Ecosystem carbon storage and sink/source of temperate forested wetlands in Xiaoxing’anling, northeast China

Wetlands play an important role in the global carbon cycle, but there are still considerable uncertainties in the estimation of wetland carbon storage and a dispute on whether wetlands are carbon sources or carbon sinks. Xiaoxing’anling are one of several concentrated distribution areas of forested wetland in China, but the carbon storage and carbon sink/source of forested wetlands in this area is unclear. We measured the ecosystem carbon storage (vegetation and soil), annual net carbon sequestration of vegetation and annual carbon emissions of soil heterotrophic respiration of five typical forested wetland types (alder swamp, white birch swamp, larch swamp, larch fen, and larch bog) distributed along a moisture gradient in this area in order to reveal the spatial variations of their carbon storage and quantitatively evaluate their position as carbon sink or source according to the net carbon balance of the ecosystems. The results show that the larch fen had high carbon storage (448.8 t ha^(−1)) (6.8% higher than the larch bog and 10.5–30.1% significantly higher than other three wetlands (P < 0.05), the white birch swamp and larch bog were medium carbon storage ecosystems (406.3 and 420.1 t ha^(−1)) (12.4–21.8% significantly higher than the other two types (P < 0.0 5), while the alder swamp and larch swamp were low in carbon storage (345.0 and 361.5 t ha^(−1), respectively). The carbon pools of the five wetlands were dominated by their soil carbon pools (88.5–94.5%), and the vegetation carbon pool was secondary (5.5–11.5%). At the same time, their ecosystem net carbon balances were positive (0.1–0.6 t ha^(−1) a^(−1)) because the annual net carbon sequestration of vegetation (4.0–4.5 t ha^(−1) a^(−1)) were higher than the annual carbon emissions of soil heterotrophic respiration (CO_(2) and CH_(4)) (3.8–4.4 t ha^(−1) a^(−1)) in four wetlands, (the alder swamp being the exception), so all four were carbon sinks while only the alder swamp was a source of carbon emissions (− 2.1 t ha^(−1) a^(−1)) due to a degraded tree layer. Our results demonstrate that these forested wetlands were generally carbon sinks in the Xiaoxing’anling, and there was obvious spatial variation in carbon storage of ecosystems along the moisture gradient.

Study of seasonal snow cover influencing the ground thermal regime on western flank of Da Xing'anling Mountains,northeastern China

Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of the soils in permafrost regions in the mid-latitudes and boreal regions, such as that on the westem flank of the Da Xing＇anling （Hinggan） Mountains, northeastern China. This paper gives a detailed analysis on meteorological data series from 2001 to 2010 provided by the Gen＇he Weather Station, which is located in a talik of discontinuous permafrost zone and with sparse meadow on the observation field. It is inferred that snow cover is important for the ground thermal regime in the middle Da Xing＇anling Mountains. Snow cover of 10-cm in thickness and five to six months in duration （generally November to next March） can reduce the heat loss from the ground to the atmosphere by 28%, and by 71% if the snow depth increases to 36 cm. Moreover, the occurrence of snow cover resulted in mean annual ground surface temperatures 4.7-8.2℃ higher than the mean annual air temperatures recorded at the Gen＇he Weather Station, The beginning date for stable snow cover establishment （SE date） and the initial snow depth （SDi） also had a great influences on the ground freezing process. Heavy snowfall before ground surface freeze-up could postpone and retard the freezing process in Gen＇he. As a result, the duration of ground freezing was shortened by at least 20 days and the maximum depth of frost penetration was as much as 90 cm shallower.

Classification,metallogenesis and exploration of silver deposits in Daxing’anling of Inner Mongolia and its adjacent areas

