soils affected by land use change: A case study in Ghapan watershed, Northern Iran

In order to study the effects of different land vegetative covers on soil quality attributes, a loess hill slope was selected in eastern Golestan Province, Ghapan watershed, Iran. Four profiles in four land uses, including Quercus natural forest; Pinus artificial forest; Cupressus artificial forest and a cultivated land, were studied. Results showed that MWD was significantly different in the studied land uses, and it varied between 1.6 mm in Quercus natural forest and o.31 mm in cultivated land use. The lowest CEC, microbial respiration rate and organic carbon were 28.4 cmol·kg^1, 177 μgCO2·g^-1·day^-1 and 1.32 % found in cultivated land use, respectively. The organic matter was considerably higher content in the forest areas than that of cultivated land use. The studies on soil profile development revealed that the natural forest soils were highly developed. The soils of the Quercus natural forest were classified as Calcic Haploxeralfs with a well developed argillie horizon unlike the cultivated soils which showed the minimum development and classified as Typic Xerorthents. The soils of the artificial forests had both mollic epipedons and were classified as Typic Calcixerolls with moderate profile development. Micromorphological studies revealed that argillic horizons had speckled and partly crystallitic b-fabric in the natural forest indicating the high landscape stability. In contrast, the crystallitic b-fabric of other land uses shows the absence of enough leaching of carbonate and the subsequent migration of clay particles indicating the unstable conditions and high soil erosion. Intense erosion of the surface horizons of cultivated land use has resulted in the outcropping of the subsurface carbonate rich horizons preventing soil development.     

Transpiration rates of Carex Meyeriana in relation to micrometerological factors in a mountain valley wetland

In order to reveal transpiration rates of wetland plants and its relationships to micro- meterological factors in a mountain valley wetland, relative humidity, air temperature, leaf temperature, soil temperature, photo flux density and transpiration rates were measured once two hours in a Carex meyeriana wetland of the Changbai Mountain valley in dry （July） and wet （September） of 2003, respectively. Results showed that the tendency of ＂decreasing after increasing＂ was obvious in wet season. However, a relatively stable trend was observed for the transpiration in dry season.. Generally, the photon flux density of Carex meyeriana was higher in wet season than that in dry season. However, the variabilities of leaf temperature, air temperature and relative humidity were similar in both seasons. Higher transpiration rates of Carex meyeriana leaves were observed in July （varied from 40 to 150 mol.m^-2.s^-1） compared to those （varied from 7 to 14 mol.m^-2.s^-1） in September. Transpiration rates were significantly correlated with air temperature （P〈0.01）, leaf temperature （P〈0.01）, and wind speed （P〈0.05）, but correlationship between relative humidity and photo flux density was not significant （P〈0.05）.     

Simulating carbon sequestration and GHGs emissions in <Emphasis Type="Italic">Abies fabric</Emphasis> forest on the Gongga Mountains using a biogeochemical process model Forest-DNDC

The process-oriented model Forest-DNDC describing biogeochemical cycling of C and N and GHGs （greenhouse gases） fluxes （CO2, NO and N2O） in forest ecosystems was applied to simulate carbon sequestration and GHGs emissions in Abies fabric forest of the Gongga Mountains at southeastern edge of the Tibetan Plateau. The results indicated that the simulated gross primary production （GPP） of Abies fabric forest was strongly affected by temperature. The annual total GPP was 24,245.3 kg C ha^-1 yr^-1 for 2005 and 26,318.8 kg C ha^-1 yr^-1 for 2006, respectively. The annual total net primary production （NPP） was 5,935.5 and 4,882.2 kg C ha^-1 yr^-1 for 2005 and 2006, and the annual total net ecosystem production （NEP） was 4,815.4 and 3,512.8 kg C ha^-1 yr^-1 for 2005 and 2006, respectively. The simulated seasonal variation in CO2 emissions generally followed the seasonal variations in temperature and precipitation. The annual total CO2 emissions were 3,109.0 and 4,821.0 kg C ha^-1 yr^-1 for 2005 and 2006, the simulated annual total N2O emissions from forest soil were 1.47 and 1.36 kg N ha^-1 yr^-1 for 2005 and 2006, and the annual total NO emissions were 0.09 and o.12 kg N ha^-1 yr^-1 for 2005 and 2006, respectively.     

