High concentrations of toxaphene in fishes from a subarctic lake

Concentrations of toxaphene and other organochlorine compounds are high in fishes from subarctic Lake Laberge, Yukon Territory, Canada. Nitrogen isotope analyses of food chains and contaminant analyses of biota, water, and dated lake sediments show that the high concentrations of toxaphene in fishes from Laberge resulted entirely from the biomagnification of atmospheric inputs. A combination of low inputs of toxaphene from the atmosphere and transfer through an exceptionally long food chain has resulted in concentrations of toxaphene in fishes that are considered hazardous to human health.     

Atmospheric lifetimes of long-lived halogenated species

The atmospheric lifetimes of the fluorinated gases CF(4), C(2)F(6), c-C(4)F(8), (CF(3))(2)c-C(4)F(6), C(5)F(12), C(6)F(14), C(2)F(5)Cl, C(2)F(4)C(12), CF(3)Cl, and SF(6) are of concern because of the effects that these long-lived compounds acting as greenhouse gases can have on global climate. The possible atmospheric loss processes of these gases were assessed by determining the rate coefficients for the reactions of these gases with O((1)D), H, and OH and the absorption cross sections at 121.6 nanometers in the laboratory and using these data as input to a two-dimensional atmospheric model. The lifetimes of all the studied perfluoro compounds are >2000 years, and those of CF(3)Cl, CF(3)CF(2)Cl, and CF(2)ClCF(2)Cl are >300 years. If released into the atmosphere, these molecules will accumulate and their effects will persist for centuries or millennia.     

广西百色烟区土壤含氯状况及烟叶氯素特征研究

【目的】研究百色烟区土壤含氯状况及烟叶氯素特征,为指导该烟区土壤平衡施肥及优质特色烟叶开发提供依据。【方法】采用GPS定位技术,在烤烟尚未施用底肥和移栽前采集耕层20 cm土样,按土壤农业化学分析方法分析土壤氮素含量特征。同时选取对应植烟地块烟叶C3F烤后样本,采用莫尔法测定其氯素含量,并对氯素营养丰缺状况进行评价。【结果】百色植烟土壤含氯量较低,平均为19.80 mg/kg,且集中分布在10～30 mg/kg范围;不同土壤类型氯含量依次为红壤＞黄壤＞水稻土＞石灰土,且有75%以上的土壤样本氯含量分布在10～30 mg/kg范围。百色烟区烟叶含氯量平均为0.10%左右,且变异程度在30%以上;各植烟县烟叶含氯量大多处于低~缺范围,其中隆林、田林、西林、乐业4县缺乏程度高达90%以上。【结论】百色烟区土壤和烟叶含氯量均较低,不利于发展优质烤烟生产,建议加强含氯肥料施用对烤烟产量和品质的效应研究,以改善烟叶质量,提高种植效益。     

The chlorine isotope composition of Earth's mantle

Chlorine stable isotope compositions (delta37Cl) of 22 mid-ocean ridge basalts (MORBs) correlate with Cl content. The high-delta37Cl, Cl-rich basalts are highly contaminated by Cl-rich materials (seawater, brines, or altered rocks). The low-delta37Cl, Cl-poor basalts approach the composition of uncontaminated, mantle-derived magmas. Thus, most or all oceanic lavas are contaminated to some extent during their emplacement. MORB-source mantle has delta37Cl 相似文献   