By the end of 2020,83 silver deposits(or ore occurrences),including four super-large-scale deposits,nine large-scale deposits,33 medium-scale deposits and 37 small-scale deposits or ore occurrences,have been proved.The amount of silver metal exceeds 86000 t with average grade of 100 g/t,which makes Daxing’anling region one of the the most important silver ore belt in China.However,the metallogenic characteristics and metallogenesis need to be clarified.The silver deposits in the study area are classified into three main types,which are magmatic hydrothermal vein type,continental volcano-subvolcanic type and skarn type,respectively.The supergiant deposits include the Shuangjianzishan deposit(silver metal amount of 15214 t with average grade of 138 g/t),the Baiyinchagandongshan deposit(silver metal amount of 9446 t with average grade of 187 g/t),the Huaobaote deposit(silver metal amount of 6852 t with average grade of 170 g/t),and the Fuxingtun deposit(silver metal amount of 5240 t with average grade of 196 g/t).The silver deposits are mainly distributed in the central and south of the Daxing’anling area,and mainly formed in the Yanshanian period.The silver polymetallic deposits in the Daxinganling area are significantly controlled by regional faults and the junction zone of volcanic rock basins and their margins.The north-east trending deep faults are the most important ore-controlling structures in this area.The distribution of silver polymetallic deposits along the main faults is obvious,and the intersection area of multiple groups of faults often form important mine catchments.The Permian is the most important ore-bearing formation in this area,but some important silver polymetallic deposits occur in Mesozoic volcanic basins or pre-Mesozoic strata.The magmatic rocks related to mineralization are mainly intermediate acidic or acidic intrusions,intermediate acidic lavas,pyroclastic rocks,and small intrusions of ultra-shallow or shallow facies of the Yanshanian Period.The mineralization element combination is mainly determined by the elemental geochemical background of surrounding rocks or source layers.In addition,the type of deposit,the distance from the mineralization center,and the degree of differentiation of ore-forming rock mass are also important influence factors.The article analyzes the prospecting prospects of each silver deposit type in the study area,discusses the relationship between mineralization center and deep prospecting,and proposes that porphyry silver deposits should be paid attention to.In the prospecting and exploration of silver deposits,comprehensive evaluation and multi-target prospecting need to be strengthened because silver can coexist or be associated with a variety of metals.

Anle138b对oAβ_(1-42)诱导大鼠海马神经元线粒体功能损伤的影响

目的探究Anle138b对慢性β淀粉样蛋白(Aβ)诱导的海马神经元线粒体功能损伤的影响。方法取出生24 h以内的SD乳鼠,原代培养海马神经元,待细胞成熟将其分为对照组(不进行任何处理)、oAβ_(1-42)组(100 nmol/L oAβ_(1-42)处理7 d)、oAβ_(1-42)+Anle138b组(100 nmol/L oAβ_(1-42)+100 nmol/L Anle138b共处理7 d)、Anle138b组(100 nmol/L Anle138b处理7 d)。各组处理结束后,应用流式细胞术检测活性氧(ROS)和线粒体膜电位(Δψm)阳性细胞的变化。结果析因设计的方差分析显示,oAβ_(1-42)和Anle138b的主效应明显(F_(oAβ1-42)=14.149、38.209,F_(Anle138b)=1.942、24.871,P<0.01),oAβ_(1-42)和Anle138b之间有交互性作用(F_(交互)=18.425、21.904,P<0.01)。单独效应分析显示,用oAβ_(1-42)处理时,Anle138b的处理效应明显(F=16.483、19.148,P<0.01);不用Anle138b处理时,oAβ_(1-42)的处理效应明显(F=14.149、38.209,P<0.01)。结论Anle138b可以减轻oAβ_(1-42)引起的海马神经元氧化应激和线粒体损伤,抑制oAβ_(1-42)对海马神经元的损伤。

Zircon SHRIMP U-Pb Dating and Geochemical Characteristics of Late Variscan Granites of the Daitongshan Copper Deposit and Lamahanshan Polymetallic-Silver Deposit, Southern Daxing'anling, China

Daxing＇anling （大兴安岭） area is one of the regions that Phanerozoic granites are extremely developed in NW China. At present, the Hercynian granitoid research lags behind the Mesozoic granitoid research. In this article, we have taken systematic petrochemistry and geochronology researches on the Hercynian granitoids in Daitongshan （代铜山） copper deposit and Lamahanshan （喇嘛罕山） silver poly- metallic deposit, which were located at southern section of Daxing＇anling metallogenic belt. Zircon SHRIMP U-Pb dating results show that, the granite aplites in Daitongshan and the gneissic granites inLamahanshan were formed at （265±5）-（268±9） Ma and （252±2）-（252.6±3.4） Ma, respectively, which were both the products of late Herynian tectonic-magmatic events. Samples from Lama- hanshan are characterized by high SiO2 （69.72 wt.%-74.65 wt.%）, high potassium （3.53 wt.%-4.55 wt.%） and low P205 （0.03 wt.%0.12 wt.%）, aluminum saturation index （A/CNK） range from 0.95 to 0.98, Rb, Nd and K are en- riched, whereas the elements such as Nb, Ta, P and Ti are depleted, which belong to I-type grani- toids. Characteristics of samples from Daitong- shan are similar to H-type granitoids. The magmasource may be mostly originated from the lithospheric mantle component which were transformated or affected by the subduction components, and its formation may be closely related with the subduction and orogenesis of the Paleo-Asian Ocean.

