配对t检验误区与率转化配对t检验方法介绍及各自应用范围

目的明确配对t检验误区与率转化配对t检验方法及各自应用范围,以使医学实践与实验研究的结果判断更为科学、准确。方法对医学实践与实验研究中遇到的具体事件,用配对t检验与率转化配对t检验进行比较。结果与治疗、稀释、保存有关的事件常规配对t检验结果无显著性差异,而采用率转化配对t检验结果有显著性或非常显著性差异;成定值改变的事件用率转化配对t检验无显著性差异,而用常规配对t检验结果有显著性差异。结论与治疗、稀释、保存有关的事件且原个体差别悬殊,应采用率转化配对t检验;而成定值的事件应采用原配对t检验。

马铃薯转化效率的因素探讨

经农杆菌介导转化了５个马铃薯品种。结果表明不同品种的马铃薯转化效率不同，试管薯度过２～３个月的休眠期后转化效率明显提高。转化效率亦随Ｔ－ＤＮＡ长度的增加而减少。

我国储蓄——投资转化漏损率的实证分析

哈罗德模型包含的经济增长保证理论成为现在经济增长理论的基石,文章根据1978～2009年的相关数据,对我国储蓄率和边际资本—产出比进行理论分析;在基础上测算了我国储蓄—投资转化漏损率,并结合哈罗德波动理论对我国近三十年的经济波动状况进行解释;最后进行总结,提出相应政策建议。

烯转化收率提升的技术开发与应用

环己醇生产工艺主要采用环己烯水合法,针对该工艺反应烯转化较低,环己醇收率不高的难题,采用实验模拟和生产应用相结合的方法研究水合反应及催化剂再生机理,考察了反应温度、催化剂浓度、催化剂再生条件及反应浆液体系环境等对烯转化收率的影响,证明了反应温度与负荷的匹配关系,印证了最佳催化剂浓度在25%~30%区间。通过优化反应及再生过程参数控制,可有效维持浆液环境稳定,实现了在减少副反应生成的前提下,获取高转化收率的技术方法,有效解决了生产过程中制约转化收率提升的技术瓶颈,在产品的产能、质量上取得了较大突破。

Improvement in Performance of Carbon-based Perovskite Solar Cells through Interface Modification with CTAC

Carbon-based perovskite solar cells have attracted much attention,due to their low cost,simple preparation process and high chemical stability.However,the devices exhibit low photoelectric conversion efficiency,owing to the presence of defects and interface impedance between the perovskite active layer and the contact interface.In order to minimize the interfacial defects and improve the charge transfer performance between the perovskite layer and the contact interface,cetyltrimethylammonium chloride(CTAC)was introduced into the lower interface of HTL-free carbon-based perovskite solar cells,because CTAC can be used as interface modification material to passivate the buried interface of perovskite and promote grain growth.It was found that CTAC can not only passivate the interface defects of perovskite,but also improve the crystalline quality of perovskite.As a result,the photovoltaic conversion efficiency of reaches 17.18%,which is 12.5%higher than that of the control group.After 20 days in air with 60%RH humidity,the cell can still maintain more than 90%of the initial efficiency,which provides a new strategy for interfacial passivation of perovskite solar cells.

Agrobacterium _mediated Transformation of Rice with Help of Bombardment

Oryza sativa L. ssp. japonica cv. Zhonghua 8, which is recalcitrant to infection of Agrobacterium tumefaciens (Smith et Townsend) Conn strain EHA105 with ordinary binary vector pCambia 1301, was transformed through Agrobacterium-mediated transformation with help of bombardment. The transformation efficiency can be raised greatly. Single copy of gene insertion in the genome of transgenic rice plants was proved by Southern analysis and the expression of GUS gene was observed. GUS gene and hygromycin-resistant gene show 3:1 segregation in progenies of the transgenic rice plants.