离子液体[BMIM]Cl与H5PV2Mo10O40双效催化降解麦草碱木质素的研究

采用常规合成法制备了杂多酸H₅PV₂Mo₁₀O₄₀,并通过FT-IR、XRD、SEM对其进行表征。研究了[BMIM]Cl单催化与{H₅PV₂Mo₁₀O₄₀+[BMIM]Cl}双效催化体系中,反应时间、温度以及H₅PV₂Mo₁₀O₄₀用量对麦草碱木质素降解的影响,并初步探讨了木质素的降解机理。结果表明:H₅PV₂Mo₁₀O₄₀中P、V、Mo相对原子质量满足1:2:10关系,并具有典型的Keggin结构;木质素降解反应中,仅离子液体[BMIM]Cl降解木质素的最佳条件为140 ℃下反应3 h,降解后固体产物中总羟基由3.49 mol/kg增加到10.92 mol/kg,液体产物中有香草醛与丁香醛生成,分别占2.00%和2.15%;{H₅PV₂Mo₁₀O₄₀+[BMIM]Cl}双效催化体系中,最佳反应条件为加入20%的H₅PV₂Mo₁₀O₄₀ 120 ℃下反应6 h,降解后固体产物中总羟基由3.49 mol/kg增加到14.12 mol/kg,摩尔质量由7.691 kg/mol降为1.589 kg/mol;液体产物中无丁香醛生成,香草醛占6.97%。初步认为:当单独[BMIM]Cl催化木质素时,H+首先进攻木质素中β-O-4键上的氧原子,正电荷转移到β位,然后水分子中氧原子向带有正电荷的β位进攻,从而催化剂的H+被消除,最后实现了β-O-4键水解断裂,生成愈创木酚,进而侧链发生氧化生成香草醛与丁香醛;当添加H₅PV₂Mo₁₀O₄₀时,[PV₂Mo₁₀O₄₀]5-中的VO₂+由V(V)→V(IV),故使模型化合物得以单电子的氧化,使木质素脱甲氧基,由紫丁香基木质素转变成愈创木基木质素,液体产物中无丁香醛生成,且香草醛质量分数升高。      

在二氯甲烷溶液里〔Cu(CH_3CN)_4〕〔MF_6〕与碘化四丁铵的反应

在本实验中,研究了［Ｃｕ（ＣＨ３ＣＮ）４］［ＭＦ６］（Ｍ＝Ｍ０或Ｗ）与碘化四丁铵（Ｃ４Ｈ９）４ＮＩ在二氯甲烷（ＣＨ２Ｃｌ２）中的反应。研究结果表明,在ＣＨ２Ｃｌ２里,（Ｃ４Ｈ９）４ＮＩ未能把［Ｃｕ（ＣＨ３ＣＮ）４］［Ｍ０Ｆ６］和［Ｃｕ（ＣＨ３ＣＮ）４］［ＷＦ６］中的Ｍ０Ⅴ和ＷⅤ还原成Ｍ０Ⅳ和ＷⅣ盐。通过分析得知,反应产物是ＣｕＩ和（Ｃ４Ｈ９）４ＮＭＦ６,配位体ＣＨ３ＣＮ被解脱出来,反应中并没有产生Ｉ２。     

Persistence of chlorinated hydrocarbon insecticides in soils

The percentages of technical aldrin, chlordane, endrin, heptachlor, Dilan, isodrin, BHC, and toxaphene remaining in Congaree sandy loam soil after 14, years were 40, 40, 41, 16, 23, 15, 10, and 45, respectively; those of purified aldrin and technical dieldrin after 15 years were 28 and 31, respectively; and the percentage of technical DDT in three soils after 17 years was 39. Treatments and maintenance of the soils were such that leaching, volatilization, photodecomposition, mechanical removal, and probably biological decomposition were at a minimum. These values may approach an upper limit of persistence of insecticides in soil.     

Monodisperse metal clusters 10 angstroms in diameter in a polymeric host: the "monomer as solvent' approach

A general methodology is presented for the dispersion of an inorganic compound within an organic polymer host through the use of solubilizing and polymerizable ligands. The dispersion of metal cluster cations 10 angstroms in diameter within a polymer host is achieved by free-radical polymerization of the hexafunctional metal cluster [Mo(6)Cl(8)(NVI)(6)](triflate)(4) with bound polymerizable ligands in N-vinylimidazole (NVI) solutions. Copolymerization of the activated cluster-bound ligands with the surrounding medium probably plays a key role in preventing aggregation and produces near monodisperse molecular clusters within the polymer matrix.     

烤烟胞质不育杂种下部叶品质性状的优势表现

以自育的3个烤烟胞质不育系和4个国内推广烤烟品种为材料,配成3×4=12个杂种,研究烤烟下部叶8个品质性状的杂种优势表现。结果表明:(1)各品质性状均存在正向或负向的离中优势。总氮有25.00%组合的正向离中优势达到显著或极显著水平;相反,总氮/烟碱、总糖和氧化钾有33.33%、25.00%和8.33%组合的负向离中优势达到显著或极显著水平;烟碱、氯、总糖/烟碱、氧化钾/氯分别各有41.67%、16.67%、8.33%、8.33%组合正向离中优势和8.33%、8.33%、33.33%、8.33%负向离中优势达到显著或极显著水平。(2)总氮、烟碱、氯分别有25.00%、16.67%和8.33%组合的超高亲优势达到显著或极显著水平,其它品质性状均不存在显著的超高亲优势。(3)烟碱、总糖/烟碱、总氮/烟碱分别有8.33%、16.67%、8.33%组合的超低亲优势达到显著或极显著水平,其它品质性状各组合均不存在显著的超低亲优势。     

