容积称重组合定量装置的研制

本文就研制开发的新型定量装置──“容积称重组合定量”装置的结构特点及工作原理进行论述，同时将DCB—2型样机试制情况作简要介绍。

地球化学元素空间定量组合求异模型及其应用

由于成矿过程的多期性与多源性,成矿区地球化学元素在空间上表现出共生组合特征。为刻画组合特征的类型与特点,提出一种地球化学元素空间定量组合求异方法,构建了因子泛克里格模型、多元序列典型趋势面模型及特征分析组合模型。将上述3种空间定量组合求异模型应用于云南哀牢山墨江地区1∶20万化探数据进行处理分析,目的在于从多元角度刻画元素异常,提高矿异常预测精度。计算结果表明:该区存在4种异常类型,反映了不同地质条件下元素共生组合及其在成岩成矿过程中的内在组配机制和空间关系。由此得出结论:在成矿预测过程中应按不同的定量组合异常类型及其相应地质背景进行预测。

基于智能计算的广西冷湿极端天气定性和定量组合预报方法研究

论文以逐日气温和降水量数据、NCEP/NCAR再分析资料以及预报场资料为基础,将表征冬季低温冷害的冷湿指数作为预报量,先利用随机森林方法进行冬季逐日冷湿极端天气定性判别预报分析,再进一步以粒子群算法为基础的模糊神经网络集成个体生成技术方法,建立一种新的非线性智能计算定量集成预报模型(PSOFNN),进行了广西冷湿极端天气定量预报模型的预报建模研究。结果表明,论文提出的这种以不同的智能计算方法构建的定性、定量综合预报分析方法,比较符合极端天气小概率事件的预报特点,其中随机森林算法构建的定性预报模型,对广西冷湿极端天气事件的预报TS评分(Threat Score)为0.77,空报率为0.23,漏报率为0,ETS评分(Equitable Threat Score)为0.41,TSS评分(True Skill Statistic)为0.53。而采用粒子群-模糊神经网络方法构建的极端冷湿指数定量集成预报模型比其他线性和非线性预报模型具有更好的预报精度。其中PSOFNN集成预报模型在预报建模样本和独立预报样本个例相同的情况下,比回归方法的预报平均绝对误差下降了25%以上,比一般的普通模糊神经网络预报平均绝对误差下降了14.37%。主要原因是因为PSO-FNN集成预报模型通过改进集成个体的预报能力和增强集成个体的种群差异性,提高了集成预报模型的预报精度。因此,该智能计算集成预报模型的泛化能力显著提高,预报结果稳定可靠,为冷湿极端天气客观预报提供了新的预报工具和预报建模方法。

基于层次-熵值分析组合方法的本溪地区水土治理综合效益定量评估研究

提出水土保持效益综合评估13项指标体系,并采用层次-熵值组合方法对变量权重进行综合设定,对本溪地区某水土保持区治理的综合效益进行评估。结果表明:评估结果可全面反映区域水土治理综合效益,相比于传统单一权重模型,评估结果更符合区域实际水土保持治理效果,结果更为准确。研究成果对于其他地区水土保持治理效益综合评定提高定量化指标体系和评估方法。

组合称重台架的动态特性分析及数字补偿

为了提高组合定量的准确度和速度,对组合称重台架进行动态特性分析,建立数学模型,分析影响称重台架动态特性因素,提出通过增加阻尼器和采用数字补偿方法提高动态特性,实验表明此方法有利于实现快速高准确度定量。

应用分类器组合模型进行岩性识别

为了达到应用模式识别对储层岩性进行准确的识别,根据不同性质分类器的组合可以较全面描述一个模式从而降低识别错误及增强识别鲁棒性这种特性,结合模糊数学中的隶属度实现了多个分类器的定量组合。应用了几种不同的分类器进行组合,同时应用某油田的岩性识别作为实例进行验证,并与单个分类器进行比较,结果表明在同等条件下组合分类器的性能要比单个分类器的性能要好得多。这说明了应用不同性质的分类器进行组合识别的分类方法是可行性和有效性。

白山地区地球化学元素组合分布特征及其地质意义

通过对吉林省白山地区1∶20万地球化学元素中Au、Cu、Pb、Zn、Co、Ni等6 504个样品进行因子泛克里格模型进行定量组合求异,最终确定白山地区地球化学元素异常是多个元素组合,揭示不同成矿作用。全区共圈定出组合异常22处,组合异常具有明显的分带性,分为3个带:Ⅰ带元素组合以Co-Mn-Ti为主,显示在玄武岩覆盖下寻找Co矿的潜力很大;Ⅱ带元素组合以As-Au-Sb为主,显示该带是金矿的密集区;Ⅲ带元素组合为Cr-Ni。该带异常为与超基性岩、暗色火山岩类有关的元素聚集过程。