Bioaccumulation of Pb<Superscript>2+</Superscript> and its effects on growth,morphology and pigment contents of <Emphasis Type="Italic">Spirulina</Emphasis> (<Emphasis Type="Italic">Arthrospira</Emphasis>) <Emphasis Type="Italic">platensis</Emphasis>

A laboratory experiment was conducted to assess the bioaccumulation of Pb²⁺ and its effects on growth, morphology and pigment contents of Spirulina (Arthrospira) platensis. The specimen cultured in Zarrouk liquid medium was treated with various initial metal concentrations (0, 5, 10, 30, 50 and 100 μg mL⁻¹). The growth of S. platensis was adversely affected by Pb²⁺ at high concentrations (30, 50 and 100 μg mL⁻¹). However, at low concentrations (5 μg mL⁻¹), Pb²⁺ could stimulate its growth slightly. The pigment contents (chlorophyll α and β carotene) were decreased in a dose-dependent manner. The highest reductions (67% and 53% respectively in chlorophyll α and β carotene) were observed in 100 μg mL⁻¹ treatment group. The LC₅₀ (96 h) of Pb²⁺ was measured as 75.34 μg mL⁻¹. Apart from a few cases of filament breakages at elevated concentrations (50 and 100 μg mL⁻¹), morphological abnormalities are not specific. Metal bioaccumulation increased with Pb²⁺ concentrations, but decreased with exposure time. The maximum accumulated amount was 188 mg g⁻¹ dry weight. The bioconcentration factor (BCF) reached to a peak at day 2, followed by a gradual reduction for all the exposure concentrations. S. platensis is able to tolerate considerably high Pb²⁺ concentrations. Consequently it can be used as a potential species to remove heavy metal from contaminated waters.     

The suitability of using leaf area index to quantify soil loss under vegetation cover

Soil erosion by water under forest cover is a serious problem in southern China. A comparative study was carried out on the use of leaf area index (LAI) and vegetation fractional coverage (VFC) in quantifying soil loss under vegetation cover. Five types of vegetation with varied LAI and VFC under field conditions were exposed to two rainfall rates (40 mm h⁻¹ and 54 mm h⁻¹) using a portable rainfall simulator. Runoff rate, sediment concentration and soil loss rate were measured at relatively runoff stable state. Significant negative exponential relationship (p < 0.05, R² = 0.83) and linear relationship (p < 0.05, R² = 0.84) were obtained between LAI and sediment concentration, while no significant relationship existed between VFC and sediment concentration. The mechanism by which vegetation canopy prevents soil loss was by reducing rainfall kinetic energy and sediment concentration. LAI could better quantify such a role than VFC. However, neither LAI nor VFC could explain runoff rate or soil loss rate. Caution must be taken when using LAI to quantify the role of certain vegetation in soil and water conservation.     

Quantitative simulation on soil moisture contents of two typical vegetation communities in Sanjiang Plain,China

Different types of vegetation occupy different geomorphology and water gradient environments in the San-jiang Plain,indicating that the soil moisture dynamics and water balance patterns of the different vegetation communi-ties might differ from each other.In this paper,a lowland system,perpendicular to the Nongjiang River in the Honghe National Nature Reserve(HNNR),was selected as the study area.The area was occupied by the non-wetland plant forest and the typical wetland plant meadow.The Microsoft Windows-based finite element analysis software package for simulating water,heat,and solute transport in variably saturated porous media(HYDRUS),which can quantita-tively simulate water,heat,and/or solute movement in variably-saturated porous media,was used to simulate soil moisture dynamics in the root zone(20-40 cm) of those two plant communities during the growing season in 2005.The simulation results for soil moisture were in a good agreement with measured data,with the coefficient of determi-nation(R2) of 0.44-0.69 and root mean square error(RMSE) ranging between 0.0291 cm3/cm3 and 0.0457 cm3/cm3,and index of agreement(d) being from 0.612 to 0.968.During the study period,the volumetric soil moisture content of meadow increased with the depth and its coefficient of variation decreased with the depth(from 20 cm to 40 cm),while under the forest the soil moisture content at different depths varied irregularly.The calculated result of water budget showed that the water budget deficit of the meadow was higher than that of the forest,suggesting that the meadow is more likely to suffer from water stress than the forest.The quantitative simulation by HYDRUS in this study did not take surface runoff and plant growth processes into account.Improved root water uptake and surface runoff models will be needed for higher accuracy in further researches.     

