高离化态S~(q+)与H_2碰撞中H_2~(r+)的库仑爆炸及解离过程研究

采用位置灵敏探测器和散射离子 反冲离子飞行时间技术测量了 90 0keV的Sq + +H2 碰撞产生的H+ 碎片的能量分布 ,实验表明部分Hr+ 2 发生解离。基于蒙特卡罗方法 ,建立了程序模拟离子与分子碰撞中的反冲离子飞行时间谱。模拟结果与实验 (S2 + +H2 ,S2 + +He)测量到的TOF谱进行了分析比较 ,并进行了定性讨论。

同位素~(106)Cd金属自支撑靶的制备及废靶的再生利用

用滚压技术制备出同位素１０６Ｃｄ自支撑靶，并成功地利用破靶膜的再生方法。制备出可供使用的靶膜。

General SU(2)(L) x SU(2)(R) x U(1)(EM) sigma model with external sources, dynamical breaking and spontaneous vacuum symmetry breaking

We give a general SU(2)(L) x SU(2)(R) x U(1)(EM) sigma model with external sources, dynamical breaking and spontaneous vacuum symmetry breaking, and present the general formulation of the model. It is found that sigma and pi(0) without electric charges have electromagnetic interaction effects coming front the internal structures. A general Lorentz transformation relative to external sources J(gauge) - (J(A mu) J(A mu)(kappa)) derived, using the general Lorentz transformation and the four-dimensional current of nuclear matter of the ground si ate with J(gauge) = 0, we give the four-dimensional general relations between the different currents of nuclear matter systems with J(gauge) not equal 0 and those with J(gauge) = 0. The relation of the density's coupling with external magnetic field is derived, which conforms well to dense nuclear matter in a strong magnetic field. We show different condensed effects in strong interaction about fermions and antifermions, and give the concrete scalar and pseudoscalar condensed expressions of sigma(0) and pi(0) bosons. About different dynamical breaking and spontaneous vacuum symmetry breaking, the concrete expressions of different mass spectra are obtained in field theory. This paper acquires the running spontaneous vacuum breaking value sigma'(0), and obtains the spontaneous vacuum breaking in tenus of the running sigma'(0), which make nucleon, sigma, and pi particles gain effective masses. We achieve both the effect of external sources and nonvanishing value of the condensed scalar and pseudoscalar paticles. It is deduced that the masses of nucleons, sigma and pi generally depend on different external sources.

beta-delayed proton decays and spin assignments for Tb-140, Dy-141 and Dy-143

The proton-rich isotopes Tb-140 and Dy-141 were produced via the fusion evaporation reaction Ca-40+ Cd-106. Their beta-delayed proton decays were studied by p-gamma coincidence in combination with a He-jet tape transport system, and half-lives, proton energy spectra, gamma-transitions following the proton emission, as well as beta-delayed proton branching ratios to the low-lying states in the grand-daughter nuclei were determined. Comparing the experimental data with statistical model calculations, the ground-state spins of Tb-140 and Dy-141 were found to be consistent with 7 and 9/2, respectively. The configuration-constrained nuclear potential energy surfaces (NPES) of Tb-140 and Dy-141 were calculated using the Woods-Saxon-Strutinsky method, which suggest the ground-state spins and parities of Tb-140 and Dy-141 to be 7(+) and 9/2(-), respectively. In addition, the configuration-constrained NPES of Dy-143 were calculated, which predict a 1/2(+) ground state and a 11/2(-) isomer with excitation energy of 198 keV. These findings are consistent with our previous experimental data on Dy-143 reported in Eur. Phys. J. A 16, 347 (2003).

Ginsenoside R-e increases fertile and asthenozoospermic infertile human sperm motility by induction of nitric oxide synthase

We investigated the effects of Ginsenoside R-e on human sperm motility in fertile and asthenozoospermic infertile individuals in vitro and the mechanism by which the Ginsenosides play their roles. The semen samples were obtained from 10 fertile volunteers and 10 asthenozoospermic infertile patients. Spermatozoa were separated by Percoll and incubated with 0, 1, 10 or 100 mu M of Ginsenoside R-e. Total sperm motility and progressive motility were measured by computer-aided sperm analyzer (CASA). Nitric oxide synthase (NOS) activity was determined by the H-3-arginine to H-3-citrulline conversion assay, and the NOS protein was examined by the Western blot analysis. The production of sperm nitric oxide (NO) was detected using the Griess reaction. The results showed that Ginsenoside R-e significantly enhanced both fertile and infertile sperm motility, NOS activity and NO production in a concentration-dependent manner. Sodium nitroprusside (SNP, 100 nM), a NO donor, mimicked the effects of Ginsenoside R-e. And pretreatment with a NOS inhibitor N-omega-Nitro-L-arginine methyl ester (L-NAME, 100 mu M) or a NO scavenger N-Acetyl-L-cysteine (LNAC, 1 mM) completely blocked the effects of Ginsenoside R-e. Data suggested that Ginsenoside R-e is beneficial to sperm motility, and that induction of NOS to increase NO production may be involved in this benefit.

