一种从低品位铅物料中回收粗铅的方法

针对现有技术不能单独处理低品位铅物料,而只能与高品位铅物料配料处理的问题,提供一种利用富氧侧吹单独处理低品位铅物料的方法.     

Ethylmalonic and methylsuccinic aciduria in ethylmalonic encephalopathy arise from abnormal isoleucine metabolism

Ethylmalonic encephalopathy (EE), an organic aciduria of unknown etiology characterized by developmental delay, hypotonia, and vascular instability associated with lactic acidemia and urinary excretion of ethylmalonic acid (EMA) and methylsuccinic acid (MSA), has been described in 11 patients. To test the possibility that the underlying biochemical defect involves isoleucine catabolism, we determined the response to oral L-isoleucine (IIe) load (150 mg/kg) in a 5-year-old girl with EE and in three healthy, age- and sex-matched controls. Following IIe load in the patient, there was accumulation of 2-methylbutyrylglycine (2-MBG) and a delayed and lower peak urinary excretion of tiglylglycine (TGL), suggesting a partial defect in 2-methyl-branched chain acylcoenzyme A dehydrogenase (2M-BCAD). In vitro measurements 2M-BCAD activity in cultured skin fibroblasts from patients with EE have been reported to be normal. Our results show that isoleucine is a source for the elevated EMA and MSA in patients with EE, and suggest a functional, possibly secondary, deficiency of activity of 2M-BCAD in vivo.     

还原挥发法从低品位含锗煤灰中提取锗

以褐煤经过一次挥发焙烧后获得的煤灰为原料、碳作为发热剂和还原剂,采用还原焙烧法富集其中的锗,考察煤灰和球团粒度、焙烧温度和时间、还原气氛等对锗挥发率的影响。结果表明,在一定范围内,还原气氛越强,锗的挥发率越高;煤灰和球团粒度对锗挥发率的影响较小;在不需额外补充气体和活性炭的条件下,在1000℃焙烧2h可使锗挥发率达到99.33%以上。     

亚甲基蓝还原浸出低品位钴土矿

采用亚甲基蓝作为还原剂,在硫酸体系中直接浸出低品位钴土矿,考察了亚甲基蓝浓度、硫酸浓度、反应温度、反应时间等对浸出率的影响。结果表明,在下述最优条件下,钴土矿中钴和锰的浸出率可同时达到99%以上:硫酸初始浓度1.6mol/L,亚甲基蓝初始浓度5g/L,反应温度95℃,浸出时间4h,液固比3∶1。     

Selective short-term memory deficits arise from impaired domain-general semantic control mechanisms.

Semantic short-term memory (STM) patients have a reduced ability to retain semantic information over brief delays but perform well on other semantic tasks; this pattern suggests damage to a dedicated buffer for semantic information. Alternatively, these difficulties may arise from mild disruption to domain-general semantic processes that have their greatest impact on demanding STM tasks. In this study, mild semantic processing impairments were demonstrated in 2 semantic STM patients. They performed well on untimed semantic tasks but were deficient in accuracy and reaction times on speeded tasks. Demanding semantic production tasks were also affected. These patients were compared with a case series of individuals with semantic aphasia whose multimodal semantic difficulties stemmed from poor cognitive control. STM and semantic performance were more impaired in this group, but there were qualitative similarities to the semantic STM patients. The difference between the 2 patient types may be a matter of degree. In semantic aphasia, severe disruption to semantic control leads to global semantic impairments, whereas in semantic STM milder disruption might impact mainly on STM tests because of the high control demands of these tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biases in three-dimensional structure-from-motion arise from noise in the early visual system

The projected pattern of retinal-image motion supplies the human visual system with valuable information about properties of the three-dimensional environment. How well three-dimensional properties can be recovered depends both on the accuracy with which the early motion system estimates retinal motion, and on the way later processes interpret this retinal motion. Here we combine both early and late stages of the computational process to account for the hitherto puzzling phenomenon of systematic biases in three-dimensional shape perception. We present data showing how the perceived depth of a hinged plane ('an open book') can be systematically biased by the extent over which it rotates. We then present a Bayesian model that combines early measurement noise with geometric reconstruction of the three-dimensional scene. Although this model has no in-built bias towards particular three-dimensional shapes, it accounts for the data well. Our analysis suggests that the biases stem largely from the geometric constraints imposed on what three-dimensional scenes are compatible with the (noisy) early motion measurements. Given these findings, we suggest that the visual system may act as an optimal estimator of three-dimensional structure-from-motion.     