Nitrogen biological cycle characteristics of seepweed (Suaeda salsa) wetland in intertidal zone of Huanghe (Yellow) River estuary

From April 2008 to November 2009,the nitrogen(N) cycle of plantsoil system in seepweed(Suaeda salsa) wetland in the intertidal zone of the Huanghe(Yellow) River estuary was studied.Results showed that soil N had sig-nificant seasonal fluctuations and vertical distribution,and the net N mineralization rates in topsoil were significantly different in growing season(p < 0.01).The N/P ratio(9.87 ± 1.23) of S.salsa was less than 14,indicating that plant growth was limited by N.The N accumulated in S.salsa litter at all times during decomposition,which was ascribed to the N immobilization by microbes from the environment.Soil organic N was the main N stock of plant-soil system,accounting for 97.35% of the total N stock.The N absorption and utilization coefficients of S.salsa were very low(0.0145 and 0.3844,respectively),while the N cycle coefficient was high(0.7108).The results of the N turnovers among compartments of S.salsa wetland showed that the N uptake amount of aboveground part and root were 7.764 g/m2and 4.332 g/m2,respectively.The N translocation amounts from aboveground part to root and from root to soil were 3.881 g/m2 and 0.626 g/m2,respectively.The N translocation amount from aboveground living body to litter was 3.883 g/m2,the annual N return amount from litter to soil was more than 0.125(-) g/m2(minus represented immobilization),and the net N mineralization amount in topsoil(0-15 cm) in growing season was 1.190 g/m2.The assessment of N biological cycle status of S.salsa wetland indicated that N was a very important limiting factor and the ecosystem was situated in unstable and vulnerable status.The S.salsa was seemingly well adapted to the low-nutrient status and vulnerable habitat,and the N quantitative relationships determined in the compartment model might provide scientific base for us to reveal the special adaptive strategy of S.salsa to the vulnerable habitat in the following studies.     

Impact of microzooplankton and Calanus sinicus (Brodsky, 1962) on phytoplankton in the Yellow Sea during early summer

Dilution incubations and Calanus sinicus addition incubations were simultaneously conducted at five stations in the Yellow Sea in June of 2004 to evaluate the impact of microzooplankton and Calanus sinicus on phytoplankton based on the Chlorophyll a (Chl-a) levels. The Chl-a growth rates (k) ranged from 0.60–1.67 d⁻¹, while microzooplankton grazed the Chl-a at rates (g) of 0.29–0.62 d^t-1. The addition of C. sinicus enhanced the Chl-a growth rate (Z) by 0.004–0.037 d⁻¹ ind.⁻¹ L. C. sinicus abundance ranged from 84.1–160.9 ind. m⁻³, which occupied 90.7%–99.1% of the copepod (>500 μm) population. The in-situ increase in phytoplankton by C. sinicus community was estimated to be 0.000 4–0.005 9 d⁻¹. These results showed that microzooplankton were the main grazers of phytoplankton, while C. sinicus induced a slight increase in the levels of phytoplankton.     

Size-fractionated phytoplankton biomass in autumn of the Changjiang （Yangtze） River Estuary and its adjacent waters after the Three Gorges Dam construction

A cruise was undertaken from 3rd to 8th November 2004 in Changjiang （Yangtze） River Estuary and its adjacent waters to investigate the spatial biomass distribution and size composition of phytoplankton. Chlorophyll-a （Chl-a） concentration ranged 0.42-1.17 μg L^-1 and 0.41-10.43 μg L^-1 inside and outside the river mouth, with the mean value 0.73 μg L^-1 and 1.86 μg L^-1, respectively. Compared with the Chl-a concentration in summer of 2004, the mean value was much lower inside, and a little higher outside the river mouth. The maximal Chl-a was 10.43 μg L^-1 at station 18 （122.67°E, 31.25°N）, and the region of high Chl-a concentration was observed in the central survey area between 122.5°E and 123.0°E. In the stations located east of 122.5°E, Chl-a concentration was generally high in the upper layers above 5 m due to water stratification. In the survey area, the average Chl-a in sizes of 〉20 μm and 〈20 μm was 0.28 μg L^-1 and 1.40 μg L^-1, respectively. High Chl-a concentration of 〈20 μm size-fraction indicated that the nanophytoplankton and picophytoplankton contributed the most to the biomass of phytoplankton. Skeletonema costatum, Prorocentrum micans and Scrippsiella trochoidea were the dominant species in surface water. The spatial distribution of cell abundance of phytoplankton was patchy and did not agree well with that of Chl-a, as the cell abundance could not distinguish the differences in shape and size of phytoplankton cells. Nitrate and silicate behaved conservatively, but the former could probably be the limitation factor to algal biomass at offshore stations. The distribution of phosphate scattered considerably, and its relation to the phytoplankton biomass was complicated.     