Cd、Pb、Cu、Zn、As复合污染在农田生态系统的迁移动态研究

１９９０—１９９５年中国科学院生态网站联网研究中，在４个生态站对重金属复合污染（Ｃｄ、Ｐｂ、Ｃｕ、Ｚｎ、Ａｓ）进行了田间迁移动态实验研究，表明３年来表土中重金属元素含量缓慢下降，输出量最大支出项目为从表层向下迁移量可比作物地上部分带去量高出几十至数百倍，为污染土壤防治工作中淋洗技术运用指出了应用前景．

Cd、Zn、菲和多效唑复合污染土壤的微生物生态毒理效应

以土壤脱氢酶、呼吸强度和微生物生物量作为生态毒理指标，通过正交实验，在室内培养条件下考察了４种不同性质的有机与无机污染物（Ｃｄ、Ｚｎ、菲和多效唑）复合污染的土壤微生物生态效应。复合投加这４种污染物能使土壤微生物活性受到不同程度的抑制，且抑制率随时间的推移而下降；３种微生物生态毒理指标之间存在着很好的相关性，但脱氢酶活性在三者中最敏感；影响土壤微生物活性的主要因子依次为：菲＞Ｃｄ＞Ｚｎ＞Ｚｎ与菲的交互作用＞Ｚｎ与多效唑的交互作用；实验表明，Ｚｎ与菲的交互作用为拮抗作用，但Ｚｎ与多效唑的复合效应机制仍不明确

Cd~(2+)、Pb~(2+)在根际和非根际土壤中的吸附-解吸行为

采用1次平衡法对Cd2+、Pb2+在小麦根际和非根际土壤中的吸附-解吸行为进行比较研究.结果表明,根际土对Cd2+和Pb2+的吸附能力高于非根际土,2类土壤对Cd2+的吸附等温线与Freundlich方程有较好的拟合性,Pb2+的等温吸附过程可由Langmuir方程与Freundlich方程来描述.双常数方程是描述根际、非根际土Cd2+和Pb2+吸附动力学行为的最优模型,其次为Elovich方程,最差模型是一级动力学方程.Cd2+、Pb2+的解吸存在滞后现象,相比于非根际土,根际土吸附态Cd2+、Pb2+的解吸率更低,Cd2+、Pb2+的解吸量与其初始吸附量之间的关系符合2次幂方程.2类土壤Cd2+、Pb2+的解吸速率随重金属初始浓度的增加而增加,随解吸时间的延长而不断降低.描述根际和非根际土Cd2+、Pb2+的解吸动力学过程的最优模型均为双常数方程,其次为Elovich方程,一级动力学方程拟合效果不佳.

Cd-Pb复合污染条件下3种花卉植物的生长反应及超积累特性研究

采用水培实验方法,研究了3种耐性较强的花卉植物在Cd-Pb复合污染条件下的生长反应及可能的超积累特性.结果表明,花卉植物种不同,其对复合污染的生长反应也不同,它们的耐性大小顺序为蜀葵(AlthaearoseaCav.)>凤仙花(ImpatiensBalsaminaL.)>金盏菊(CalendulaofficinalisL.);Cd对植物生长的影响较大、Pb的影响相对较小.3种花卉植物对重金属的积累量都是根部大于地上部;蜀葵对重金属Cd具有很强的耐性和积累性,在Cd、Pb复合污染条件下极具植物修复的潜力.对于这3种花卉植物,Cd-Pb相互作用效应与多种因素有关,包括重金属之间的浓度组合、植物种和植株部位等,表现得极为复杂,不仅仅是单纯的加和、拮抗或协同作用.

