湖泊沉积物内源磷分布及其相关性研究

以太湖为研究对象，研究了湖泊内源磷以磷化氢形态的释放问题。结果表明，湖泊沉积物中的磷主要以铁磷和钙磷形态存在。湖泊沉积物中磷化氢含量与总磷、溶解态磷、铁磷、钙磷、铝磷呈显著相关，与有机磷、闭蓄态磷、交换态磷相关性不显著，表明在沉积物各种形态磷转化为磷化氢的机制中，无机磷最有可能为磷化氢形成的前体物，磷化氢可能作为富营养化湖泊中磷的生物地球化学循环的一部分，参与沉积物磷的释放过程。     

南方内陆富营养化湖泊沉积物磷形态特征研究

采用连续提取法和欧洲SM T法对福建省山仔水库和西湖表层沉积物的磷形态进行分级提取测定。分析结果表明,两者的总磷含量分别与国内发生富营养化的深水库、浅层湖泊表层沉积物总磷含量相当,说明沉积物可能是上覆水中溶解性磷的重要来源。2个湖泊沉积物无机磷都占大多数,无机磷中铁磷含量远远高于铝磷和钙磷的含量,山仔水库铁磷占总磷量的35%～45%,西湖铁磷占总磷量的60%以上,2个湖泊表层沉积物中低百分含量的钙磷和闭蓄态磷表明沉积物中磷主要来自人为输入。     

海河干流柱芯不同粒径沉积物中有机质和磷形态分布研究

采用欧洲标准测试委员会制定的SMT法(标准测试方法)对海河干流不同粒径级柱芯沉积物中各种形态的磷进行分级提取和测定,并在此基础上讨论不同深度、不同粒径沉积物中磷形态分布特征.结果表明,在邢家圈和张家嘴两采样点,海河沉积物颗粒组成以细砂、极细砂为主,占总量的40%～60%.沉积物中总磷含量在560～1100μgP·g-1之间.在所有不同粒径沉积物中钙结合态磷(HCl-P)含量最高,占总磷的60%～80%,可交换态磷(Ex-P)含量极微,占总磷的2%～3%,不同粒径下各形态磷含量的高低顺序为:钙结合态磷(HCl-P)>有机磷(OP)>铁铝氧化物结合态磷(NaOH-P)>可交换态磷(Ex-P);张家嘴采样点表层沉积物中磷形态含量高于其他沉积深度磷含量,表明近年来,沉积的磷主要以人为输入为主;钙磷含量随粒径变化复杂,其他各形态磷的含量均随沉积物粒径变小而增高.此外,对各形态磷之间以及各形态磷与沉积物理化性质之间的相关性进行了讨论.     

广东省主要水稻土有效磷钾测定法的研究 Ⅰ.水稻土的磷素形态及有效磷的测定

本文对花岗岩、玄武岩水稻土及三角洲沉积水稻土的磷素形态,有效磷源及其提取方法进行了研究。花岗岩和玄武岩水稻土无机磷以闭蓄态磷为主,铁磷次之,有效磷源主要是铁磷和铝磷。三角洲沉积水稻土无机磷也以闭蓄态磷为主,铁磷和钙磷的相对含量与土壤酸碱度有关。三角洲沉积酸性水稻土的有效磷源为铁磷和铝磷,中性、弱碱性水稻上为铝磷。用6种化学方法对三类水稻土进行了测定,以A值及四造水稻吸磷量、产量作为参比项进行校验,结果以Olsen法最好,并提出了该法对上述土壤的临界值。     