区域地球化学元素分布与组合求异方法

在与单元素异常处理方法比较基础上,应用多元素空间分布与空间定量组合求异方法,以吉林白山地区1∶20万化探测量数据处理分析为例,进行空间定量组合求异模型研究,建立了该区的中大比例尺因子--泛克里格模型,应用DEM原理表达三维元素空间分布模型,并给出地质解译。结果表明:多元空间定量组合求异法较传统单元素求异法不仅精度更高,更能反应元素空间的内在结构与关联性,且提供了更多的地学信息,尤其使DEM的三维表达更为直观。

基于地球化学组合求异的津巴布韦奇马尼马尼地区成矿预测

如何有效地解释评价异常是化探找矿取得成功的关键,传统的地球化学异常处理方法一般是以单一元素的含量值与背景值的差异来圈定异常,因子-泛克立格求异模型则建立在矿床主成矿期元素共生组合与地球化学异常之间的对应关系。采用因子-泛克立格模型对津巴布韦东部奇马尼马尼地区进行成矿预测,结果表明:奇马尼马尼地区存在7种元素组合,分别对应于不同的岩性组合,F4和F6元素组合异常可作为区内热液成矿指示标志,与东部塔卡金矿套合程度高。利用该模型圈定了5处找矿远景区,Ⅰ号远景区为铜镍金钛铁矿成矿有利区,Ⅱ号远景区具有与塔卡金矿相似的地球化学组合背景,Ⅲ号、Ⅳ号和Ⅴ号远景区则具寻找热液型金铜矿及多金属矿的潜力。

加注罐内气体量对挤压式加注精度的影响

简述航天推进剂加注系统的定量方式,对挤压式加注中由加注罐内气体量变化对加注系统定量精度的影响进行分析和理论计算。分析结果表明,加注罐内气体量对加注系统定量精度影响显著。为消除加注罐内气体量变化对加注系统定量精度的影响,引入一种全新的地面定量方式,即电子秤和流量积算仪组合定量方式。详细介绍了其原理、组成,并通过试验验证了其合理性。同时通过试验测试结果和理论计算公式,得到加注罐内气枕部分推进剂蒸气的含量,为推进剂蒸气的处理提供依据。

Effects of Cr content on microstructure and mechanical properties of single crystal superalloy

Two experimental single crystal superalloys with 2% Cr and 4% Cr (mass fraction) were cast in a directionally solidified furnace, while other alloying element contents were kept unchanged. The effects of Cr content on the microstructure, phase stability, tensile properties at 1100 °C and stress rupture properties at 1070 °C and 160 MPa of the single crystal superalloy were investigated. The results show that the size ofγ′ phase particles become small and uniform, and the cubic shape turns a little regular with the increase of Cr content. Theγ′ directional coarsening and rafting were observed in the 2% Cr and 4% Cr alloys after long term aging (LTA) at 1100 °C. The rafting rate ofγ′ phase increased with increasing Cr content. Needle-shaped topologically close packed (TCP) phases precipitated and grew along fixed direction in both alloys. The precipitating rate and volume fraction of TCP phases significantly increased with the increase of Cr content. The tensile property of the alloy increased and the stress rupture properties of the alloy decreased with the increase of Cr content at high temperature. The increase of Cr content increased the partition ratio of TCP forming elements, Re, W, and Mo, and the saturation degrees of these elements inγ phases increased. Therefore, the high temperature phase stability of the alloy decreased with the increase of Cr content.

Quantitative analysis of globularization and modeling of TC17 alloy with basketweave microstructure

The globularization behavior and mechanism of TC17 alloy with basketweave microstructure were investigated, and the models of dynamic and static globularization kinetics were established. The quantitative and metallographic results show that the globularization of α phase is sensitive to the parameters of deformation and heat treatment. By EBSD analysis, the formation and evolution mechanisms of intra-α boundaries are related to discontinuous dynamic recrystallization and continuous dynamic recrystallization, which can form α grains with high and low misorientations between neighbour grains after the heat treatment, respectively. Based on the globularization behavior and mechanism, two modified JMAK models are developed to predict the dynamic and static globularization kinetics, and the mean absolute relative errors(MARE) of 10.67% and 13.80% indicate the accuracy of the dynamic and static globularization kinetics models. The results of this work can provide guidance for controlling microstructure of titanium alloy.