Anle138b对oAβ_(1-42)诱导海马神经元突触毒性作用影响

目的探究Anle138b对慢性β淀粉样蛋白寡聚体1-42(oAβ_(1-42))诱导的海马神经元突触毒性作用影响。方法培养原代海马神经元细胞,细胞发育成熟后分为对照组(不进行任何处理)、oAβ_(1-42)组(100 nmol/L oAβ_(1-42)处理7 d)、Anle138b组(50 nmol/L Anle138b处理2 d)、oAβ_(1-42)+Anle138b组(100 nmol/L oAβ_(1-42)+50 nmol/L Anle138b共处理7 d)、oAβ_(1-42)+Anle138b 2 d组(100 nmol/L oAβ_(1-42)处理7 d,在oAβ_(1-42)处理的最后2 d加用50 nmol/L Anle138b)。各组处理结束后,应用单细胞膜片钳技术检测自发性兴奋性突触后电流(sEPSCs)的幅值、频率、半衰减时间。结果各组海马神经元细胞sEPSCs幅值、半衰减时间比较差异无统计学意义(F=2.215、1.043,P>0.05)。各组sEPSCs频率比较差异有统计学意义(F=15.490,P<0.001),两两比较显示,oAβ_(1-42)组的sEPSCs频率较对照组明显增加(q=6.507,P<0.001),oAβ_(1-42)+Anle138b组和oAβ_(1-42)+Anle138b 2 d组的sEPSCs频率较oAβ_(1-42)组明显降低(q=9.517、9.471,P<0.001),其他组间比较差异均无统计学意义(P>0.05)。结论Anle138b不仅可以预防慢性oAβ_(1-42)诱导的海马神经元细胞突触毒性作用,还可以消除慢性oAβ_(1-42)诱导的海马神经元细胞突触毒性作用。

突变型β-连环蛋白基因对肝细胞增殖的影响

目的 :探讨突变型 β -连环蛋白基因对肝细胞增殖的影响。 方法 :用阳离子脂质体lipofectamine将突变型 β -连环蛋白基因导入小鼠肝细胞系AML12 ,建立AML12S33Y细胞系。用流式细胞仪和细胞计数比较这两种细胞的生长情况 ;比较这两种细胞在软琼脂中形成的克隆以及在免疫缺陷小鼠体内的成瘤情况。结果 :AML12细胞增殖明显快于AML12S33Y细胞 (P <0 0 1) ,提示突变型 β -连环蛋白能促进肝细胞的增殖。 4周后AML12S33Y细胞在软琼脂中可形成小克隆 ,但不能在免疫缺陷小鼠皮下形成肿瘤。结论 :突变型β -连环蛋白可以促进肝细胞增殖 ,但无致瘤性。

Aβ通道在阿尔茨海默症发病过程中的作用及其机制

β-淀粉样蛋白(Aβ)产生的神经毒性是阿尔茨海默症(Alzheimer’s disease,AD)的主要发病机理。Aβ发挥毒性的一种机制是形成离子通道从而破坏细胞内Ca^(2+)动态平衡。研究表明,Aβ与质膜的相互作用定位于高胆固醇的脂筏结构域,Aβ通道形成与质膜上胆固醇的含量变化密切相关,胆固醇参与Aβ寡聚化,并形成神经毒性淀粉样蛋白通道,从而破坏了膜的完整性,改变了细胞内钙稳态。本综述将从Aβ通道的定位,装配,研究方法,作用机制,相关药物等方面论述,还总结了AD研究最新进展,阐明目前关于AD假说与离子通道假说之间的内部联系,为阐明AD发病机制并开发治疗阿尔茨海默症新型药物的研究方向提供思路。