Evolution of histone H4 and H3 genes in different ciliate lineages

The histones H4 are known as highly conserved proteins. However, in ciliates a high degree of variation was found compared both to other eukaryotes and between the ciliate species. To date, only H4 histones of species belonging to two distantly related classes have been investigated. In order to obtain more detailed information on histone H4 variation in ciliates we undertook a comprehensive sequence analysis of PCR-amplified internal H4 fragments from 12 species belonging to seven out of the nine currently recognized ciliate classes. In addition, we used PCR primers to amplify longer fragments of H3 and H4 genes including the intergenic region. The encoded amino acid sequences reveal a high number of differences when compared with those of other eukaryotes and the ciliate species investigated. Furthermore, in some species H4 gene variants were detected, which result in amino acid differences. The greatest number of substitutions and insertions found was in the amino terminal region of the H4 histones. However, all sequences possess a conserved region corresponding to those of all other eukaryotic H4 histones. The histone gene variations were used to reconstruct phylogenetic relationships. The tree from our data matches perfectly with the ribosomal RNA data: The heterotrichs, which were considered as a late branching lineage, diverge at the base of the ciliate tree and groups formerly thought to represent ancestral lineages now appear as highly derived ciliates.     

Early biochemical signals arise from low affinity TCR-ligand reactions at the cell-cell interface

The kinetics of acid release by a mixture of T cells and antigen presenting cells were measured with a microphysiometer during a brief exposure to antigenic peptides. We find that some of the early biochemical events that lead to cellular proliferation cause a specific increase in the rate of acid release. The duration of this increase in acid release reflects the life-time of the peptide-MHC complexes. Peptides that form long-lived complexes produce a response that is stable for more than an hour. Serial TCR engagement is suggested by the observation that the amplitude of this stable response can be rapidly shifted up or down with additional agonist peptide or with antibodies that block T cell receptor binding. Cells briefly exposed to a peptide that forms short-lived peptide-MHC complexes produce a response that decays rapidly as peptide is washed away. A quantitative analysis of the kinetics of this decay in acidification demonstrates that intercellular TCR-ligand reactions are rapid, reversible, and of low apparent affinity with < 20% of peptide-MHC ligand bound to a TCR at any one time. These results demonstrate that the fraction of peptide-MHC ligands bound to TCRs at the cell-cell interface is no higher than anticipated from the affinities observed in solution for isolated TCRs and ligands.     

低品位氧化锰矿酸浸制备硫酸锰

研究一步法还原浸出低品位氧化锰矿制备硫酸锰工艺。使用亚硫酸盐作为还原剂,采用黄铁矾法除铁,硫化盐法去除重金属离子,最终制备出适用于电解的硫酸锰溶液。结果表明:矿样10g,硫酸用量6mL,亚硫酸钠用量6g,90℃浸出100min,可以获得的96.42%锰浸出率;控制中和调浆终点pH=2.5,铁浸出率0.02%;控制除杂终点pH=4.5时,滤液达到合格电解液的标准。     

低品位氧化铜矿制备硫酸铜研究

介绍了低品位氧化铜矿制备硫酸铜的工艺研究。氧化铜矿经硫酸浸出一铁屑置换,产出的海绵铜再经硫酸重溶后,按传统方法制备硫酸铜结晶产品。或是投入密闭鼓风炉熔炼粗铜。该工艺铜的浸出率为90％左右,置换率约为93—98％,铜总回收率80—85％。     

高钙低品位石煤提取五氧化二钒新工艺

文章对高钙低品位石煤提钒工艺进行了研究,提出了选矿冶炼联合提钒新工艺,并获得了理想的浸出效果。该工艺与传统工艺相比,可有效降低冶炼成本,提高钒的回收率,开辟了低品位石煤钒矿提取五氧化二钒新途径,提高了低品位钒矿的资源综合利用率。     

低品位铝矿直接生产氧化铝材料制备技术研究

氧化铝生产对铝矿的品质要求高、耗用量大,现有资源已无法满足氧化铝生产的需求,低品位铝矿虽然品质较差,但是通过合理安排生产工艺,依旧可以作为氧化铝生产的重要原料补充.基于此,提出低品位铝矿直接生产氧化铝材料制备技术研究.通过研究对比三种成熟的生产工艺路线,选择出拜耳法工艺实现氧化铝生产,在此基础上,设计了低品位铝矿直接生...     

Overly literal interpretations of speech in autism: understanding that messages arise from minds

Children with autism and children with Down's syndrome watched the following enactment. A protagonist put one item in location A and another in location B and then left the scene. Subsequently, the items were swapped the other way round. Finally, the protagonist (who remained ignorant of the swap) requested the item in A. The observing child participant was asked to judge (1) which item the protagonist wanted and (2) which item the protagonist put in A. Unlike children with Down's syndrome, those with autism made more errors in judging that the speaker wanted the item in B than in judging that the item the speaker put in A is now in B; children with autism wrongly tended to interpret utterances literally, and they did this significantly more frequently than children with Down's syndrome. We conclude that children with autism have a difficulty making nonliteral interpretations that cannot be explained as (1) a realist bias, (2) an inability to inhibit a prepotent response, and (3) a failure to keep track of the exchange of items.     

