时序电路分析中状态表与状态图输出的合理描述

在现有各版本的数字电子技术教材中,在时序电路分析中状态表与状态图的输出状态均存在着概念描述不清晰的现象。为了有助于时序电路的分析与理解,本文完善了状态表的描述方法,修改了状态图的绘制原则。补充与完善后的状态表与状态图在其输出的概念描述上更加直观与清晰。

Ground response and failure mechanism of gob-side entry by roof cutting with hard main roof

This study is the result of long-term efforts of the authors’team to assess ground response of gob-side entry by roof cutting(GSERC)with hard main roof,aiming at scientific control for GSERC deformation.A comprehensive field measurement program was conducted to determine entry deformation,roof fracture zone,and anchor bolt(cable)loading.The results indicate that GSERC deformation presents asymmetric characteristics.The maximum convergence near roof cutting side is 458 mm during the primary use process and 1120 mm during the secondary reuse process.The entry deformation is closely associated with the primary development stage,primary use stage,and secondary reuse stage.The key block movement of roof cutting structure,a complex stress environment,and a mismatch in the supporting design scheme are the failure mechanism of GSERC.A controlling ideology for mining states,including regional and stage divisions,was proposed.Both dynamic and permanent support schemes have been implemented in the field.Engineering practice results indicate that the new support scheme can efficiently ensure long-term entry safety and could be a reliable approach for other engineering practices.

Characterization of dynamic microstructural evolution of AA7150 aluminum alloy at high strain rate during hot deformation

The AA7150 aluminum alloy was compressed to various strains at strain rate of 10 s（-1） and temperatures of 300 °C and 450 °C, respectively. Flow stress behavior, substructure evolution, morphology and spatial distribution of precipitates were studied based on differential scanning calorimetry analysis and transmission electron microscope observation. The results showed that dynamic flow softening occurs during hot deformation. The main softening mechanism could be concluded as dynamic recovery at 300 °C and continuous dynamic recrystallization at 450 °C. The clear heterogeneous spatial distributions of precipitates are found during deformation and enhanced with increased strain. Higher contents of Cu in T phases are found at 450 °C than at 300 °C, which present a transformation process from T phases to S phases as well. The associated evidence of dynamic precipitation on dislocations and particle-stimulated nucleation, as well as the detailed microstructural inherited relationship and morphological texture（particles preferred orientation） were characterized.

Review of forest ecology studies in China

As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the process of sustainable development. However, due to the complexity of the forest ecosystem and the relatively delay or lack of the related research technology, the science is still in the case of immature and questions. This paper summarized and reviewed briefly the development and the present case of the forest ecology, then pointed out the existing problems in the forest ecosystem researches. In the end, we discussed several fields that need to pay more attention to in future researches.

Current situation of Chinese forestry tactics and strategy of sustainable development

Based on the analysis of the current situation of Chinese forestry and a series of ecological, environmental, eco-nomic, and social problems, this paper emphasized on the importance of forests in social and economic development in China The author pointed out that sustainable development, particularly the sustainable development of forestry, is the inevitable choice to solve the problems of ecological environment and social economics. The objectives, criteria, and strategies of sus-taining forestry were also demonstrated and expounded, from the viewpoints of ecology, economics, and sociology.

同步时序逻辑电路的设计

同步时序逻辑电路是计算机及其他数字系统中的一种常用电路。本文通过一个设计实例 ,详细说明同步时序逻辑电路的设计思路和设计方法。

从白居易的一首诗谈朦胧诗

近年,中国诗坛上崛起一种朦胧诗.对此,众说纷纭,褒贬各异.至于朦胧诗始于何时,鼻祖是谁,也各持已见,众说不一.翻阅白居易晚年所写的《花非花》诗,我想,这可能是中国最早的朦胧诗吧.此诗只有六句:“花非花,雾非雾,夜半来,天明去.来如春梦几多时?去似朝云无觅处!”用现代汉语可译为:“它是花吗,却又不是花;它像雾呢,可又不是雾.夜半它悄悄地到来,天明又匆匆地离去.来时像春天的梦,迷离恍惚;去时如天边的朝云,游离飘浮,去向不知何处!”

Dynamic Behavior of Voltage Across Small Capacitance Josephson Junction

Aim To study the dynamic behavior of voltage across small capacitance Josephson junction. Methods A model of the mesoscopic Josephson junction coupled with a single mode quantized radiation field was used. Results A Gaussian type envelope factor exhibiting quantum collapse and revival(CR) phenomenon was obtained. Conclusion It is shown that for the squeezed state the time evolution of the voltage can exhibit drastically quantum CR phenomenon.

身边笑料

“飞吻”与“变态” 在上“脉冲与数字电路”课时,老师说:“三个最基本的门电路是:与门、或门,还有一个是什么门呢?

