溶胶—凝胶法制备纳米TiO2—Al2O3复合粉体

采用溶胶－凝胶法合成了纳米８ｗｔ％ＴｉＯ２Ａｌ２Ｏ３复合粉体．考察了反应温度、溶液初始ｐＨ值、柠檬酸用量及分散剂等对平均粒径的影响规律,确定了优化工艺条件．合成粒子呈球形,粒径分布均匀,单分散性好,平均粒径为１５ｎｍ,ＢＥＴ比表面积为１４０．６ｍ２／ｇ．     

铅蓄电池正极活性物质利用率

通过实验电池和产品电池（６Ｖ－６０Ａｈ）放电容量测定,筛选出数种有效添加剂,得到了几个较好的配方,提高了铅蓄电池正极活性物质利用率。通过循环伏安法（ＣＶＡ）、Ｘ射线衍射分析、扫描电镜（ＳＥＭ）、孔率以及电导的测定,探讨了不同添加剂对ＰｂＯ２电极组成、结构和性能的影响。     

Differences in the liability to self-administer intravenous cocaine between C57BL/6 x SJL and BALB/cByJ mice

Application of animal models of psychostimulant abuse for experimentation in mice is becoming increasingly important for studying the contribution of genetic differences, as well as the roles of selected (targeted) genes, in specific behaviors. The purpose of this study was to investigate strain differences in cocaine self-administration behavior between C57BL/6 x SJL hybrid mice and BALB/cByJ mice. These two strains were chosen because BALB/cByJ mice have a well-developed behavioral pharmacological profile, and hybrid strains on a C57BL/6 background are commonly used for generating transgenic expressing and knockout mutant mice. C57BL/6 x SJL mice dose-dependently acquired cocaine self-administration (1.0 mg/kg/injection but not 0.25 mg/kg/injection) by responding selectively in the active nose-poke hole and maintaining stable levels of daily drug intake; they also exhibited a characteristic inverted-U-shaped cocaine dose-effect function. BALB/cByJ mice failed to acquire cocaine self-administration at either dose under the same test conditions. The strain differences observed in self-administration did not seem to be attributed to other behavioral differences because the two strains exhibited similar amounts of spontaneous nose-poking in the absence of reinforcers, and BALB/cByJ mice responded more than C57BL/6 x SJL mice in a food-reinforced nose-poke operant task. Importantly, the dose-effect function for the motor stimulating effects of cocaine (3.8-30 mg/kg intraperitoneally) suggests enhanced sensitivity but reduced efficacy of cocaine in stimulating motor activity in BALB/cByJ mice relative to the C57BL/6 x SJL hybrid mice. These results indicate that the decreased liability of BALB/cByJ mice to acquire cocaine self-administration is not the result of differences in spontaneous activity or performance, but may reflect different sensitivities to the reinforcing, or rate-disrupting, properties of cocaine. The data support an influence of genetic background in the liability to self-administer cocaine. Thus, a hypothesis is proposed that the decreased liability of BALB/cByJ mice to acquire cocaine self-administration is related to differences in brain monoamine systems linked to the high "emotionality" profile of BALB/c mice in novel or fearful situations, including perhaps cocaine administration.     

工频自动加压装置中的干扰及其抑制

主要对在实验室内进行工频耐压试验,试品击穿放电时所产生的严重干扰现象进行分析研究,提出了抑制干扰的方法。     

无汞碱锰电池专用EMD

以碳酸锰贫矿为原料,采用悬浮电解法改善固相表面性能,使用高效添加剂去除钼、铁等金属杂质,生产无汞碱性锌锰电池专用电解二氧化锰;产品纯度高、视比重大,吸液量更适合碱性锌锰电池的技术要求。制成的电池内电阻小、大电流连续放电性能优越、高压放电容量提高;电池阴极成型好,能满足碱性锌锰电池生产的工艺要求。     