黄河上游沉积物中磷的存在形态及生物可利用性

采用七步连续提取法分别对黄河上游11个不同段位表层沉积物样中7种形态磷进行了分离分析,探讨了其变化规律和分布特征,分析了其生物可利用性及对黄河及海洋水体营养状况的影响。结果表明:所获得沉积物中磷的7种赋存形态为:交换态磷(Ex-P)、铝结合态磷(Al-P)、铁结合态磷(Fe-P)、闭蓄态磷(Obs-P)、自生钙结合磷(Ca-P)、原生碎屑磷(De-P)和有机磷(OP),其中De-P和Ca-P的含量范围分别为139.08～482.89mg.kg-1和40.30～125.55mg.kg-1,二者共占总磷(TP,为各形态磷的总和)含量的约87%,是沉积磷和无机磷(IP,前6种磷形态之和)的主要存在形态;OP含量范围为6.14～36.74mg.kg-1,平均占TP的4%;Ex-P、Al-P、Fe-P和Obs-P含量均较低,平均值分别为7.53、25.85、5.05mg.kg-1和0.64mg.kg-1,共占TP含量的约9%。各形态磷的含量分布直接与取样点及沉积物粒径有关。Ex-P、Al-P、Fe-P、Or-P和部分Ca-P作为黄河表层沉积物中潜在的生物可利用磷(BP),其总量至少占TP的5.91%～30.17%。根据黄河每年进入渤海的输沙量可初步估算出黄河泥沙入海后为海洋提供的BP的量达3.21～8.92万t。     

黄河表层沉积物中磷的分布特征及磷的生物可利用性

采用改进的七步连续提取法分别对黄河中下游流域5个不同段位表层沉积物中总磷(TP)、有机磷(OP)及各种无机磷形态进行了分析,研究并探讨了沉积物中磷的分布特征及其对河海町能产生的影响,为预测黄河乃至渤海流域的营养状况、预防及科学管理等提供理论依据.结果表明,所测黄河表层沉积物中TP含量范围为240.71~576.59 μg·~(-1).以无机磷(IP)为主,占TP含量的85.73%～98.48%;OP含量占TP的1.52%～14.27%.受陆地河流和海流注入的影响,所研究沉积物样中TP、IP和0P含量的最大值均出现在靠近黄河口的渤海浅海区,其次是黄河口.IP分为6种形态磷.即交换态磷(Ex-P)、铝结合态磷(AI-P)、铁结合态磷(Fe-P)、闭蓄态磷(Obs-P)、自生钙结合磷(Ca-P)和原生碎屑磷(De-P),其中以De-P为主,其次是Ca-P,分别占TP的52.47%～73.67%和18.32%～38.20%,Ex-P、Fe-P和Al-P含量均相对较低,Obs-P含量最低.各形态磷的空间分布均与调查区沉积物粒径有一定相关性,粒径小于0.063 mm的沉积物样中TP和IP含量均最高.Ex-P、Al-P、Fe-P、Or-P和部分Ca-P作为黄河表层沉积物中潜在的生物可利用磷,其总量至少占TP的6.09%～24.46%.     

沉积物中磷形态的化学连续提取法应用研究

对水体沉积物中磷的环境地球化学研究中较普遍采用的7步法连续提取磷分级方案在实际应用中出现的一些问题进行了探讨。从该方法对水系沉积物成分分析标准物质GSD—12及太湖沉积物的分析结果看，该方法的应用中各形态的重现性问题必须得到重视，尤其是闭蓄态磷的提取中，实际操作中要尽量避免因沉积物固结容器底部而降低提取剂的提取效率，对于提取离心液过滤难的问题也一定要解决好。可交换态磷、铝磷和铁磷的提取液由于磷浓度低，可以不将其后的漂洗液混入后测定，以提高待测液中磷的浓度。另外，从GSD—12与太湖沉积物中磷形态特征的相似性看，GSD—12可以考虑作为淡水水体沉积物磷形态分级的标准物质，从而解决不同文献、不同研究项目在沉积物形态分析方面缺乏可比性的问题。     

pH对红枫湖表层沉积物吸附与释放磷的影响

为给进一步治理红枫湖提供参考资料,对沉积物中磷在大范围pH(2～12)下的吸附与释放特性进行了模拟试验.结果表明:红枫湖沉积物可溶性磷的存在形态包括有机磷、无机磷、铝/铁磷和钙磷等,铝/铁磷和钙磷为主要形态.红枫湖沉积物对磷的理论吸附量较大,说明,在上覆水含磷浓度较高的情况下,沉积物仍能吸附大量的磷污染物,在红枫湖水污染较轻的情况下,沉积物中的磷将释放,导致水体富营养化.pH对磷吸附的影响呈倒“U”型,对磷释放的影响呈“U”型,随着pH增大,磷的释放量也增大,这是由OH-交换能力的增强和红枫湖沉积物中可交换的铝/铁磷和钙磷含量较高所致.     