Estimation of permafrost thermal behavior using Fourier series model

Permafrost,being an important component of the cryosphere,is sensitive to climate change.Therefore,it is necessary to investigate the change of temperature within permafrost.In this study,we proposed a Fourier series model derived from the conduction equation to simulate permafrost thermal behavior over a year.The boundary condition was represented by the Fourier series and the geothermal gradient.The initial condition was represented as a linear function relative to the geothermal gradient.A comparative study of the different models(sinusoidal model,Fourier series model,and the proposed model)was conducted.Data collected from the northern Da Xing’anling Mountains,Northeast China,were applied for parameterization and validation for these models.These models were compared with daily mean ground temperature from the shallow permafrost layer and annual mean ground temperature from the bottom permafrost layer,respectively.Model performance was assessed using three coefficients of accuracy,i.e.,the mean bias error,the root mean square error,and the coefficient of determination.The comparison results showed that the proposed model was accurate enough to simulate temperature variation in both the shallow and bottom permafrost layer as compared with the other two Fourier series models(sinusoidal model and Fourier model).The proposed model expanded on a previous Fourier series model for which the initial and bottom boundary conditions were restricted to being constant.

一种基于时空联合的实时视频降噪算法

针对监控视频图像的特点,提出了一种基于时空联合的实时视频降噪算法。该算法通过结合多帧图像进行运动检测,自适应地区分图像的运动区域和静止区域,对静止区域采用时域加权均值滤波,对运动区域采用空域ANL滤波。实验结果表明,该算法由于准确地区分了图像的运动区域和静止区域,充分利用了视频的时域、空域信息,在不造成运动拖影的前提下,能够显著提高视频的信噪比和图像的主观质量,同时满足实时性要求。

Anle138b对慢性AβOs诱导海马神经元毒性作用影响

目的观察二苯基吡唑化合物Anle138b对β淀粉样蛋白寡聚体(AβOs)诱导的海马神经元毒性作用的影响。方法原代培养的海马神经元细胞成熟后,将其分为空白对照组、AβOs处理组(用0.1μmol/L AβOs处理7 d)和Anle138b处理组(用0.1μmol/L AβOs处理7 d,在AβOs处理的后2 d加用0.1μmol/L Anle138b)。使用乳酸脱氢酶(LDH)试剂盒检测细胞损伤情况,采用蛋白质免疫印迹(Western blot)法检测凋亡蛋白cleaved caspase-3的表达。结果与空白对照组相比较,AβOs处理组海马神经元细胞LDH释放量增加(F=14.810,q=7.481,P<0.01),凋亡蛋白cleaved caspase-3的表达升高(F=6.677,q=4.816,P<0.05)。与AβOs处理组相比,Anle138b处理组海马神经元细胞LDH释放量降低(q=5.310,P<0.05),凋亡蛋白cleaved caspase-3的表达有下降趋势,但差异无统计学意义(P>0.05)。结论 Anle138b在慢性AβOs诱导的海马神经元凋亡模型中具有一定的保护作用。

触发商务投影新标准 领略夏普新境界

据夏普投影机总代理神州数码介绍,夏普日前隆重推出两款商务精品--PG-AN100S和PG-AN100X投影机,一举刷新了多项主流商务投影机标准,成为商务投影机的精英.

燃油直喷发动机的优势及其对MOSFET的新要求

石油价格上涨等各种因素推动了汽车行业对更高等级燃油经济性的需求,而制造商同时又需要满足客户在产品性能方面的期望,这给制造商带来了莫大挑战。一种现实可行的应对策略就是改进所使用的燃油供给机制。本文着重介绍了燃油供给系统的演进以及燃油直喷技术的出现及其对于提高燃油效率和提升性能的作用,并探讨了该技术对于功率MOSFET的要求以及安森美半导体的先进功率MOSFET产品如何应对这些要求。

How the Yue Yi lun Was Lost： Calligraphy, the Cultural Legacy, and Tang Women Rulers

Abstract Dating back to at least the Han dynasty, calligraphy has been a powerful object of culture and a medium of elite education, document preparation, and character evaluation. Discourses surrounding rulers and calligraphy form an important sub-strand in materials on calligraphy, and these accounts often depict calligraphy as a vehicle capable of reflecting a ruler＇s moral character. This paper explores narratives that blame early Tang women power-holders, in particular, the Taiping and Anle Princesses, for borrowing and subsequently losing precious calligraphic items that were considered the authentic work of Wang Xizhi. The analysis focuses on the ways in which the different narratives describe the physical movement or location of the Wang Xizhi pieces in relation to contemporary rule and factional politics. The narratives interpret the calligraphic manuscripts as an example of the cultural inheritance, to which the ruler should properly relate in particular ways. In this way, the fate of the Wang Xizhi artifacts is understood in terms of the complex relationship between imperial power and the court＇s cultural legacy.