Predicting the reproduction strategies of several microalgae through their genome sequences

Documenting the sex and sexual reproduction of the microalgae is very difficult, as most of the results are based on the microscopic observation that can be heavily influenced by genetic, physiological and environmental conditions. Understanding the reproduction strategy of some microalgae is required to breed them in large scale culture industry. Instead of direct observation of sex and sexual reproduction under microscope, the whole set or the majority of core meiosis genes may evidence the sex and sexual reproduction in the unicellular algae, as the meiosis is necessary for maintaining the genomic stability and the advantages of genetic recombination. So far, the available genome sequences and bioinformatic tools(in this study, homolog searching and phylogenetic analysis) allow us to propose that at least 20 core meiosis genes(among them ≥6 must be meiosis specific) are enough for an alga to maintain its sexual reproduction. According to this assumption and the genome sequences, it is possible that sexual reproduction was carried out by Micromonas pusilla and Cyanidioschyzon merolae, while asexual reproduction was adopted by Bigelowiella natans, Guillardia theta, Nannochloropsis gaditana, N. oceanica, Chlorella variablis, Phaeodactylum tricornutum and Thalassiosira pseudonana. This understanding will facilitate the breeding trials of some economic microalgae(e.g., N. gaditana, N. oceanica, C. variablis and P. tricornutum). However, the reproduction strategies of these microalgae need to be proved by further biological experiments.     

注浆堵水后试验排水期间矿井残留水量估算

注浆堵水后期,矿井试验排水是对注浆效果进行综合评定,同时也是检查矿井是否具备复矿条件的重要指标。但由于各个矿井地质条件的差异性,致使试验排水得到的一些数据存在一定的歧义,从而误导正常的判断,进而影响矿井生产。以新疆兴陶大北矿业公司大北煤矿试验排水为例,阐述影响矿井试验排水的主要因素,并提出简单估算矿井残留水量的方法,为类似矿井提供了借鉴。     

The impact of compensatory measures on public support for carbon taxation: an experimental study in Sweden

This study aims at better understanding how, and to what extent, perceptions of a policy instrument’s distributional effects impact on policy support, focusing on the case of CO₂ taxes on petrol in Sweden. Through a large-scale (N?=?5000) randomized survey experiment with a 2?×?3 factorial design, the extent to which perceptions of fairness determine attitudes to a suggested increase of the Swedish CO₂ tax is explored. Furthermore, the study considers whether these effects change with the level of the suggested tax increase, as well as whether negative sentiments can be alleviated by combining it with a compensatory measure in the shape of a simultaneous income tax cut financed by the revenues from the tax increase. The results show that a higher tax increase is both viewed as more unfair and enjoys weaker support. Furthermore, compensatory measures can be a powerful policy design tool to increase perceptions of the policy as fair, but the effect of compensation on policy support is conditioned by the individual’s left–right ideological position. Whereas people self-identifying to the right react favourably to compensatory measures, people self-identifying to the left become less supportive of a tax increase when combined with a simultaneous cut in income taxes.

Key policy insights

• Perceptions of fairness are highly important for explaining public support for climate policy tools, specifically CO₂ taxes.

• Compensatory measures can be a powerful policy design tool to increase perceptions of the policy as less unfair.

• However, the effect of compensatory measures on policy support is conditioned by ideological position, and only successful among people to the ideological right.

• In contexts dominated by right-wing ideals, a combination of a tax and a compensatory scheme may be a successful route forward towards increased climate policy support.

• In left-oriented contexts the results imply that a CO₂ tax without compensation seems more likely to increase support.

     