Quantification of photosynthetic inorganic carbon utilisation via a bidirectional stable carbon isotope tracer

The amount of bicarbonate utilised by plants is usually ignored because of limited measurement methods. Accordingly, this study quantified the photosynthetic assimilation of inorganic carbon （COe and HCO3-） by plants. The net photosynthetic COa assimilation （PN）, the photosynthetic assimilation of CO2 and bicarbonate （PN＇）, the proportion of increased leaf area （lEA） and the stable carbon isotope composition （δ13C） of Orychophragmus violaceus （Ov） and Brassica juncea （B j） under three bicarbonate levels （5, 10 and 15 mm NaHCO3） were examined to determine the relationship among PN, PN＇ and fLA. PN＇, not PN, changed synchronously with fLA. Moreover, the proportions of exogenous bicarbonate and total bicarbonate （including exogenous bicarbonate and dissolved CO2-generated bicarbonate） utilised by Ov were 2.27 % and 5.28 % at 5 mm bicarbonate, 7.06 % and 13.28 % at 10 mm bicarbonate, and 8.55 % and 17.31% at 15 mm bicarbonate, respectively. Meanwhile, the propor- tions of exogenous bicarbonate and total bicarbonate uti- lised by Bj were 1.77 % and 3.28 % at 5 mm bicarbonate, 2.11% and 3.10 % at 10 mm bicarbonate, and 2.36 % and 3.09 % at 15 mm bicarbonate, respectively. Therefore, the dissolved CO2-generated bicarbonate and exogenous bicarbonate are important sources of inorganic carbon for plants.

On a Generalization of Some Restrictive Distribution Theorems

This paper is on a distribution question of Ⅰ type in the combinatorics (see: 'Ke Zhao, Wei WanDi, combinatorial theory, science press, 1981. '). Suppose n distrinct balls, m distinct boxes. The capacity set of every box is Now,place the n balls into the m boxes. Thenumber of distinct placed ways is expressed by , and simply by And it is called the distribution number.Main result is:Theorem The exponential generating function of sequence isThus .there is the recurrence relationhere (integer set).

The molecular mechanisms of Yang Wei Kang Liu powder on anticancer and reducing chemotherapy side-effect in combination with chemotherapy

Objective:We studied the molecular mechanisms of Yang Wei Kang Liu Power(YWKL,traditional Chinese medicine for nourishing stomach and anticancer) on anticancer and reducing chemotherapy side-effect in combination with chemotherapy.Methods:615 pre-cancer mouse model of YWKL for 10 days and CTX 1 time,semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR) to detect bone marrow granulocyte-macrophage colony-stimulating factor(GM-CSF) gene and cancer proto-oncogene Bcl-2,c-myc expression.Results:YWKL in combination with chemotherapy could obviously promoted the expression of GM-CSF gene and inhibited the expression of Bcl-2 and c-myc oncogenes of FC 615 mice.Conclusion:The molecular mechanisms of anticancer and reducing chemotherapy side-effect of YWKL in combination with chemotherapy are to promote the expression of GM-CSF gene and inhibit the expression of Bcl-2 and c-myc oncogenes.

Coca-Cola＇s Proposed Acquisition of Huiyuan： Revisiting the MOFCOM Decision

This paper revisits the Coca-Cola/Huiyuan case, using quantitative methods. We first estimate the demand system of carbonated soft drinks and juices, using the data of the 4-digit code Chinese soft drink industry. We then define the relevant market by implementing the SSNIP test （a.k.a. the hypothetical monopolist test）. Finally, we evaluate the unilateral effect on the juices market with merger simulation. Our results show that carbonated soft drinks and juicess are in two separate relevant markets. More importantly, there may, be a significant unilateral effect on the juices market based on scenario analysis. 7his result confirms the MOFCOM decision itself, but highlights that competition damage comes more from unilateral efect than from the dubious portfolio effect.

Use of compositional and combinatorial nanomaterial libraries for biological studies

Abstract The rapid development and production of nanomaterials has created some concerns about their potential hazard on the environment, human health and safety. However, since the list of materials that may gen- erate such concerns is very long, it is impossible to test them all. It is therefore usually recommended to use some small compositional nanomaterial libraries to perform ini- tial toxicity screening, based on which combinatorial libraries are then introduced for more in-depth studies. All nanomaterials in the compositional and combinatorial libraries must be rigorously characterized before any bio- logical studies. In this review, several major categories of physicochemical properties that must be characterized are discussed, along with different analytical techniques that are commonly used. Some case studies from the University of California Center for Environmental Implications of Nanotechnology are also chosen to demonstrate the effec- tive use of compositional and combinatorial nanomaterials libraries to identify the role of some key physicochemical properties and to establish true quantitative structure-ac- tivity relationships. Examples on how to use the knowledge generated from those studies to design safer nanomaterials for improved biological applications are also presented.