黄东海陆架区沉积物中磷的形态分布及生物可利用性

采用1992年Ruttenberg连续提取法(SEDEX)将黄东海陆架区沉积物中的磷分为交换态磷(Ex-P),Fe结合态磷(Fe-P),自生磷(Au-P),碎屑磷(De-P),有机磷(Or-P),分析了各形态磷的平面和垂直分布特征;利用沉积物年代序列测定的结果,探讨了柱状沉积物中不同形态磷的含量变化,并进一步分析了该区域磷形态的生物可利用性。结果表明,黄东海陆架区表层沉积物各形态磷平均含量为:Au-P(140.72 μg/g)>De-P(59.23 μg/g)>Or-P(32.69 μg/g)>Fe-P(29.91 μg/g)>Ex-P(5.92 μg/g);各形态磷在沉积时间序列上分布不同,反映了不同时期人类活动和气候环境等因子对磷埋藏量影响的不同,其中Au-P在长江口H1-18站位含量比南黄海中部3个站位要低得多;调查区表层潜在生物有效磷为13.55%左右,仅仅占沉积磷中的一小部分。     

黄河中游表层沉积物中无机磷的化学形态研究

采用连续浸提法对黄河中游不同粒级表层沉积物中无机磷的各种存在形态进行了研究。结果发现,黄河中游表层(5cm)沉积物中总无机磷的含量范围为1187.08～1467.98μg.g-1,平均为1360.68μg.g-1;在所有不同粒级的表层沉积物中Ca-P含量占总无机磷的绝大部分,Fe-P含量极微,各形态无机磷含量的高低顺序为:钙结合态磷(Ca-P)、闭蓄态磷(Obs-P)、铝结合态磷(Al-P)、吸附态磷(Ads-P)和铁结合态磷(Fe-P);除Ca-P(Fe-P不确定)外,其他各形态磷的的含量均随沉积物粒度变细而增高。     

Web2.0,以个人为中心的互联网时代的到来

本文介绍了Web2．0的知识和背景，对Web2．0出现的基础以及典型技术和应用作了阐述，同时对其作出了前景展望。     

Virus Location and Lymphocyte Apoptosis in Lymph Nodes of Piglets Infected with PCV-2

The present study has been performed to understand the location of the virus, type of apoptotic cells, and their relation to lymph nodes of piglets infected with porcine circovirus type Ⅱ （PCV-2）. Nine 32-day-old conventional piglets free of infection with PCV-2 were used, and distributed into three groups： control group （n = 3）, piglets inoculated with PCV-2 alone （PCV-2, n = 3）, and PCV-2 inoculated and KLH immunostimulated group （PCV-2 ＋ KLH, n = 3）. Superficial inguinal lymph nodes from all piglets were collected for histological examination after 32 days postinoculation, and immunohistochemistry for PCV-2 detection. Location of apoptotic cells was detected with TdT-mediated dUTP nick end labeling （TUNEL） and cell cycle, and the apoptotic rates were measured by flow cytometry. The characteristic histopathological lesions of the piglets in PCV-2 and PCV-2 ＋ KLH were lymphocyte depletions in the cortex and paracortex of the lymph nodes, epithelioid-like macrophage infiltration, and intracytoplasmic inclusion bodies presented in epithelioid-like macrophages. PCV-2 was mainly found in epithelioid-like macrophages by immunohistochemistry. In the lymph nodes, lymphocytes presented higher apoptotic rates in the cortex by TUNEL, special B-cell areas, and similar apoptotic cells were found in this compartment in the control. The apoptotic rates of the lymph nodes were 0.41, 3.34, and 4.88% in the control, PCV-2, and PCV-2 ＋ KLH groups by flow cytometry, respectively. The apoptotic rates of lymph nodes for PCV-2 and PCV-2 ＋ KLH piglets were significantly higher than those for the control group （P〈0.05 and P〈0.01）. The proliferation index （PI） was 0.17_＋0.01, 0.12_＋0.01 and 0.12_＋0.04 in the control, PCV-2, and PCV-2 ＋ KLH group, the PI of the control group was higher than that of the other groups, but without the statistical difference. PCV-2 can induce lymphocyte depletion in lymph nodes of piglets by blocking cell proliferation and promoting apoptosis. This is one o     