Correction

A typographical error in Table 1 of my paper "The Validity of the Use of Tracers to Follow Chemical Reactions" (Science, 1949, 110, 14), under the entries for chlorine makes the estimated maximum ratios for the tracers Cl(36) and Cl(38) somewhat ambiguous. The stable isotopes should be written as Cl (natural abundance). The ratios were calculated for reactions with the tracers Cl(36) and Cl(38) in systems containing chlorine of natural isotopic abundance. Due attention has been given to the fact that the Cl(35) and Cl(37) will react at different rates.     

EuTiNiO4Cl纳米晶的抗凝血作用研究

[目的]研究EuTiNiO4Cl纳米晶的抗凝血作用。[方法]利用溶胶凝胶法制备EuTiNiO4Cl纳米晶,在一定温度下真空干燥凝胶,在不同温度下进行X射线衍射分析,之后用不同浓度的EuTiNiO4Cl纳米晶对体重为(20±2)g的健康小白鼠进行灌胃,以血液出现拉丝现象作为测定血液凝固的指标,研究EuTiNiO4Cl纳米晶的抗凝血作用。[结果]在350、400和450℃时纳米晶的XRD峰非常宽,说明此温度下其晶型为不定型;在500、600和700℃时纳米晶的XRD峰高而尖;EuTiNiO4Cl纳米晶的粒径随温度的升高而增大,其晶型由不定型变为多晶型。抗凝血试验表明EuTiNiO4Cl纳米晶具有良好的抗凝血作用。当EuTiNiO4Cl纳米晶浓度为2.5×10-3mol/L时,其抗凝血效果最好。[结论]EuTiNiO4Cl纳米晶的抗凝血性能良好。     

氯在烤烟中的分布研究

应用＾３６Ｃｌ研究氯在烤烟器官中的分布,结果表明,各器官含氯量是：叶〉茎〉根,叶含氯量分别比根,茎高 ３２．００％和２８．００％,根、茎、叶吸收总氯量分别占全株总氯量的９．０２％,１９．１２％和７１．８０％,随着施氯量的增加,烤烟叶含氯量增加,施５．０ｇ／株氯,叶含氯量分别比对照（未施氯）和施１．０ｇ／株,３．０ｇ／株氯高２４．３０％,１２．２０％和８．５４％,烤烟氯利用率随施氯量的增加而下降,施     

Atmospheric trace gases in antarctica

Trace gases have been measured, by electron-capture gas chromatography and gas chromatography-mass spectrometry techniques, at the South Pole (SP) in Antarctica and in the U.S. Pacific Northwest (PNW) ( approximately 45 degrees N) during January of each year from 1975 to 1980. These measurements show that the concentrations of CCl(3)F, CCl(2)F(2), and CH(3)CCl(3) have increased exponentially at substantial rates. The concentration of CCl(3)F increased at 12 percent per year at the SP and at 8 percent per year in the PNW; CCl(2)F(2) increased at about 9 percent per year at both locations, and CH(3)CCl(3) increased at 17 percent per year at the SP and 11.6 percent per year at the PNW site. There is some evidence that CCl(4) ( approximately 3 percent per year) and N(2)O (0.1 to 0.5 percent per year) may also have increased. Concentrations of nine other trace gases of importance in atmospheric chemistry are also being measured at these two locations. Results of the measurements of CHClF(2)(F-22), C(2)Cl(3)F(3)(F-113), SF(6), C(2)-hydrocarbons, and CH(3)Cl are reported here.     