Present situation and prospects of forest ecological network in Jilin Province, China

This paper makes a brief introduction of the ecological environment, forestry achievements, and the existing questions of Jilin Province. The task of forest ecological network and eight questions demanding prompt solution were discussed based on the present situation of forestry in Jilin Province. The author also made prospects for future application of bio-technique, infor-mation technology, new material technology and nuisance-free forest health technology in forest ecological network.

Research on the Dynamic Simulation System of Maize Growth

Dynamic simulation system of maize growth is developed by the physiological and ecological model,morphological structure model,computer science and virtual reality technology,to improve the level of precise operation of maize production.The computer graphics algorithms,virtual reality technology,animation design and information integration technology are applied to maize production by this system.establishment of dynamic simulation system of maize growth is conducive to raise level of precise operation in maize production.The system also can assist the relevant production research and testing,to reduce cost and improve efficiency.

Analysis and implementation of a new hyperchaotic system

Based on a modified Lorenz system, a relatively simple four-dimensional continuous autonomous hyperchaotic system is proposed by introducing a state feedback controller. The system consists of four coupled first-order ordinary differential equations with three nonlinear cross-product terms. Some dynamical properties of this hyperchaotic system, including equlibria, stability, Lyapunov exponent spectrum and bifurcation, are analysed in detail. Moreover, an electronic circuit diagram is designed for demonstrating the existence of the hyperchaos, and verifying computer simulation results.

Practical pattern-based design recovery approach

A practical approach is presented to enlarge the recoverable scope and improve the precision of pattern recovery. To specify both structural aspects and behavioral aspects of design patterns, we introduce traditional predicate logic combined with Alien's interval-based temporal logic as our theoretical foundation. Moreover, we take the Visitor pattern as an example to illustrate how to specify design patterns to support recovery of design patterns besides structural category. The experimental results show that the approach presented is practical for recovering design information of real world systems.

Cyclooxygenase 2 polymorphism and colorectal cancer:-765G>C variant modifies risk associated with smoking and body mass index

AIM： To explore whether cyclooxygenase 2 （COX-2） -765G〉C polymorphism is associated with susceptibility of colorectal cancer （CRC） and to evaluate the risk of colorectal cancer in relation to environmental exposures and polymorphism. METHODS： We conducted a case-control study of 137 patients with colorectal cancer and 199 cancerfree controls in northeast China. Multivariate logistic regression analysis was performed to calculate the adjusted odds ratio （OR） and 95% confidence interval （95% CI）. RESULTS： The -765G〉C polymorphism was not independently associated with CRC risk. However, risk associated with the polymorphism differed by smoking and body mass index （BMI）. Smoking and BMI associated risks were stronger among those with -765GG genotype, showing that smokers had a 2.682-fold greater risk of CRC than nonsmokers （51/43 vs 68/126, P = 0.006）. Compared to those with a normal body mass index （BMI 18.5-22.9）, those with overweight （BMI 23-24.9） had a 3.909-fold higher risk of CRC （OR = 3.909, 95% CI = 2.081-7.344; P 〈 0.001）, while those with obesity （BMI 〉 25） had a 2.031- fold higher risk of CRC （OR = 1.107, 95% CI = 1.107-3.726; P = 0.022）. is not associated with an increased risk of CRC, -765GG genotype appears to be related to an increased risk in the presence of smoking and higher BMI.

Wilson disease: Identification of two novel mutations and clinical correlation in Eastern Chinese patients

AIM: To study mutations in the P-type ATPase (ATP7B) gene responsible for Wilson disease (WD) in the Eastern Chinese population, and the possible correlation of specific mutations with clinical characteristics. METHODS: Mutations of the ATP7B gene were sought by means of direct sequencing in 50 Eastern Chinese WD patients of Han ethnic origin. RESULTS: Two novel mutations, Asp96Gly and Asp196Glu, were first identified. We also compared the characterization of mutations in ATP7B with the clinical findings, and a significant correlation with hepatic manifestations between patients carrying the Arg778Leu mutation and those without was found. CONCLUSION: Gene sequencing analysis was shown to have a high detection rate and accuracy. It may become the first priority in screening of WD patients.

The role of botanical gardens in scientific research, conservation, and citizen science

