种植模式和施肥对黄土旱塬农田土壤团聚体及其碳分布的影响

本研究以长武黄土高原农业生态试验站33年长期定位试验处理为研究对象,选取撂荒(R)、小麦连作(CK/W)、小麦玉米轮作(L),小麦连作选取单施氮肥(N)、单施磷肥(P)、施氮磷肥(NP)、单施有机肥(M)、氮肥配施有机肥(NM)、磷肥配施有机肥(PM)、氮磷肥配施有机肥(NPM)共10种不同种植模式和施肥田间处理,运用干湿筛法和TOC法,分析长期不同施肥和种植模式下黄土旱塬农田土壤力稳性和水稳性团聚体数量、稳定性、各粒级团聚体中全碳和有机碳的分布特征,以及各粒级团聚体对碳分布的贡献。结果表明: 力稳性团聚体以>0.25 mm大团聚体为主,含量>67%,施肥使其减少;连作减少了微团聚体,而轮作增加了微团聚体且其效果大于施肥处理。水稳性团聚体以<0.25 mm微团聚体为主,含量>61%;施肥和耕作均减少了水稳性微团聚体。不同施肥方式和种植模式均降低了团聚体破坏率(PAD),增加了大团聚体(R_0.25)含量。施用有机肥显著提高了力稳性团聚体各粒级中全碳和有机碳含量;连作和轮作增加了各粒级团聚体中全碳含量,但轮作显著降低了有机碳含量。单施氮、磷肥使土壤全碳含量降低,而氮磷复合肥和有机肥使土壤全碳含量显著增加;种植模式对全碳的影响较施肥处理小,连作和轮作使土壤全碳增加。除单施氮、磷肥外,复合施肥和施用有机肥使土壤有机碳显著增加;不同种植模式对土壤有机碳的影响小于施肥处理,轮作使有机碳含量降低。微团聚体对土壤全碳和有机碳的贡献率最大,可达21.2%~33.6%;不同施肥和种植模式使微团聚体全碳的贡献率增加,施肥处理中NP和NPM显著增加了微团聚体的全碳和有机碳贡献率,轮作对微团聚体全碳和有机碳的增加趋势贡献最显著。     

长期施肥对黑土团聚体分布和碳储量变化的影响

用干筛与湿筛2种方法测定了22年长期田间定位试验地土壤风干及水稳性团聚体含量，研究了施肥对黑土团聚体组成、有机碳含量及有机碳库储量的影响。试验设不施肥（CK）、无机肥（NP、NPK）和无机-有机肥配施（NPK+OM）4个处理。结果表明，黑土团聚体以0.25～1 mm团聚体为主。经过湿筛法土壤各粒级水稳性团聚体含量重新分配，表现为以0.25～1 mm粒级为中心，大团聚体含量减少，微团聚体含量增加。与长期不施肥比较，长期施用化肥及有机-无机肥配施显著增加了>2 mm大团聚体含量和0.05～0.25 mm微团聚体含量，各级团聚体有机碳含量显著增加，总有机碳及各级团聚体储量增加，有机质积累，土壤结构得到改善，固碳潜力增加，有机-无机配施效果更加明显。     

长期施肥对水稻土有机碳分布及化学结合形态的影响

采用湖南省4个23年连续施肥的稻田长期定位试验,研究了施肥对湖南省水稻土有机碳分布及化学键合形态的影响。试验设不施肥(CK)、化肥(NPK)、中量有机肥(MOM)和高量有机肥(HOM)4个处理。结果表明:在所有施肥处理中,水稳性团聚体均以0.25～1mm和2～5mm粒径含量最高,分别达全土总量的18%～43%和13%～48%。中、高量有机肥处理显著增加了>1mm大团聚体含量以及有机碳在大团聚体中的分配,其中0.25～1mm和1～2mm粒径团聚体中有机碳含量均略高于其余粒径组。与不施肥比较,钙结合态有机碳(Ca-SOC)占总有机碳的比例在2%～4%左右且随有机肥施用呈下降趋势,而铁铝结合态有机碳Fe(Al)-SOC占总有机碳的18%～33%呈上升趋势。有机肥施用条件下,有机碳在大团聚体中的分布的增加、Fe(Al)-SOC的提升以及Ca-SOC的降低意味着土壤有机碳物理和化学保护作用的增强,有利于稻田土壤有机碳的积累,是有机肥施用条件下保持稻田土壤较高固碳速率的重要原因。     