Cd和表面活性剂复合污染对小麦叶片若干生理性状的影响

研究了溶液培养条件下Cd-直链十二烷基本磺酸钠（LAS）、Cd-十六烷基三甲基溴化铵（CTAB）和Ch-聚氧乙烯山梨醇月桂酸酯（Tween-80）3种复合污染对小麦生理状态的影响．结果表明，表面活性剂促进Cd在小麦叶中的积累，其效应顺序为CTAB＞LAS＞Tween80．Cd和表面活性剂复合污染条件下，小麦叶中Cd的大量积累导致的细胞膜脂过氧化水平大大高于单纯Cd污染下的水平．细胞中SH基含量降低和叶片外渗液紫外吸收的上升．表明细胞膜受到损伤．复合污染使小麦叶中叶绿素的含量显著下降．

Se和Cd在土壤-植物系统中的迁移与食品安全

本文就Se和Cd在土壤-植物系统中的迁移及其与食品安全及人体健康之间的潜在关系进行了综合评述。Cd和Se在植物中积累并迁移到植物的可食或收获部分,取决于土壤条件、气候因子、农艺管理措施等。Cd是对食物链造成污染的重要元素,其在土壤中的富集通常是由工农业生产或城市人为污染造成的,减少Cd对土壤的污染及Cd污染土壤的生物修复已成为土壤学、环境科学及生态学研究的热点。Se是一种对动植物有益的元素,在土壤中含量过低会引发人体疾病,但Se含量过高也会导致污染并引发人体疾病;土壤中的高浓度Se通常来自于含Se量高的母岩以及燃煤的灰尘污染;基于食品安全的需要,中国在重视Se素营养补给的同时,要防止富Se地区及人为因素造成的Se污染。

长期施肥对黑土中Cu、Cd含量及其剖面分布的影响

以经过8个不同施肥处理的黑土样品为材料,研究长期不同施肥处理下,黑土中Cu、Cd含量的差异。采用原子吸收分光光度法和Tessier-连续提取法,研究黑土中全Cu、全Cd和有效Cu、有效Cd的含量差异。结果表明,有机肥的长期施用,会使土壤中Cu、Cd与有机质发生络合并使Cu、Cd在土壤表层累积;秸秆和氮磷钾(S+NPK)化肥的长期配合施用,有利于作物对有效Cu和Cd的吸收,从而使Cu、Cd在土壤中没有明显积累;NP及NPK处理下,二铵、氯化钾肥对土壤中Cu、Cd积累的影响不明显。长期耕作不施肥(CK)处理时,因无外源Cu、Cd,以及作物对有效Cu、Cd的长期吸收,土壤中Cu、Cd含量低于不耕作不施肥(休闲)处理的。从垂直剖面上看,Cu、Cd主要积累在黑土表层,而表层以下不同施肥处理间Cu、Cd含量的差异和变幅不大。有机肥料能明显地向土壤中带入Cu、Cd,造成Cu、Cd在土壤表层的积累,并由于植物体的吸收对人体造成潜在危害,而其他化学肥料对土壤中Cu和Cd积累的影响不明显。本研究为人们的生产实践提供了施肥理论和依据,并且对土壤的污染防治也具有现实意义。

粉煤灰对钝化污泥重金属有效性影响

通过添加不同比例的粉煤灰对城市生活污泥进行钝化,系统的研究了粉煤灰对钝化污泥中金属元素Cd、Pb、Cu、Zn、Ni、Cr、Mn、Fe含量及其有效化的影响。结果表明:粉煤灰对污泥中有效态Cd、Pb、Ni、Cr、Mn、Fe具有钝化作用,其中对Cd和Fe的钝化效果最明显;但对Cu却有促进其向有效态转化的作用;总体上看钝化污泥人工土壤中重金属含量符合国家农用标准,而其中有效态Cd、Pb、Ni、C r的含量均远远低于对植物体造成毒害的临界水平。

负载型纳米钛酸锶钡对水中Cd~(2+)吸附行为研究

采用络合溶胶-凝胶法制备了钛酸锶钡溶胶,将其浸渍在硅胶G上,经高温煅烧后,制得固载于硅胶G上的纳米钛酸锶钡,以X射线衍射(XRD)、扫描电镜(SEM)和傅里叶变换红外光谱(FTIR)进行了表征。以火焰原子吸收为检测手段,系统地研究了负载型纳米钛酸锶钡对水中Cd2+的吸附行为。结果表明,纳米钛酸锶钡能够牢固地负载于硅胶G表面。当介质的pH值为4~7时,该吸附剂对水中的Cd2+具有很强的吸附能力,其吸附行为符合Freundlich吸附等温模型和HO准二级动力学方程式,并分别计算了吸附过程的焓变(ΔΗ),自由能变(ΔG)和熵变(ΔS)等热力学参数,表明该吸附过程是自发的吸热物理过程。被吸附的Cd2+可用1 mol.L-1的硝酸完全洗脱回收。将其应用于水中痕量Cd2+的吸附,建立了负载型纳米钛酸锶钡吸附富集,火焰原子吸收法测定水中痕量Cd2+的新方法。用于自来水和地表水中镉的测定,结果满意。