Serendipity in diagnostic imaging: magnetic resonance imaging of the breast

BACKGROUND: Magnetic resonance imaging (MRI) of the breast has been proposed as a noninvasive diagnostic test for evaluation of suspicious ("index") lesions noted on mammography and/or clinical breast examination (CBE). However, women may have incidental ("serendipitous") lesions detected by MRI that are not found on mammography or CBE. To understand better whether or not biopsy procedures should be performed to evaluate serendipitous lesions, we estimated the breast cancer risk for women with this type of lesion. METHODS: A decision analysis model was used to estimate the positive predictive value (i.e., the chance that a woman with a serendipitous lesion has cancer) of MRI for serendipitous lesions in women who had an abnormal mammogram and/or CBE suspicious for cancer (where a biopsy procedure is recommended). We restricted the analysis to data from women whose index lesions were noncancerous and used meta-analysis of published medical literature to determine the likelihood ratios (measures of how test results change the probability of having cancer) for MRI and the combination of CBE and mammography. The positive predictive value of MRI was calculated using the U.S. population prevalence of cancer (derived from registry data) and the likelihood ratios of the diagnostic tests. RESULTS: Under a wide variety of assumptions, the positive predictive value of MRI was extremely low for serendipitous lesions. For instance, assuming sensitivity and specificity values for MRI of 95.6% and 68.6%, respectively, approximately four of 1000 55- to 59-year-old women with serendipitous lesions would be expected to have cancer (positive predictive value = 0.44%, 95% confidence interval = 0.24%-0.67%). CONCLUSION: In women with a suspicious lesion discovered by mammography and/or CBE that is found to be benign, serendipitous breast lesions detected by MRI are extremely unlikely to represent invasive breast cancer. Immediate biopsy of such serendipitous lesions may, therefore, not be required.     

纤维除雾器及其在化工生产中的应用

介绍了雾粒的形成原因，纤维除雾器的除雾机理，床层设计，产品分类，清洁状态下压力降计算及安装方法，以及纤维除雾在化工行业的典型应用，建议在我国进一步推广应用。     

Effects of mulch and mineral fertilizer on crop, weevil and soil quality parameters in highland banana

The decline of cooking banana production in parts of East Africa hasbeen associated with a loss of soil fertility and increased pest pressure.Previous work indicated that the use of mineral fertilizers at recommendedratesis not financially viable on plantations where pest pressure is high. Theobjectives of this study were to determine the effects of half the recommendedrates of mineral fertilizers and organic mulch on banana yield, soil and foliarnutrient status, soil water and pest damage in the central region of Uganda.Thestudy was conducted in a four-year old banana plantation infested with weevils.Treatments consisted of mineral fertilizer alone, mulch alone, a combination ofmulch with fertilizer, and a control (no mulch from outside the plot, ormineralfertilizer applied). Fruit yield was generally low (mean of 7.4 Mgha^–1 yr^–1) and increases above thecontrol ranged from 1.1 to 2.0 Mg ha^–1 yr^–1. Banana yield was significantly higher in the solemulch treatment than in the control. However, there were no significantdifferences in yield among the treatments that received external inputs. Thus,there was no demonstrable yield advantage of combining mineral fertilizer withmulch. At the end of the trial, soil K concentrations in the two treatmentsthatwere mulched, were almost twice those of the control, but this difference wasnotstatistically significant. Concentrations of Ca and Mg did not differ withtreatment. Soil available P significantly increased when mineral fertilizer andorganic mulch were combined. Treatments that received organic mulch were lowerin foliar concentrations of N and Mg, and higher in K. Soil water content wasgreater in the surface soil layer in the treatments that received mulch,presumably due to less surface run-off and evaporation, since there was nochangein surface soil porosity. The effect of organic and inorganic amendments had noimpact on weevil damage, which remained above 5% at the end of the trial. Weconclude that where weevil damage is over 5% of the cross section near thecollar, banana production may not be economically increased through use ofeither mineral fertilizer and/or organic mulch.     

低等规聚丙烯的研制 Ⅳ.聚合催化剂的制备

以二乙氧基镁为载体的主要原料，采用三氯化铝使二乙氧基镁氯化制备载体，再采用四氯化钛进行载钛，得到一种丙烯聚合催化剂，并对其进行了表征。经流相本体法丙烯聚合评价实验表明，此催化剂的活性为30－60kg/g，全聚物在沸庚烷中不溶部分为13％－30％。并对影响催化剂活性和立体选择性的各种因素进行了讨论，给出并比较了催化剂小试、模试和中试的实验结果。