长期施肥对小麦-玉米作物系统土壤颗粒有机碳和氮的影响

通过对华北平原小麦-玉米轮作农田生态系统18年田间施肥试验，研究了长期不同施肥处理对耕层(0～20 cm)土壤颗粒有机碳和氮及矿质结合有机碳和氮的影响.施肥处理包括化肥NPK不同组合（NPK、NP、NK、PK）、全部施用有机肥(OM)、一半有机肥+化肥NPK(1/2OMN)及不施肥(CK)共7个处理.结果表明：各施肥处理均能在不同程度上增加土壤颗粒有机碳和氮及矿质结合有机碳和氮含量，提高土壤颗粒有机碳和氮分配比例及颗粒有机质C/N.施肥处理颗粒有机碳和氮储量较不施肥处理分别增加11.7%～196.8%和13.0%～152.2%，土壤颗粒有机碳对总有机碳储量增加的贡献率为31.5%～67.3%，土壤颗粒有机氮对全氮储量增加的贡献率为14.3%～100.0%；矿质结合有机碳和氮储量较不施肥处理分别增加2.0%～75.0%和0.0%～69.8%.各处理颗粒有机碳和氮及矿质结合有机碳和氮储量均以OM处理最高，且有机肥与化肥NPK配施高于单施化肥各处理，而化肥处理中NPK均衡施用效果最好.说明施用有机肥、有机肥与化肥NPK配施及化肥NPK均衡施用是增加土壤颗粒有机碳和氮及矿质结合有机碳和氮的关键.     

不同施肥处理黑土覆膜后秸秆碳氮在团聚体中的固存特征

地膜覆盖是提高作物产量的重要措施,理解覆膜条件下黑土团聚体中外源碳和氮的固存特征,为深刻认识地膜覆盖措施的可持续应用提供理论依据。选取长期定位试验站(29年)不施肥(CK)、单施化肥(NPK)和有机肥配施化肥(MNPK)3个典型施肥处理,表层土壤(0—20 cm)添加¹³C¹⁵N双标记玉米秸秆后设置裸地和覆膜的田间原位微区培养试验,探讨不同施肥处理结合覆膜黑土团聚体中有机碳和全氮对秸秆来源碳和氮的响应。结果表明,与裸地相比,所有处理覆膜后微团聚体(<0.25 mm)中秸秆来源碳和氮的含量平均降低了26.49%和32.05%。覆膜MNPK与裸地处理相比大团聚体(>0.25 mm)中秸秆来源碳和氮的含量显著降低了35.58%和15.97%,但大团聚体中原土壤有机碳的含量提高了9.16%。在CK和NPK处理微团聚体中,秸秆来源碳占该粒级团聚体有机碳的比例表现为覆膜>裸地,而在MNPK处理各粒级团聚体中则表现为裸地>覆膜。无论覆膜与否,秸秆来源碳对团聚体有机碳和秸秆来源氮对团聚体全氮的贡献率受施肥处理的影响表现为CK>N...     

不同施肥处理对红壤性水稻土微团聚体有机碳汇的影响

在田间定位试验区 ,研究了不同施肥处理对表层红壤性水稻土微团聚体组成以及土壤有机碳在各级微团聚体中分布和赋存的影响。结果表明 ,红壤性水稻土中 0 .0 2～ 0 .0 5 mm微团聚体所占比例最大 ,达 4 0 % ;其次是 0 .0 0 2～ 0 .0 2 mm和 0 .0 5～0 .1mm的微团聚体 ;>0 .2 mm微团聚体占的比例最小。长期施用无机肥 (NPK)、有机肥 (猪粪 紫云英绿肥 ) (OM)、无机肥与有机肥配施 (NPKM) ,能显著增加 0 .0 0 2～ 0 .0 2 mm微团聚体的含量而降低 <0 .0 0 2 m m微团聚体的含量。土壤有机碳含量与0 .0 0 2～ 0 .0 2 mm微团聚体含量之间呈显著正相关关系 ;而与 <0 .0 0 2 mm微团聚体含量呈显著负相关关系。各级微团聚体有机碳含量从高到低顺序为 :>0 .2 mm,0 .1～ 0 .2 mm,<0 .0 0 2 m m,0 .0 5～ 0 .1m m,0 .0 0 2～ 0 .0 2 mm,0 .0 2～ 0 .0 5 m m。 OM、NPKM处理能显著增加 >0 .0 0 2 mm各级微团聚体有机碳的赋存量 ,新增加的有机碳主要向微团聚体 0 .1～ 0 .0 5 m m,0 .0 5～ 0 .0 2 mm和 0 .0 2～ 0 .0 0 2 mm富集 ,它们是土壤有机碳的主要载体。 3种施肥处理对提高土壤有机碳赋存效果高低顺序为 :NPKM>OM>NPK。     