Plant diversity is currently being lost at an unprecedented rate, resulting in an associated decrease in ecosystem services. About a third of the world＇s vascular plant species face the threat of extinction due to a variety of devastating activities, including, over-harvesting and over exploitation, destructive agricul- tural and forestry practices, urbanization, environmental pollution, land-use changes, exotic invasive species, global climate change, and more. We therefore need to increase our efforts to develop integrative conservation approaches for plant species conservation. Botanical gardens devote their resources to the study and conservation of plants, as well as making the world＇s plant species diversity known to the public. These gardens also play a central role in meeting human needs and providing well-being. In this minireview, a framework for the integrated missions of botanical gardens, including scientific research, inJex situ conservation, plant resource utilization, and citizen science are cataloged. By reviewing the history of the development of Kunming Botanical Garden, we illustrate successful species conservation approaches （among others, projects involving Camellia, Rhododendron, Magnolia, Begonia, Alliurn, Ne- penthes, medicinal plants, ornamental plants, and Plant Species with Extreme Small Populations）, as well as citizen science, and scientific research at Kunming Botanical Garden over the past 80 years. We emphasize that Kunming Botanical Garden focuses largely on the ex situ conservation of plants from Southwest China, especially those endangered, endemic, and economically important plant species native to the Yunnan Plateau and the southern Hengduan Mountains. We also discuss the future chal- lenges and responsibilities of botanical gardens in a changing world, including： the negative effects of outbreeding and/or inbreeding depression; promoting awareness, study, and conservation of plant species diversity; accelerating global access to information about plant diversity; increasing capacity building and training activities. We hope this minireview can promote understanding of the role of botanical gardens.

Pharmacogenomics in colorectal cancer: The first step for individualized-therapy

Interindividual differences in the toxicity and response to anticancer therapies are currently observed in practically all available treatment regimens. A goal of cancer therapy is to predict patient response and toxicity to drugs in order to facilitate the individualization of patient treatment. Identification of subgroups of patients that differ in their prognosis and response to treatment could help to identify the best available drug therapy according the genetic profile. Several mechanisms have been suggested to contribute to chemo-therapeutic drug resistance: amplification or overexpression of membrane transporters, changes in cellular proteins involved in detoxification or in DNA repair, apoptosis and activation of oncogenes or tumor suppressor genes. Colorectal cancer (CRC) is regarded as intrinsically resistant to chemotherapy. Several molecular markers predictive of CRC therapy have been included during the last decade but their results in different studies complicate their application in practical clinical. The simultaneous testing of multiple markers predictive of response could help to identify more accurately the true role of these polymorphisms in CRC therapy. This review analyzes the role of genetic variants in genes involved in the action mechanisms of the drugs used at present in colorectal cancer.

A populational survey of 45S rDNA polymorphism in the Jefferson salamander Ambystoma jeffersonianum revealed by fluorescence in situ hybridization(FISH)

The chromosomal localization of 45S ribosomal RNA genes in Ambystoma jeffersonianum was determined by fluorescence in situ hybridization with 18S rDNA fragment as a probe (FISH-rDNA). Our results revealed the presence of rDNA polymorphism among A.jeffersonianum populations in terms of number,location and FISH signal intensity on the chromosomes. Nine rDNA cytotypes were found in ten geographically isolated populations and most of them contained derivative rDNA sites. Our preliminary study provides strong indication of karyotypic diversification of A.jeffersonianum that is demonstrated by intraspecific variation of 45S rDNA cytotypes. rDNA cytotype polymorphism has been described in many other caudate amphibians. We predict that habitat isolation,low dispersal ability and decline of effective population size could facilitate the fixation and accumulation of variable rDNA cytotypes during their chromosome evolution.

Identification of Phase and Sex-related ISSR Markers of Red Alga Gracilaria lemaneiformis

Six ISSR primers are employed to display the polymorphism of different phases and sexes of red alga Gracilaria lemaneiformis, and two of them, P1 and P3, amplified distinct band patterns. The ISSR pattern amplified by primer P1 of the female gametophyte is identical to that of tetrasporophyte, but distinct from that of male gametophyte. Of the bands produced by primer P3, one is specific to female gametophyte. Three morphologically similar fronds can be easily identified using ISSR technique. Two specific markers, SM1 andSF3, related to male gametophyte and female gametophyte, are cloned and sequenced. The homologous sequences of SM1 are found to encode a hypothetical protein. There is no homologous sequence of SF3 that can be found in GenBank.

Comprehensive screening for reg1α gene rules out association with tropical calcific pancreatitis

AIM: To investigate the allelic and haplotypic association of reg1α gene with tropical calcific pancreatitis (TCP). Since TCP is known to have a variable genetic basis, we investigated the interaction between mutations in the susceptibility genes, SPINK1 and CTSB with reg1α polymorphisms. METHODS: We analyzed the polymorphisms in the reg1α gene by sequencing the gene including its promoter region in 195 TCP patients and 150 ethnically matched controls, compared their allele and haplotype frequencies, and their association with the pathogenesis and pancreaticolithiasis in TCP and fibro-calculous pancreatic diabetes. RESULTS: We found 8 reported and 2 novel polymo-rphisms including an insertion-deletion polymorphism in the promoter region of reg1α. None of the 5' UTR variants altered any known transcription factor binding sites, neither did any show a statistically significant association with TCP. No association with any reg1α variants was observed on dichotomization of patients based on their N34S SPINK1 or L26V CTSB status. CONCLUSION: Polymorphisms in reg1α gene, including the regulatory variants singly or in combination with the known mutations in SPINK1 and/or CTSB genes, are not associated with tropical calcific pancreatitis.