市级综合气象信息分析与管理系统的设计与实现

以抚顺地区3个国家基本站50余年气象资料为依托，采用Microsoft Excel工作表实现由气候和农业气候2部分构成的气象与农业综合信息处理系统的基本思路、方法、内容、用途和使用情况。为了实现气候分析及应用的科学化、客观化、系统化、规范化、程序化及连续化的业务目标，按业务流程设计与实现的，包括资料处理、气候趋势模拟、气候预测、气候鉴定、季节性信息化处理、农作物产量预报、气候生产潜力分析等一系列内容在内的系统建设。关键是解决了大量的计算问题，建立了区域性通用模式。     

Multi-variable grey model (MGM (1,n,q)) based on genetic algorithm and its application in urban water consumption

Urban water consumption has some characteristics of grey because it is influenced by economy, population, standard of living and so on. The multi-variable grey model （MGM（1,n））, as the expansion and complement of GM（1,1） model, reveals the relationship between restriction and stimulation among variables, and the genetic algorithm has the whole optimal and parallel characteristics. In this paper, the parameter q of MGM（1,n） model was optimized, and a multi-variable grey model （MGM（1 ,n,q）） was built by using the genetic algorithm. The model was validated by examining the urban water consumption from 1990 to 2003 in Dalian City. The result indicated that the multi-variable grey model （MGM（1,n,q）） based on genetic algorithm was better than MGM（1,n） model, and the MGM（1,n） model was better than MGM（1,1） model.     

Molecular detection of virulence genes in Campylobacter species isolated from livestock production systems in South Africa

Campylobacter species are a major cause of foodborne bacterial infections in both developed and developing countries worldwide. Campylobacter jejuni is responsible for the majority of infections. This study was conducted to identify virulenceassociated genes in Campylobacter species isolated from livestock production systems in South Africa. A total of 250 fecal samples consisting of cattle(n=50), chickens(n=50), goats(n=50), sheep(n=50) and pigs(n=50) were randomly collected from livestock in Eastern Cape and KwaZulu-Natal provinces of South Africa between April and October 2018. The samples were analyzed for the presence of virulence genes in Campylobacter species using molecular PCR-based methods. It was found that 77 and 23% of Campylobacter jejuni and Campylobacter coli respectively were isolated from all the livestock samples. There were positive significant(P0.05) correlations amongst all the virulence genes that were investigated. Chisquare and Fisher's exact tests were implemented to test for the effect of livestock species on the presence or absence of virulence genes. The study demonstrated that most of livestock species can potentially cause zoonotic infections and food poisoning due to the high prevalence of Campylobacter. The high prevalence of virulence genes highlights the significance of Campylobacter in livestock production systems in South Africa. This requires the implementation of one-health approaches to reduce the impact of foodborne and zoonotic diseases for the welfare of human and animal health.     

不同施肥水平对木薯氮磷钾养分积累、分配及其产量的影响

 【目的】通过比较不同施肥水平下木薯氮磷钾养分积累、分配和产量的差异，探讨粤北坡岗地优质高产木薯氮磷钾养分的最佳用量。【方法】以木薯品种南美119为材料，采用“3414”方案，在粤北翁源进行大田试验。试验共设14个处理。【结果】施肥处理的氮素主要分配到地上部，不施肥处理的氮素则主要分配到根部；不同施肥处理的磷素均主要分配到地上部；不施肥处理和不施钾处理的钾素主要分配到根部，不施氮处理的钾素在根、冠间分配较均衡。在木薯不同生长阶段，植株氮磷钾含量均呈下降趋势，但施氮、磷、钾化学肥料处理植株氮磷钾含量的下降速度小于不施氮、磷、钾化学肥料的处理。处理N2P2K2的氮、磷、钾含量和积累量在各生育期均为最大，不施肥处理（N0P0K0）的氮、磷、钾含量和积累量在各生育期均为最小（P＜0.05）。产量最高的是N2P3K2处理，为22 694.06 kg·hm-2，其次是N2P2K2处理，为21 417.87 kg·hm-2。【结论】木薯产量、氮磷钾养分积累及其在根冠间的分配，对施肥水平高度敏感, 适当比例的氮磷钾肥配合施用既可以显著增加木薯植株的氮磷钾含量和积累量，又可以提高产量。在粤北坡岗地木薯生产中，氮素最重要，在氮素得到满足的条件下，磷素较钾素更重要。在本试验条件下，氮磷钾养分最佳用量为358.80 kgN·hm-2、89.10 kg P2O5·hm-2和187.50 kg K2O·hm-2。     