Catalytic wet oxidation of aniline over Ru catalysts supported on a modified TiO_2

The catalytic wet air oxidation of aniline over Ru catalysts supported on modified Ti 2 （Ti 2, Ti0.9Ce0.1O2, Ti0.9Zr0.1O2） is investigated. A series of characterization techniques are conducted to determine the relationship between the physico-chemical properties and the catalytic performance. As a result of the good metal dispersion and large number of surface oxygen species, the Ru/Ti0.9 Zr0.1O2 catalyst presents the best catalytic activity among the tested samples. The effects of the operating conditions on the reaction are investigated and the optimal reaction conditions are determined. Based on the relationship between the by-products concentration and the reaction time, the reaction path for the catalytic oxidation of aniline is established. Carbonaceous deposits on the surface of the support are known to be the main reason for catalyst deactivation. The catalysts maintain a constant activity even after three consecutive cycles.

卷烟卷制质量与车间温湿度的关系

为确定不同档次卷烟在卷制过程中适宜的车间环境温湿度条件,以不同档次的烤烟型配方烟丝和成品烟支为材料,进行了不同环境温湿度条件下其整丝率转化率、卷烟单支重量和空头率与温湿度的关系研究。结果表明,各档次卷烟在卷制过程中适宜的车间环境温湿度为一类烟24℃、RH57%;二类烟25.5℃、RH60%;三类烟26.5℃、RH62%。在此条件下,烟支的重量较轻,空头率较低。卷烟车间在生产过程中,宜根据产品的不同档次设定不同的车间温湿度,必要时可采取分时段、分区域的加工方法,以更有针对性地提高不同档次卷烟产品的质量。

Biotransformation of Gastrodin by Mucor spinosus

Microbial transformation of gastrodin by Mucor spinosus strain 3.3450, resulted in a product with a transformation rate close to 100 per cent. This product was identified as p-hydroxy benzyl alcohol on the basis of its 1H, 13C NMR and EI-MS spectral data. It could be inferred that the enzyme responsible for the biotransforma-tion reaction was a kind of extracellular and constitutive enzyme since the transformation reaction of the substrate could be carried out in cell free extracts of the fermentation broth of the Mucor spinosus.

Effects of the Ice Bath Time after Heat Shock and the Incubation Time on the Efficiency of Chemical Transformation Method

[Objective] The aim of the research was to study the effect of the ice bath time after heat shock and the incubation time on the transformation efficacy,and to establish a simple and quick transformation method.[Method]Competent cells were prepared with two buffer solutions;with the ice bath time after heat shock and the recovery time as the variables,the relationship between these two factors and transformation efficacy was studied.[Result]The transformation efficacy was the best when the ice bath time was 2 min and the recovery time was 30 or 40 min;when the ice bath time and the recovery time was 0 min,a certain amount of transformants still could be obtained.[Conclusion]The ice bath time after heat shock and the recovery time had certain impact on transformation efficacy,but they were not the decisive factors.Therefore,in the general transformation experiment,these two steps could be omitted.

Photoinhibition and Photooxidation in Leaves of indica and japonica Rice Under Different Temperatures and Light Intensities

Physiological indices related to the efficiency (F-v/F-m) of light energy conversion in PS II and the peroxidation of membrane lipid were measured in leaves of Oryza sativa L. sp. indica rice cv. 'Shanyou 63' and sp. japonica rice cv. '9516'' under different temperatures and fight intensities for 4 days. No changes in F-v/F-m and membrane lipid peroxidation product (MDA) were observed, so neither photoinhibition nor photooxidation happened in both rice cultivars under moderate temperature and medium light intensity. However, F-v/F-m dropped obviously with no change in MDA contents, and photoinhibition appeared in indica rice cv. 'Shanyou 63' under medium temperature and strong light intensity. Furthermore, both photoinhibition and photooxidation were observed in two rice cultivars under chilling temperature and strong light intensity. Experiments with inhibitors under chilling temperature and strong light intensity showed that indica rice had a decrease in DI protein content and SOD activity, and the extent of inhibition of xanthophyll. cycle and nonphotochemical quenching (qN) was larger, and a higher level of MDA was observed. The photoinhibition and photooxidation in indica rice were more distinct as compared with japonica rice. The authors suggested that PS II light energy conversion efficiency (F-v/F-m) and membrane lipid peroxidation were the key indices for the detection of photooxidation.