盐胁迫下胡杨的离子响应

分析土壤和植物组织中的各种离子关系,发现胡杨对盐分不是简单的抿吸机制;对根系环境中的ＮａＣｌ,胡杨吸收的钠离子显著少于不耐盐的杂种胡杨,而吸收的氯离子却大大超过后者,这与以往报道盐胁迫的胡杨根细胞中形成大量富含氯离子的小液泡是一致的,是一种特殊的区隔化构造,与杂种胡杨相比,胡杨有相对较发达的茎干组织,根和茎干占植株总生物量的比例较大,能吸收和储存有害盐离子而减少其进入叶组织,这是胡杨抗盐性的形态解     

Atmospheric residence time of CH3Br estimated from the junge spatial variability relation

The atmospheric residence time for methyl bromide (CH3Br) has been estimated as 0.8 +/- 0.1 years from its empirical spatial variability relative to C2H6, C2Cl4, CHCl3, and CH3Cl. This evaluation of the atmospheric residence time, based on Junge's 1963 general proposal, provides an estimate for CH3Br that is independent of source and sink estimates. Methyl bromide from combined natural and anthropogenic sources furnishes about half of the bromine that enters the stratosphere, where it plays an important role in ozone destruction. This residence time is consistent with the 0.7-year value recently calculated for CH3Br from the combined strength estimates for its known significant sinks.     

含氯肥料对烤烟叶片含氯量的影响

盆栽试验表明,烟叶含Cl量与施Cl量呈极显著线性正相关,但随生长时期而降低,至成熟期低于0.4％。在肥料含Cl0％～12％时,烟叶产量随施Cl量增加而增加,以施含Cl 12％的肥料最高,比对照增产41.3％。但含Cl 15％时,则有毒害作用,产量明显降低。施Cl 3％～9％有助于提高烟叶含K量和调节K_2O/Cl比,而对烟株N,P营养无明显影响。提高烟叶品质和产量的适宜肥料含Cl量为6％～9％(即施Cl 74～107mg/kg±)。     

不同烃链长度咪唑类离子液体对玉米幼苗生长的影响

为探讨离子液体(ILs)对农业生物的毒性,以典型农作物玉米为材料,采用水培法研究三种不同烃链长度离子液体1-丁基-3-甲基咪唑氯盐([C4mim]Cl)、1-己基-3-甲基咪唑氯盐([C6mim]Cl)和1-辛基-3-甲基咪唑氯盐([C8mim]Cl)在不同浓度下对幼苗的根、茎生长以及部分生理生化指标的影响。结果表明:三种离子液体对玉米幼苗根、茎干重均有显著抑制作用。由EC50值得出,抑制程度表现为[C4mim]Cl[C6mim]Cl[C8mim]Cl,且对根重的抑制大于茎重。随三种离子液体处理浓度增加,玉米幼苗根、茎抗氧化酶系(SOD、POD、CAT、APX)总体呈下降趋势,而丙二醛(MDA)含量显著升高,表明氧化胁迫可能是离子液体产生毒性的重要原因。     

Synthesis of inorganic fullerene-like molecules

The reaction of [Cp*Fe(eta5-P5)] with Cu(I)Cl in solvent mixtures of CH2Cl2/CH3CN leads to the formation of entirely inorganic fullerene-like molecules of the formula [[Cp*Fe(eta5:eta1:eta1:eta1:eta1:eta1-P5)]12[CuCl]10[Cu2Cl3]5[Cu(CH3CN)2]5] (1) possessing 90 inorganic core atoms. This compound represents a structural motif similar to that of C60: cyclo-P5 rings of [Cp*Fe(eta5-P5)] molecules are surrounded by six-membered P4Cu2 rings that result from the coordination of each of the phosphorus lone pairs to CuCl metal centers, which are further coordinated by P atoms of other cyclo-P5 rings. Thus, five- and six-membered rings alternate in a manner comparable to that observed in the fullerene molecules. The so-formed half shells are joined by [Cu2Cl3]- as well as by [Cu(CH3CN)2]+ units. The spherical body has an inside diameter of 1.25 nanometers and an outside diameter of 2.13 nanometers, which is about three times as large as that of C60.     

C1 inhibitor: evidence for decreased hepatic synthesis in hereditary angioneurotic edema

Although the Cl inhibitor was detected in 5 to 10 percent of normal hepatic parenchymal cells by means of the immunofluorescent technique, none was seen in liver biopsies from two individuals with hereditary angioneurotic edema having low concentrations of Cl inhibitor in the serum. In contrast, the percentages of cells which reacted with fluorescent antiserums to C4 and transferrin were normal. These data suggest that in most subjects with hereditary angioneurotic edema, there is decreased synthesis of the C1 inhibitor but normal synthesis of C4, and that the disease results from this biosynthetic error.