THE DENSITIES OF CHANGJIANG ESTUARINE WATERS

The International Eq一lation of State of Seawater,1980 and the PraeticalSalinity Scale,1978 have been adoPted by theUNESCO江CES沼COR八APSOJoint Panel ono‘eanogral,hie Tables and Standards(JPOTS),and endorsed bythese organizati6ns(Miller‘〕and Poisson,1981;Uneseo,1981).Th已new equa-tion and the Praetieal Salinity Seale are to be used for all values Published fromJan .1,1982 .The new equation 15 aeeurate for use in all oeeanie surfaee waters,but eannot be aeeurately aPPlied to…     

The inhibitory degree between Skeletonema costatum and dinoflagllate Prorocentrum donghaiense at different concentrations of phosphate and nitrate/phosphate ratios

Interactions between Skeletonema costatum (S. costatum) and Prorocentrum donghaiense (P. donghaiiense) were inves-tigated using bi-algal cultures at different concentrations of phosphate (PO4-P) and nitrate/phosphate (N/P) ratios. Experiments were conducted under P-limited conditions and the Lotka-Volterra mathematical model was used to simulate the growth of S. costatum and P. donghaiense in the bi-algal cultures. Both of these two species were inhibited significantly in bi-algal culture. The results of the simulation showed that the inhibitory degree of S. costaum by P. donghaiense was high when the concentration of PO4-P was low (0.1μmolL-1/2 d), but that of P. donghaiense by S. costaum was high with increased PO4-P supply (0.6μmolL-1/2 d). At low concen-tration of PO4-P (0.1μmolL-1/2 d), or high concentration of PO4-P (0.6μmolL-1/2 d) with high N/P ratio (160), the interactions be-tween S. costatum and P. donghaiense were dependent on the initial cell densities of both species. At high concentration of PO4-P (0.6μmolL-1/2 d) with low N/P ratio (25 or 80), S. costatum exhibited a survival strategy superior to that of P. donghaiense. The de-gree of inhibition of P. donghaiense by S. costaum increased with elevated N/P ratio when the medium was supplemented with con-centration 0.1μmolL-1/2 d of PO4-P. The degree of inhibition to P. donghaiense by S. costaum increased with elevated N/P ratio at low concentration of PO4-P (0.1 μmolL-1/2 d). This trend was conversed at high concentration of PO4-P (0.6μmolL-1/2 d). However, the degree of inhibition of S. costaum by P. donghaiense increased with the increased N/P ratio at different PO4-P concentrations (0.1μmolL-1/2 d and 0.6μmolL-1/2 d). These results suggested that both phosphate concentration and N/P ratio affected the competition between S. costaum and P. donghaiense: P. donghaiense is more competitive in environments with low phosphate or high N/P ratio and the influence of N/P ratio on the competition was more significant with lower phosphate concentration.     

Dynamic model for oil slick dispersion into a water column—A wind-driven wave tank experiment

A dynamic experiment for oil dispersion into a water column was performed with a 21 m long, 0.5 m wide, and 1 m high wind-driven wave tank. At wind velocity between 6–12 m/s and with the oil slick kept constant (about 1 μm), the rate of the oil content increase in the water column could be approximated from the difference between the dispersion rate (R) of the oil slick and the coagulation rate (R′) of the dispersed oil slick. Assuming the coagulation rate is directly proportional to the concentration of the water dispersed oil slick (i. e.R′-K ^*C), the integral form of the dynamic model can be expressed asC=R ^* [1−exp(−K ^*t)]/K and parametersR andK can be regressed with a computer. The relative deviation of model results from the experimental data was mainly less than 10%. The oil slick dispersion rate (R) had exponential relationship with the wind velocity (U), and can be fitted with a formulaR=A ^* (U+1) ^B . The fitted constant of the coagulation rate,K(0.8–3.0^* 10⁻³ min⁻¹) did not have significant relationship with the wind velocity.     