Oxidative Dehydrogenation of Alkanes using Oxygen-Permeable Membrane Reactor

The oxidative dehydrogenation （ODH） reactions of ethane and propane were investigated in a catalytic membrane reactor, incorporating oxygen-permeable membranes based upon La2Ni0.9V0.1O4＋δor Ba0.5Sr0.5Co0.8Fe0.2O3-δ. As a compromise between the occurrence of a measureable oxygen flux and excessive homogenous gas phase reactions, the measurements were conducted at an intermediate temperature, either at 550 or 650 oC. The results show the dominating role of the oxygen flux across the membrane and available sites at the membrane surface in primary activation of the alkane and, hence, in achieving high alkane conversions. The experimental data of ODH of propane and ethane on both membrane materials can be reconciled on the basis of Mars-van Krevelen mechanism, in which the alkane reacts with lattice oxygen on the membrane surface to produce the corresponding olefin. It is further demonstrated that the oxygen concentration in the gas phase and on the membrane surface is crucial for determining the olefin selectivity.

Characteristic Change of Several Forest Landscapes Between 1896 and 1986 in Heilongjiang Province

Five forest landscapes in the maps of forest distribution in Heilongjiang Province in 1896 and 1986 were digitized and analyzed through GIS software. The results show that during the 90 years the total patch areas for Picea and Abies forest, Pinus sylvestris var. mongolica Litvin forest and Pinus koraiensis Sieb. et Zucc. forest had decreased about 87%, 40% and 84%, respectively. However, the total patch areas for broad leaved forest at the north of 51°N area had increased about 500%. The north frontier of broad leaved forest had moved towards northwest about 290 km. The fractal dimensions of Picea and Abies forest and mixed coniferous and broad leaved forest in 1986 were less than theirs in 1896, respectively. However, the fractal dimension of Pinus synvestris forest, Pinus koraiensis and broad leaved forest were more than theirs in 1896, respectively. Picea and Abies forest, Pinus synvestris forest, Pinus koraiensis and broad leaved forest became more fragmented. The transition percentages of Pinus sylvestris forest, Picea and Abies forest, Pinus koraiensis forest to themselves were less than the percentages to the mixed coniferous and broad leaved forest, respectively.

Effects of Echinacea Compound on the Immune Function of Weaned Piglets

[Objective] This study aimed to investigate effects of Echinacea compound on the immune function of weaned piglets. [Method] Eighty Duroc x Landrace x Yorkshire crossbred piglets were randomly divided into four groups： control group （drug-free group）, 1.5% close group, 1.0% dose group and 0.5% dose group. Blood samples of piglets were collected at 20, 35, 50, 60, 70 and 80 days old, respective- ly, to determine neutrophil leukocyte percentage in peripheral blood, lymphocyte trapsformation rate and the levels of antibodies against classical swine fever, porcine reproductive and respiratory syndrome disorder. [Result] Applying a certain dose of Echinacea compound could significantly increase neutrophil leukocyte per- centage in peripheral blood and lymphocyte transformation rate （P〈0.05）, and ex- tremely significantly improve the levels of antibodies against classical swine fever, porcine reproductive and respiratory syndrome disorder （P〈0.01）. [Conclusion] Echi- nacea compound has played a certain role in promoting nonspecific and specific im- mune function of piglets.

Corrosion resistance of cerium conversion film electrodeposited on Mg-Gd-Y-Zr magnesium alloy

The cerium conversion film was applied to improving the corrosion resistance of Mg-Gd-Y-Zr magnesium alloy. The film was electrodeposited on the surface of the Mg-RE alloy in cerium nitrate solution. The compositions and morphologies were analyzed by X-ray diffraction(XRD), scanning election microscopy (SEM). The corrosion behaviors of the film were investigated electrochemical impedance spectroscopy (EIS), potentiodynamic polarization tests and immersion tests. The results show that the optimum parameters for electrochemical deposition are as follows: pH 10.0, time 30 min, 50 mmol/L Na2CO3 and temperature 25 ℃ by the designed experiments according to the orthogonal table L(9, 34). The corrosion protection efficiency is dependent on the deposition parameters. The cerium conversion film shows better corrosion protection behavior than chromate conversion film on Mg-Gd-Y-Zr magnesium alloy.