昭通太阳背斜山地浅层页岩气"三维封存体系"富集成藏模式

本文系统分析了太阳地区构造断裂系统、顶底板条件、沉积岩相、优质页岩展布、源储条件及富集高产规律,提出了"多场协同多元耦合"共同作用下太阳背斜区山地浅层页岩气"三维封存体系"富集成藏赋存模式,具有5个特征:①页岩储层上覆龙马溪组一段二亚段—石牛栏组厚层致密页岩和泥灰岩,下伏临湘组—宝塔组厚层致密瘤状灰岩,具有良好的封隔层条件,形成了封存体系的顶板和底板;②压扭应力背景下形成的断裂系统属于挤压性逆冲断层、压扭性走滑断层,断层的纵向封闭性好,有效地保护了优质页岩气藏;③断层两盘页岩气层对接岩性均为致密泥灰岩和灰岩,侧向封堵性防止了页岩气泄漏点出现,使得山地浅层页岩气仍具有连续型气藏特征;④前陆盆地"水体滞留+火山灰沉降"造就了"海洋漂浮生物繁盛+缺氧强还原"深水陆棚沉积环境,形成了"富碳、高硅、低黏、高脆"的优质烃源岩储集体,构建了"规模生烃、高效吸附富集"的页岩微纳米级储集孔隙空间;⑤页岩储层具有相对小的地应力和两向水平应力差,既利于在中低泵压下的储层压裂施工作业,又具备体积压裂打碎页岩形成复杂缝网和气井获得高产的关键要素.提出了复杂构造区山地浅层页岩气"多元富集高产"的规律性认识,即:前陆盆地深水缺氧强还原环境促使了"富碳、高硅、低黏"页岩储层发育(沉积成岩控制源储特征)、持续良好的三维封闭保存体系有效保护了富有机质页岩生烃留烃富烃和超压保孔(保存条件控制天然气藏)、页岩脆性与地应力以及水平应力差决定了体积压裂改造的难易程度并影响了人造页岩气藏的构建效果(应力可压性控制人造气藏)、Ⅰ类优质页岩气储层连续厚度和地层压力系数决定了页岩气禀赋的资源储量丰度与气井高产(烃储禀赋控制单井产量).研究成果对中国南方复杂构造区海相浅层页岩气的高效勘探开发具有重要的借鉴引领和指导意义.     

空气潜孔锤钻进技术在沉积岩地热深井中的应用

目前采用空气潜孔锤钻进技术的沉积岩地热钻井深度多在1000 m左右,地层深度越大,空气潜孔锤钻进的难度也会随之增大。在辽宁康平某地热井应用空气潜孔锤技术钻进,实现了沉积岩地热井深度的突破,钻井深度达到2250 m。全井采用空气钻进技术施工,通过选择合适的工作风压和风量,以期促进对该技术在沉积岩地热深井中的推广应用。     

天津东丽湖深部岩溶热储探测与储层参数研究及其开发利用潜力分析

【研究目的】天津市地热资源储量丰富、开发利用程度高,蓟县系雾迷山组三、四段白云岩热储是目前的主力开采层位,随着开发强度不断增大,部分地区开采潜力已达极限。探测深部地热资源、增加可开采资源量,成为保障天津地区地热可持续开发的有效途径之一。【研究方法】本次研究以东丽湖为重点研究区,开展深部热储地球物理探测,实施地热科学钻探CGSD-01井。【研究结果】主要结果包括：（1）CGSD-01井在3715m钻遇雾迷山组二段,上覆雾迷山组三段底部发育一套紫红色泥质白云岩夹浅灰色细晶白云岩,厚度约73m,裂隙不发育,具有隔水-弱透水性质;（2）CGSD-01井成井深度4051.68m,孔底温度105℃,单位涌水量1.53m³/h·m,渗透系数0.40m/d,导水系数48.69m²/d;（3）雾迷山组二段地热水类型为Cl·SO₄·HCO₃-Na型,矿化度1.7g/L,初步推断地热水来源于大气降水,主要发生混合、阳离子交替吸附、碳酸盐岩溶解、硫酸盐还原等作用,且未达到平衡;（4）蓟县系雾迷山组二段单井最大涌水量可达130m³/h,出水温度100℃,单井可满足约30万m2建筑物供暖需求。【结论】在天津地区深部热储第二空间首次探获高产能雾迷山组二段新储层,探明了热储结构和主要参数,显示出良好的资源前景。     

北京平原区第四系热物性参数特征及对浅层地热能开采的影响因素分析

【研究目的】 岩土热物性是影响浅层地热能资源评价及利用的重要参数。【研究方法】 在北京平原区各冲洪积扇采集了695件第四系岩土样品进行热物性及土工参数测试,分析了热物性参数特征及其对浅层地热能开采的影响。【研究结果】 北京平原区第四系岩土热导率平均值为1.465~2.022 W/(m·K),热扩散率平均值为0.450×10^-6~0.841×10^-6 m²/s,比热容平均值为2.323~3.080 MJ/(m³·K),热导率（λ）与热扩散率（κ）值存在一定的线性关系,相关方程为λ =1.6973κ + 0.6127。第四纪松散沉积物颗粒越细,热导率值越低;含水率0~5%范围内,热导率随含水率增加迅速增大,含水率5%~20%范围内,热导率增加变缓并趋于稳定,含水率20%~40%范围内,热导率随含水量增大而降低;在天然状态下,热导率随着密度的增加而增大,随着孔隙比的增加而降低;样品温度在0~40 ℃范围内,热导率随温度升高呈先减小后增大的趋势,20 ℃时热导率最低。【结论】 第四系热物性参数随地质条件变化而变化,热物性参数大小会影响浅层地热能储存、采集和扩散能力,热导率、热扩散率及比热容越大,岩土蓄热和导热能力越强。     