长期退耕对红壤团聚体碳氮磷生态化学计量特征的影响

目前,长期退耕恢复如何影响红壤团聚体组成及其碳氮磷生态化学计量特征还不十分清楚。本研究基于湖南红壤试验站连续27年的长期定位试验,选取常规施肥耕作和退耕恢复两个处理,采集0～15 cm耕层土样,利用湿筛法探讨了土壤团聚体粒级组成及其碳氮磷含量与生态化学计量特征对长期退耕的响应规律。结果显示:相比于常规施肥耕作方式,退耕恢复处理下:①土壤水稳性大团聚体( 0.25 mm)总量显著增加,微团聚体(0.053～0.25 mm)和矿质颗粒(0.053 mm)含量显著降低;②土壤有机碳和全氮含量显著增加,全磷含量显著降低,其中有机碳含量在各个粒级团聚体中均显著增加,全氮含量则在大团聚体(2和0.25～2 mm)与微团聚体(0.053～0.25 mm)中显著增加,而全磷含量在各粒级团聚体中均显著降低。另外,0.25～2 mm粒级大团聚体对土壤碳氮磷养分贡献率最高;③土壤C∶N、C∶P和N∶P显著升高,但C∶N在各粒级团聚体中表现较为稳定,而C∶P和N∶P变异性较大,在各粒级土壤团聚体中均有显著升高。综上,退耕恢复增强了耕层土壤的团聚作用,使碳、氮、磷更集中赋存于大团聚体中,对土壤结构、团聚体质量有改善作用,但对于磷素限制作用的增强值得今后注意。     

化肥和有机肥长期施用对红壤酶活性的影响

选择长期定位试验中的不施肥对照(CK)、单施化肥(NPK)、单施有机肥(OM)及化肥有机肥配施(NPKM)4种处理,研究了长期化肥和有机肥互作对旱地红壤酶活性的影响及酶活性与土壤理化性质、微生物生物量的关系。结果表明,施肥特别是化肥和有机肥的交互作用能不同程度促进参与碳、氮循环的总体酶活性增加;其中,OM对酶活性的促进作用强于NPK,NPKM的酶活性最高。与CK相比,施用有机肥的处理(即OM和NPKM)会降低参与碳循环酶和参与氮循环酶的比值,而NPK不影响该比值。OM处理的单位微生物量碳酶活性和单位有机碳酶活性均显著低于其他处理,而在NPK处理中这两项指标最高,OM和NPKM处理则提高了单位微生物量氮酶活性。一方面说明有机肥可以缓解土壤微生物的碳限制,但是供氮能力相对不足,而与化肥配施缓解了氮素的限制状况;另一方面暗示有机肥可以提高土壤生物的生态效率。总之,化肥和有机肥配施能够在碳氮资源的生物有效性上形成互补关系,能够同时促进土壤生物和作物生长,从而满足土壤生态系统服务功能持续发挥的需要。     

长期施肥对水稻土颗粒有机碳和矿物结合态有机碳的影响

在23a的田间定位试验区,研究了长期施肥对水稻土颗粒有机碳和矿物结合态有机碳的影响.结果表明,在不施肥(CK)、无机肥(NPK)、有机肥(猪粪 紫云英绿肥)(OM)和无机肥与有机肥配施(NPKM)处理中,A层游离态和闭蓄态颗粒有机物含量比P层高,随着土层的加深呈下降的趋势;而矿物态有机物呈相反的趋势.增施有机肥(NPKM,OM处理)有利于提高土壤中游离态和闭蓄态颗粒有机物及其有机碳的含量以及占土壤有机碳的比例.团聚体中颗粒有机物占土壤团聚体重量的比例及颗粒有机物的有机碳含量均随着团聚体粒径的减小而明显增加.增施有机肥显著提高了团聚体特别是微团聚体(<0.25mm)中颗粒有机物及其有机碳的含量.团聚体中颗粒有机物的有机碳含量显著高于容积土壤中颗粒有机物的有机碳含量.这些结果表明微团聚体对颗粒有机物具有富集和保护作用. 和闭蓄态颗粒有机物含量比P层高,随着土层的加深呈下降的趋势;而矿物态有机物呈相反的趋势.增施有机肥(NPKM,OM处理)有利于提高土壤中游离态和闭蓄态颗粒有机物及其有机碳的含量以及占土壤有机碳的比例.团聚体中颗粒有机物占土壤团聚体重量的比例及颗粒有机物的有机碳含量均随着团聚体粒径的减小而明显增加. 施有机肥显著提高了团聚体特别是微团聚体(<0.25mm)中颗粒有机物及其有机碳的含量.团聚体中颗粒有机物的有机碳含量显著高于容积土壤中颗粒有机物的有机碳含量.这些结果表明微团聚体对颗粒有机物具有富集和保护作用. 和闭蓄态颗粒有机物含量比P层高,随着土层的加深呈下降的趋势;而矿物态有机物呈相反的趋势.增施有机肥     