Kinetic mechanism of magnesium production by silicothermic reduction of CaO·MgO in vacuum

The investigation of silicothermic reduction of CaO·MgO was carried out using a self-developed thermogravimetric analysis(TGA)instrument under vacuum and high temperature conditions.The TG data of pellets prepared with calcined dolomite,ferrosilicon and fluorite were determined at the heating rates of 1.5,2.0,2.5 and 3.0℃/min in 5 Pa vacuum at 300−1400℃,respectively.Model-free analysis and model-based analysis were applied for simulating the kinetic mechanism.By analyzing the characteristics of the initial and final reaction temperatures of TG curve,ratio of half-width of derivative TG curve and kinetic parameters,a conclusion was made that the most probable mechanism function is the first order formal chemical reaction with activation energy of 233.42 kJ/mol and pre-exponential factor of 5.14×1010 s−1.This study provides the basic data of dynamics of silicothermic magnesium production under vacuum conditions.

Lignite oxidative desulphurization. Notice 2： effects of process parameters

The influence of main characteristics upon conversion directions of the lignite organic part during its oxidation desulphurization was studied. The optimum temperature values, the ratio oxidant ： raw material, and time of coal stay in the reaction zone, which provide the maximum degree of sulphur conversion and hydrogen sulphide content in desulphur- ization gases, were calculated. The process implemented under these conditions will decrease environment pollution by sulphur dioxide during further lignite burning at least to 55 %-60 % and utilize sulphur in coal in the form of desul- phurization gases with hydrogen sulphide content of 7 %. Such obtaining sulphur. The effect of the above three factors on the depth was studied. gases can be reprocessed by the known methods of and character of the coal organic matter transformation

Three Stage Equilibrium Model for Coal Gasification in Entrained Flow Gasifiers Based on Aspen Plus

A three stage equilibrium model is developed for coal gasification in the Texaco type coal gasifiersbased on Aspen Plus to calculate the composition of product gas, carbon conversion, and gasification teml^erature. The model is divided into three stages including pyrolysis and combustion stage, char gas reaction stage, and gas p.hase reaction stage. Part of the water produced in thepyrolysis and combust!on stag.e is assumed to be involved inthe second stage to react with the unburned carbon. Carbon conversion is then estimated in the second stage by steam participation ratio expressed as a function of temperature. And the gas product compositions are calculated from gas phase reactions in the third stage. The simulation results are consistent with published experimental data.

Preparation and characterization of spinel LiMn_2O_4 nanorods as lithium-ion battery cathodes

The hydrothermal synthesis of single-crystallineβ-MnO2 nanorods and their chemical conversion into single-crystalline LiMn2O4 nanorods by a simple solid-state reaction were reported.This method has the advantages of producing pure,single-phase and crystalline nanorods.The LiMn2O4 nanorods have an diameter of about 300 nm.The discharge capacity and cyclic performance of the batteries were investigated.The LiMn2O4 nanorods show better cyclic performance with a capacity retention ratio of 86.2% after 100 cycles.Battery cyclic studies reveal that the prepared LiMn2O4 nanorods have high capacity with a first discharge capacity of 128.7 mA·h/g.

Identification of voltage sag source location using S and TT transformed disturbance power

An alternative method was introduced for voltage sag source location based on S and TT transformed disturbance powers. It is done to avoid the wrong and inconclusive detection of conventional disturbance power method proposed in the literature. Unlike in the case of the traditional method, the proposed method first transforms the recorded voltage and current during the sag event to some special features before calculating the new version of disturbance powers. The effectiveness of the proposed method has been verified through simulation and actual data from an industrial power system. The results show that the presented method can correctly detect the location of voltage sag source.