页岩气储层粘土矿物孔隙特征及其甲烷吸附作用

粘土矿物是页岩的主要组成矿物,与页岩气的赋存和富集密切相关。粘土矿物因其特殊的晶体结构,在晶层之间、矿物内部以及矿物颗粒之间形成了不同类型的孔隙,这些孔隙的大小、形貌和比表面积决定着粘土矿物的甲烷吸附能力。为此,本文综述了粘土矿物的孔隙结构以及孔隙中的水和有机质对甲烷吸附性的影响,指出不同类型的粘土矿物孔隙发育与形貌特征存在差异,蒙脱石中多发育圆形、狭缝状的微孔且总比表面积最大,导致蒙脱石在所有粘土矿物中的甲烷吸附量最大;伊利石与高岭石中多发育中孔与大孔,吸附甲烷的能力低于蒙脱石。粘土矿物孔隙中的水与有机质显著影响到甲烷的吸附能力,水分子会占据孔隙表面,降低了甲烷的吸附能力,但可溶有机质对粘土矿物甲烷吸附能力的具体影响目前尚不明了。同时,根据页岩气勘探需求指出了本方向某些有待深入探讨的问题。     

Evaluating a satellite-based seasonal evapotranspiration product and identifying its relationship with other satellite-derived products and crop yield: A case study for Ethiopia

Satellite-derived evapotranspiration anomalies and normalized difference vegetation index (NDVI) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data are currently used for African agricultural drought monitoring and food security status assessment. In this study, a process to evaluate satellite-derived evapotranspiration (ETa) products with a geospatial statistical exploratory technique that uses NDVI, satellite-derived rainfall estimate (RFE), and crop yield data has been developed. The main goal of this study was to evaluate the ETa using the NDVI and RFE, and identify a relationship between the ETa and Ethiopia’s cereal crop (i.e., teff, sorghum, corn/maize, barley, and wheat) yields during the main rainy season. Since crop production is one of the main factors affecting food security, the evaluation of remote sensing-based seasonal ETa was done to identify the appropriateness of this tool as a proxy for monitoring vegetation condition in drought vulnerable and food insecure areas to support decision makers. The results of this study showed that the comparison between seasonal ETa and RFE produced strong correlation (R² > 0.99) for all 41 crop growing zones in Ethiopia. The results of the spatial regression analyses of seasonal ETa and NDVI using Ordinary Least Squares and Geographically Weighted Regression showed relatively weak yearly spatial relationships (R² < 0.7) for all cropping zones. However, for each individual crop zones, the correlation between NDVI and ETa ranged between 0.3 and 0.84 for about 44% of the cropping zones. Similarly, for each individual crop zones, the correlation (R²) between the seasonal ETa anomaly and de-trended cereal crop yield was between 0.4 and 0.82 for 76% (31 out of 41) of the crop growing zones. The preliminary results indicated that the ETa products have a good predictive potential for these 31 identified zones in Ethiopia. Decision makers may potentially use ETa products for monitoring cereal crop yields and early warning of food insecurity during drought years for these identified zones.     

长牡蛎(Crassostrea gigas)两个Dmrt家族基因的时空表达

本文以长牡蛎27个幼虫发育阶段个体以及成体的5个组织织作为实验材料,采用实时荧光定量PCR技术对其Dmrt家族中的2个基因(CgDsx和CgDmrtA2)的表达模式以及在性别决定中的作用进行了研究。结果表明,长牡蛎CgDsx基因在胚胎发育初期有大量表达,从囊胚期到担轮幼虫初期表达量最高,之后表达量开始降低,在D形幼虫后一直维持在极低的表达水平,此后仅在成体的雄性性腺中具有高度表达。由此可见,CgDsx可能也对早期胚胎发育起一定调控作用,同时参与了性别决定。CgDmrtA2在长牡蛎所有组织中均有表达,各组织间表达差异不显著,在D形幼虫至壳顶后期表达量较高,说明它参与了胚胎中后期的发育过程,可能与神经的形成相关,但是其具体功能还需要进一步研究。