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We explored topography-dependent variations of spruce (Picea jezoensis var. komarovii) growth in response to climatic change, and abrupt decline in its climatic sensitivities to temperature under global warming in the Changbai Mountain, Northeast China. Variations in the mountain slope direction, being different in radiation intensity and soil moisture, might exert a profound influence on the growth-climate relationship, which potentially brings indeterminacy in sensitivity to temperature under climate warming. To better understand the spatial variation in this influence, we used dendrochronological methods to determine the relationship between the radial growth of spruce (P. jezoensis var. komarovii) and climate in three aspects at an elevation of approximate 1200 m in the Changbai Mountain. The results indicated obvious correlations among the three spruce chronologies, and the radial growth presented more positive correlations with spring temperature (rather than summer or winter temperature), with April temperature on the south-facing slope and negative with precipitation on the north- and west-facing slopes. Despite the sensitivities to temperature were abruptly declined by the increasing temperature, the year- occurrences were inconsistent with records from 1996, 1995 and 1989 on the north (in May), west (in May) and south (in Apr), respectively. The negative relationship with May precipitation has become stronger since 1982 on the north and west for the increasing amount of precipitation. Therefore, given the declined sensitivity of spruce growth to climate warming, which can be shown among three different slopes, the divergent point would be difficult to precisely disentangle in investigating the temporal stability base on the variation in species, habitat and data analytical method.

Following the distribution characteristics of根据兴安落叶松在大兴安岭山脉的分布特征,沿纬度设置了9个采样点,分析了兴安落叶松径向生长对气候因子响应的空间差异和时间动态。结果表明:总体上所有采样点的兴安落叶松径向生长与夏季(6—8月)标准化降水蒸散指数(SPEI)及降水量、2月SPEI及降水量呈正相关,与3月温度呈负相关。在空间上,南部年均温较高区域的兴安落叶松径向生长与2月SPEI呈显著正相关,在北部年均温较低的区域与3月温度呈显著负相关。在时间上,兴安落叶松生长-气候关系不稳定。随着温度升高,在年均温较高区域,夏季SPEI和降水量对树木生长的正效应以及夏季温度的负响应显著增强;在年均温较低区域,树木生长与3月温度负响应增强更明显。这表明气候变化改变了树木生长-气候关系,而且存在明显空间差异。在未来气候暖干化的背景下,大兴安岭兴安落叶松径向生长会受到抑制,在年均温较高且降水量较少的南部地区会因夏季水分亏缺和冬季干旱而衰退,温度较低的北部地区则可能因冬季干旱和冬季变暖而使生长受到抑制。.

Spectral analysis for detecting migration heavy metals in toys is widely used in domestic and international standards. In this paper, intelligent analysis system for detection heavy metals was developed utilizing Internet of Things based on current spectral analysis instruments. And the virtual application of instrumentations such as bar code scanner, balance, digital temperature/humidity recorder, spectrum analyzer and central server could be realized by using Service Oriented Architecture (SOA). The test results from different equipments and different types of data such as sample information and environmental parameters were collected automatically. And they were transported to the central server in real time. The data processing model which met the requirements of spectral analysis was embedded in the system. In that way, the system has the features of real-time data storage, automatic report generating and so on. As a result, the data recording and processing time could be decreased dramatically. Meanwhile, the risk of manual operation could be effectively reduced with improved efficiency and data processing accuracy.

Changbai Mountain is one of the hotspots for tree ring research in Northeast China, with a large number of related research results having been published. To clarify the advance of tree ring research in Changbai Mountain and understand the responses of tree radial growth to climate factors, we reviewed the related literature and analyzed the differences among them based on tree species identity, elevation, and detrended methods. The radial growth of trees in Changbai Mountain was generally affected by temperature and precipitation, with greater influence of temperature. The relationship between tree radial growth and climate variables varied across both species and altitudes. Most studies reported that the radial growth of conifers were mainly affected by temperature in early growing season (April-May) and growing season precipitation (June-August). The radial growth of broadleaved trees were mainly affected by the temperature in previous and current growing season, the precipitation in dormancy season (November-March), and the precipitation in the current growing season. The previous September precipitation had significant effects on the radial growth of conifers and broadleaved trees. However, many studies had reported different or even opposite results. Most of the differences in the results of the studies appeared at low and medium altitudes, indicating that the altitudinal location of sampling points had impacts on the results. In addition, the detrended method was also the main cause for the variation of results across different studies. Comparatively, the linear or negative exponential detrended method might increase the effective significance of precipitation, especially the effect of precipitation on tree growth during dormancy period, and also strengthen the effective significance of the temperature at the end of the growing season. This study showed the habitat and the detrended method used in chronology were the main reasons for the difference of results among the studies. Therefore, for tree ring research in Changbai Mountain, the number of sampling sites should be increased and the detrended method should be carefully selected.长白山是我国东北地区树木年轮学研究的热点区域之一,迄今已在学术期刊上发表了大量相关的研究论文.为了弄清当前长白山树木年轮研究的进展,阐明树木径向生长对气候因子的响应规律,本文总结了发表在学术期刊上的有关文献,依据研究的树种、采样点海拔和去趋势方法等,对比分析了不同研究结果的差异及其形成原因.总的来看,长白山树木径向生长受温度和降水的共同作用,且温度的影响更大;树木径向生长-气候关系具有明显的树种和海拔差异.大多数研究支持: 针叶树主要受当年生长季前(4—5月)温度和生长季(6—8月)降水的显著影响;阔叶树则主要受当年、上年生长季温度和休眠期(上年11月至次年3月)、当年生长季降水的显著影响;上年9月降水对针、阔叶树种径向生长均有显著作用.同时,许多研究也出现了不同甚至截然相反的研究结果.研究结果差异最大的多出现在低、中海拔,表明在低、中海拔,采样点的选择可能对研究结果有较大影响.另外,年表去趋势方法也是造成研究结果不同的主要原因之一.相比较而言,采用线性或负指数去趋势方法在研究结果中显著增加了降水的作用,尤其是显著增加了休眠期降水对树木生长的影响,同时也显著增强了当前生长季末期(9—10月)温度的作用.本研究表明,采样点的小生境和年表构建时采用的去趋势方法是造成研究结果差异的主要原因,因此,在长白山开展树木年轮学研究,应增加采样点的数量,慎重选择去趋势方法.

