Early development of Costaria costata (C. Agardh) Saunders and cultivation trials

Costaria costata(C.Agardh) Saunders is one of common kelps distributed in many coastal areas worldwide;however,in China,no reports have been made on cultivation of the genus.To investigate potential cultivation of the species in the northern part of China,trials on isolation and preservation of the gametophytes were conducted using C.costata from Korea;growth and development of the gametophytes were observed.We showed that at 10±1°C,60 μmol m-2s-1 and 12:12 h(L:D),freshly released zoospores settled down wit...     

Structural analysis and anti-complement activity of polysaccharides extracted from Grateloupia livida (Harv.) Yamada

Polysaccharides were extracted from Grateloupia livida(Harv.) Yamada using hot water(extracted product denoted WGW) and then degraded in dilute sulfuric acid(degraded product denoted WGWD). The degraded mixture was then separated into four fractions through anion exchange chromatography on 2-diethylaminoethanol(DEAE)-Bio-Gel Agarose FF gel. Electrospray ionization collision-induced dissociation tandem mass spectrometry(ESI-CID-MS/MS) was performed to elucidate the structural features of all fractions. In combination with nuclear magnetic resonance spectroscopy(NMR)and infrared spectroscopy(IR) data, the major polysaccharide structures were concluded to be μ-carrageenan and κ-carrageenan. μ-Carrageenan usually has a backbone of alternating 1,3-linked β-D-galactopyranose residues sulfated at C-4 and 1,4-linked a-D-galactopyranose residues sulfated at C-6, while κ-carrageenan consists of alternating 1,3-linked β-D-galactopyranose residues sulfated at C-4 and 1,4-linked a-D-3,6-anhydrogalactopyranose residues. Trace v-carrageenan, composed of 1,3-linked β-D-galactopyranose residues sulfated at C-4 and 1,4-linked a-D-galactopyranose residues sulfated at C-2 and C-6, was also detected. Furthermore, the polysaccharide had a backbone comprising 1,3-linked β-D-galactopyranose and1,4-linked α-L-galactopyranose sulfated at C-6, which is the agarose precursor. The hydroxy groups in the galactopyranose were partially substituted by methyl and pyruvic acid acetal(PA) groups. The anticomplementary activities of WGW and its derivatives against classical pathways were measured. The native polysaccharides in WGW had higher activities, while the derivatives had much weaker activities. This indicated that the molecular weight and sulfate content were important factors affecting the anti-complement activity.     

钦州沿海1997年汛期暴雨预报浅析

通过分析钦州沿海１９９７年汛期１４个暴雨过程知道,该年汛期暴雨具有次数多、量级小的特点,其主要影响系统是锋面、切变线;７００ｈＰａ层低能舌叠置在８５０ｈＰａ相对高能区上,在钦州沿海形成位势不稳定区,是整个汛期暴雨具有显著的共同的前期特征。     

Genetic study of Kelp"901"strain

Based on DNA extraction and optimization of random amplified reaction (RAPD) to the gametophytes and sporophytes of Kelp “901” strain, genetic study on variation was conducted to its parents and offsprings of F₆, F₇, F₈, and F₉ generation. RAPD results have shown that among 30 selected primers for gametophytes, 297 loci ranging from 200 to 3 000 bp were obtained in the average of 9.9 loci for each primer. This indicated a high polymorphic rate with RAPD detection. UPGMA (unweighted pair-group method arithmetic average) analysis showed that each male and female gametophyte of a generation could be clustered into one pair separately. The genetic distances of the Kelp 901 generation were 0.3212–0.4767, and the maximum was between F₇ and F₈ (0.4767). Identity analysis showed that F₆ generation was more close to the female parent (0.6593), and F₇ generation was more close to the male parent (0.578 8). To the sporophytes study in 24 selected primers for RAPD amplification, 191 loci ranging from 230–2800 bp were obtained, in the average to each primer of 8.0 loci. The heterozygosity to six populations were male parent (0.2239), female parent (0.1072), F₆ (0.2164), F₇(0.2286), F₈(0.2296) and F₉(0.3172). The nearest genetic distance was 0.083 5(F₈, F₉). Total heterozygosity (H_T) of F₆, F₇, F₈ and F₉ generations was 0.3186, the average heterozygosity (H_S) for F₆, F₇, F₈ and F₉ generations was 0.2480, and deduced coefficient of population differentiation (G_st) was 22.2%. Six sequence characterized amplified regions (SCAR) were preliminary screened through RAPD analysis. It needed to be verified in detail as they are significant for molecular marker assistance in breeding and selectingLaminaria.     