Micromorphology of surface crusts in the Knersvlakte, South Africa

Soils in the Knersvlakte are particularly prone to crusting and have lower inherent infiltrability than other soils across western southern Africa. Micromorphological techniques were used to examine the structure and porosity of soil crusts in the Knersvlakte to ascertain why crusting is so intense in this region. Quantile regression using boundary lines was employed to examine the relationships between infiltrability and soil properties for all samples （n = 67）. This analysis showed that infiltrability is potentially maximal at low water- dispersible ＇clay plus silt＇ content and low silt content （r^2 = 0.72 and 0.64; respectively, n = 67） （Figure 2）. The strength of crusts, pH, EC, clay mineralogy, and water-dispersible clay, silt and ＇clay plus silt＇ content were compared, and a pore analysis using optical microscopy was undertaken on images of six soil thin sections （n = 6） （circular and parallel polarizers）. Pore analysis was further undertaken on five horizontal slices of equal dimensions taken through each soil thin section. The porosity samples with low infiltrability （〈 100 mm·hr^-1, n = 4） had greater crust strength, lower porosity （both total and in the least porous slice） and greater water-dispersible ＇day plus silt＇ and silt content than the porosity samples with high infiltrability （〉 100mm·hr^-1, n = 2）. The porosity samples with low infiltrability showed a trend of lower pH and greater water dispersible clay percentage. Porosity varied within the porosity samples due to the presence of dense clay/silt bands （〈 0.5 mm in width） with relatively few air vesicles. The porosity samples with horizontal slices of low porosity （but large numbers of air vesicles） had low infiltrability, while those without slices of low porosity （and relatively few air vesicles） had high infiltrability. We conclude that the intense crusting and resultant low infiltrability of soils in the Knersvlakte appears to be related to the formation of thin, dense clay/silt bands in the pedoderm.     

Construction of cDNA library from intestine, mesentery and coelomocyte of Apostichopus japonicus Selenka infected with Vibrio sp. and a preliminary analysis of immunity-related genes

The aquaculture of sea cucumber Apostichopus japonicus (Echinodermata, Holothuroidea) has grown rapidly during recent years and has become an important sector of the marine industry in Northern China. However, with the rapid growth of the industry and the use of non-standard culture techniques, epidemic diseases of A. japonicus now pose increasing problems to the industry. To screen the genes with stress response to bacterial infection in sea cucumber at a genome wide level, we constructed a cDNA library from A. japonicus Selenka (Aspidochirotida: Stichopodidae) after infecting them with Vibrio sp. for 48 h. Total RNA was extracted from the intestine, mesentery and coelomocyte of infected sea cucumber using Trizol and mRNA was isolated by Oligotex mRNA Kits. The ligated cDNAs were transformed into DH5α, and a library of 3.24×105 clones (3.24×105 cfu mL-1) was obtained with the sizes of inserted fragments ranging from 0.8 to 2.5 kb. Sequencing the cDNA clones resulted in a total of 1106 ESTs that passed the quality control. BlastX and BlastN searches have identified 168 (31.5%) ESTs sharing significant homology with known sequences in NCBI protein or nucleotide databases. Among a panel of 25 putative immunity-related genes, serum lectin isoform, complement component 3, complement component 3-like genes were further studied by real-time PCR and they all increased more than 5 fold in response to Vibrio sp. challenge. Our library provides a valuable molecular tool for future study of invertebrate immunity against bacterial infection and our gene expression data indicates the importance of the immune system in the evolution and development of sea cucumber.     