The fan industry has developed rapidly because of the large demand in the fields of thermal power, metallurgy and so on. There are many manufacturers in Zhejiang Province. However, energy efficiency projects are not carried out sufficiently in those factories. Compared with foreign standards on fan energy efficiency such as ANSI/AMCA 205 and ISO 12759, national standard GB 19761 still has some disparity in the scope of application, the energy efficiency classification and definition of energy efficiency. Using the experience of foreign standards and vigorously promoting the energy efficiency projects in the fan manufacturing enterprises could accelerate the development of domestic standard system on fan energy efficiency and entire fan industry.

In the field of chemical testing, it is of great importance to improve the accuracy and efficiency and reduce the risk caused by artificial factor with modern intelligent methods, which are critical to the standard development of testing labs. In this paper, intelligent control during the whole process of chromatography and mass spectrometry analysis with cloud computing technology was realized and discussed in detail. The intelligent testing system could be applied to the chemical analysis labs and spread to other fields.

This paper presents a reliable method for simultaneous analysis of ten kinds of fatty acid methyl esters in biodiesel with high performance liquid chromatography equipped with diode array detector. The separation column was a Pursuit XRs C18 (250 mm×4.6 mm) and the mobile phase was a mixture of methanol and acetonitrile (80:20, V/V). The analytical performance parameters such as linearity, accuracy, precision, limit of detection and limit of quantification were discussed. The calibration curves of ten components show good linearity with the correlation coefficient greater than 0.99. The proposed method is time and cost-effective, which could be used for the determination of the FAMEs in the commercial biodiesel product.

Transmittance is the key factor to the quality of solar glass. At present visible light transmittance (380-780 nm) and solar direct transmittance (300-2500 nm) were used to evaluate the light transmission property without considering the specificity of solar glass. In this work a new parameter of effective transmittance in the 380-1200 nm region which was consistent with the spectral response range of solar cells was proposed and calculated to evaluate the property. The value of effective transmittance lies between that of visible light transmittance and solar direct transmittance. Using effective transmittance instead could reflect the performance of solar glass on real applications properly.

Solar glass of low iron content plays an important role to increase the optical absorption of solar cells. The national standard stipulates the iron content in the glass without specified testing method. In this paper, we conducted three parallel analytical methods (1,10-Phenanthroline spectrophotometry, FAAS and ICP-OES) to determine the iron content in the same glass and evaluated the results in terms of detection limit, accuracy and precision. Although all three methods can detect the existence of iron, the analytical results are different to some extent. At last we propose a preferred method for commercial solar glass monitoring.

Two kinds of hybrid ultraviolet (UV) photodetectors based on TiO2 nanocrystals capped with and without oleic acid (OA) and poly(9,9-dihexylfluorene) (PFH) were prepared from solution and characterized to study the effects of the surface ligand on the device function. Both devices showed obvious photovoltaic effect, high UV-sensitive photoconductivity, and fast response time. The hybrid device containing TiO2 nanocrystals with bare surface exhibited a photocurrent density of 91 μA/cm2 at zero bias under 3.2 mW/cm2 UV irradiation, corresponding to a photosensitivity of 28.4 mA/W. The other device containing OA-capped TiO2 nanocrystals showed a photocurrent density of 19 μA/cm2 and a photosensitivity of 5.9 mA/W under the same condition. It was found that capping TiO2 with OA had a beneficial effect on its solubility in organic solvent. On the contrary, a barrier might be formed, significantly influencing the charge-transfer behavior. This negative effect overcompensated the positive influence due to improved morphology and lowered the photosensitivity of the device.