Observation of female gamete (Carpogonia) germination of Porphyra yezoensis and P. oligospermatangia

Several papers have reported that part or whole leafy thallus seemingly consisting of zygotospores can give rise to both blades and conchocelis in the same culture ofPorphyra. Study on samples of wild and cultivatedPorphyra yezoensis andP. oligospermatangia were conducted to clarify the origination of the young blades in the culture. It is confirmed that single cells on the blade of both species, which normally intermixed with zygotospores, germinated into young blades. TEM and SEM observation has shown that the single cells ofPorphyra yezoensis had typical features of female gamete (carpogonia) but archeospore. Therefore, the female gametes are responsible in developing leafy thalli. This project was sponsored by the NSFC (No. C-0205-05-39770593)     

特长套铣筒在埋钻事故中的应用

以往用煤田钻探常用的套铣筒处理一起普通的埋钻事故耗时费力,又容易滋生次生事故。在使用特长套铣筒处理钻孔中的埋钻事故,可以大大缩短处理事故的时间,减少了工人的劳动强度,收到事半功倍的效果。特长套铣筒采用石油专用的带丝扣套管,每根套管长度12m左右,套管之间用管箍连接,总长度一般在80~100m,套铣筒的下端接套铣筒钻头。套铣筒的规格根据孔内事故钻具的最大外径确定,通常比事故钻具最大外径大两个级差,而又比孔径小两个级差。套铣筒钻头的规格应该比事故钻头的规格小一级或等于事故钻头的外径,钻头合金宜采用孕镶粉未合金或其它抗耐磨合金。山西某煤矿送料孔钻探到497m时埋钻,用普通方法处理上部272m钻具用时24d,改用特长套铣筒处理剩余225m钻具仅用时10d,体现了高效率的特点,为大孔径勘探孔埋钻事故的处理,找到了一条比较快速的处理方法。     

塔里木盆地古新世海进特征与石膏成因模式

由塔里木及邻区古新统剖面分析,石膏层位于海侵层位的上部,并沿自西向东的海进方向渐次升高.结合生物相分析认为,石膏是在海进条件下形成的,其成因模式符合“分离盆地说”成盐理论.     

河北省铁矿资源及开发利用现状

河北省铁矿产量排名全国第一,但存在着铁矿石后备资源量不足;小矿山产量大,但占有资源储量少;超贫铁矿地质勘查程度低,底数不清;铁矿选矿厂问题严重等问题,因此必须①进一步加大地勘工作经费投入,对成矿条件较好的异常区域进行工程验证,扩大铁矿资源储量;②实施以主要和优势矿山企业为龙头的资源开发整合战略;③在进一步加强对含铁基性岩和含铁变质岩超贫铁矿的勘查程度基础上,根据市场需求,有序进行开发;④选矿厂厂址选择必须贯彻我国工业建设的各项方针政策。     

新冠肺炎疫情的空间扩散过程与模式研究

研究新冠肺炎疫情的空间扩散过程与模式对于防疫抗疫资源的合理配置、突发公共卫生事件的管理与应对以及未来公共卫生体系的完善具有重要意义。本文综合时间和空间尺度,从地理学视角研究了新冠肺炎疫情的城际空间扩散过程,归纳总结扩散模式,并揭示了其影响因素。研究发现：新冠肺炎疫情在中国的发展主要经历了6个阶段,并在空间上表现出邻近扩散、迁移扩散、等级扩散和廊道扩散等地理模式;地理邻近性、人口流动、人口规模、交通网络、疫情防控管理等因素对疫情的空间扩散具有显著影响。新冠肺炎疫情的空间扩散过程和模式一定程度上是“流空间”网络下人类社会经济活动空间组织模式的一种反映,与地理邻近性、社会经济联系的跨区域性及人类活动的时空规律等密切相关。本研究以期为世界各国的疫情防控措施制定提供参考,也为中国未来应对公共卫生应急风险提供经验借鉴。     

华蓥山志留纪地层的再认识及其在油气普查勘探上的意义

华蓥山以东、以北和重庆以下,三峡以上的长江南北两岸的川东地区,70年代后期至今,由原石油工业部,即现在中国石油天然气总公司,四川石油管理局川东气矿,先后在这里勘探到“石炭系”工业气层,现已建成近十个大、中、小型多层气田,其中高产气层常与被称为“石炭系”角砾白云岩密切相关。这个气层分布广,多在100m厚度以内,横向变为或厚或薄的不均一体。但往东南向湖北方向,公认的中石炭统黄龙灰岩,厚度多大于100m,且几乎全是灰岩,至今尚未发现有好的气层或油气显示。该区中石炭世确有浅海碳酸盐沉积,自东向西,自湖北向四川东部和东南部展布。