Application of swat model in the upstream watershed of the Luohe River

1INTRODUCTIONIntheHuanghe(Yellow) Riverbasin, soilerosionisaseriousproblem,whilerunoffandsedimentyieldsim-ulation hasnotbeenextensivelystudiedonthebasisofGIS(GeographicInformationSystem) and dis-tributedhydrologicalmodel.Inthisstudy,theLushiwatershed,whichislocatedattheupstreamoftheLushiHydrologicalStationintheLuoheRiver—thebiggesttributary oftheHuanghe Riveranddown-streamofXiaolangdiDam,isselectedasthestudyarea.ThelevelofsoilerosioninLushiwatershedismoderatein theHuangheRiverbas…     

Standing crop and primary production of benthic microalgae on the tidal flats in Yueqing Bay

The standing stock and primary production of benthic microalgae on tidal flats were measured seasonally at 3 transects (Puqing, Dahengchuang and Puqi) in Yueqing Bay during 2002 2003. The results showed that the integral chlorophyll a (Chl a) concentration in tidal flat mud exhibited a seasonal variation with the order of magnitude: winter (14.0 4.2 mg m-2) > spring (13.0 6.3 mg m-2) > autumn (7.7 5.9 mg m-2) > summer (4.6 3.2 mg m-2). The primary production showed an order of magnitude: spring (270.5 224.9 mgC m-2 d-1)>winter (238.7 225.5 mgC m-2 d-1)>autumn (214.1 56.2 mgC m-2 d-1)>summer (71.6 44.6 mgC m-2 d-1). Both chlorophyll a and primary production showed maximum values in the surface layer of sediment, and decreased rapidly with increasing depth due to sun light limitation. The results of variance analysis indicated that seasonal variation and tidal flat condition affected Chl a greatly, but had no significant effect on primary production. The annual primary production of benthic microalgae on tidal flats in Yueqing Bay was estimated at 16143 tons carbon, which is sufficient to support 1.02×105 tons shellfish production. The environmental factors affecting chlorophyll and primary production on the tidal flats in Yueqing Bay were discussed. By comparing with other bays on China’s coast, it was observed that Yueqing Bay is a region with high benthic microalgae standing crop and primary production, which may be related to the type of its sediment.     

Effects of nutritional factors on the growth and heterotrophic eicosapentaenoic acid production of diatom <Emphasis Type="Italic">Nitzschia laevis</Emphasis>

The effects of several nutritional factors on the growth and eicosapentaenoic acid (EPA) production of diatom Nitzschia laevis were studied. 4 LDM (quadrupled concentration of the nutrient salt) was the optimal concentration of nutrient salt for the growth and EPA production of N. laevis. The growth of N. laevis was inhibited when the glucose concentration was either lower than 10 gL⁻¹ or higher than 15 gL⁻¹. Both sodium nitrate and urea were good nitrogen sources for the growth and EPA production, while ammonium chloride seriously decreased the dry cell weight (DW) and the EPA content. Silicate seriously influenced the growth of N. laevis. The maximum DW of 2.34 gL⁻¹ was obtained in the presence of 150 mgL⁻¹ Na₂SiO₃·9H₂O. The EPA content remained almost the same when the silicate concentration was lower than 150 mgL⁻¹; however, higher silicate concentrations resulted in a steady decrease of EPA content. Low medium salinity (⩽29) did not seem to influence the DW of N. laevis, and high salinity resulted in a decrease of DW. The highest EPA content (4.08%) and yield (110 mgL⁻¹) were observed at the salinity of 36 and 29, respectively.     

Effects of NO and Different Media on the Growth of Prorocentrum micans

1Introduction NOisadiffusible,gaseousfreeradicalthatplaysimportantrolesinanimalsandplants.Itfunctionsin diseaseresistance,abioticstress,celldeath,respira tion,senescence,rootdevelopments,germinationandhormoneresponses.Itisanunusualsignalinthatitis areactive,lipophilicandvolatilefreeradicalthatcanbecytotoxic.ThewidespreadbiologicalsignificanceofnitricoxidewasrecognizedbySciencein1992whichnamedthefreeradicalNO‘Moleculeoftheyear’,andin1998theNobelPrizeinPhysiologyandMedicinewasawardedforwor…     

Preliminary Study on the Responses of Three Marine Algae,Ulva pertusa （ Chlorophyta ） , Gelidium amansii （ Rhodophyta ）and Sargassum enerve （ Phaeophyta）, to Nitrogen Source and Its Availability

1　Introduction　Inrecentyears ,eutrophicationhasbecomeaworld wideenvironmentalprobleminthecoastalarea.Aqua culturebecomesaseriouspollutionsourcelikesewagedischarge .Wasteproductsfromfishfarmsconsistma inlyofnitrogen ,phosphorusandcarbondioxide .Inpen bas…