不同地下水位和施肥管理对水稻土有机碳组分的影响

利用自1981年开始的红壤性水稻土长期定位试验,对耕层土壤不同有机碳组分进行分析,以探究不同地下水位(低水位80 cm、高水位20 cm)和施肥(高量有机肥、常量有机肥、化肥)管理对红壤性水稻土有机碳组分数量和分配的影响。结果表明:各处理土壤的颗粒有机碳(POC)含量为6.29~11.77 g·kg-1,高、低水位下,各施肥处理的POC含量均随着有机肥施用量的增加而增加,但高水位下POC增加的幅度更大;高、低水位下,有机肥处理的颗粒有机碳占总有机碳的比例(fPOC/TOC、oPOC/TOC)均显著高于化肥处理,且在低水位下这种差异尤为显著;土壤中各有机碳组分均与土壤总有机碳TOC和2 mm团聚体结合态有机碳含量存在极显著正相关;在高水位或低水位区,有机肥的施用均能大幅度提高土壤TOC和POC,且在高水位下有机碳的积累更为明显。     

New amino-dithiaphospholanes and phosphoramidodithioites and their rhodium and iridium complexes

New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn₂NPSCH₂CH₂S^a(P-S^a) (Bn = benzyl, 4), Bn₂NPSCHCHS^a(CH₂)₃C^aH₂(P-S^a)(C^a-S^a) (6) and Bn₂NP(4-XC₆H₄OMe)₂ (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)₂] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl₂Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the ν_CO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The ¹J_PRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the ¹J_PSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh₃. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh₃.     

Astrocytes and Synaptosomes Transport and Metabolize Lactate and Acetate Differently

Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.     

Rapporteur report: Basics and technology and metrology and standards

The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.     

白蚁与动物及微生物的共生类型及其机制

综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生（宾主共栖和异种共栖）、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌（原生动物、细菌、真菌和放线菌）和外生菌（蚁巢伞菌等）间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用（如纤维素酶）及今后研究物种间的协同进化提供了基础资料。     

Relative and combined effects of ethanol and protein deficiency on strontium and barium bone content and fecal and urinary excretion

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.     

Cytoskeleton and mitochondrial morphology and function

It has been well established that the cytoskeleton is an essential modulator of cell morphology and motility, intracytoplasmic transport and mitosis, however cytoskeletal linkage to the organelles has not been unequivocally demonstrated. Indeed, cytoskeleton appears to be essential in determining and modulating gene phenotype as a function of cellular environment. According to recent studies, the organization of the cytoskeleton network together with associated protein(s) could be essential in regulating mitochondrial function and particularly the permeability of the mitochondrial outer membrane to ADP. The aim of this chapter is to summarize the main properties of the cytoskeletal environment of mitochondria and the possible role(s) of this network in mitochondrial function in myocytes.     

Prostaglandin and thromboxane production by human and guinea-pig macrophages and leucocytes

The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE₂, PGD₂, PGF_2α, TXB₂ and 6-keto-PGF_1α. In all types studied PGE₂ and TXB₂ were the major products formed. The identification of PGE₂ and TXB₂ was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.     

Cross-reactivity between storage and dust mites and between mites and shrimp

Many patients have sensitivities to multiple species of storage and house dust mites. It is not clear if this is because patients have multiple sensitivities to species-specific mite allergens or if these mites share many cross-reacting allergens. Our objective was to further define the cross-allergenicity between several species of storage and house dust mites using crossed-immunoelectrophoresis (CIE), crossed-radioimmunoelectrophoresis (CRIE), immunoblotting, and ELISA. CIE and CRIE reactions revealed that storage mites shared two cross-antigenic molecules and one of these bound IgE in a serum pool from mite allergic patients. Antibody in anti-sera built to each species of mite recognized many SDS–PAGE resolved proteins of other mite species and this suggested the potential for other cross-reactive allergens. Among patient sera, IgE bound to many different proteins but few had IgE that bound to a protein with common molecular weights across the mite species and this suggested mostly species-specific allergens. Antiserum built to each mite species precipitated one protein in shrimp extracts that bound anti-Der p 10 (tropomyosin) and IgE in the serum pool. Anti-Der p 10 showed strong binding to shrimp tropomyosin but very little to any of the mite proteins. ELISA showed the mite extracts contained very little tropomyosin. The storage and dust mites investigated contain mostly species-specific allergens and very small amounts of the pan-allergen tropomyosin compared to shrimp and snail.