红苕饲粮中添加铜和/或喹乙醇对猪生产性能及某些血液生化指标的影响

选体重约38公斤的长白(♂)×成华(♀)杂交猪20头,随机分为四组,饲予四种不同的饲粮,研究饲粮中添加铜和/或喹乙醇对猪生产性能和某些血液生化指标的影响。结果表明:基础组、加铜组、加喹乙醇组和两者同时加组全期日增重分别为674、761、796、678克,日采食量分别为2.50、2.65、2.74、2.40公斤,饲料利用率分别为3.73、3.49,3.44、3.54,添加铜和/或喹乙醇对试验第65天血清铜兰蛋白、尿素氨及屠宰率、背膘厚和眼肌面积无显著影响(p>0.05);添加铜使65天血清碱性碱酸酶活性极显著增高(p<0.01),添加喹乙醇有使之升高的趋势,两者同时添加时,碱性酸磷酶活性降低。     

Current progress on genetic interactions of rice with rice blast and sheath blight fungi

Analysis of genetic interactions between rice and its pathogenic fungi Magnaporthe oryzae and Rhizoctonia solani should lead to a better understanding of molecular mechanisms of host resistance, and the improvement of strategies to manage rice blast and sheath blight diseases. Currently, dozens of rice resistance (R) genes against specific races of the blast fungus have been described. Among them, ten were molecularly characterized and some were widely used for breeding for genetic resistance. The Pi-ta gene was one of the best characterized rice R genes. Following the elucidation of its molecular structure, interaction, distribution, and evolution, user friendly DNA markers were developed from portions of the cloned genes to facilitate the incorporations of the Pi-ta mediated resistance into improved rice varieties using marker assisted selection (MAS). However, rice blast is still a major threat for stable rice production because of race change mutations occurring in rice fields, which often overcome added resistance based on single R genes, and these virulent races of M. oryzae pose a continued challenge for blast control. For sheath blight, progress has been made on the exploration of novel sources of resistance from wild rice relatives and indica rice cultivars. A major quantitative trait locus (QTL), named qSB9-2, was recently verified in several mapping populations with different phenotyping methods, including greenhouse methods. The ability to identify qSB9-2 using greenhouse methods should accelerate the efforts on the qSB9-2 fine mapping and positional cloning.     

仙人掌超氧化物歧化酶提取与纯化研究

以仙人掌为试验材料,采用硫酸铵分级沉淀法得到超氧化物歧化酶（Superoxide Dismutase,SOD）粗酶液。然后用Sephadex（葡聚糖凝胶）G-75层析柱层析对粗酶液进行进一步纯化,最后用邻苯三酚法测定酶活力,并对酶活力主要影响因素（包括pH值、温度、抑制剂）进行了研究。结果显示仙人掌SOD酶比活力为751.56U.mg-1。pH值为7.5~8.5时酶活力最大,稳定性也好。温度维持在25~30℃时酶活力最高。由于过氧化氢和氰化钾均能使仙人掌SOD的酶活力显著下降,因而可以初步判断从仙人掌中提取到的SOD是Cu.Zn-SOD。     

锌对镉·汞复合污染下豌豆幼苗生长的影响

以豌豆为试验材料,采用水培方法研究了锌对镉、汞复合污染下的豌豆种子萌发与生长的影响。结果显示,锌浓度≤100.0 mg/L时促进豌豆种子的萌发,锌浓度为200.0和300.0 mg/L时抑制豌豆种子的萌发。当镉、汞的浓度为3.0 mg/L时,100.0 mg/L锌的解毒效应最明显,表现为能够促进镉、汞胁迫下豌豆种子萌发和幼苗生长,降低豌豆幼苗根尖细胞畸变率,提高豌豆幼苗的叶绿素含量及过氧化物酶活性;但当锌浓度≥200.0 mg/L时,与镉、汞协同迫害豌豆幼苗的生长。