Effects of 4-amino-2-methyl-cantharidinimide on GABA_C receptors

The antiepileptic effect of 4-amino-2-methyl-cantharidinimide（AMC） was reported,but its mechanism remains unknown.In this study,we investigated the effects of AMC on a rat model of penicillin-induced epilepsy.The doses of 88 and 22 mg/kg AMC and the dose of 154 mg/kg sodium valproate（VPA） were administered intragastrically（i.g.） 30 min before penicillin injection,respectively.The epileptiform activity was verified by electrocorticographic（ECoG） recordings.The levels of GABA and GABAC receptors in hippocampus were determined by immunohistochemistry,and real-time polymerase chain reaction（RT-PCR） technique was used to detect the mRNA expression of GABAC receptor ρ2.The mean frequency and amplification of spike epileptiform activity were significantly decreased in AMC and VPA-pretreated rats compared with those of non-pretreated penicillin-induced epilepsy（PIE） group.The levels of GABA,GABAC receptors and the mRNA expression of GABAC receptors ρ2 in AMC and VPA-pretreated rats were significantly increased as compared with PIE group.These findings indicate that AMC and VPA have an antiepileptic effect on PIE in rats,and the antiepileptic effect of AMC may be mediated by the GABAC receptors and GABA.

Effect of Lichong decoction on expression of Bcl-2 and Bcl-2-associated X protein mRNAs in hysteromyoma model rat

OBJECTIVE:To study on effects of Lichong decoction on expression of apoptosis-controlling genes,Bcl-2 and Bcl-2-associated X protein(Bax) mRNAs in hysteromyoma tissue of the hysteromyoma model rat.METHODS:Fifty Wistar female rats were randomly divided into a normal group,a model group,a Lichong decoction group,a Guizifuling capsule group and a Mifepristone group.The hysteromyoma rat model was established by intraperitoneal injection of exogenous estrin and progestogens.Pathological examination of uterine tissue,uterine coefficient and uterine transverse diameter were made under optic microscope and expressions of Bcl-2 and Bax mRNAs in uterine tissue in the groups were detected with real-time fluorescent quantitative polymerase chain reaction(PCR) technique.RESULTS:After treatment,under microscope it was found that in the Lichong decoction group myometrium thinned,muscle fiber slightly overgrowth or long and thin,regular arrangement,inserting phenomenon of inner circular muscle and external longitudinal muscle was occasionally or not seen in the Lichong decoction group.The uterine coefficient and the uterine transverse diameter significantly decreased(P<0.01),and Bcl-2 mRNA expression significantly decreased(P<0.01) and Bax mRNA expression significantly increased in hysteromyoma tissue(P<0.01) in the Lichong decoction group as compared with the model group.CONCLUSION:Therapeutic effects of Lichong decoction on hysteromyoma is related with decrease of Bcl-2 mRNA expression and increase of Bax mRNA expression.

Differentiation of rat adipose tissue-derived mesenchymal stem cells towards a nucleus pulposus-like phenotype in vitro

Objective： To differentiate rat adipose tissue-derived mesenchymal stem cells （ADSCs） into cells with a nucleus pulposus-like phenotype in vitro, so as to lay a foundation for the cell-based transplantation therapy of degenerated intervertebral discs. Methods： Rat ADSCs were isolated only from the subcutaneous inguinal region and purified by limited dilution. ADSCs of the third passages were analyzed by fluorescence activated cell sorter （FACS） to detect the cell surface markers （Sca-1, CD44, CD45, CDI lb）. To induce ADSCs to- wards a nucleus pulposus-like phenotype, ADSCs were immobilized in 3-dimensional alginate hydrogels and cultured in an inducing medium containing transforming growth factor-beta1 （TGF- β1） under hypoxia （2% O2）, while control groups under normoxia （21% O2） in alginate beads in medium with or without the presence of TGF-β 1. Semiquantitative reverse transcription polymerase chain reaction （RT-PCR） was carried out to evaluate phenotypic and biosynthetic activities in the process of differentiation. Meanwhile, Alcian blue staining were used to detect the formation of sulfated glycosaminoglycans （GAGs） in the differentiated cells. Results： The purified ADSCs were fibroblast-like and proliferated rapidly in vitro. The flow cytometry showed that ADSCs were positive for Sca-1 and CD44, negative for CD45 and CD11b. The results of RT-PCR manifested that the gene expressions of Sox-9, aggrecan and collagen Ⅱ, which were chondrocyte specific, were upregulated in medium containing TGF-β1 under hypoxia （2% O2）. Likewise, gene expression of HIF-1 a, which was characteristics of in- tervertebral discs, was also upregulated. Simultaneously, Alcian blue staining exhibited the formation of many GAGs. Conclusions： The approach in our experiment is a simple and effective way to acquire a large quantity of homogenous ADSCs. Rat ADSCs can be differentiated into nucleus pulposus-like cells. ADSCs may replace bone marrow mesenchymal stem cells as a new kind of seed cells in regeneration of degenerated intervertebral discs using cell transolantation therarw.