The embryonic central nervous system lineages of Drosophila melanogaster. I. Neuroblast lineages derived from the ventral half of the neuroectoderm

Central nervous system development in Drosophila starts with the delamination from the neuroectoderm of about 30 neuroblasts (NBs) per hemisegment. Understanding the mechanisms leading to the specification of the individual NBs and their progeny requires the identification of their lineages. Here we describe 17 embryonic NB lineages derived from the ventral half of the neuroectoderm and we assign these lineages to identified medial and intermediate NBs. The lineages are composed of interneurons (NB 1-2, NB 2-1, MP2, NB 4-1, NB 5-1, NB 5-3, NB 6-1, NB 6-2, and NB 7-2), interneurons and motoneurons (NB 3-1, NB 3-2, NB 4-2, NB 5-2, NB 7-1, and NB 7-3), or interneurons, motoneurons, and glial cells (NB 1-1 and NB 2-2). NB 1-1, NB 2-2, and NB 3-1 form segment-specific lineages. Neuroectodermal progenitors forming NB 2-1, NB 5-1, and NB 7-3 divide while still in the ectoderm to give rise to an additional epidermoblast. Expression of segmentation genes is not lineal in the clones of NB 1-2 and NB 7-3 (engrailed), NB 1-1, NB 4-2, and NB 7-1 (even-skipped), and NB 7-1 (gooseberry-proximal). The timing of delamination for individual NBs as well as the number of their progeny is not strictly invariant. The 17 NBs produce about 200 neurons and only three glial cells, corresponding to about 70% of the estimated total number of neurons and 10% of the glial cells per thoracic and abdominal hemisegment. Previously identified neural cell types were linked to particular lineages and we introduce a systematic terminology for the ventral nerve cord neurons. The wild-type clones provide a foundation for the analysis of mutants, expression patterns, and experimental manipulations.     

A serial study of new MS lesions and the white matter from which they arise

OBJECTIVE: To compare MS normal-appearing white matter (NAWM) where new gadolinium-enhancing (Gd+) lesions do and do not arise. METHODS: A total of 22 relapsing-remitting MS patients and 11 healthy control subjects completed as many as 12 monthly brain MRI sessions. Quantitative measures of gadolinium enhancement (GDR), water proton density (PDN), water proton T2 relaxation time constants (T2), magnetization transfer ratio (MTR), and T1-weighted signal intensity (T1N) were followed serially in healthy control and MS NAWM. RESULTS: A total of 129 new Gd+ lesions were identified in 11 patients. PDN, T2, MTR, and T1N were diffusely abnormal in MS NAWM. NAWM regions in which new Gd+ lesions arose have increased GDR, PDN, and T2, and reduced MTR and T1N compared with contralateral homologous NAWM regions in which no new Gd+ lesions arose. Differences between these NAWM regions preceded lesion appearance for at least several months. After lesions became visible, GDR returned to baseline within 2 months, and PDN and MTR had larger residual abnormalities than T2 or T1N. CONCLUSIONS: Quantitative MRI measures are diffusely abnormal in MS NAWM. These measures are, on average, more abnormal in NAWM regions in which new Gd+ lesions arise. After the appearance of Gd+ lesions, measures of PDN and MTR may provide more appealing markers of relatively irreversible tissue damage than measures of T2 and T1N.     

低品位石煤浮选及提钒工艺研究

采用浮选的方法,对开采价值低的低钒低碳石煤中的钒进行富集,对碳进行回收利用,并提出“浮选脱碳（精煤）—碳（精煤）焙烧浮选钒矿-酸浸物料-萃取提钒”的工艺路线。经小试及扩试生产实践,钒的总回收率可达75．10％。     

低品位复杂矿烧结优化试验研究

为研究新疆地区低品位复杂矿对烧结矿质量的影响,利用60 kg烧结杯开展低品位复杂矿烧结配矿优化研究工作,探讨不同碱度、不同配碳量以及不同燃料粒级配比对烧结矿性能的影响。试验结果表明:碱度在1.65~1.75时,转鼓强度下降5个百分点,低温还原粉化指数最低,烧结矿的自然粉化较为严重。碱度在1.75~2.0时,转鼓强度随着碱度上升而增强;配碳量的增加,烧结矿强度和低温还原粉化(RDI)指数有所改善;而随着小于1 mm燃料粒度所占比例的增加,烧结矿的强度和RDI_(+3.15)指数都有变差的趋势,小于1 mm燃料粒度比例占30%的时候,烧结矿的质量最好。